WO2024154074A1

WO2024154074A1 - Patient support apparatus having an elevation system

Info

Publication number: WO2024154074A1
Application number: PCT/IB2024/050457
Authority: WO
Inventors: Jimmy Laflamme; Philippe VERRET; Jérôme GOSSELIN; Sylvain Beaulieu; Christian Gauvin; Steve Bolduc; Jérôme MARCOTTE; William TREMBLAY; Luc Petitpas
Original assignee: Umano Medical Inc
Current assignee: Umano Medical Inc
Priority date: 2023-01-18
Filing date: 2024-01-17
Publication date: 2024-07-25
Anticipated expiration: 2025-07-18
Also published as: EP4651845A1; AU2024209433A1

Abstract

A patient support apparatus has a base, a patient support assembly moveably connected to the base, and an elevation system operatively connecting the base to the patient support assembly. The elevation system has head end and foot end lift assemblies movable to raise and lower a corresponding one of a head end and a foot end of an upper frame of the patient support assembly. One of the lift assemblies includes: a lift leg unit having a first end portion pivotably connected to the upper frame and a second end portion pivotably connected to the base, the second end portion being movable relative to the base in a longitudinal direction; a support leg unit pivotably connected to the base and pivotably connected to the lift leg unit; and an actuator connected between the base and the support leg unit to actuate the lift assembly between extended and collapsed positions.

Description

PATIENT SUPPORT APPARATUS HAVING AN EUEVATION SYSTEM

CROSS-REFERENCE

[0001] The present patent application claims priority from United States Provisional Patent Application Serial Number 63/480,413 filed January 18, 2023, the contents of which are incorporated herein in their entirety.

FIEED OF TECHNOEOGY

[0002] The present technology relates to patient support apparatuses, and in particular to hospital beds.

BACKGROUND

[0003] Patient support apparatuses such as hospital beds are designed to accommodate many of a patient’s needs, including for example controlling an elevation of a patient support assembly on which the patient rests. Some hospital beds, such as those intended for intensive care unit (ICU) settings, have more advanced functions that allow the bed to assume a variety of bed positions to help the patient and/or help a caregiver provide treatment to the patient.

[0004] However, advanced functions of a hospital bed typically require integrating many components and therefore a more efficient use of the limited space provided by a hospital bed could be useful. In addition, as the hospital bed transitions between different positions, for example moving to a full chair position from which the patient can be helped to stand on his/her feet, a weight of the hospital bed can be shifted and therefore certain parts of the hospital bed may be subjected to significant loads. Furthermore, many hospital beds incorporate a complex and costly design of their patient support assemblies and require a multitude of actuators to achieve the different positions of the bed.

[0005] In view of the foregoing, there is a need for a patient support apparatus that addresses at least some of these drawbacks.

SUMMARY

[0006] It is an object of the present technology to ameliorate at least some of the inconveniences present in the prior art. [0007] According to an aspect of the present technology, there is provided a patient support apparatus comprising: a base; a patient support assembly moveably connected to the base and configured to accommodate a patient thereon, the patient support assembly comprising an upper frame and a deck connected to the upper frame; and an elevation system operatively connecting the base to the patient support assembly to move the patient support assembly relative to the base, the elevation system comprising a head end lift assembly and a foot end lift assembly that are movable to raise and lower a corresponding one of a head end and a foot end of the upper frame respectively, at least one of the head end lift assembly and the foot end lift assembly comprising: a lift leg unit comprising: a first end portion pivotably connected to the upper frame; a second end portion pivotably connected to the base, the second end portion being movable relative to the base in a longitudinal direction of the patient support apparatus; a support leg unit pivotably connected to the base, the support leg unit being pivotably connected to the lift leg unit between the first and second end portions; and an actuator connected between the base and the support leg unit to actuate the at least one of the head end lift assembly and the foot end lift assembly between an extended position and a collapsed position, the corresponding one of the head end and the foot end of the upper frame being further from the base in the extended position than in the collapsed position of the at least one of the head end lift assembly and the foot end lift assembly.

[0008] In some embodiments, the actuator comprises: a base end that is pivotably connected to the base about a base pivot axis, the base pivot axis being fixed relative to the base; and an extendable end that is movable relative to the base end, the extendable end being connected to the support leg unit.

[0009] In some embodiments, a longitudinal distance between the base end of the actuator and the corresponding one of the head end and the foot end of the upper frame is greater than a longitudinal distance between the extendable end of the actuator and the corresponding one of the head end and the foot end of the upper frame.

[0010] In some embodiments, in the extended position of the at least one of the head end lift assembly and the foot end lift assembly, the corresponding one of the head end and the foot end of the upper frame is at its maximum height; in the collapsed position of the at least one of the head end lift assembly and the foot end lift assembly, the corresponding one of the head end and the foot end of the upper frame is at its minimum height; and the actuator rotates about the base pivot axis by an angle of less than 5° between the extended and collapsed positions. [0011] In some embodiments, the actuator rotates about the base pivot axis by an angle of less than 3° between the extended and collapsed positions.

[0012] In some embodiments, the actuator rotates about the base pivot axis by an angle of approximately 1° between the extended and collapsed positions.

[0013] In some embodiments, the actuator is an electrical linear actuator.

[0014] In some embodiments, the support leg unit comprises: a left support leg member and a right support leg member laterally spaced from each other; and a central brace connecting the left support leg member to the right support leg member, the actuator being connected to the central brace.

[0015] In some embodiments, throughout a motion between the extended and collapsed positions, each of the left and right support leg members is partially disposed above a corresponding one of a head end and a foot end of the base.

[0016] In some embodiments, the base comprises an external base frame and an internal base frame surrounded at least in part by the external base frame; the internal base frame is connected to the external base frame via at least one load cell configured to sense a load of components supported by the internal base frame; throughout the motion between the extended and collapsed positions, each of the left and right support leg members is disposed above a corresponding one of a head end and a foot end of the external base frame.

[0017] In some embodiments, the patient support apparatus further comprises at least one intermediate connector connecting the internal base frame to the left and right support leg members, the at least one intermediate connector extending above a head end transversal member of the external base frame.

[0018] In some embodiments, the patient support apparatus comprises at least one intermediate connector connecting the internal base frame to the left and right support leg members, the intermediate connector located below a head end transversal member of the base frame.

[0019] In some embodiments, each at least one intermediate connector is formed by a bracket connector and an L-bracket, the L-bracket being affixed to a lower surface of the head end transversal member and the bracket connector extending below the head end transversal member of the base frame, the bracket connector affixed to a corresponding L-bracket at one end thereof and pivotably attached to a corresponding one of the left and right support leg members at another end thereof.

[0020] In some embodiments, the patient support apparatus further comprises a pair of caps fitted to left and right sides of the lift leg unit, each cap including a cord retaining clip, the cord retaining clips of the caps forming extensions opposingly oriented to enable cord-like elements to be wrapped therebetween.

[0021] In some embodiments, the lift leg unit comprises a left lift leg member and a right lift leg member laterally spaced from each other; and the left and right support leg members are pivotably connected to the left and right lift leg members, respectively.

[0022] In some embodiments, each of the left and right lift leg members defines a connection recess; and part of each of the left and right support leg members is received within the connection recess of a respective one of the left and right lift leg members.

[0023] In some embodiments, the at least one of the head end lift assembly and the foot end lift assembly further comprises: a linkage pivotably connecting the first end portion of the lift leg unit to the upper frame, the linkage comprising a left link and a right link, each of the left and right links having a first link end and a second link end, the first link end being pivotably connected to the first end portion of the lift leg unit, the second link end being pivotably connected to the upper frame.

[0024] In some embodiments, each of the left and right lift leg members are generally S- shaped.

[0025] In some embodiments, each of the left and right lift leg members comprises: a first elongated section comprising the first end portion; a second elongated section comprising the second end portion, the first and second elongated sections extending generally parallel to each other; and an angled section interconnecting the first and second elongated sections, the angled section being angled relative to the first and second elongated sections.

[0026] In some embodiments, the left and right support leg members are pivotally connected to the left and right lift leg members at the angled sections thereof. [0027] In some embodiments, in the collapsed position: the first and second end sections extend generally horizontally; and the first end section is disposed vertically higher than the second end section.

[0028] In some embodiments, the second end portion of the lift leg unit is longitudinally slidable along the base.

[0029] In some embodiments, the at least one of the head end lift assembly and the foot end lift assembly is the head end lift assembly.

[0030] In some embodiments, the actuator is a single actuator; and the foot end lift assembly comprises two actuators for actuating the foot end lift assembly.

[0031] In some embodiments, the patient support apparatus is a bed.

[0032] In some embodiments, the patient support apparatus is movable between a horizontal position and a full chair position.

[0033] In some embodiments, the deck comprises a back support deck section, a seat deck section, a thigh deck section, and a foot deck section that are movably connected to each other.

[0034] According to another aspect, there is provided a patient support apparatus comprising: a base; a patient support assembly moveably connected to the base and configured to accommodate a patient thereon, the patient support comprising an upper frame and a deck connected to the upper frame; and an elevation system operatively connecting the base to the patient support assembly to move the patient support assembly relative to the base, the elevation system comprising a head end lift assembly and a foot end lift assembly that are movable to raise and lower a head end and a foot end of the upper frame respectively, at least one of the head end lift assembly and the foot end lift assembly comprising: a lift leg unit pivotably connected to the upper frame and to the base; a support leg unit pivotably connected to the base and to the lift leg unit; a first actuator and a second actuator for actuating the at least one of the head end lift assembly and the foot end lift assembly, the first and second actuators being extendable, each of the first and second actuators having a first end and a second end that is movable relative to the first end, the first ends of the first and second actuators being pivotably connected to one of the support leg unit and the lift leg unit; and a linkage pivotably connecting the first and second actuators to the base in order to coordinate actuation of the first and second actuators, the second end of the first actuator being pivotably connected to the linkage about a first pivot axis, the second end of the second actuator being pivotably connected to the linkage about a second pivot axis generally parallel to the first pivot axis, the linkage being pivotably connected to the base about a third pivot axis generally parallel to the first and second pivot axes such that the first and second pivot axes are pivotable about the third pivot axis.

[0035] In some embodiments, the first, second and third pivot axes are aligned such that a plane contains the first, second and third pivot axes.

[0036] In some embodiments, the first and second pivot axes are disposed at equal distances from the third pivot axis.

[0037] In some embodiments, the linkage comprises: a first actuator link pivotably connected to the second end of the first actuator to allow rotation thereof about the first pivot axis; a second actuator link pivotably connected to the second end of the second actuator to allow rotation thereof about the second pivot axis; and an interconnecting link connected to the first and second actuator links, the interconnecting link being pivotably connected to the base.

[0038] In some embodiments, the interconnecting link is a shaft; and the linkage further comprises first and second outer links pivotally connecting the shaft to the base, the first and second outer links being pivotable about the third pivot axis.

[0039] In some embodiments, the patient support apparatus further comprises: a controller in communication with the first and second actuators, the controller being operable to control the first and second actuators, wherein, throughout a motion of the at least one of the head end lift assembly and the foot end lift assembly, the linkage pivots about the third pivot axis in response to the positions of the second ends of the first and second actuators 230 being uncoordinated.

[0040] In some embodiments, the patient support apparatus further comprises a sensing device configured to measure a parameter indicative of a position of at least one of the first and second actuators relative to the linkage, the controller being in communication with the sensing device, the controller being operable to control the first and second actuators based on the parameter measured by the sensing device. [0041] In some embodiments, the controller is configured to selectively stop actuation of the first and second actuators in response to a value of the measured parameter being indicative of a potential collision between the first or second actuators and the linkage.

[0042] In some embodiments, the sensing device is a potentiometer.

[0043] In some embodiments, the first and second actuators are electrical linear actuators.

[0044] In some embodiments, the patient support apparatus is a bed.

[0045] In some embodiments, the patient support apparatus is movable between a flat horizontal position and a full chair position.

[0046] In some embodiments, the deck comprises a back support deck section, a seat deck section, a thigh deck section, and a foot deck section that are movably connected to each other.

[0047] According to another aspect of the present technology, there is provided a patient support apparatus comprising: a base; a patient support assembly moveably connected to the base and configured to accommodate a patient thereon, the patient support assembly comprising an upper frame and a deck connected to the upper frame, the deck comprising a plurality of deck sections that are movable relative to each other, the upper frame comprising a fixed portion and a sliding portion, the sliding portion being slidable relative to the fixed portion in a longitudinal direction of the patient support apparatus, the deck sections being connected to the sliding portion such that, in response to the sliding portion sliding relative to the fixed portion, the deck sections are displaced in order to change a position of the bed; and an elevation system operatively connecting the base to the patient support assembly to move the patient support assembly relative to the base.

[0048] In some embodiments, the fixed portion is a first fixed portion; the upper frame further comprises a second fixed portion, the sliding portion slidably engaging the first fixed portion and the second fixed portion; the first fixed portion defines a head end of the upper frame; and the second fixed portion defines a foot end of the upper frame.

[0049] In some embodiments, the plurality of deck sections comprises a back deck section, a seat deck section, and a foot deck section; and the seat deck section is fixed relative to the sliding portion. [0050] In some embodiments, the foot deck section is movably connected to the second fixed portion

[0051] In some embodiments, the elevation system comprises: a head end lift assembly connected between a head end of the upper frame and the base; and a foot end lift assembly connected between a foot end of the upper frame and the base.

[0052] In some embodiments, the head end lift assembly is connected to the fixed portion.

[0053] In some embodiments, the fixed portion is a first fixed portion; the upper frame further comprises a second fixed portion, the sliding portion slidably engaging the first fixed portion and the second fixed portion; the first fixed portion defines a head end of the upper frame; the second fixed portion defines a foot end of the upper frame; and the foot end lift assembly is connected to the sliding portion.

[0054] In some embodiments, the first and second fixed portions are separate or alternatively unitary.

[0055] In some embodiments, the patient support assembly further comprises an actuator operatively connecting the sliding portion to the fixed portion, the actuator being operable to selectively cause the sliding portion to slide relative to the fixed portion.

[0056] In some embodiments, there is provided a patient support apparatus comprising: a base comprising an external base frame and an internal base frame; a patient support assembly configured to accommodate a patient thereon, the patient support assembly comprising an upper frame and a deck connected to the upper frame; and an elevation system operatively connecting the internal base frame to the patient support assembly to move the patient support assembly relative to the base, the elevation system comprising a head end lift assembly and a foot end lift assembly that are movable to raise and lower a corresponding one of a head end and a foot end of the upper frame respectively; at least one intermediate connector connecting the internal base frame to one of the head end lift assembly and the foot end lift assembly, the at least one intermediate connector located adjacent to a transversal member of the external base frame such that the one of the head end lift assembly and the foot end lift assembly is disposed outside of a perimeter of the external base frame and is supported by the internal base frame. [0057] In some embodiments, the at least one intermediate connector extends above the transversal member.

[0058] In some embodiments, the at least one intermediate connector is affixed to a top surface of a transversal member of the internal base frame at one end thereof, and pivotably attached to the one of the head end lift assembly and the foot end lift assembly at an opposite end thereof.

[0059] In some embodiments, at least two intermediate connectors are provided laterally displaced away from one another relative to the pivotably attached one of the head end lift assembly and the foot end lift assembly.

[0060] In some embodiments, the at least one intermediate connector extends below the transversal member.

[0061] In some embodiments, the at least one intermediate connector is affixed to a lower surface of a transversal member of the internal base frame at one end thereof, and pivotably attached to the one of the head end lift assembly and the foot end lift assembly at an opposite end thereof.

[0062] In some embodiments, at least two intermediate connectors are provided laterally displaced towards one another relative to the pivotably attached one of the head end lift assembly and the foot end lift assembly.

[0063] In some embodiments, a pivot of the one of the head end lift assembly and the foot end lift assembly, at a lower end thereof, is disposed outside of the perimeter of the external base frame.

[0064] Embodiments of the present technology each have at least one of the above- mentioned objects and/or aspects, but do not necessarily have all of them. It should be understood that some aspects of the present technology that have resulted from attempting to attain the above-mentioned objects may not satisfy these objects and/or may satisfy other objects not specifically recited herein.

[0065] Additional and/or alternative features, aspects, and advantages of embodiments of the present technology will become apparent from the following description, the accompanying drawings, and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] For a beter understanding of the present technology, as well as other aspects and further features thereof, reference is made to the following description which is to be used in conjunction with the accompanying drawings, where:

[0067] Fig. 1 is a perspective view, taken from a top, left side, of a hospital bed according to an embodiment of the present technology, showing the bed in a flat horizontal position;

[0068] Fig. 2 is a right-side elevation view of the bed of Fig. 1;

[0069] Fig. 3 is a perspective view, taken from a top, rear, right side, of a base, an elevation system, and a patient support assembly of the bed of Fig. 1, showing a head end lift assembly and a foot end lift assembly of the elevation system in a fully extended position;

[0070] Fig. 3 A is a perspective view, taken from a top, rear, right side, of part of the head end lift assembly of Fig. 3;

[0071] Fig. 4 is a perspective view, taken from a top, front, left side, of the base of the bed of Fig. 1;

[0072] Fig. 5 is a right-side elevation view of the bed of Fig. 1, showing the bed in the flat horizontal position and with the head end and foot end lift assemblies in fully collapsed positions;

[0073] Fig. 5 A is a right-side elevation view of the patient support assembly of the bed of Fig. 1, showing a deck thereof in a configuration corresponding to the flat horizontal position of the bed;

[0074] Fig. 5B is a right-side elevation view of the patient support assembly of the bed of Fig. 1, showing the deck in another configuration;

[0075] Fig. 6 is a right-side elevation view of the bed of Fig. 1, showing the bed in a full chair position;

[0076] Fig. 7 is a perspective view, taken from a top, front, right side, of the head end lift assembly and the foot end lift assembly of the bed of Fig. 1, showing the head end and foot end lift assemblies in their fully extended positions; [0077] Fig. 8 is a perspective view, taken from a top, rear, right side, of the head end lift assembly and the foot end lift assembly of Fig. 7;

[0078] Fig. 9 is a right-side elevation view of the head end and foot end lift assemblies of Fig. 7;

[0079] Fig. 10 is a cross-sectional view of the head end lift assembly of Fig. 7 taken along a vertical plane extending longitudinally;

[0080] Fig. 11 is a perspective view, taken from a top, front, right side, of a lower end of a lift leg member of the head end lift assembly and part of the base of the bed of Fig. 1 ;

[0081] Fig. 12 is a perspective view, taken from a top, front, right side, of the head end and foot end lift assemblies of the bed of Fig. 1, showing the head end and foot end lift assemblies in their fully collapsed positions;

[0082] Fig. 13 is a right-side elevation view of the head end and foot end lift assemblies of Fig. 12;

[0083] Fig. 14 is atop plan view of the head end and foot end lift assemblies of Fig. 12;

[0084] Fig. 15 is a block diagram of a controller for controlling the head end and foot end lift assemblies of the bed of Fig. 1;

[0085] Fig. 16 is a perspective view, taken from a top, front, right side, of the foot end lift assembly of the bed of Fig. 1;

[0086] Fig. 17 is a perspective view, taken from a top, front, right side, of the foot end lift assembly of Fig. 16;

[0087] Fig. 18 is a detailed view of section A of Fig. 9, showing a lower portion of the foot end lift assembly in the fully extended position thereof;

[0088] Fig. 19 is a detailed view of section B of Fig. 13, showing the lower portion of the foot end lift assembly in the fully collapsed position thereof;

[0089] Fig. 20 is a perspective view, taken from a top, front, right side, of a head end fixed member of the patient support assembly of the bed of Fig. 1; [0090] Fig. 21 is a perspective view, taken from a top, front, right side, of a foot end fixed member of the patient support assembly of the bed of Fig. 1;

[0091] Fig. 22 is a perspective view, taken from a top, rear, right side, of portion of the head end lift assembly according to an alternative embodiment;

[0092] Fig. 23 is a perspective view taken from below the alternative embodiment shown in Fig. 22;

[0093] Fig. 24 is a cross-sectional side view taken along line A-A of the alternative embodiment shown in Fig. 22;

[0094] Fig. 25 is a partial bottom view taken from below the right comer of the alternative embodiment shown in Fig. 22;

[0095] Fig. 26 is a perspective view of an additional embodiment including the embodiment of Fig. 22 and optional cord retaining clips;

[0096] Fig. 27 is a perspective view of yet another embodiment in simplified form showing details of an alternative upper frame;

[0097] Fig. 28 is an exploded view of the embodiment of Fig. 27; and

[0098] Fig. 29 is an exploded view of the alternative upper frame of Fig 27 showing details of the fixed and sliding portions thereof.

DETAILED DESCRIPTION

[0099] A patient support apparatus 10 in accordance with an embodiment of the present technology is illustrated in Figs. 1 and 2. The patient support apparatus 10 may be used in a medical setting for supporting a patient. In this embodiment, the patient support apparatus 10 is a hospital bed 10 that is used in a hospital, and in particular in an intensive care unit (ICU) setting. Notably, hospital beds used in the ICU of a hospital typically have additional functions that are not required in other settings. It is contemplated that, in other embodiments, the patient support apparatus 10 may be a different type of patient support apparatus such as, for example, a stretcher, a motorized chair, an operating room table, or other specialty tables (e.g., an examination table). [00100] With reference to Fig. 1, the bed 10 has a head end 12 and a foot end 14 opposite each other and defining a length of the bed 10 therebetween. As will be appreciated, in use, when the patient is lying on the bed 10, the patient’s head is closer to the head end 12 while the patient’s feet are closer to the foot end 14. The bed 10 also has a left end 16 and a right end 18 which define atransverse dimension (i.e., a width) of the bed 10 therebetween. Some of the structural components of the bed 10 will be designated hereinafter as “right”, “left”, “head” and “foot” from the reference point of an individual lying on his/her back on the bed 10 with his/her head oriented toward the head end 12 of the bed 10 and his/her feet oriented toward the foot end 14 of the bed 10. The bed 10 has a headboard 15 at the head end 12, a footboard (not shown) at the foot end 14, and side rails 17 on the left and right ends 16, 18 (only the side rails 17 on the left side 16 being shown herein) which may prevent the patient from falling off the bed 10.

[00101] The bed 10 has a base 20 and a patient support assembly 22 operatively connected to the base 20. The patient support assembly 22 is configured to accommodate the patient thereon. As best shown in Fig. 4, in this embodiment, the base 20 has an internal base frame 35 and an external base frame 37 at least partly surrounding the internal base frame 35. The internal base frame 35 is connected to the external base frame 37 by a plurality of load cells 39 (shown in dashed lines in Fig. 4) configured to sense a load of components supported by the internal base frame 35. The internal base frame 35 may thus alternatively be referred to as a “weighed” base frame. In this embodiment, four load cells 39 are provided at the four comers of the rectangular base 20. It is contemplated that more or fewer load cells 39 may be included in other embodiments.

[00102] It should be understood that load cells are transducers designed to convert force or load into an electrical signal that can be easily measured and monitored. These devices play a crucial role in various industries, such as manufacturing, aerospace, and healthcare, where precise measurement of force is essential. Load cells come in various types, including strain gauge, hydraulic, and pneumatic, each tailored to specific applications and load ranges. Strain gauge load cells, for instance, use the deformation of a strain-sensitive material to generate an electrical signal proportional to the applied force. Their high accuracy and reliability make them suitable for applications ranging from industrial scales to material testing machines. Load cells are integral components in ensuring accurate and efficient monitoring of forces, contributing to improved quality control, safety, and performance across diverse sectors. In the context of the present invention, any suitable known load cell may therefore be utilized without straying from the intended scope of the invention.

[00103] With continued reference to Fig. 4, in this embodiment, the internal base frame 35 has left and right elongated members 41 (only the right elongated member 41 being shown in Fig. 4) extending longitudinally from a head end to a foot end of the base 20. The internal base frame 35 also has a head end transversal member 43, a foot end transversal member 45 and two middle transversal members 47. The transversal members 43, 45, 47 extend transversally and connect the left and right elongated members 41. Furthermore, in this embodiment, the external base frame 37 has left and right elongated members 49 extending longitudinally from the head end to the foot end of the base 20. The external base frame 37 also has a head end transversal member 50 and a foot end transversal member 52 interconnecting the left and right elongated members 49. As will be appreciated, the left and right elongated members 49 and the head end and foot end transversal members 50, 52 of the external base frame 37 surround at least in part the internal base frame 35. As shown in Fig. 1, casters 24 are connected to the base 20, namely to the external base frame 37, by respective pivots (not shown) to allow the bed 10 to be moved and maneuvered along a floor. Other configurations of the base 20 are also contemplated.

[00104] An elevation system 100 operatively connects the patient support assembly 22 to the base 20 to move the patient support assembly 22 relative to the base 20, namely selectively raising or lower the patient support assembly 22 relative to the base 20. In addition to raising and lowering the patient support assembly 22, the elevation system 100, which will be described in detail further below, also allows the bed 10 to assume a number of different positions such as a flat horizontal position (shown in Figs. 1, 2 and 5), a Trendelenburg position, a reverse Trendelenburg position, a cardiac chair position, and a full chair position (Fig. 6). It is contemplated that, in other embodiments, the bed 10 may be configured to assume fewer positions. For instance, in some cases, the bed 10 may permanently remain in the flat horizontal position and simply be raised and lowered by the elevation system 100 (e.g., the bed 10 may transition only between the two positions shown in Figs. 2 and 5).

[00105] As shown in Figs. 1 and 2, the patient support assembly 22 includes an upper frame 25 and a deck 40 that is connected to the upper frame 25 for supporting the patient thereon. In use, a patient support surface (not shown), namely a mattress, is disposed on the deck 40 to comfortably support the patient. In this embodiment, the deck 40 includes a back deck section 42, a seat deck section 44, a thigh deck section 46, and a foot deck section 48 which are disposed longitudinally consecutive to each other in the flat horizontal position of the bed 10. The back deck section 42, seat deck section 44, thigh deck section 46 and foot deck section 48 have a back deck panel 70, a seat deck panel 72, a thigh deck panel 74 and a foot deck panel 76, respectively. The deck panels 70, 72, 74, 76 define respective support surfaces on which the mattress is disposed. The deck sections 42, 44, 46, 48 are movably connected to each other. In particular, the back deck section 42 and the thigh deck section 46 are pivotably connected to the seat deck section 44. The foot deck section 48 is pivotably connected to the thigh deck section 46 about a pivot 53 (Fig. 6). The seat deck section 44 is fixed to the upper frame 25 but is also movable with a movable portion of the upper frame 25, as will be described in greater detail further below. In this embodiment, the movement of the foot deck section 48 as the bed 10 transitions between different positions is dependent on the movement of the other deck sections, namely of the thigh deck section 46 to which it is connected. That is, the foot deck section 48 is not directly acted upon by an actuator external to the foot deck section 48 in order to change its position. Instead, the foot deck section 48 follows the motion described by the actuation of the thigh deck section 46.

[00106] It is contemplated that the deck 40 may have a different number of deck sections in other embodiments (e.g., three deck sections). The motion of the different deck sections 42, 44, 46, 48 between the flat horizontal position and the full chair position of the bed 10 will be described in more detail below.

[00107] The elevation system 100 has a head end lift assembly 102 and a foot end lift assembly 104 which connect the base 20 to the head end and the foot end of the upper frame 25, respectively. The head end lift assembly 102 and the foot end lift assembly 104 may be actuated to selectively raise or lower a respective one of the head end and the foot end of the upper frame 25. Notably, each of the head end lift assembly 102 and the foot end lift assembly 104 may be raised to a fully extended position (shown for both assemblies 102, 104 in Figs. 1 to 3 and 7 to 9) and lowered to a fully collapsed position (shown for both assemblies 102, 104 in Figs. 5 and 12 to 14). The lift assemblies 102, 104 may be controlled symmetrically so that that the lift assemblies 102, 104 are in equivalent extended positions at the same time (e.g., both in the fully extended position or both in the fully collapsed position), or they may also be controlled asymmetrically so that they are in different extended positions at the same time. For example, as shown in Fig. 6, in some cases, the head end lift assembly 102 may be in the fully extended position while the foot end lift assembly 104 is in the fully collapsed position or vice- versa (e.g., in the Trendelenburg position).

[00108] In this embodiment, the head end lift assembly 102 and the foot end lift assembly 104 are configured differently from one another as shown. However, it is contemplated that, in some embodiments, the head end lift assembly 102 and the foot end lift assembly 104 may be identical to each other.

[00109] With reference to Figs. 7 to 9, the head end lift assembly 102 includes a lift leg unit 110 and a support leg unit 112 pivotably connected to the lift leg unit 110. The lift leg unit 110 has an upper end portion 114 that is pivotably connected to the upper frame 25 (see Figs. 2 and 3), and a lower end portion 116 that is pivotably connected to the base 20. In particular, the lower end portion 116 is movable relative to the base 20 in the longitudinal direction of the bed 10. More specifically, as will be described in more detail below, the lower end portion 116 is slidable along the base 20 in the longitudinal direction.

[00110] The lift leg unit 110 includes left and right lift leg members 118 laterally spaced from each other such that the left and right lift leg members 118 are disposed on opposite sides of a longitudinal centerplane of the bed 10 (i.e., a plane extending longitudinally and bisecting the width of the bed 10). The lift leg unit 110 also includes bracing members 120 that extend between and interconnect the left and right lift leg members 118. In this embodiment, each of the lift leg members 118 is hollow, notably defining an internal cavity 119 (Figs. 10, 11). This may allow routing cables through the internal cavities 119 of the lift leg members 118 to keep the cables hidden from view. Furthermore, in this embodiment, the lift leg members 118 are generally S-shaped. In particular, each leg member 118 has two end sections 126 (which define respective ones of the upper and lower end portions 114, 116 of the lift leg unit 110) that are elongated and generally parallel to each other, and an angled section 129 interconnecting the two elongated end sections 126 and disposed at an angle relative thereto. As may be seen in Figs. 12 and 13, in the fully collapsed position of the head end lift assembly 102, for each lift leg member 118, the end section 126 that is closest to the head end of the bed 10 is disposed vertically higher than the other elongated end section 126 (that is furthest from the head end of the bed 10). Moreover, in the fully collapsed position of the head end lift assembly 102, the end sections 126 extend generally horizontally. As such, the S-shaped configuration of the lift leg members 118 is helpful to make the head end lift assembly 102 occupy less space, particularly in a longitudinally central area of the bed 10, than might otherwise be possible with a different shape of the lift leg members 118.

[00111] In this embodiment, connecting flanges 122 extend from the upper ends of the lift leg members 118. In particular, as shown in Figs. 12 and 13, in the fully collapsed position of the head end lift assembly 102, the connecting flanges 122 extend downward from the upper ends of the lift leg members 118. The head end lift assembly 102 has a linkage 140 that pivotably connects the upper ends of the lift leg members 118 to the connecting flanges 122. In this embodiment, the linkage 140 includes left and right links 141 that are pivotably connected to respective ones of the connecting flanges 122. More specifically, each link 141 has two opposite ends, with one end being pivotably connected to a corresponding connecting flange 122 and the other end being pivotably connected to the upper frame 25. The links 141 may allow the elevation system 100 to extend one of the head end lift assembly 102 and the foot end lift assembly 102 while collapsing the other to achieve the Trendelenburg or reverse Trendelenburg position. It is contemplated that, in other embodiments, the linkage 140 and connecting flanges 122 may be omitted. For instance, in some cases, the lift leg members 118 may be directly pivotably connected to the upper frame 25. Notably, in such cases, the upper ends of the lift leg members 118 may be both pivotably connected to the upper frame 25 and slidable relative thereto. For example, pivots formed between the upper ends of the lift leg members 118 and the upper frame 25 may move along a longitudinal slot defined by the upper frame 25.

[00112] As mentioned above, the lower end portion 116 of the lift leg unit 110 is slidable along the base 20. To that end, the lower ends of the lift leg members 118 are in a sliding relationship with the base 20. In particular, in this embodiment, the lift leg unit 110 has slide members 142 connected to the lower ends of the left and right lift leg members 118. In this example, each slide member 142 is rectangular and extends on a lateral outer side of a corresponding one of the left and right lift leg members 118 (i.e., on the side of the lift leg member 118 that is furthest from the longitudinal centerplane of the bed 10). In particular, a pivot shaft 143 extends through the lower end of the corresponding lift leg member 118 and into the corresponding slide member 142 such that the slide member 142 is secured to the lift leg member 118. The pivot shaft 143 is fixed on the slide member 142 while the lift leg member 118 is pivotable about an axis of the pivot shaft 143. [00113] The slide members 142 may be configured differently in other embodiments. For example, the slide members 142 may have a different shape and size than those described above.

[00114] As shown in Fig. 11, in this embodiment, in order to guide the slide members 142, the base 20 defines slide channels 144 that receive respective ones of the slide members 142. Each slide channel 144 is defined by elongated walls 145 that extend laterally inwardly from respective ones of the elongated members 41 of the base 20. The elongated walls 145 are vertically spaced from each otherto define the slide channel 144 therebetween. In this example, the slide channels 144 extend horizontally and longitudinally such that the movement of the slide members 142 along the slide channels 144 remains horizontal. The slide channels 144 may extend diagonally in other embodiments such that the movement of the slide members 142 has a longitudinal component and a vertical component. It is contemplated that the slide members 142 may be guided differently in other embodiments.

[00115] With reference to Figs. 7 to 9, in this embodiment, the support leg unit 112 includes left and right support leg members 160 that are laterally spaced from each other. The left and right support leg members 160 are connected to each other by a central brace 162 which, in this embodiment, includes two transverse members 163. In this embodiment, the left and right support leg members 160 are identical to each other and therefore only one of the support leg members 160 will be described herein. It is to be understood that the same description applies to the other support leg member 160.

[00116] The support leg member 160 extends from an upper end 164 to a lower end 166. The upper end 164 of the support leg member 160 is pivotably connected to a corresponding one of the lift leg members 118, between the upper and lower ends thereof. As may be seen, the support leg member 160 and the lift leg member 118 together form an inverted Y-shape when seen from the side. In this embodiment, the upper end 164 is pivotably connected to the angled section 129 of the corresponding lift leg member 118 such that a pivot formed by the upper end 164 is disposed at the angled section 129. As shown in Figs. 8 and 10, in this embodiment, the upper end 164 of the support leg member 160 is received within a connection recess 168 defined by the corresponding lift leg member 118, between the inner and outer lateral sides of the lift leg member 118. This may be helpful to limit the space occupied by the support leg unit 112, notably by clearing more space centrally between the lift leg members 118, thereby preserving more space for other components that are disposed at the base 20. Furthermore, in this embodiment, the support leg member 160 is hollow, notably defining an internal cavity 167 (Fig. 10) that extends from the lower end 166 to the upper end 164, therefore allowing cables to be routed therethrough. In particular, as shown in Fig. 10 which illustrates a crosssection of the right support leg member 160 and the right lift leg member 118, a cable 55 may be routed through the internal cavity 167 of the support leg member 160 and, at the upper end 164, through the internal cavity 119 of the lift leg member 118 via an opening 121 of the lift leg member 118. In particular, in this instance, the cable 55 is routed upward through the upper end of the lift leg member 118 to be connected to an electronic component supported by the upper frame 25.

[00117] It is contemplated that, in other embodiments, the upper end 164 may be connected to the corresponding lift leg member 118 differently. For instance, the connection recess 168 of the lift leg member 118 may be omitted and the upper end 164 of the support leg member 160 may be disposed laterally adjacent to the lift leg member 118.

[00118] The lower end 166 of the support leg member 160 is pivotably connected to the base 20. More specifically, in this embodiment, as best shown in Fig. 3A, the lower end 166 is pivotably connected to a corresponding one of left and right support leg connectors 170 which are connected to respective ones of the elongated members 41 or the head end transversal member 43 of the internal base frame 35 of the base 20. The support leg connectors 170 may therefore be thought of as intermediate connectors between the internal base frame 35 and the support leg members 160. In this embodiment, the support leg connectors 170 are generally hook-shaped and extend in part above the head end transversal member 52 of the base 20. That is, part of each support leg connector 170 extends vertically higher than the head end transversal member 52 and is simultaneously longitudinally and transversally aligned therewith (i.e., viewed from the top, the support leg connectors 170 overlap the head end transversal member 52). It is contemplated that, in other embodiments, a single support leg connector spanning the width of the base 20 may be implemented instead of two support leg connectors 170. The support leg connectors 170 allow a pivot connection of the head end lift assembly 102 to the base 20 to be located outside of a perimeter of the external base frame 37 while still being supported by the internal base frame 35, thereby ensuring that the loads supported by the head end lift assembly 102 are measured by the load cells 39 (which measure the loads supported by the internal base frame 35). This may minimize the length of the base 20 of the bed 10 thereby making it less cumbersome and minimizing the risk of a user hitting his/her legs on the base 20, as the bed is typically pushed by users from the head end thereof.

[00119] In this embodiment, the support leg member 160 is generally L-shaped. Notably, the support leg member 160 has two angled sections 172, 174 extending from respective ones of the upper end 164 and the lower end 166. In the fully extended position of the head end lift assembly 102, as shown in Figs. 7 to 9, the angled section 172 extends upwardly and forwardly (i.e., away from the longitudinal centerpoint of the bed 10) from the lower end 166, and the angled section 174 extends upwardly and rearwardly (i.e., towards the longitudinal centerpoint of the bed 10) from the angled section 172. The L-shape of the support leg member 160 allows the support leg member 160 to extend above the head end transversal member 52 of the base 20, thereby remaining clear therefrom throughout the motion of the head end lift assembly 102 between the fully extended position and the fully collapsed position. Moreover, the shape of the support leg member 160 allows the head end transversal member 52 of the base 20 to be positioned further from the head end 12 of the bed 10 which may be helpful to make space at the head end 12 for stowing user-actuated handles that are used to control a motorized wheel (not shown) of the bed 10.

[00120] Although the lift leg unit 110 and the support leg unit 112 have been described as including two leg members each (notably two lift leg members 118 and two support leg members 160 respectively), it is contemplated that one or both of the lift leg unit 110 and the support leg unit 112 may have a single leg member in other embodiments. For example, the lift leg unit 110 may have a single central lift leg member and/or the support leg unit 112 may have a single central support leg member.

[00121] Referring to Figs. 7 to 9 and 12 to 14, the head end lift assembly 102 also includes an actuator 130 that is connected between the base 20 and the support leg unit 112 in order to actuate the head end lift assembly 102 between the fully extended position and the fully collapsed position (and any position intermediate the fully extended and fully collapsed positions). In the fully extended position of the head end lift assembly 102, the head end of the upper frame 25 is at its maximum height (i.e., at its furthest position from the base 20), while in the fully collapsed position, the head end of the upper frame 25 is at its minimum height (i.e., at its closest position to the base 20). The actuator 130 is a linear actuator that extends and retracts in order to actuate the head end lift assembly 102. In particular, in this embodiment, the actuator 130 is an electric linear actuator. It is contemplated that the actuator 130 may be another type of linear actuator in other embodiments.

[00122] The actuator 130 has a base 150, an outer tube 151 connected to the base 150, and an extension rod 152 extending from the outer tube 151. The base 150 defines a base end 154 of the actuator 130, while the extension rod 152 defines an extendable end 156 (Fig. 8) of the actuator 130 that is movable relative to the base end 154. A housing 158 of the actuator 130 covers a motor (not shown) that is operatively connected to the extension rod 152 to selectively drive the extension rod 152 in and out of the outer tube 151. For instance, the extension rod 152 is operatively connected to the motor by a lead screw and a plurality of gears that are covered by the housing 158.

[00123] As shown in Figs. 9 and 10, the base end 154 is pivotably connected to the base 20 about a base pivot axis 176 that is fixed relative to the base 20. More specifically, the base end 154 is pivotably connected to one of the middle transversal members 47 of the internal base frame 35, namely the transversal member 47 closest to the head end 12 of the bed 10. The extendable end 156 is pivotably connected to the central brace 162 of the support leg unit 112 about a movable pivot axis 178. Notably, the movable pivot axis 178 moves longitudinally and vertically as the head end lift assembly 102 moves between the fully extended and fully collapsed positions. Thus, a longitudinal distance between the base end 154 and the head end 12 of the bed 10 is greater than a longitudinal distance between the extendable end 156 and the head end 12 of the bed 10.

[00124] As the head end lift assembly 102 moves between the fully extended position and the fully collapsed position, the actuator 130 rotates about the fixed base pivot axis 176. As may be appreciated from Figs. 5 and 6, the angle by which the actuator 130 rotates about the base pivot axis 176 between the fully extended position and the fully collapsed position of the head end lift assembly 102 is relatively small. Notably, the angle by which the actuator 130 rotates about the base pivot axis 176 between the fully extended position and the fully collapsed position is less than 5°. More specifically, the angle by which the actuator 130 rotates about the base pivot axis 176 between the fully extended position and the fully collapsed position is less than 3°. In this embodiment, the angle by which the actuator 130 rotates about the base pivot axis 176 between the fully extended position and the fully collapsed position is approximately 1°. Therefore, as will be appreciated, the actuator 130 achieves the full range of motion of the head end lift assembly 102 with a limited rotational movement about the base pivot axis 176. This may maximize the amount of free space available underneath the upper frame 25 along a longitudinally central portion of the bed 10 which may be helpful for performing certain procedures on the patient, such as a fluoroscopy for example where the area underneath the upper frame 25 is utilized.

[00125] As shown in Fig. 15, a controller 450 is in communication with the actuator 130 and is operable to control actuation thereof. That is, the controller 450 selectively causes the extension and retraction of the actuator 130, based on user inputs and/or sensor inputs (e.g., a limit switch). In this embodiment, the controller 450 is in communication with a user input device (not shown) that is operable by a caregiver and disposed on one of the side rails 17 of the bed 10. For instance, the user input device may be a touch screen interface that is operated by a user (e.g., a caregiver). In other embodiments, the user input device may be disposed remotely from the bed 10. The controller 450 has a processor unit 452 for carrying out executable code, and a non-transitory memory unit 454 that stores the executable code in a non-transitory medium (not shown) included in the memory unit 454. The processor unit 452 includes one or more processors for performing processing operations that implement functionality of the controller 450. The processor unit 452 may be a general-purpose processor or may be a specific-purpose processor comprising one or more preprogrammed hardware or firmware elements (e.g., application-specific integrated circuits (ASICs), electrically erasable programmable read-only memories (EEPROMs), etc.) or other related elements. The non- transitory medium of the memory module 454 may be a semiconductor memory (e.g., readonly memory (ROM) and/or random-access memory (RAM)), a magnetic storage medium, an optical storage medium, and/or any other suitable type of memory. While the controller 450 is represented as being one entity in this implementation, it is understood that the controller 450 may comprise separate entities for controlling components separately.

[00126] Referring back to Figs. 7 to 9 and 12 to 14, the foot end lift assembly 104 will now be described in greater detail . The foot end lift assembly 104 has a lift leg unit 210 and a support leg unit 212 pivotally connected to the lift leg unit 210. The lift leg unit 210 has an upper end portion 214 that is pivotably connected to the upper frame 25 (see Figs. 2 and 3), and a lower end portion 216 that is pivotably connected to the base 20.

[00127] The lift leg unit 210 includes left and right lift leg members 218 laterally spaced from each other such that the left and right lift leg members 218 are disposed on opposite sides of the longitudinal centerplane of the bed 10. Each lift leg member 218 extends from an upper end 225 to a lower end 235. The lift leg unit 210 also includes a bracing member 220 that extends between and interconnects the left and right lift leg members 218. The lift leg members 218 are similarly configured to the lift leg members 118 described above, namely being hollow and generally S-shaped. In particular, each leg member 218 has two end sections 226 (which define respective ones of the upper and lower end portions 214, 216 of the lift leg unit 210) that are elongated and generally parallel to each other, and an angled section 229 interconnecting the two elongated end sections 226 and disposed at an angle relative thereto. As may be seen in Figs. 12 and 13, in the fully collapsed position of the foot end lift assembly 104, for each lift leg member 218, the end section 226 that is closest to the foot end 14 of the bed 10 is disposed vertically higher than the other elongated end section 226 (that is furthest from the foot end 14 of the bed 10). Moreover, in the fully collapsed position of the foot end lift assembly 104, the end sections 226 extend generally horizontally. As described above for the lift leg members 118, the S-shaped configuration of the lift leg members 218 is helpful to make the foot end lift assembly 104 occupy less space, particularly in a longitudinally central area of the bed 10, than might otherwise be possible with a different shape of the lift leg members 218. As will be appreciated from Fig. 13, the space saving effect may be even greater when both the lift leg members 118 of the head end lift assembly 102 and the lift leg members 218 of the foot end lift assembly 104 have this shape.

[00128] The lower end portion 216 of the lift leg unit 210 is slidable along the base 20. To that end, the lower ends of the lift leg members 218 are in a sliding relationship with the base 20. In particular, in this embodiment, the lift leg unit 210 has slide members 142 connected to the lower ends of the left and right lift leg members 218. The slide members 142 have been described above with respect to head end lift assembly 102 and therefore will not be described herein again. The slide members 142 slide longitudinally along respective slide channels 144 of the base 20 as described above.

[00129] As shown in Figs. 7 and 8, the support leg unit 212 includes left and right support leg members 260 that are laterally spaced from each other. The left and right support leg members 260 are connected to each other by a central brace member 262. In this embodiment, each of the left and right support leg members 260 is elongated and extends from an upper end 261 to a lower end 263. The shape of the support leg members 260 may vary in other embodiments. The upper end 261 of each support leg member 260 is pivotably connected to a corresponding one of the lift leg members 218, between the upper and lower ends thereof. As may be seen, the support leg member 260 and the lift leg member 218 together form an inverted Y-shape when seen from the side. In this embodiment, the upper end 261 of each support leg member 260 is pivotably connected to the angled section 229 of the corresponding lift leg member 218 such that a pivot formed by the upper end 261 is disposed at the angled section 229. As shown in Fig. 7, in this embodiment, the upper end 261 of each support leg member 260 is received within a connection recess 268 defined by the corresponding lift leg member 218, between the inner and outer lateral sides of the lift leg member 218. As noted above, this may be helpful to limit the space occupied by the support leg unit 212, notably by clearing more space centrally between the lift leg members 218, thereby preserving more space for other components that are disposed at the base 20. The support leg members 260 may also be hollow similarly to the support leg members 160 which may allow cables to be routed therethrough as explained above.

[00130] It is contemplated that, in other embodiments, the upper ends 261 of the support leg members 260 may be connected to the lift leg members 218 differently. For instance, the connection recesses 268 of the lift leg members 218 may be omitted and the upper ends 261 of the support leg members 260 may be disposed laterally adjacent to the lift leg members 218.

[00131] The lower end 263 of each support leg member 260 is pivotably connected to a corresponding one of the left and right elongated members 41 of the internal base frame 35. The support leg members 260 therefore pivot about a pivot axis 265 (Figs. 9, 13) extending transversely through the lower ends 263 of the support leg members 260.

[00132] Because the foot end lift assembly 104 may be subjected to heavier loads than the head end lift assembly 102 due the patient’s weight as well as the weight of the deck 40 being particularly concentrated near the foot end 14 of the bed 10 in certain positions (e.g., the full chair position shown in Fig. 6), in this embodiment, the foot end lift assembly 104 includes two actuators 230 for actuating the foot end lift assembly 104. Notably, the combined cost of the two actuators 230 is less than the cost of a single heavy-duty actuator that would be able to counter the high loads applied on the foot end lift assembly 104.

[00133] The two actuators 230 are laterally spaced from each other such that they may be referred to as left and right actuators 230. In operation, the actuators 230 are extended or retracted to cause the foot end lift assembly 104 to be raised or lowered between the fully extended and fully collapsed positions. In this embodiment, the actuators 230 are connected between the lift leg unit 210 and the base 20. It is contemplated that the actuators 230 may be connected between the support leg unit 212 and the base 20 in other embodiments.

[00134] In this embodiment, the left and right actuators 230 are identical to each other, and therefore a single one of the two actuators 230 will be described in detail herein. It is to be understood that the same description applies to the other actuator 230. The actuator 230 is a linear actuator and therefore is extendable between a maximum extension position, whereby the actuator 230 is at its maximum length (measured between a base end 254 and an extendable end 256 of the actuator 230), and a minimum extension position whereby the actuator 230 is at its minimum length. A base 250 of the actuator 230 defines the base end 254.

[00135] The actuator 230 has a base 250, an outer tube 251 connected to the base 250, and an extension rod 252 extending from the outer tube 251. The base 250 defines the base end 254 while the extension rod 252 defines the extendable end 256 that is movable relative to the base end 254. The base end 254 of the actuator 230 is connected to the base 20 and defines a base pivot axis 276 (Figs. 18, 19) about which the actuator 230 pivots. The base pivot axis 276 extends transversely. A housing 258 of the actuator 230 covers a motor (not shown) that is operatively connected to the extension rod 252 to selectively drive the extension rod 252 in and out of the outer tube 251. For instance, the extension rod 252 is operatively connected to the motor by a lead screw and a plurality of gears that are covered by the housing 258.

[00136] In this embodiment, the actuator 230 is an electric linear actuator. It is contemplated that the actuator 230 may be another type of linear actuator in other embodiments.

[00137] As shown in Fig. 15, in this embodiment, the actuators 230 are in communication with the controller 450. The controller 450 selectively causes the extension and retraction of the actuators 230, based on user inputs and/or sensor inputs (e.g., a limit switch). In this embodiment, the controller 450 is in communication with a user input device (not shown). Although in this embodiment the controller 450 controls the actuator 130 of the head end lift assembly 102 and also the actuators 230 of the foot end lift assembly 104, it is contemplated that, in other embodiments, separate controllers may control the actuator 130 and the actuators 230.

[00138] As shown in Fig. 16, in this embodiment, the extendable end 256 of the actuator 230 is connected to the lift leg unit 210. In particular, the extendable end 256 is pivotably connected to a corresponding one of the lift leg members 218 and is disposed laterally inwardly therefrom. As such, in this embodiment, the extendable ends 256 of the actuators 230 are disposed laterally between the lift leg members 218. A fastener 219 (e.g., a bolt) extends through the extendable end 256 and engages the corresponding lift leg member 218 to secure the extendable end 256 thereto. A bracket 270 connected to the transversal member 220 supports the fastener 219 and partially surrounds the extendable end 256.

[00139] As may be appreciated from Fig. 18, the actuators 230 are positioned such that, in a side view of the foot end lift assembly 104, centerlines extending through the extension rods 252 of the actuators 230 converge toward each other at the extendable ends 256 and diverge away from each other at the base ends 254. Therefore, the base pivot axes 276 of the two actuators 230 (at the base ends 254) are not coaxial with each other. Furthermore, the base pivot axes 276 of the actuators 230 are movable, notably being pivotable about a common pivot axis 280 extending transversely. In particular, a linkage 272 pivotably connects the actuators 230 to the base 20 about the common pivot axis 280 in order to coordinate actuation of the left and right actuators 230. Notably, as will be described below, the linkage 272 allows the actuators 230 to be extended and retracted in coordination with each other to minimize imbalances in the forces exerted thereby which may otherwise damage the actuators 230.

[00140] With reference to Figs. 17 and 18, in this embodiment, the linkage 272 includes an actuator link 282 for each actuator 230. Each actuator link 282 forms a clevis including two link flanges 283 that straddle the base end 254 of a respective one of the actuators 230. A fastener (e.g., a bolt) extends through the actuator links 282 and the base end 254 of the corresponding actuator 230 to secure the actuator 230 to the actuator link 282 and allow rotation of the actuator 230 about the corresponding base pivot axis 276. In this embodiment, the actuator links 282 are connected to each other by an interconnecting link 284 which in turn is pivotably connected to the base 20 about the common pivot axis 280.

[00141] In this embodiment, the interconnecting link 284 is a hollow shaft that extends transversely and to which the actuator links 282 are connected. Notably, the actuator links 282 are fixedly connected to the shaft 284 as part of each link flange 283 extends into a corresponding opening defined by the shaft 284.

[00142] The linkage 272 also includes left and right outer links 286 that pivotably connect the shaft 284 to the base 20. In particular, each outer link 286 is connected to the shaft 284 in order to rotate together therewith. In this embodiment, each outer link 286 defines an opening at one end thereof through which the shaft 284 extends. At the other end, each outer link 286 is connected to a corresponding pivot member 288 that is fixed to the internal base frame 35 of the base 20. In particular, a fastener 290 extends through the pivot member 288 and the outer link 286 to secure the pivot member 288 and the outer link 286 to the internal base frame 35. The pivot members 288 are coaxial with each other and define the common pivot axis 280 about which the linkage 272 is rotatable.

[00143] As will be appreciated, the linkage 272 allows the base pivot axes 276 defined at the base ends 254 of the actuators 230 to pivot about the common pivot axis 280 defined between the linkage 272 and the base 20. Notably, as shown in Figs. 18 and 19, the base pivot axes 276 are distanced from the common pivot axis 280 in order to pivot thereabout. Indeed, the base pivot axes 276 are disposed at equal distances from the common pivot axis 280. Moreover, in this embodiment, the common pivot axis 280 and the base pivot axes 276 are aligned such that a plane Pl contains the common pivot axis 280 and the base pivot axes 276. This may be helpful to optimize the balance of the forces exerted by the actuators 230. It is contemplated that, in other embodiments, the common pivot axis 280 and the base pivot axes 276 may not be aligned in such a manner as for a plane to contain the common pivot axis 280 and the pivot axes 276.

[00144] This configuration of the foot end lift assembly 104 allows the extension and retraction of the two actuators 230 to be automatically coordinated. In particular, throughout the motion of the foot end lift assembly 104 between the fully extended position and the fully collapsed position, the linkage 272 pivots about the common pivot axis 280 in response to the positions of the extendable ends 256 of the two actuators 230 being uncoordinated, including if the actuators 230 extend or retract at different rates and/or if the actuators 230 are of slightly different lengths. As will be appreciated, by allowing the actuators 230 to pivot about the common pivot axis 280, the extension and retraction of the actuators 230 will be coordinated such that the extendable ends 256 generally keep up with each other. The linkage 272 therefore provides an effective mechanical solution for coordinating the actuators 230. Moreover, such a mechanical solution for the coordination of the actuators 230 avoids having to adopt a software control solution that may be more complex and costly to implement.

[00145] Furthermore, with reference to Fig. 17, in this embodiment, a sensing device 292 is provided to avoid a potential collision of the actuators 230 with some of the components of the linkage 272. The sensing device 292 is configured to measure a parameter indicative of the positions of the actuators 230 relative to the linkage 272. The sensing device 292 is in communication with the controller 450 and transmits a signal thereto that indicates a value of the parameter indicative of the positions of the actuators 230 relative to the linkage 272. The controller 450 may therefore control the actuators 230 based on the parameter measured by the sensing device 292. Notably, in this example, the controller 450 is configured to stop actuation of the actuators 230 in response to the value of the measured parameter being indicative of a potential collision between one or both of the actuators 230 and the linkage 272.

[00146] In this embodiment, the sensing device 292 is a potentiometer. The potentiometer 292 has a shaft 294 that is received by a coupler portion 295 of an actuator coupling bracket 296. The actuator coupling bracket 296 engages one of the actuators 230 and rotates together therewith about the base end 254 thereof. In particular, in this embodiment, the actuator coupling bracket 296 engages the base 250 of the actuator 230. The coupler portion 295 defines an opening for receiving the shaft 294 therein. In this example, the coupler portion 295 is supported on one side thereof by the fastener that extends through the base end 254 of the actuator 230. Different shapes and position of the actuator coupling bracket 296 are contemplated.

[00147] In use, when the base ends 254 of the actuators 230 pivot about the common pivot axis 280, the actuator coupling bracket 296 pivots together with the actuator 230 with which it is engaged. As the actuator coupling bracket 296 rotates, the shaft 294 of the potentiometer 292 is rotated, thereby changing the resistance value of the potentiometer 292. Based on the resistance value of the potentiometer 292, the controller 450 may determine if either of the actuators 230 is moving into potential collision with the linkage 272, namely with the shaft 284.

[00148] It is contemplated that, in some embodiments, the head end lift assembly 102 may have the same configuration as the foot end lift assembly 104. Conversely, in other embodiments, the foot end lift assembly 104 may have the same configuration as the head end lift assembly 102, for example in cases where the bed 10 may not need to be placed in the full chair position.

[00149] With reference to Fig. 3, the upper frame 25 will now be described in greater detail. In this embodiment, the upper frame 25 has two fixed portions 31, 33, namely a head end fixed portion 31 and a foot end fixed portion 33, and a sliding portion 30 that slides longitudinally relative to the fixed portions 31, 33. The upper frame 25 may thus be sometimes referred to as a “sliding frame assembly”. The sliding portion 30 includes left and right elongated sleeve members 302 extending longitudinally and spaced apart from each other. The elongated sleeve members 302 are hollow in order to receive part of the head end and foot end fixed portions 31, 33 therein. Each of the elongated sleeve members 302 has a rectangular cross-sectional profile. Transverse members 304, one of which is shown in Fig. 3, interconnect the elongated sleeve members 302. . The seat deck section 44 is fixedly connected to the elongated sleeve members 302 and thus moves longitudinally together therewith.

[00150] The head end fixed portion 31 includes left and right head end fixed members 306. Each head end fixed member 306 is partly received within a corresponding one of the elongated sleeve members 302. As shown in Fig. 20, the right head end fixed member 306 includes an elongated body 307 extending from a head end 310 to a foot end 312. A pivot pin 314 is connected to the elongated body 307 at the head end 310. The pivot pin 314 is configured to pivotably connect the corresponding link 141 of the head end lift assembly 102 thereto to allow the link 141 to pivot about an axis of the pivot pin 314. As such, the head end lift assembly 102 is coupled to the head end fixed portion 31. Two rollers 316 are connected to the foot end 312 of the elongated body 307. The axes about which the rollers 316 rotate are vertically and longitudinally spaced from each other. In use, the rollers 316 engage respective inner surfaces of the corresponding elongated sleeve member 302 in order to allow the elongated sleeve member 302 to slide relative to the head end fixed member 306. The left head end fixed member 306 is a mirror image of the right head end fixed member 306 and therefore will not be described in detail herein. As will be appreciated, the left and right head end fixed members 306 are interconnected to each other by the head end lift assembly 102.

[00151] As shown in Fig. 3, the foot end fixed portion 33 includes left and right foot end fixed members 308. Each foot end fixed member 308 is partly received within a corresponding one of the elongated sleeve members 302. As shown in Fig. 21, the right foot end fixed member 308 includes an elongated body 318 extending from a head end 320 to a foot end 322. Two rollers 324 (one of which is shown in Fig. 21) are connected to the head end 320 of the elongated body 318. The axes about which the rollers 324 rotate are vertically and longitudinally spaced from each other. In use, the rollers 324 engage respective inner surfaces of the corresponding elongated sleeve member 302 in order to allow the elongated sleeve member 302 to slide relative to the foot end fixed member 308. In this embodiment, a connection bracket 326 is connected to the foot end 322 of the elongated body 318. As shown in Fig. 3, the connection bracket 326 has a pin 328 extending laterally inwardly for connecting the foot end deck section 48 thereto as will be described in more detail further below. The left foot end fixed member 308 is a mirror image of the right foot end fixed member 308 and therefore will not be described in detail herein. As shown in Fig. 3, atransverse foot end support 330 is connected to the connection brackets 326 of the left and right foot end fixed members 308, thereby connecting the left and right foot end fixed members 308 together. The upper end of the foot end lift assembly 104, namely the upper ends of the lift leg members 218, is connected to foot end fixed portion 33. Notably, each lift leg member 218 of the foot end lift assembly 104 is connected to a corresponding one of the left and right foot end fixed members 308 through a longitudinal slot 221 defined by each of the elongated sleeve members 302, on an inner side thereof. As such, in use, as the sliding portion 30 slides relative to the head end and foot end fixed portion 31, 33, the connection between the foot end lift assembly 104 and the foot end portion 33 is displaced along the slots 221.

[00152] As will be understood, as the head end lift assembly 102 and the foot end lift assembly 104 are connected to the head end fixed portion 31 and the foot end fixed portion 33 respectively, a longitudinal distance between the respective connections of the head end and foot end lift assemblies 102, 104 and the upper frame 25 is fixed.

[00153] The upper frame 25 may be configured differently in other embodiments. For instance, in other cases, the roles of the sliding portion 30 and the fixed portions 31, 33 may be inversed. That is, the portions 31, 33 may be slidable while the portion 30 is fixed. Such examples of a sliding frame assembly are described in detail in International Patent Application No. PCT/IB2022/056645, filed July 19, 2022, the entirety of which is incorporated by reference herein.

[00154] An actuator 340 (Fig. 3) is connected between the transverse foot end support 330 and the sliding portion 30 of the upper frame 25 to cause the sliding portion 30 to slide on the fixed portions 31, 33. The actuator 340, which may be controlled by a controller such as the controller 450 previously described, is selectively extended and retracted to slide the sliding portion 30 toward the head end 12 of the bed 10 or toward the foot end 14 of the bed 10.

[00155] As shown in Fig. 6, in order to cause the bed 10 to transition from the flat horizontal position to the full chair position, in this embodiment, the head end lift assembly 102 is actuated to be in the fully extended position while the foot end lift assembly 104 is actuated to be in the fully collapsed position. The back deck section 42 is actuated via an actuator (not shown) that forces left and right arms 360 (only one of which is shown in Fig. 6) connected between the sliding portion 30 of the upper frame 25 and the back deck section 42 to pivot the back deck section 42 relative to the seat deck section 44. The back deck section 42 also moves longitudinally and vertically away from the seat deck section 44 via guides (not shown) that direct the movement of the back deck section 42. The actuator 340 is also controlled to retract to its minimum length which causes the sliding portion 30 of the upper frame 25 to slide toward the foot end 14 of the bed 10, therefore driving the deck sections 42, 44, 46, 48 with it. A frame 370 of the foot deck section 48 includes left and right channels 372 (only one of which is shown in Figs. 5, 5A, 6) that receive respective rollers 374 (Fig. 3, Fig. 5A) connected to the connection brackets 326 of the foot end fixed members 308. The foot deck section 48 is therefore connected to the foot end fixed portion 33 via the channels 372 which, in the flat horizontal position of the bed 10, extend downward and toward the foot end 14 from their upper ends to their lower ends (see Fig. 5A). As the actuator 340 retracts to its minimum length, the rollers 374 move along the corresponding channels 372 and the foot deck section 48 pivots relative to the thigh deck section 46 about the pivot 53 interconnecting them. The foot deck section 48 is thus reoriented as it pivots about the pivot 53 and about the pins 374, ending in a vertical position of the foot deck section 48 shown in Fig. 6. In order to provide greater control of the motion of the foot deck section 48, the thigh deck section 46 may also be pivoted relative to the seat deck section 44 via an actuator 378 (partially shown in Fig. 5A) connected between the thigh deck section 46 and the sliding portion 30 of the upper frame 25. This pivoting motion of the thigh deck section 46 also causes the foot deck section 48 to move upwardly, as shown in Fig. 5B. The thigh deck section 46 may also be pivoted to reach other positions of the bed 10, such as the cardiac chair position for example. More details of the movement of the deck sections 42, 44, 46, 48 are provided in International Patent Application No. PCT/IB2022/056645, filed July 19, 2022.

[00156] From the above, it should be understood that Fig. 20 and Fig. 21 form a two-part configuration whereby both sets (right and left) of the head end fixed members 306 and the foot end fixed members 308 are slidingly assembled within their respective elongated sleeve members 302 (as seen in Fig. 3). While such a two-part configuration shown and described hereinabove may be utilized, a further embodiment may be provided whereby the two-part configuration is instead unitary as illustrated further by Figs. 27 to Fig. 29. [00157] With reference to Fig. 27, there is illustrated a perspective view of yet another embodiment in simplified form showing details of an alternative upper frame 25a. Fig. 28 is an exploded view of the embodiment of Fig. 27, while Fig. 29 is an exploded view of the alternative upper frame 25a of Fig. 27 showing details of the fixed and sliding portions thereof. In such additional embodiment in accordance with the present invention, the upper frame 25a includes left and right elongated members 368 joined by the transverse foot end support 330 near a foot end thereof and a transverse head end support (not shown) near a head end thereof. The upper frame 25a also includes elongated sleeve members 302a themselves joined by a transverse member 304. Additional transverse members may interconnect the elongated sleeve members 302a.

[00158] Accordingly, this alternative upper frame 25a includes a single fixed portion 2801 and a sliding portion 2800 that slides in a telescoping manner along the fixed portion in a concentric configuration. In particular, as best shown in Figs. 28 and 29, the fixed portion 2801 includes the left and right elongated members 368 and interconnecting transverse members extending therebetween, while the sliding portion 2800 includes the elongated sleeve members 302a, whereby the elongated sleeve members 302a are concentric to the inner placed left and right elongated members 368. The sliding of the elongated sleeve members 302a along the elongated members 368 is facilitated by rollers 324 disposed partly within the elongated members 368 and configured to engage respective inner surfaces of the elongated sleeve members 302a. As can be seen in Fig. 27, and as described in relation to the upper frame 25, the foot end lift assembly 104 is pivotably connected to the fixed portion 2801, the pivot connection therebetween extending through slots 221a (one of which is shown in Fig. 27) defined by the sleeve members 302a. As previously described above, the actuator 340 connected between the transverse member 304 and the transverse foot end support 330 is responsible for controlling the position of the sliding portion relative to the fixed portion. To achieve the chair position, the actuator 340 retracts to its minimum length, moving the sliding portion 2800 toward the foot end of the fixed portion 2801 (thereby moving the seat deck section 44 which is fixed to the sliding portion 2800 and the other deck sections 42, 46, 48 therewith) and in doing so also controls the angular position of the foot deck section (element 48 as seen in Fig. 1 and Fig. 2) via the arrangement of the rollers 374 and channels 372 described above, thereby orienting the foot deck section 48 to a more upright position. [00159] As will be appreciated from the above, the configuration of the upper frame 25, namely including the sliding portion 30, allows for a simple and efficient manner in which the deck sections 42, 44, 46, 48 may be displaced to reach different positions of the bed 10.

[00160] Various modifications to the embodiments described above will now be shown and described with regard to alternative embodiments illustrated by Fig. 22 to Fig. 26.

[00161] With reference to Fig. 22, there is shown a perspective view, taken from atop, rear, right side, of a portion of the head end lift assembly according to an alternative embodiment 2200. While all parts of the overall patient support apparatus as previously shown and described are substantially unchanged, this alternative embodiment contrasts with that portion best shown in Fig. 3A in terms of the manner in which the right and left support leg members 160 are connected to the head end transversal member 43 of the internal base frame 35. In this alternative embodiment 2200, the right and left support leg members 160 are substantially identical to element 160 in Fig. 3 A and again formed by two angled sections and attached to the head end transversal member 43 of the internal base frame 35. However, each right and left support leg member 160 is attached to the head end transversal member 43 from below (rather than from above as previously shown in Fig. 3A) via an intermediate connector comprised of an L-bracket 2202 and a bracket connector 2201.

[00162] In this alternative embodiment 2200, the L-bracket 2202 is fixed to the underside of the head end transversal member 43. Bracket connectors 2201 are provided as an intermediate element to pivotably connect each respective right and left support leg member 160 to a corresponding L-bracket 2202. This allows movement of the right and left support leg members 160 during raising/lowering of the patient support apparatus while the L-brackets 2202 and bracket connectors 2201 remain fixed relative to the base of the patient support apparatus. Such raising/lowering being previously shown by Fig. 2 relative to Fig. 5. An advantage of attaching each right and left support leg member 160 to the head end transversal member 43 from below is that the L-brackets 2202 and bracket connectors 2201 are therefore located unobtrusively under the base of the patient support apparatus. In this manner, tangling of cords, patient intravenous lines, or the like may be advantageously avoided. As well, each of the L-brackets 2202 and bracket connectors 2201 are advantageously located inwardly away from each adjacent caster 24 to allow for full 360 degrees of movement by the casters 24 without potentially pinching obstructing objects (e.g., cables) between the casters 24 and the intermediate connectors. [00163] With reference to Fig. 23, there is illustrated a perspective view taken from below the alternative embodiment shown in Fig. 22. Here, the L-brackets 2202 are visible welded to the underside of the head end transversal member 43. Notably, a shank 2203 of each L-bracket 2202 (see Fig. 24) is inserted into a corresponding opening of the head end transversal member 43 and a weld is made at their interface to secure the L-bracket 2202 to the head end transversal member 43. While the L-brackets 2202 are connected to the head end transversal member 50 by welding in this example, it should be understood that any means of affixing the L-brackets may be accomplished including, but not limited to, mechanical fasteners (e.g., bolts), soldering, or any suitably high-strength connection. As may be clearly seen at the right side of Fig. 23, the L-bracket 2202 is spaced inwardly from the caster 24 such that there is sufficient clearance therebetween regardless of the swivel action of the caster 24. Likewise, the bracket connector

2201 is affixed to the L-bracket 2202 without any interference to the swiveling caster 24. In this manner, the casters 24 are free to swivel unimpeded by either the L-brackets 2202 or bracket connectors 2201. As shown, the bracket connectors 2201 are affixed to the L-brackets

2202 via bolts while the right and left support leg members 160 are pivotably connected to the bracket connectors 2201 as previously discussed.

[00164] With reference to Fig. 24, there is shown a cross-sectional, side view taken from line A-A in the alternative embodiment shown in Fig. 22. Here, the relative positions of the L- bracket 2202 and bracket connector 2201 are shown. It should be noted that while two separate components comprising the L-bracket 2202 and bracket connector 2201 are shown and described, these components may be provided as a unitary element without straying from the intended scope of the present invention. Such unitary element would of course be affixed to the head end transversal member 43 at one end and pivotably attached to a respective one of the support leg members 160 as would the two separate components. From Fig. 24, it may be seen that the L-bracket 2202 is mounted below the head end transversal member 50, but does not extend vertically past the midpoint of the caster 24. In this manner, suitable and sufficient ground clearance is ensured for smooth operation and movement of the patient support apparatus.

[00165] With reference to Fig. 25, there is illustrated a partial bottom view taken from below the right comer of the alternative embodiment shown in Fig. 22. The bracket connector 2201 is affixed to the L-bracket 2202 as shown and previously described and extends outwardly from the head end transversal member 50 so as to align its end with the pivot point at the lower end of the support leg members 160. Thus, the fixed bracket connectors 2201 are pivotably attached to the support leg members 160 enabling movement of the support leg members 160 as previously described. As shown, caster 24 is located adjacent yet sufficiently distanced from the bracket connector 2201 and the L-bracket 2202 so as to allow full and unimpeded swivel movement of the caster 24.

[00166] As will be understood, the embodiment of Figs. 22 to 25 allows an unobstructive manner in which to connect the head end lift assembly 102 of the elevation system to the internal base frame 35 (which as described above is weighed by the load cells 39) at a location outside of a perimeter of the external base frame 37. In other words, despite the external base frame 37 surrounding the internal base frame 35, the intermediate connectors circumvent the external base frame 37 and enable a pivot connection between the support leg members 160 of the head end lift assembly 102 and the internal base frame 35 (via the intermediate connectors) outside of the perimeter of the external base frame 37. This may minimize the length of the base 20 of the bed 10 thereby making it less cumbersome and minimizing the risk of a user hitting his/her legs on the base 20, as the bed is typically pushed by users from the head end thereof.

[00167] With reference to Fig. 26, there is illustrated a perspective view of an additional embodiment 2600 including the embodiment of Fig. 22 and optional cord retaining clips 1801. The cord retaining clips 1801 are provided as extensions of caps 1800 which are snapped onto, removably affixed, or otherwise fitted onto underlying elements (i.e., linkages 140 as seen in Figs. 3 and 8) of the patient support apparatus at the head end thereof. In this example, the caps 1800 overlie the linkages 140 and are fastened thereto via fasteners (not shown). The caps 1800 thus limit access to the underlying linkages 140. It should be understood that the caps 1800 and the cord retaining clips 1801 are provided as a unitary element preferably fabricated from a suitable material such as, but not limited to, plastic or metallic material.

[00168] The cord retaining clips 1801 are oriented such that they form extensions facing in opposite directions as shown. In this manner, any cord-like elements related to patient devices and monitoring equipment such as, but not limited to lead wires, outlet cords, electronics cabling, or the like (shown by dotted line) may be conveniently and neatly wrapped upon the opposing extensions. The material selected for forming the caps 1800 and the cord retaining clips 1801 may be selected to be sufficiently pliant to allow the caps 1800 to allow the cord retaining clips 1801 to flex or otherwise yield when cords wrapped thereupon are inadvertently pulled. While high impact plastic may be a suitable material, it should be understood that any high-density rubber or semi-flexible polymer may be used to form the caps 1800 and the cord retaining clips 1801 without straying from the intended scope of the present invention.

[00169] Modifications and improvements to the above-described embodiments of the present technology may become apparent to those skilled in the art. The foregoing description is intended to be exemplary rather than limiting. The scope of the present technology is therefore intended to be limited solely by the scope of the appended claims.

Claims

1. A patient support apparatus comprising: a base; a patient support assembly moveably connected to the base and configured to accommodate a patient thereon, the patient support assembly comprising an upper frame and a deck connected to the upper frame; and an elevation system operatively connecting the base to the patient support assembly to move the patient support assembly relative to the base, the elevation system comprising a head end lift assembly and a foot end lift assembly that are movable to raise and lower a corresponding one of a head end and a foot end of the upper frame respectively, at least one of the head end lift assembly and the foot end lift assembly comprising: a lift leg unit comprising: a first end portion pivotably connected to the upper frame; a second end portion pivotably connected to the base, the second end portion being movable relative to the base in a longitudinal direction of the patient support apparatus; a support leg unit pivotably connected to the base, the support leg unit being pivotably connected to the lift leg unit between the first and second end portions; and an actuator connected between the base and the support leg unit to actuate the at least one of the head end lift assembly and the foot end lift assembly between an extended position and a collapsed position, the corresponding one of the head end and the foot end of the upper frame being further from the base in the extended position than in the collapsed position of the at least one of the head end lift assembly and the foot end lift assembly.

2. The patient support apparatus of claim 1, wherein the actuator comprises: a base end that is pivotably connected to the base about a base pivot axis, the base pivot axis being fixed relative to the base; and an extendable end that is movable relative to the base end, the extendable end being connected to the support leg unit.

3. The patient support apparatus of claim 2, wherein a longitudinal distance between the base end of the actuator and the corresponding one of the head end and the foot end of the upper frame is greater than a longitudinal distance between the extendable end of the actuator and the corresponding one of the head end and the foot end of the upper frame.

4. The patient support apparatus of claim 2 or 3, wherein: in the extended position of the at least one of the head end lift assembly and the foot end lift assembly, the corresponding one of the head end and the foot end of the upper frame is at its maximum height; in the collapsed position of the at least one of the head end lift assembly and the foot end lift assembly, the corresponding one of the head end and the foot end of the upper frame is at its minimum height; and the actuator rotates about the base pivot axis by an angle of less than 5° between the extended and collapsed positions.

5. The patient support apparatus of claim 4, wherein the actuator rotates about the base pivot axis by an angle of less than 3° between the extended and collapsed positions.

6. The patient support apparatus of claim 5, wherein the actuator rotates about the base pivot axis by an angle of approximately 1° between the extended and collapsed positions.

7. The patient support apparatus of any one of claims 1 to 6, wherein the actuator is an electrical linear actuator.

8. The patient support apparatus of any one of claims 1 to 7, wherein the support leg unit comprises: a left support leg member and a right support leg member laterally spaced from each other; and a central brace connecting the left support leg member to the right support leg member, the actuator being connected to the central brace.

9. The patient support apparatus of claim 8, wherein, throughout a motion between the extended and collapsed positions, each of the left and right support leg members is disposed above a corresponding one of a head end and a foot end of the base.

10. The patient support apparatus of claim 9, wherein: the base comprises an external base frame and an internal base frame surrounded at least in part by the external base frame; the internal base frame is connected to the external base frame via at least one load cell configured to sense a load of components supported by the internal base frame; throughout the motion between the extended and collapsed positions, each of the left and right support leg members is disposed above a corresponding one of a head end and a foot end of the external base frame.

11. The patient support apparatus of claim 10, further comprising at least one intermediate connector connecting the internal base frame to the left and right support leg members, the at least one intermediate connector extending above a head end transversal member of the external base frame.

12. The patient support apparatus of claim 10, further comprising at least one intermediate connector connecting the internal base frame to the left and right support leg members, the intermediate connector located below a head end transversal member of the external base frame.

13. The patient support apparatus of claim 12, wherein each at least one intermediate connector is formed by a bracket connector and an L-bracket, the L-bracket being affixed to a lower surface of the head end transversal member and the bracket connector extending below the head end transversal member of the base frame, the bracket connector affixed to a corresponding L-bracket at one end thereof and pivotably attached to a corresponding one of the left and right support leg members at another end thereof.

14. The patient support apparatus of any one of claims 8 to 13, wherein: the lift leg unit comprises a left lift leg member and a right lift leg member laterally spaced from each other; and the left and right support leg members are pivotably connected to the left and right lift leg members, respectively.

15. The patient support apparatus of claim 14, wherein: each of the left and right lift leg members defines a connection recess; and part of each of the left and right support leg members is received within the connection recess of a respective one of the left and right lift leg members.

16. The patient support apparatus of claim 14 or 15, wherein the at least one of the head end lift assembly and the foot end lift assembly further comprises: a linkage pivotably connecting the first end portion of the lift leg unit to the upper frame, the linkage comprising a left link and a right link, each of the left and right links having a first link end and a second link end, the first link end being pivotably connected to the first end portion of the lift leg unit, the second link end being pivotably connected to the upper frame.

17. The patient support apparatus of any one of claims 14 to 16, wherein each of the left and right lift leg members are generally S-shaped.

18. The patient support apparatus of any one of claims 14 to 17, wherein each of the left and right lift leg members comprises: a first elongated section comprising the first end portion; a second elongated section comprising the second end portion, the first and second elongated sections extending generally parallel to each other; and an angled section interconnecting the first and second elongated sections, the angled section being angled relative to the first and second elongated sections.

19. The patient support apparatus of claim 18, wherein the left and right support leg members are pivotally connected to the left and right lift leg members at the angled sections thereof.

20. The patient support apparatus of claim 18 or 19, wherein, in the collapsed position: the first and second end sections extend generally horizontally; and the first end section is disposed vertically higher than the second end section.

21. The patient support apparatus of any one of claims 1 to 20, wherein the second end portion of the lift leg unit is longitudinally slidable along the base.

22. The patient support apparatus of any one of claims 1 to 21, wherein the at least one of the head end lift assembly and the foot end lift assembly is the head end lift assembly.

23. The patient support apparatus of any one of claims 1 to 22, wherein: the actuator is a single actuator; and the foot end lift assembly comprises two actuators for actuating the foot end lift assembly.

24. The patient support apparatus of any one of claims 1 to 23, wherein the patient support apparatus is a bed.

25. The patient support apparatus of any one of claims 1 to 24, wherein the patient support apparatus is movable between a horizontal position and a full chair position.

26. The patient support apparatus of any one of claims 1 to 25, wherein the deck comprises a back support deck section, a seat deck section, a thigh deck section, and a foot deck section that are movably connected to each other.

27. The patient support apparatus of any one of claims 1 to 26 further comprising a pair of caps fitted to left and right sides of the lift leg unit, each cap including a cord retaining clip, the cord retaining clips of the caps forming extensions opposingly oriented to enable cord-like elements to be wrapped therebetween.

28. A patient support apparatus comprising: a base; a patient support assembly moveably connected to the base and configured to accommodate a patient thereon, the patient support comprising an upper frame and a deck connected to the upper frame; and an elevation system operatively connecting the base to the patient support assembly to move the patient support assembly relative to the base, the elevation system comprising a head end lift assembly and a foot end lift assembly that are movable to raise and lower a head end and a foot end of the upper frame respectively, at least one of the head end lift assembly and the foot end lift assembly comprising: a lift leg unit pivotably connected to the upper frame and to the base; a support leg unit pivotably connected to the base and to the lift leg unit; a first actuator and a second actuator for actuating the at least one of the head end lift assembly and the foot end lift assembly, the first and second actuators being extendable, each of the first and second actuators having a first end and a second end that is movable relative to the first end, the first ends of the first and second actuators being pivotably connected to one of the support leg unit and the lift leg unit; and a linkage pivotably connecting the first and second actuators to the base in order to coordinate actuation of the first and second actuators, the second end of the first actuator being pivotably connected to the linkage about a first pivot axis, the second end of the second actuator being pivotably connected to the linkage about a second pivot axis generally parallel to the first pivot axis, the linkage being pivotably connected to the base about a third pivot axis generally parallel to the first and second pivot axes such that the first and second pivot axes are pivotable about the third pivot axis.

29. The patient support apparatus of 28, wherein the first, second and third pivot axes are aligned such that a plane contains the first, second and third pivot axes.

30. The patient support apparatus of claim 28 or 29, wherein the first and second pivot axes are disposed at equal distances from the third pivot axis.

31. The patient support apparatus of any one of claims 28 to 30, wherein the linkage comprises: a first actuator link pivotably connected to the second end of the first actuator to allow rotation thereof about the first pivot axis; a second actuator link pivotably connected to the second end of the second actuator to allow rotation thereof about the second pivot axis; and an interconnecting link connected to the first and second actuator links, the interconnecting link being pivotably connected to the base.

32. The patient support apparatus of claim 31, wherein: the interconnecting link is a shaft; and the linkage further comprises first and second outer links pivotally connecting the shaft to the base, the first and second outer links being pivotable about the third pivot axis.

33. The patient support apparatus of any one of claims 28 to 32, further comprising: a controller in communication with the first and second actuators, the controller being operable to control the first and second actuators, wherein, throughout a motion of the at least one of the head end lift assembly and the foot end lift assembly, the linkage pivots about the third pivot axis in response to the positions of the second ends of the first and second actuators being uncoordinated.

34. The patient support apparatus of claim 33, further comprising a sensing device configured to measure a parameter indicative of a position of at least one of the first and second actuators relative to the linkage, the controller being in communication with the sensing device, the controller being operable to control the first and second actuators based on the parameter measured by the sensing device.

35. The patient support apparatus of claim 34, wherein the controller is configured to selectively stop actuation of the first and second actuators in response to a value of the measured parameter being indicative of a potential collision between the first or second actuators and the linkage.

36. The patient support apparatus of claim 34 or 35, wherein the sensing device is a potentiometer.

37. The patient support apparatus of any one of claims 28 to 36, wherein the first and second actuators are electrical linear actuators.

38. The patient support apparatus of any one of claims 28 to 37, wherein the patient support apparatus is a bed.

39. The patient support apparatus of any one of claims 28 to 38, wherein the patient support apparatus is movable between a flat horizontal position and a full chair position.

40. The patient support apparatus of any one of claims 28 to 39, wherein the deck comprises a back support deck section, a seat deck section, a thigh deck section, and a foot deck section that are movably connected to each other.

41. A patient support apparatus comprising : a base; a patient support assembly moveably connected to the base and configured to accommodate a patient thereon, the patient support assembly comprising an upper frame and a deck connected to the upper frame, the deck comprising a plurality of deck sections that are movable relative to each other, the upper frame comprising a fixed portion and a sliding portion, the sliding portion being slidable relative to the fixed portion in a longitudinal direction of the patient support apparatus, the deck sections being connected to the sliding portion such that, in response to the sliding portion sliding relative to the fixed portion, the deck sections are displaced in order to change a position of the bed; and an elevation system operatively connecting the base to the patient support assembly to move the patient support assembly relative to the base.

42. The patient support apparatus of claim 41, wherein: the fixed portion is a first fixed portion; the upper frame further comprises a second fixed portion, the sliding portion slidably engaging the first fixed portion and the second fixed portion; the first fixed portion defines a head end of the upper frame; and the second fixed portion defines a foot end of the upper frame.

43. The patient support apparatus of claim 41, wherein: the plurality of deck sections comprises a back deck section, a seat deck section, and a foot deck section; and the seat deck section is fixed relative to the sliding portion.

44. The patient support apparatus of claim 43, wherein the foot deck section is movably connected to the second fixed portion

45. The patient support apparatus of claim 41, wherein the elevation system comprises: a head end lift assembly connected between a head end of the upper frame and the base; and a foot end lift assembly connected between a foot end of the upper frame and the base.

46. The patient support apparatus of claim 45, wherein the head end lift assembly and the foot end lift assembly are connected to the fixed portion.

47. The patient support apparatus of claim 46, wherein: the fixed portion is a first fixed portion; the upper frame further comprises a second fixed portion, the sliding portion slidably engaging the first fixed portion and the second fixed portion; the first fixed portion defines a head end of the upper frame; the second fixed portion defines a foot end of the upper frame; and the foot end lift assembly is connected to the second fixed portion.

48. The patient support apparatus of one of claims 42 or 47 wherein the first and second fixed portions are separate.

49. The patient support apparatus of one of claims 42 or 47 wherein the first and second fixed portions are unitary.

50. The patient support apparatus of one of claims 41 to 49, further comprising an actuator operatively connecting the sliding portion to the fixed portion, the actuator being operable to selectively cause the sliding portion to slide relative to the fixed portion.

51. A patient support apparatus comprising: a base comprising an external base frame and an internal base frame; a patient support assembly configured to accommodate a patient thereon, the patient support assembly comprising an upper frame and a deck connected to the upper frame; and an elevation system operatively connecting the internal base frame to the patient support assembly to move the patient support assembly relative to the base, the elevation system comprising a head end lift assembly and a foot end lift assembly that are movable to raise and lower a corresponding one of a head end and a foot end of the upper frame respectively; at least one intermediate connector connecting the internal base frame to one of the head end lift assembly and the foot end lift assembly, the at least one intermediate connector located adjacent to a transversal member of the external base frame such that the one of the head end lift assembly and the foot end lift assembly is disposed outside of a perimeter of the external base frame and is supported by the internal base frame.

52. The patient support apparatus of claim 51, wherein the at least one intermediate connector extends above the transversal member.

53. The patient support apparatus of claim 51 or 52, wherein the at least one intermediate connector is affixed to a top surface of a transversal member of the internal base frame at one end thereof, and pivotably attached to the one of the head end lift assembly and the foot end lift assembly at an opposite end thereof.

54. The patient support apparatus of claim 52 or 53, wherein at least two intermediate connectors are provided laterally displaced away from one another relative to the pivotably attached one of the head end lift assembly and the foot end lift assembly.

55. The patient support apparatus of claim 51, wherein the at least one intermediate connector extends below the transversal member.

56. The patient support apparatus of claim 51 or 55, wherein the at least one intermediate connector is affixed to a lower surface of a transversal member of the internal base frame at one end thereof, and pivotably attached to the one of the head end lift assembly and the foot end lift assembly at an opposite end thereof.

57. The patient support apparatus of claim 55 or 56, wherein at least two intermediate connectors are provided laterally displaced towards one another relative to the pivotably attached one of the head end lift assembly and the foot end lift assembly.

58. The patient support apparatus of any one of claims 51 to 57, wherein a pivot of the one of the head end lift assembly and the foot end lift assembly, at a lower end thereof, is disposed outside of the perimeter of the external base frame.