GB2177906A

GB2177906A - Control arrangement for support appliance

Info

Publication number: GB2177906A
Application number: GB08617165A
Authority: GB
Inventors: David Warren
Original assignee: Mediscus Products Ltd
Current assignee: Mediscus Products Ltd
Priority date: 1985-07-15
Filing date: 1986-07-15
Publication date: 1987-02-04
Also published as: GB8517832D0; GB8617165D0

Abstract

A hospital bed has a patient- supporting surface provided by a plurality of transversely-extending, inflatable sacs. Air-operated bellows (206, 207) are provided for raising and lowering the head and foot sections of the bed, and a tilt actuator is provided for tilting the bed. A control arrangement is provided for operating the bed functions. The control arrangement includes a manually- operable control device (204), and a pneumatically-operable control device (110). The control device (110) includes mouth pieces (113), which a patient can suck or blow to operate the functions of the bed. <IMAGE>

Description

SPECIFICATION Control Arrangement for Support Appliance This invention relates to a control arrangement for a support appliance and in particular for a hospital bed.

One form of a specialised hospital bed is the air support system sold under the trade mark "Mediscus". As described in our British Patent Specification No. 1474018, a patient-supporting surface is provided by a plurality of transverselyextending, inflatable sacs, and the bed includes air-operated bellows for raising and lowering the foot end or head section of the bed. The bed described in the above-mentioned patent specification also includes a sub-frame, which is pivotably mounted on a trolley or carriage, and includes means such as an electrically driven actuator for altering the attitude of the sub-frame with respect to the carriage or trolley.The inflatable air sacs are supported on articulated sections, and bellows are provided which act between the head and foot sections and a base board included in the sub-frame so that the contour of the patient supporting surface can be altered to suit the patient's wishes or nursing requirements. Also, movement of the actuator enables the whole subframe to be pivoted, so as to achieve Trendelenberg and reverse Trendelenberg attitudes.

It is desirable that these various functions of the bed can be controlled by the patient, so that he can adjust his position into the most comfortable or convenient position. However, patients who are permanently or temporarily paralysed may be unable to operate a control knob button or lever.

The present invention therefore provides a control arrangement for a hospital bed of the type hereinbefore defined, the control arrangement including first and second control devices for actuating the functions of the bed, the first control device being a manually-operable device, and the second control device being a pneumatic device having a plurality of mouth pieces, the pneumatic device being operable by a patient sucking or blowing on the mouth pieces.

The arrangement may further comprise a changeover valve for switching control between the first and second control devices. Preferably, however, the arrangement may further comprise an attitude posture control box for controlling the functions of the bed, the attitude posture control box being connected to the first and second control devices in such a manner that the functions of the bed can be actuated by either of the control devices.

In a preferred embodiment, the second control device has a two-part housing, one of said housing parts carrying the mouth pieces, and wherein a membrane is positioned between the two parts of the housing. This permits the second control device to be dismantled easily, for sterilisation, so that the risk of cross-infection is reduced at change of patient.

The invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 represents a partial view of the side of a bed manufactured in accordance with the above mentioned British patentspecification; Figure 2 is a part-sectional view of a three-port valve used to change-over from a hand-controlled unit to a mouth-controlled unit; Figure 2A is an end view of the changeover valve looking in the direction A in Figure 2; Figure 3 is a part-sectional view of a preferred form of mouth-controlled unit; and Figure 4 is a side elevation of the bed, and shows, in exploded manner, a modified form of control arrangement.

Referring to the drawings, Figure 1 shows the side rail 1 of the bed close to its headboard 2, and includes a sideboard 3 attached to the headboard 2.

A control unit (handset) 4 is removably clipped to a top rail 41 of the side rail 1, the control unit 4 incorporating three rocker switches 5,6 and 7. The switches 5,6 and 7 are, in effect, small air pumps. In one position, they generate a positive, slightly increased pressure pulse in the air tube to which they are connected. In the other position, a corresponding reduced pressure pulse is produced.

The control unit 4 is connected, by three-core air tubes 8 and 38, to pressure-sensitive microswitches (not shown) located in the base of the bed subframe via a change-over valve 9. These microswitches operate solenoid valves (not shown) arranged to admit or exhaust air from head and foot bellows (not shown), orto actuate an electrical actuator (not shown) for tilting the bed.

A mouth piece control unit 10 is also connected to the change-over valve 9, the control unit 10 being supported on a flexible and adjustable goose-neck 11 from a clamp 12 removably attached to the sideboard 3. Thus, the control unit 10 is adjustable so that mouth pieces 13, 14 and 15 projecting therefrom can easily be reached by a patient for sucking or blowing air into the respective mouth piece. The mouth pieces 13, 14 and 15 are connected, via respective air tubes 16, to the change-over valve 9. Thus, when the mouth pieces 13, 14 and 15 are connected through their respective tubes 16 via the valve 9 to the pressure-sensitive microswitches in the sub-frame of the bed, the functions of the bed can be controlled by sucking or blowing air into an appropriate mouth piece.

The contruction of the change-over valve 9 is shown in Figures 2 and 2A. As can be seen, the vaive 9 comprises a tubular body 20, in which a piston 21 is slidingly received. Longitudinal movement of the piston 21 in the bore of the tube 20 is limited by a screw 22 projecting into a slot 23, and by a spring-loaded ball 24 locating in one of two grooves 25 or 26. The piston 21 is formed with longitudinallyspaced reduced portions forming annular spaces 27, 28 and 29, the space 29 being hidden by the casing 20. These spaces 27, 28 and 29 are separated by flexible rings 30. Mounted at the top of the valve 9 (as seen in Figures 2 and 2A) are the tubes 38 leading to the actuator control box housing the pressure sensitive microswitches, whilst spaced on opposite sides of the valve are the tubes 8 and 16 leading respectively to the control unit 4 and to the mouth control unit 10.The annular spaces 27,28 and 29 in the valve 9 are arranged so that, in one position of the valve, either the tubes 8 or the tubes 16 communicate with the tubes 38 leading to the actuator control box. On pulling on a knob provided at the free end of the piston 21, the valve 9 is switched over to its other position, thereby enabling the other function of the valve to be utilised.

Figure 3 shows a preferred form of mouth piece control unit 110. The control unit 110 inciudes two complementary housing members 111 and 112. The housing member 111 carries three mouth pieces 113, and the housing member 112 carries an air tube ferrule 114. The housing members 111 and 112 define three chambers 11 3a, each of which is connected to a respective pneumatic tube (not shown). The three pneumatic tubes leave the control unit 110 via the air tube ferrule 114. A membrane 115 is positioned between the two housing members 111 and 112. The provision of the membrane 115 permits easy replacement of the housing member 111 (together with its mouth pieces 113). Thus, on changing patients, the risk of cross-infection can be substantially reduced, as the housing member 111 and the membrane 115 can be removed, sterilised and repiaced.Alternatively, these items can be replaced by similar items from stock.

Figure 4 shows a modified control arrangement which does not require a change-over valve. This figure shows the same type of bed as that of Figure 1, but in more detail. This bed includes a side rail 201, to which is clipped a control unit (handset) 204.

The control unit 204 contains three pneumatic switches which generate electric signals for actuating an attitude posture control box 205. The attitude posture control box 205 is used to control the head and foot bellows 206 and 207 of the bed, and to actuate an electrical actuator for tilting the bed.

The modified control arrangement includes a mouth piece control unit 110 of the type shown in Figure 3. This unit 110 forms a separate control for the control box 205. Thus, when a patient sucks or blows on any one of the mouth pieces 113, a pressure signal is generated in the appropriate pneumatic tube, and this signal is fed to an oral control unit 208. This oral control unit 208 contains three pneumatic micro-switch assemblies (not shown)-oneforeach of the pneumatic tubes.

These micro-switch assemblies provide electrical signals for actuating the attitude posture control box 205, and so to control the head and foot bellows 206 and 207, and the tilt actuator.

The provision of two separate electrical controls for the attitude posture control box 205 means that there is no longer a requirement for a manual change-over switch of the type needed in the control arrangement of Figure 1.

It will be appreciated that the valve control arrangements described above may be used to control functions of support appliances other than the Mediscus bed, and may be used with any of the support appliances described in our pending patents and applications including the following, U.K. Patents Nos. 14429441601808; U.K. Patent Specifications Nos. 2070426 and 2141333 and U.K.

Patent Application No. 8511903.

Claims

1. A control arrangement for a hospital bed of the type hereinbefore defined, the control arrangement inciuding first and second control devices for actuating the functions of the bed, the first control device being a manually-operable device, and the second control device being a pneumatic device having a plurality of mouth pieces, the pneumatic device being operable by a patient sucking or blowing on the mouth pieces.

2. An arrangement as claimed in claim 1, further comprising a change-overvalveforswitching control between the first and second control devices.

3. An arrangement as claimed in claim 1, further comprising an attitude posture control box for controlling the functions of the bed, the attitude posture control box being connected to the first and second control devices in such a manner that the functions of the bed can be actuated by either of the control devices.

4. An arrangement as claimed in any one of claims 1 to 3, wherein the second control device has a two-part housing, one of said housing parts carrying the mouth pieces, and wherein a membrane is positioned between the two parts of the housing.

5. A control arrangement for a hospital bed, the control arrangement being substantially as hereinbefore described with reference to, and as illustrated by, Figs. 1 and 2 or Figs. 3 and 4 of the accompanying drawings.