STRETCHER TROLLEY INCORPORATING ILLUMINATION MEANS
The present invention relates to a stretcher trolley and a method of operating a stretcher trolley. The present invention is particularly, although not exclusively, applicable to stretcher trolleys for use in ambulances.
Existing stretcher trolleys frequently have to be used in situations where there is no lighting, or only very dim lighting available. For instance, such trolleys have to be taken down dark alleys to where a patient may have slumped. Once a patient has been located and treated the stretcher trolley then has to be found and the patient correctly placed on the trolley. This is not as easy as it may sound as the edge of the trolley may not be well defined to the paramedics and the patient could find themselves being swung against the side of the stretcher rather than being placed over and then lowered onto the stretcher.
Furthermore, the trolleys have a very definite head and foot section. It is quite easy, particularly when the paramedics have to work quickly, for the patient to be located the wrong way round. This can have an adverse effect on the patient either because the stretcher cannot be configured to the optimum configuration for the patients' condition, or because the patient will be orientated in a position which does not allow optimum access to them in the ambulance or because they have to be taken off the trolley and then returned in the correct position.
Yet another problem comes when taking the trolley back up the dark alley or obstructions and pot holes may be present such that the wheels of the trolley could hit against or fall into either stopping the trolley or causing the trolley to tip over, both of which events are detrimental to the patient, quite apart from the risk to the paramedics from such obstructions .
A still further problem comes when the stretcher has to be inserted into the ambulance. Typically a forward end of the trolley will be supported with the floor of the ambulance with a guide rail of the floor being engaged with a guide slot on the stretcher. Whilst the ambulance has internal lights, these generally shine down from an upper area of the interior of the ambulance. Consequently the cooperating portions of the guide rail and slot are placed in shadow by the stretcher and they can be difficult to engage.
It is an object of the present invention to attempt to overcome at least some of the above or other disadvantages .
According to one aspect of the present invention a stretcher trolley incorporates illumination means.
The illumination means may be located at one end region of the stretcher trolley or at both end regions. The illumination means may include control means . Where illumination means are located at both end regions the illumination means at each end region may include separate control means .
The illumination means may include a power source comprising battery means. The battery means may be rechargeable. The control means may be arranged to ensure that the illumination means are turned off when the battery means are being recharged.
The stretcher trolley may include connection means arranged, in use, to receive a power charging connection means. The power charging connection means may be provided on an ambulance.
The illumination means may be arranged to emit light downwardly or, alternatively or additionally, downwardly and away from the stretcher means .
The illumination means may be arranged to emit light to identify a particular portion such as a side or end of the stretcher. The illumination means may be arranged to emit different light from opposed portions of the stretcher. The illumination means may be arranged to emit light to identify a side of the stretcher at at least one end region of the stretcher. The illumination means may be arranged to emit light intermittently from at least one portion of the stretcher.
The illumination means may be arranged to be located over, for instance directly above, at least one wheel of the stretcher trolley and preferably over each wheel of the stretcher trolley.
The illumination means may include an ambient light level detector arranged to switch on the illumination means when the ambient level falls below a predetermined level.
The illumination means may include at least one light in which the area of illumination cast by that light is adjustable. At least two such lights may be provided and those lights may be independently adjustable.
The illumination means may include at least one portion that is adjustably mounted on the stretcher trolley and which may be pivotally mounted thereon. The illumination means may be arranged to alter the direction that light is emitted as the trolley is moved between raised and lowered positions, for instance by being attached to a portion of the trolley that undergoes a change in angle when moving between the raised and lower positions.
The illumination means may comprise a hollow member on which the lighting means are mounted. The hollow member may contain control means and alternatively or additionally, may house battery means.
According to another aspect of the present invention a method of operating a stretcher trolley incorporating illumination means comprises turning the illumination means on .
The method may comprise causing light to be emitted from at least one side or alternatively or additionally from at least one end or, alternatively or additionally, downwardly, or alternatively or additionally, downwardly and away from the stretcher trolley.
The method may comprise adjusting the direction in which a light is emitted. The method may comprise adjusting the area of light emitted.
The method may comprise automatically causing the light from at least one end region to be altered in the direction in which the light is emitted when the stretcher trolley is moving from a raised position to a lower position.
The method may comprise causing light to be emitted from one end region of the trolley when the trolley is being moved or, alternatively or additionally, from both end regions of the trolley. The method may comprise causing light to be emitted forwardly from the trolley, for instance when the trolley is stationary. The method may comprise emitting light intermittently such as by flashing from at least one portion of the stretcher, which intermittent light may assist in identifying the correct head region of the trolley.
The illumination means may include charging connection means that are arranged to be automatically disconnected if the trolley is moved a significant distance from the charging connection means.
According to a further aspect of the present invention illumination means are provided that are arranged to be mounted on a trolley to provide a stretcher trolley incorporating illumination means as herein referred to or a stretcher trolley for use in a method of operation as herein referred to.
The present invention includes any combination of the herein referred to features or limitations. The invention may be carried into practice in various ways but one embodiment will now be described, by way of example, and with reference to the accompanying drawings, in which :-
Figure 1 is a perspective view of a stretcher trolley 10 according to a first embodiment of the present invention with the trolley being in the raised position, and
Figure 2 is a side view of the trolley 10 in the lower position.
Figure 3 is a schematic cross section through a lighting unit;
Figure 4 is a schematic cross-section through one end of the lighting unit; and
Figure 5 is a schematic circuit diagram of the lighting unit;
Figure 6 is a schematic diagram of an alternative embodiment of a lighting arrangement that can be applied to the front section of a stretcher, and
Figure 7 is a view similar to Figure 6 of a lighting portion that can be applied to a rear part of the stretcher.
As shown in Figure 1 the trolley 10 includes a support portion 12 defined by a back support portion 12a, a buttock support portion 12b and a leg support portion 12c. The
angles of the back and leg support portions can be varied on the trolley by altering the angles of props that extend to beneath the support portion to the main frame of the trolley. The operation of such supports is well known and will not be described further. A mattress 14 can be located on the support portion 12 , as shown in Figure 2.
The trolley includes an upper quadrilateral frame 16 and a lower quadrilateral frame 18. The frames 16 and 18 are connected together by a first leg frame 20 that is pivotally connected to an end section 18a of the lower frame and a second leg frame 22. The leg frame 22 is connected to the side sections 18b of the lower frame via blocks 24 connected to the side sections 18b. The legs 22 are connected to the block 24 via rollers 26 that permit the legs 22 to move relative to the blocks 24 to a limited degree between the ends of the blocks in the direction of extent of the side sections 18a.
The leg frames 20 and 22 are connected together by a horizontal pivot rod 28.
The upper end of the leg frame 22 is pivotally connected, at each side, to a bar 30. Each end of the bar 30 is connected via a shaft 32 to the side of the upper frame 16.
The leg frame 22 is connected to the upper frame 16 by a sliding connection 34 in a well known manner such that, upon pulling of a handle 36 a lug restraining relative sliding movement is released from a slot 38 and the upper leg is able to slide towards or away from the end portion 16b of the upper frame. When the handle 36 is released the spring loaded lug returns into the next slot 38 that it
comes into alignment with. This sliding movement of the upper end of the leg frame 20 causes the height of the stretcher to be raised or lowered. In the lowermost position sockets 40 are lowered on to spindles 42 of the upper frame and lower frame respectively, as shown in Figure 2. In that position the upper frame rests on the lower frame and the leg frames are substantially parallel to each other.
In the raised position shown in Figure 1 the trolley can be manoeuvred by being rolled along wheels 44 which can rotate about a horizontal axis and also about a vertical axis depending downwardly from each corner of the lower frame. In the raised position the trolley can approach an ambulance such that wheels 45, which can rotate about a horizontal axis and which are connected to the upper frame towards the front end 16c just below that end, rest on the floor of the ambulance. If desired the wheels 45 can be arranged to be at a slightly greater height than the floor of the ambulance. The rear of the trolley in the region of the rear end 16b of the front can then be lifted to pivot the trolley about the wheels 44 and to bring the wheels 45 into contact with the floor of the ambulance. The lower frame is then brought up to the upper frame and detachably retained in position. The trolley is then pushed into the ambulance . Removal of the trolley from the ambulance and the lifting of the upper frame relative to the lower frame is a reversal of the above described sequence .
In the lower position shown in Figure 2 it is possible to manoeuvre the trolley with the wheels 44 providing the rolling motion required. The wheels 45 are just off the floor.
One of the lighting units is shown in Figure 3. It will be appreciated though that both lighting units are substantially the same.
The unit includes a pair of spaced lights 48 and 50 and each of which are arranged to emit light in a direction generally transverse to the axial extent of a tube on which they are mounted. At one end of the tube a green light 52 is mounted with a red light 54 being located at the opposite end. The green and red lights 52 and 54 emit light away from their respective ends.
A switch 56 is mounted at a middle portion of the unit and can have one of three positions, those being off, on and a charging position. The lighting unit that is not shown may have a switch with only two positions, those being on and off. A lead 58 connects the two lighting units together to allow both units to be simultaneously charged. A further lead 60 also extends only from the unit 46 shown to a male socket 62 fixed to the side of the stretcher. A lead within the ambulance can be plugged into the socket 62 to allow for recharging. Should an operator take a trolley out of the ambulance without disconnecting the charging lead, the male and female sockets will automatically be pulled apart to ensure that those parts will not be damaged and with the female connector remaining with the vehicle to prevent a power short .
Before describing the details of the unit further, the various ways of operating the unit with a stretcher will be described.
Each tube can be orientated such that illumination from the lights 48 and 50 can shine downwardly or downwardly and away from the trolley, or downwardly and towards the trolley or away from the trolley. The tubes can be fixed to the trolley or, alternatively, one or each tube can be rotatably mounted on the trolley.
When a stretcher is being wheeled from an ambulance along a poorly illuminated way, the leading unit can be turned on. The lights 48 and 50 from the leading unit can illuminate the leading wheel area of the trolley or the area slightly in advance of the leading wheel area or both to enable the leading paramedic to tread safely and to ensure that no harm comes to the trolley. The trailing unit can also be illuminated, if desired, to assist the paramedic at that end.
Once at the scene of the patient, if the patient is nearby, the stretcher can be pointed towards the patient and the unit nearest the patient can be swivelled such that the lights 48 and 50 illuminate the scene. In this respect, the lighting unit may be mounted in brackets that are attached at each side of the trolley with the brackets being located inwardly of the lights 52 and 54 and with the unit being able to swivel in the bracket by overcoming a friction force exerted by the brackets.
Each light 48 and 50 includes a rotatable lens 64 that can be moved in order to vary, independently, the pool of light given. This can be of use both when manoeuvring the trolley and also when illuminating the scene of a patient.
When a patient is to be placed onto the trolley not only do the lights 48 and 50 assist in locating the trolley but also the green and red lights 52 and 54 show the paramedics which side of the trolley is facing them such that they can ensure that the patient is placed on the trolley with their head at the correct end.
The return of the trolley, with the patient on, to the ambulance is carried out with the lights being used as previously described.
When the trolley is being engaged with the floor of an ambulance the leading lights 48 and 50 will illuminate the guide of the ambulance floor and the socket of the trolley (not shown) to enable them to be clearly seen and quickly engaged.
From Figures 1 and 2 it can be seen that when the trolley is moved from a raised to a lowered position, because one of the units 46 is mounted on the cross links 20, the illumination from the lights 48 and 50 moves from the general direction indicated by arrow 66 to the general direction of arrow 68.
The pool of illumination given by each light 48 and 50 can be arranged to be directed at each wheel, directly above each of which the lights are mounted. Furthermore, the pool cast by each light can give an indication of the height of the stretcher with a smaller pool indicating a lower height on the lights are closer to the ground.
The components of the lighting unit 46 will now be described in greater detail . As shown in Figure 3 the
tube 70 includes openings 72 at each end. Each green and red light 52 and 54 is mounted in a resilient bung 74 that is plugged into the respective openings 72. The bungs 74 are held in place by caps 76 that screw onto the threaded exterior of the ends of the tube. The caps 76 include an opening 78 through which illumination from the green or red lights 52 and 54 exits or through which those lights extend.
The lights 48 and 50 are mounted on stub tubes 80 that have their hollow axis extending radially from the tube 70. The stub tubes 80 have their interior in communication with the interior of the tube 70. Caps 82 secure each light 48 and 50 to the stub tubes by engaging with a threaded exterior thereof. Rotation of the caps adjust the area of light cast.
Two sets of three batteries 84 are mounted end to end within the tube 70, each battery having their positive end facing the centre portion of the tube. Leads 86 connect the green and red lights 52 and 54 and the lights 48 and 50 to the batteries and leads 88 connect each battery set to the switch 56. With the switch in the on position all lights of the lighting unit are illuminated. In an alternative embodiment, the batteries can be mounted on the trolley at a location remote from the lights.
The caps can be provided with tamperproof or tamper evident connections, if desired. The length of the leads can be such that the bungs cannot be removed without the leads being pulled off the connections to the lights 48 and 50 or the connection to the battery sets.
The details of the bungs 74 and cap 76 are shown in more detail in Figure 4 with the interior of the bungs housing two resistors 90 and 92 in series to comprise a 15 ohm 114 watt resistance to ensure that the power is reduced for the green and red lights that comprise LED's.
As shown in Figure 5, the lights 48 and 50 are connected to the negative side of the batteries and the positive side (which may comprise the tube 70) to ensure that they receive more power than the LED's. Each set of batteries 84 may be connected by a 47 ohm 5 watt resistor and a diode to provide the voltage required for the lights 48,50 and 52,54.
The electrical components may be mounted on a printed circuit board.
During the charge mode, all lights are off an each battery set receives a charge at a rate of C/10. C/10 means that, when the battery voltage is 12V, for instance, it receives a 10% overcharge of 13V to charge the battery. It may take 14 to 16 hours to charge the batteries that may comprise sub-C batteries (more than one battery cell) and 800 milliamperes may be drawn whilst charging. The lights may remain at a satisfactory illumination for a period of 1 hour after the batteries have been charged.
The batteries are insulated from the walls of the tube. The lighting units can be fitted to an existing trolley or can be fitted to a trolley during manufacture.
The lighting unit shown in Figures 6 and 7 are arranged to be attached to the front part 16a and the rear part 16b of
the stretcher. Alternatively, the lighting unit can be mounted centrally across the trolley in the region of the lights 52 and 54. The units shown in Figures 6 and 7 can have any of the features referred to earlier in relation to the angle of the lighting and the purpose of the lighting or any other aspect thereof, as and where applicable.
The sections 16b and 16c of the stretcher are approximately 500 mm wide. Figures 6 and 7 show an array of 16 LED's 100 in an upper row of 16 LED's above a coincident lower row also of 16 LED's. The length of the rows of LED's are approximately 165 mm. In use, the LED's are mounted in the mid region at the ends 16a and c of the stretcher. In an alternative embodiment (not shown) there may be 20 LED's in each row.
Batteries 102 are provided at each end of each array of LED's 100.
When the vehicle is located in an ambulance, a power recharge input 104 can be provided whereby the power from the ambulance unit can be used to recharge the batteries 102, as described in relation to the previous embodiment.
Each of the units can be provided with a light sensor 106 which, in use, is arranged to detect the ambient light level and, in the event that the ambient light level falls sufficiently below a predetermined value, the LED's are caused to be illuminated. A switch 108 is provided whereby the unit can be deactivated such that, regardless of the ambient light level, the LED's do not illuminate. This feature is of particular importance when the
stretcher is stored in a vehicle and the vehicle may be out of use.
The LED's may flash or not flash. Preferably though the LED's are continuously illuminated.
The colour of the LED's may be red at both ends or red at one end and amber at the other. Although not shown, a flashing LED, which may also be of red, may be provided at the head end whereby, in a particular dark situation, an operator is able to determine the orientation of the stretcher such that a patient can be located with their body being correctly located on the stretcher. This flashing LED may be mounted to emit light from each side at one end of the stretcher.
The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
All of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) , may be replaced by alternative features serving the same,
equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
The invention is not restricted to the details of the foregoing embodiment ( s ) . The invention extend to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , or to any novel one, or any novel combination, of the steps of any method or process so disclosed.