GB2506661A

GB2506661A - Patient lifting device actuated by pneumatic air bladders

Info

Publication number: GB2506661A
Application number: GB1217899.2A
Authority: GB
Inventors: Dane Mcgee
Original assignee: Engineered Assistance Ltd
Current assignee: Engineered Assistance Ltd
Priority date: 2012-10-05
Filing date: 2012-10-05
Publication date: 2014-04-09
Also published as: GB2521791A; WO2014053856A1; GB2521791B; GB201507644D0; GB201217899D0

Abstract

A patient lifting device comprises a plurality of pneumatically inflatable bladders or air bags 21, each bladder being confined within a container having a base 32, vertical side members 33 and a lifting member 22 adjustable between upper and lower positions. The lifting members are arranged to be raised or lowered as the bladder is inflated and a hoist member 19 with an attachment 16 for a patient harness or support extends from each lifting member. The lifting device includes an air pump, preferably a low pressure air compressor, a pneumatic conduit 31 connecting the pump to the bladders, and a pressure regulation valve. Optionally, the lifting member has a horizontal face engaging a bladder. The side members may be guide rails which engage channels in the lifting members. Optionally, a sheet of low friction material which may be of annular shape is present between the each bladder and its container.

Description

PATIENT LIFTING DEVICE

This invention relates to a device for lifting a patient, particularly but not exclusively from a seated location.

Current mobile patient hoists are powered by hydraulic hand-pumped pistons or by means of electrically powered linear actuators. Such devices suffer from various disadvantages. For example, may be difficult to use by a person lacking the necessary strength and mobility to manoeuvre the hoist when loaded with the weight of a patient.

According to the present invention, a patient lifting device comprises: a plurality of pneumatically inflatable bladders; each bladder being confined within a container; the container having a base, vertically extending side members and a lifting member vertically displaceable between upper and lower positions and arranged to be moved from a lower position to an upper position as the bladder is inflated; a pump; a pneumatic conduit communicating between the pump and the bladders; a pressure regulation valve; and a plurality of hoist members, each extending from a respective lifting member, and having an attachment for engagement with a patient harness or support.

An assembly of two patient lifting bladders and containers may be arranged so that the distance between them is adjustable.

Use of the pneumatically inflatable lifting arrangement of this invention confers several advantages. An electrical power supply connected directly to the frame of the device is not essential. Gearing arrangements may not be necessary, reducing the complexity of construction and maintenance. The device of this invention is reliable, easy to repair and is not noisy in use.

The lifting device may comprise two inflatable bladders and containers, one located on either side of a patient's chair or mounted onto a floor-standing frame. The distance between the two bladder units may be adjusted to suit the size of a patient, for example, a bariatric patient, and also to facilitate lifting of a patient out of a wider chair than may be accomplished conveniently and comfortably using a conventional hoist.

Use of two or more pneumatic actuators allows infinitely variable adjustment of the io height of each and may provide a self-levelling or self-balancing capability. Use of a pneumatic system has an advantage over a hydraulic system that a reservoir for hydraulic fluid is not necessary and leaks of hydraulic fluid are not possible.

In preferred embodiments, the pump is actuated manually, electrically or both.

The lifting member has a horizontal downward-facing surface arranged to engage an upper surface of a bladder in use.

In preferred embodiments, the bladder has parallel upper and lower surfaces connected by one or more expandable side portions, for example having a concertina construction with alternating hinged panels.

A sheet of low friction material may be provided between the bladder and container. The low friction material may comprise polymer coated paper or a polymeric sheet. The sheet may form an annular sleeve around the sides of the bladder and may be located between the sides of the bladder and an interior surface of the container in order to reduce friction and wear of the bladder material in use.

The container side members are preferably vertically extending guides, for so example, rods or grooved or ribbed formations. The lifting member may have a corresponding multiplicity of channels or slots to engage the rods.

Preferably each member is confined in a cage-like container having parallel vertically extending bars to constrain the movement of the bladder as it expands from a as lower to an upper position or collapses in the opposite direction.

The pump may comprise a low pressure air compressor. Use of low pressure air to lift a patient eliminates a range of moving parts that would be required for a traditional electrically powered hoist. A sudden loss of pressure through failure of the compressor or a leak in one of the bladders or in the conduit system, may not afford a catastrophic movement of the patient as the reduction in height of the hoist may be limited to the to maximum rate of air loss from either of the Bladders or other part of the system.

In preferred embodiments, the device operates on both sides of a patient simultaneously and does not have any moving parts located in front of the patient. It can be used to simply lift a patient by a suitable amount off a chair and then allow the patient to be lowered back down onto a suitably designed commode pan or other chair, as desired, without the need to move the lifting device to another location. Therefore, the risk of the patient falling is considerably reduced, for example, following use of an incorrectly sized sling.

In preferred embodiments, the hoist members each have a pair of attachments so that the four straps of a range of commercially available slings may be used at the optimum position for safety and comfort of a patient. Use of a spreader bar, commonly used in front of a patient's face, may be avoided. Also, the fixing points may be wider, preventing crushing or compression of a patient's torso and legs during lifting. The lifting device of the present invention may be attached to either side of an existing chair frame using suitably desired catch plates or it may be mounted as a stand-alone device on a floor plate with brace bars fitted to maintain stability during the lifting process.

The invention is further described by means of example, but not in any limitative so sense, with reference to the accompanying drawings, of which:-Figure 1 shows a lifting device in accordance with the present invention; Figure 2 shows a lifting device in accordance with the invention, not having a brace bar; Figure 3 shows a chair-mounted version of a device in accordance with this invention; Figure 4 shows the conduit arrangement; Figure 5 shows the lifter arrangement in greater detail; Figure 6 shows a close up of the carabiner bar of the device shown in Figure 5; Figure 7 shows a detail of the lifting members; Figure 8 is a further detail of the device; Figure 9 shows successive stages in raising of the device; and Figure 10 further illustrates the bladder assembly.

Figure 1 shows a floor mounted stand-alone lifting assembly comprising two patient lifting devices in accordance with the present invention. The assembly has two sides. The devices on the left hand side of the lifter frame (1) and on the right hand side of the lifter frame (2) are connected to a floor plate (4) by means of a spring loaded safety catches or pins. These may be designed so that a specially shaped tool is required to access them to disengage the sides of the lifter from the floor plate. This serves to prevent accidental movement of the sides of the lifter when in use. A brace bar (3) extends between upper portions of the two frame members (1) and (2). Castors (30) enable each side of the frame to transported independently to and from the chosen location of the floor plate prior to mounting. In another embodiment the floor plate may have lockable castors fitted to it, to enable the device to be moved in either a loaded or unloaded condition.

Figure 2 shows a similar assembly of two lifting devices not having a brace bar (3).

The floor plate (4) is sufficiently rigid to avoid the need for additional bracing. In particular, the need for a brace bar adjacent a patient's face or head may be avoided. A conduit indicated generally at (31) is shown in more detail in Figure 4. A pump (not shown) is connected to an input conduit (13) communicating with a pressure relief valve F (12). The pressure relief valve (12) may be a spring valve type connected to an air bladder (11) communicating with an inlet conduit (10). The inlet conduit (10) is connected by 3D spring clips (9) to inlet control valves (8) of respective bladders (21) as shown in Figure 5.

Each bladder (21) is located within a chamber having a cage-like construction. The chamber has a lower portion (32) end portions (33) and two arrays of vertically extending parallel bars (20). A moveable plate (22) has slots arranged to allow slidable engagement with the bars (20) so that the plate (22) may be raised and lowered as the bladder (21) inflates or deflates.

Figure 6 shows a pair of vertically extending hoist members (19) which have caps (18) to carry a carabiner bar (1 7). A pair of attachment carabiners or other attachment means (16) are fastened to the bar (17) to allow attachment to a harness (not shown).

Shear pins (23) serve to prevent overloading of the apparatus during use. In a preferred example 8mm diameter 303 grade stainless steel pins are held in place by external circlips to prevent their unauthori sed removal.

Figure 7 shows how the lifter members (19) are supported during raising and lowering by support wheels (26). The wheels (26) reduce friction and assist with lifting.

The wheels are mounted to the lifter top plate (24) and lifter middle plate (25). Each hoist member (19) is fitted at the base with shear pins (not shown) to prevent the hoist member (19) from coming out of contact with the support wheels (26) unless the operator presses and holds a spring loaded safety catch (27) in an open position while lifting the members (19) out of the lifter frame.

Figure 9 shows the device with the bladder in a fully deflated (a), half inflated (b) and fully inflated (c) positions. The safe working load and lift height can be varied by increasing or reducing the height of the lifter frame and the dimensions of the air bag clamp plate (not shown) to increase or decrease the area that the low pressure air acts on.

Claims

CLAIMS1. A patient lifting device comprising: a plurality of pneumatically inflatable bladders; each bladder being confined within a container; the container having a base, vertically extending side members and a lifting member vertically displaceable between upper and lower positions and arranged to be moved from a lower position to an upper position as the bladder is inflated; a pump; a pneumatic conduit communicating between the pump and the bladders; is a pressure regulation valve; and a plurality of hoist members, each extending from a respective lifting member, and having an attachment for engagement with a patient harness or support.
2. A patient lifting device as claimed in claim 1, wherein the lifting member has a horizontal downward facing surface arranged to engage an upper surface of a bladder in use.
3. A patient lifting device as claimed in claim 1 or 2, wherein the bladder has parallel upper and lower surfaces.
4. A patient lifting device as claimed in any preceding claim wherein the container side members are vertically extending guides.
5. A patient lifting device as claimed in claim 4, wherein the lifting member has a so multiplicity of channels to engage the guide members.
6. A patient lifting device as claimed in any preceding claim wherein each member is confined in a container having parallel vertically extending bars.as
7. A patient lifting device as claimed in any preceding claim, wherein the pump is a low pressure air compressor.
8. A patient lifting device as claimed in any preceding claim, wherein a sheet of low friction material is located between the bladder and container.
9. A patient lifting device as claimed in claim 8, wherein an annular sheet of low friction material is provided around sides of the bladder.
10. A patient lifting device as claimed in any preceding claim, wherein the distance io between the inflatable bladders and the container is adjustable.
11. A patient lifting device as claimed in claim 10, wherein the hoist members are not connected by a brace bar.