Damping device for a patient lifting device

Abstract

A damping device (40) for a patient lifting device (100a, b), the damping device (40) comprising a body (42) formed of a deformable visco-elastic material; and at least one aperture (41) configured to receive a connecting unit (21, 22) of the patient lifting device (110a, b), wherein the damping device (40) is configured, when positioned between a patient sling (20) of the patient lifting device (100a, b) and a patient hoist (200a, b) of the patient lifting device (100a, b), to dissipate kinetic energy by deformation in response to a shock load occurring during a patient fall.

Description

[0001] DAMPING DEVICE FOR A PATIENT LIFTING DEVICE

[0002] TECHNICAL FIELD

[0003] The present invention relates to patient handling systems and, more specifically, to a damping device for a patient lifting device configured to reduce impact forces during patient falls.

[0004] BACKGROUND

[0005] Patient lifting devices are commonly used in healthcare settings to assist in the lifting and transferring of patients. Patient lifting devices, are commonly used to raise, lower and transfer patients who are disabled or who otherwise have mobility problems. Two common types of patient lifting devices are stanchionmounted lifts, also known as floor lifts, and ceiling lifts. However, there is a risk of injury if the patient falls.

[0006] Floor lifts often have a hoist assembly. The hoist assembly may be disposed at the upper end of a floor lift. The floor lift has a wheeled base, which allows for the lift to be moved along the ground to different locations. For example, the floor lift might be wheeled to position the hoist assembly and a lifting member over or adjacent to a patient. The lifting member may then be lowered to receive the patient and subsequently raise the lifting member and patient so that they may be wheeled elsewhere to be lowered and placed.

[0007] A ceiling lift may be utilized in a similar manner; however, the hoist assembly is movably engaged to ceiling-mounted tracks such that the hoist assembly can be moved about the track from location to location. A ceiling lift may be described as a motor unit movable along a track with a flexible member attached to a lifting member. The motor unit commonly comprises a transmission, batteries and a control module.

[0008] Generally, the lifting member which may be in the form of a spreader bar, such as a two-point attachment spreader bar, a three-point attachment spreader bar, a four-point attachment spreader bar, a five-point attachment spreader bar or a powered spreader bar for adjusting the angle of the patient in the spreader bar, for suspending a patient harness or sling.

[0009] In order to lift the patient, a patient sling is attached to the spreader bar. The patient is seated or lays on top of the patient sling, whereby the patient lift raises the patient sling and thereby the patient.

[0010] In field of walking training and patient rehabilitation, the usage of so-called dynamic lifts has increased. Dynamic lifts provides dynamic unloading based on the load exerted by the patient to the spreader bar or sling or the elevation of the sling. Hence, when the walking patient begins to fall or lose balance the motor controlling the lift provides additional lifting force allowing the lift to pull the patient back to standing.

[0011] This is associated with additional challenges for the sling since the sling has to provide comfortable support even during rapid movement and loading or unloading. A need has been identified for a sling suitable both for dynamic and conventional lifts.

[0012] In the light of the above, there is a need for a device which addresses and mitigates the safety risks for a patient wearing a patient sling.

[0013] SUMMARY OF THE INVENTION

[0014] The present disclosure relates to patient lifting devices. Further, the disclosure relates to a damping device for patient lifting device. With the above description in mind, then, an aspect of some embodiments of the present invention is to provide a damping device for a patient lifting device, which is adapted to dampen the fall of a patient. The damping device of the present invention seeks to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination.

[0015] One embodiment of the present invention relates to a damping device for use in patient lifting systems, such as ceiling lifts or floor lifts, to enhance patient safety during lifting, transferring, or ambulation activities. The damping device comprises a body formed of a deformable visco-elastic material and at least one aperture for engagement with a connecting unit, such as a strap or cord. When subjected to a shock-load caused by a patient fall, the damping device dissipates kinetic energy through plastic deformation and, in some embodiments, frictional interaction with the connecting unit.

[0016] In one aspect, the damping device is ladder-shaped and includes multiple apertures arranged to permit zig-zag threading of the connecting unit, thereby increasing frictional damping and energy dissipation. In another aspect, the damping device comprises a compression cylinder configured to deform axially under load. Both configurations allow adjustable engagement to tailor damping characteristics for different patient weights and activities.

[0017] The invention further encompasses a patient lifting system comprising a patient sling, a spreader bar, a patient hoist, and at least one damping device positioned between the sling and the hoist. The system may include dynamic or conventional lifts and spreader bars of various configurations.

[0018] The features of the above-mentioned embodiments can be combined in any combinations.

[0019] BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further objects, features and advantages of the present invention will appear from the following detailed description of the invention, wherein embodiments of the invention will be described in more detail with reference to the accompanying drawings, in which:

[0021] FIG. 1 is a front view of a patient sling according to one embodiment during use.

[0022] FIG. 2a, 2b is a patient lifting device including a damping device according to one embodiment of the disclosure.

[0023] FIG. 3a illustrates patient lifting device including a damping device according to one embodiment of the disclosure.

[0024] FIG. 3b illustrates patient lifting device including a damping device according to one embodiment of the disclosure.

[0025] FIG. 3c illustrates patient lifting device including a damping device according to one embodiment of the disclosure.

[0026] FIG. 3d illustrates patient lifting device including a damping device according to one embodiment of the disclosure.

[0027] FIG. 4 illustrates a spring mass model according to one embodiment of the disclosure.

[0028] FIG. 5 show a damping device according to one embodiment of the disclosure.

[0029] FIG. 6 show a damping device according to one embodiment of the disclosure.

[0030] FIG. 7 shows a damping device according to one embodiment of the disclosure.

[0031] DETAILED DESCRIPTION

[0032] Embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference signs refer to like elements throughout.

[0033] A patient lifting device is composed of a patient hoist assembly and a patient sling. The patient lifting system is a ceiling lift 100a movable along a track or a floor lift 100b having a wheeled base. As for the patient sling, it is attached to the patient lifting device and its purpose is the support or carry a patient.

[0034] FIG 1 and 2 depicts a patient lifting device 100a, 100b with a body support sling 20. The patient lifting device 100a, 100b is versatile and can be used for transferring patients, assisting in ambulation, lifting patients, and providing general support during movement. The sling 20 is for supporting a patient 10 from a patient hoist assembly 200a, 200b. The patient hoist assembly 200a, 200b have a spreader bar 30. The spreader bar 30 is a two-point or four-point spreader bar. Supporting herein refer to providing support to the patient 10 while the sling 20 is worn by the patient 10, for example during transferring, ambulating, exercising, walking or standing. Thus, the sling 20 is adapted to provide support to the patient 10 during any one of transferring, ambulating, standing, and walking. The sling 20 is adapted to suspend the patient 10 from the patient hoist assembly 200a, 200b.

[0035] In one embodiment, the patient lifting device is a ceiling lift 100a, shown in FIG. 1 and FIG. 2a, anchored to the ceiling by a rail structure, i.e. a track, and provided with a patient hoist assembly 200a being provided with the spreader bar 30. The ceiling lift 100a is a dynamic ceiling lift, which is configured to dynamically unload the patient while the patient moves around, or a conventional ceiling lift, which is configured to raise and lower a patient in a linear manner. In one embodiment, shown in FIG. 2b, the patient lifting device is a floor lift 100b. The floor lift 100b comprises a wheel-mounted platform with a vertically extending unit provided with the hoist assembly 200b, the patient hoist assembly 200b being provided with the spreader bar 30.

[0036] The patient hoist assembly 200a, b is provided with a connection unit 22, i.e. a cord. The cord 22 is adapted to be attached to the spreader bar 30.

[0037] Referring to FIG. 1 , the sling 20 comprises a leg support portion 24. The leg support portion 24 is adapted to support the thighs of a patient. Accordingly, the leg support portion 24 is adapted to support the thighs of a patient during use, i.e. worn by the patient.

[0038] The sling 20 comprises a torso support portion 25. The torso support portion 25 is adapted to support the torso of the patient 10. Accordingly, the torso support portion 25 is adapted to support the torso of the patient when the sling

[0039] 20 is installed on the patient, i.e. worn by the patient.

[0040] The sling 20 comprise one or more connection units 21 , i.e. straps. The straps

[0041] 21 is adapted to be attached to the spreader bar 30 of patient hoist assembly 200a, 200b. In one embodiment, the connecting portion comprises a front pair of straps and a rear / back pair of straps.

[0042] The leg support portions 24 are attached to the torso support portion 25. The leg support portions 24 each comprise a thigh-wrapping portion adapted to wrap around the thigh of the patient. This allows for an increased mobility in the sling 20 for the patient 10, since relative movement between the torso support portion 25 and the leg support portion 24 is accommodated by the attachment portion between the leg support portions and the torso support portions. According to an aspect, the torso support portion 25 is adapted to wrap around the torso of the patient.

[0043] In order to rehabilitate patients and improve their mobility, an ambulation patient sling 20 is used to assist patients for standing or walking activities. During such activities, there is a likelihood for the patient to fall. Such fall results in shock or impact on the patient lifting device caused by the quick deceleration of the patient. In one aspect, if deceleration is unabsorbed, this impact could generate a load greater than the lift's maximum capacity (Safe Working Load) causing potential damage to the lift and / or the patient.

[0044] The proposed invention is a damping device with purpose to absorb the impact load caused by a patient falling during rehabilitation and limiting it to an acceptable level and preventing lift damage. This damping device is positioned between the patient sling and the patient lifting device.

[0045] The damping device mitigates peak impact loads transmitted to the patient lifting system, reducing the risk of injury to the patient and preventing damage to the lifting equipment. The device is adaptable to multiple positions within the lifting system and provides variable damping through adjustable engagement patterns. Materials such as rubber, thermoplastic polyurethane, and silicone ensure durability and consistent performance across a range of patient weights.

[0046] FIG. 2a shows a ceiling lift 100a with a dual damper device 40 configuration. The damping device 40, i.e. a damper, is designed to be used with a patient sling 20 that supports a patient 10. The damper 40 comprises at least one aperture 41 and is capable of adjustably engaging the connection units 21 , 22. The damper 40 is configured to enhance safety by deforming and absorbing shocks and reducing the impact of falls when using the sling 20, thereby cushioning the patient 10 in the event of a fall. The damper 40 is adaptable and can be positioned in various configurations to ensure optimal performance.

[0047] With reference to FIG 3a - d, the damping device 40 can be positioned at different positions A, B, C, D on connection units 21 , 22 between the patient sling 20 and the patient hoist assembly 200a, 200b. The damping device 40 can be placed at any one of the positions: A: on a connection unit 21 , i.e. a strap, connecting the patient sling 20 to the spreader bar 30, as shown in FIG. 3a,

[0048] B: at a connection point between the strap 21 of the patient sling 20 and the spreader bar 30, as shown in FIG. 3b,

[0049] C: on a connection unit 22, i.e. the cord, connecting the spreader bar 30 to the patient hoist assembly 200a, 200b, as shown in FIG 3c, or

[0050] D: at a connection point between the connection unit 22 of the patient hoist assembly 200a, 200b and the spreader bar 30, as shown in FIG. 3d.

[0051] This flexibility allows for optimal placement based on specific needs and configurations.

[0052] The aperture 41 can be of various shapes, shown in FIG 5-7, including rectangular, square, oval, or circular.

[0053] In some embodiment, the damper 40 includes at least two apertures 41 through which the connection unit 21 , 22 can be threaded and allowing the connection unit 21 , 22 to be weaved through in a zig-zag pattern. The device’s ladder-like shape and the inclusion of multiple apertures provide several points of energy absorption. This design distributes the force more evenly, further reducing the risk of injury.

[0054] The damping device 40 are configured to absorb the impact caused by the patient falling during ambulation activities. The absorbing elements in these damping devices are comparable to a mass spring damper model 60, shown in FIG 4, in which a spring 61 and a damper 62 are the material of the damper device 40. Additional friction in certain configurations adds damping force.

[0055] In one aspect, the damper 40 is made from a resilient, deformable visco-elastic material such as rubber or thermoplastic polyurethane (TPU), silicone, ethylene-vynil acetate, polyisoprene, butyl rubber, chloroprene or styrene butadiene. These materials are chosen for their ability to absorb and dissipate energy efficiently, which helps in cushioning the impact regardless of the patient’s weight. In one embodiment, the body 42 exhibits visco-elastic behavior characterized by a loss factor, tan 5, sufficient to provide both elastic energy storage and viscous energy dissipation during transient loading. The visco-elastic material can deform under stress and return to its original shape, providing consistent shock absorption. This elasticity allows the device to adapt to different levels of force exerted by patients of varying weights. These materials are also known for their resilience and ability to return to their original shape after deformation, ensuring long-term effectiveness. In one embodiment, the damping device is provided with a surface texturing or high-friction coatings at regions of contact with the connecting unit 21 , 22 to increase frictional damping.

[0056] The shape and number of apertures 41 can influence the damping effect. Multiple apertures or a zig-zag threading pattern can distribute the load more evenly, enhancing the device’s ability to handle heavier weights. This feature ensures a secure fit and enhances the device’s ability to absorb energy efficiently.

[0057] The connection units 21 , 22 include a first distal end, a second distal end, and a length there between. The length can slide through the aperture 41 of the damping device 40. The connection units 21 , 22 may also form a loop 21c, 22c, shown in FIG 7, that slides around the aperture 41 .

[0058] The damping device 40 is designed to handle different patient weights through its material properties and structural design. The damping device 40 can be adjustably engaged with the connection units 21 , 22, allowing for customization based on the patient’s weight. This adjustable engagement ensures that the device can be securely attached and provide optimal shock absorption for different patients. For lighter patients, the damping device 40 absorbs less energy but still provides sufficient cushioning to prevent injury. For heavier patients, the damping device 40 absorbs more energy, deforming more significantly to dissipate the increased force. The combination of material properties and structural design ensures that the damping device 40 performs consistently across a range of patient weights. This consistency is crucial for maintaining safety and comfort during lifting and transferring operations.

[0059] FIG 5 and 6 shows embodiments of a damping device 40 in the shape of a ladder. Ladder 40 is a rectangular slotted ladder with two or more apertures 41. A part of the connection unit 21 , 22 is weaved in the apertures 41 in a "zigzag” pattern, shown in FIG. 6. The zigzag threading pattern increases a contact length and frictional area between the connecting unit 21 , 22 and the ladder shaped body 42 to augment damping. Dissipation of the energy will be done by deformation of the ladder 40 and friction between the ladder 40 and the connection unit 21 , 22. The plurality of apertures 41 are arranged to define a rectangular slotted ladder permitting adjustable engagement positions of the connecting unit 21 , 22 to tailor damping characteristics for different patient weights. The device’s ladder-like shape and the inclusion of multiple apertures provide several points of energy absorption. In one embodiment, body of the damper 42 comprises a ladder shaped body having a plurality of apertures 41 , the apertures 41 being sized and arranged to permit the connecting unit 21 , 22) to be threaded therethrough in a zig zag pattern. Wherein energy dissipation is provided by plastic deformation of the ladder shaped body 42 and frictional interaction between the body 42 and the connecting unit 21 , 22 during a patient fall. In one embodiment, the ladder shaped body 42 includes reinforcement ribs disposed between adjacent apertures 41 to control local stiffness and tune deformation under load. This design distributes the force more evenly, further reducing the risk of injury.

[0060] FIG 7 shows another embodiment of a damping device 40, a compression cylinder. A part of the connection unit 21 c, 22c is formed as a loop and wrapped around the compression cylinder 40 and is configured to compress the compression tube 40 during impact. In one embodiment, the body of the damper 42 comprises a compression cylinder formed of the deformable visco elastic material and provided with an engagement surface configured to be compressed by a looped portion 21 c, 22c of the connecting unit 21 , 22. Wherein energy is dissipated by axial compression of the compression cylinder 42 during a patient fall. The compression cylinder 42 comprises a tubular wall configured to undergo radial bulging during axial compression, thereby enhancing energy dissipation. In one embodiment, the compression cylinder 42 includes one or more axial slots or cavities 41 configured to collapse progressively under impact to provide staged damping.

[0061] The disclosed damping device 40 has the ability to dissipate kinetic energy through plastic deformation, significantly reducing the impact of shock loads during a fall. This damping device 40 enhances patient safety by minimizing the risk of injury. Overall, the damping device 40 offers a combination of safety, flexibility, durability, and versatility that makes it a superior solution compared to existing options in patient lifting systems.

[0062] The invention also encompasses a patient lifting system 100a, b, shown in FIG. 1 -3, for damping a fall of a patient 10. The system includes a patient sling 20. In one embodiment, the patient sling is having a leg support portion 24, a torso support portion 25, and at least a first and a second connection unit 21. Further the system includes a spreader bar 30 configured to connect the patient sling 20 to a patient hoist 200a, b of the system. The system is provided with the damping device 40 positioned on a connecting unit 21, 22 disposed between the patient sling 20 and the patient hoist 200a, b. The damping device 40 is configured to reduce an impact load transmitted to the patient lifting system by dissipating kinetic energy upon a patient fall. The disclosed system provides for enhanced patient safety by reducing the impact of falls, versatile positioning options for the damping device 40 and adjustable engagement with connection units 21, 22. In one embodiment, the damping device 40 is configured to adjust the engagement length and / or routing of the at least one connecting unit 21, 22 through at least one aperture 41. The damping device 40 is configured to limit a peak impact load to, at or below a predetermined safe working load of the patient hoist 200a, b. In one embodiment, the connecting unit comprises a strap 21 of the patient sling 20. In one embodiment, the connecting unit comprises a cord 22 connecting a spreader bar 30 to the patient hoist 200a, b of the patient lifting system 100a, b.

[0063] The invention includes a complete system for damping a patient’s fall, comprising the damping device, a patient sling with leg and torso support portions, and a patient hoist that works with the sling and damping device to ensure safe and controlled lifting operations. The damping device offers several advantages over existing solutions in patient lifting systems. This integration ensures that all components work together seamlessly to provide maximum safety and support during lifting operations. The system is suitable for various patient handling tasks, including transferring patients, assisting in ambulation, lifting patients, and providing general support. This versatility makes it a valuable addition to any healthcare setting.

[0064] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" "comprising," "includes" and / or "including" when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0065] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0066] The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should be regarded as illustrative rather than restrictive, and not as being limited to the particular embodiments discussed above. The different features of the various embodiments of the invention can be combined in other combinations than those explicitly described. It should therefore be appreciated that variations may be made in those embodiments by those skilled in the art without departing from the scope of the present invention as defined by the following claims.

[0067] Reference numbers

Claims

CLAIMS1 . A damping device (40) for a patient lifting system (100a, b), the damping device (40) comprising: a body (42) formed of a deformable visco-elastic material; and at least one aperture (41 ) configured to receive a connecting unit (21 , 22) of the patient lifting system (100a, b); wherein the damping device (40) is configured, when positioned between a patient sling (20) of the patient lifting system (100a, b) and a patient hoist (200a, b) of the patient lifting system (100a, b), to dissipate energy by deformation in response to a shock-load occurring during a patient fall.

2. The damping device (40) according to claim 1 , wherein the body (42) comprises a ladder-shaped body having a plurality of apertures (41 ); the apertures (41 ) being sized and arranged to permit the connecting unit (21 , 22) to be threaded therethrough in a zigzag pattern; wherein energy dissipation is provided by plastic deformation of the ladder-shaped body (42) and frictional interaction between the body (42) and the connecting unit (21 , 22) during a patient fall.

3. The damping device (40) according to claim 1 , wherein the body (42) comprises a compression cylinder formed of the deformable visco-elastic material and provided with an engagement surface configured to be compressed by a looped portion (21c, 22c) of the connecting unit (21 , 22); wherein energy is dissipated by axial compression of the compression cylinder (42) during a patient fall.

4. The damping device (40) according to any one of claims 1-3, wherein the visco-elastic material comprises at least one of: rubber, thermoplastic polyurethane (TPU), silicone, ethylene-vinyl acetate (EVA), polyisoprene, butyl rubber, chloroprene, or styrene-butadiene rubber (SBR).

5. The damping device (40) according to any one of claims 1-3, wherein the at least one aperture (41 ) is shaped as a rectangle, square, oval, or circle.

6. The damping device (40) according to claim 2, wherein the plurality of apertures (41 ) are arranged to define a rectangular slotted ladder permitting adjustable engagement positions of the connecting unit (21 , 22) to tailor damping characteristics for different patient weights.

7. The damping device (40) according to claim 2, wherein the zigzag threading pattern increases a contact length and frictional area between the connecting unit (21 , 22) and the ladder-shaped body (42) to augment damping.

8. The damping device (40) according to claim 3, wherein the compression cylinder (42) comprises a tubular wall configured to undergo radial bulging during axial compression, thereby enhancing energy dissipation.

9. The damping device (40) according to any one of claims 1-3, wherein the connecting unit comprises a strap (21 ) of the patient sling (20).

10. The damping device (40) according to any one of claims 1-3, wherein the connecting unit comprises a cord (22) connecting a spreader bar (30) to the patient hoist (200a, b) of the patient lifting system (100a, b).

11. The damping device (40) according to any one of claims 1-3, wherein the damping device (40) is positioned:(A) on a strap (21 ) of the patient sling 20;(B) at a connection point between the strap (21 ) and a spreader bar (30) of the patient lifting device (100a, b);(C) on a cord (22) connecting the spreader bar (30) to the patient hoist (200a, b); or(D) at a connection point between the cord (22) and the spreader bar (30).

12. The damping device (40) according to any one of claims 1-3, wherein the body (42) exhibits visco-elastic behavior characterized by a loss factor (tan 5) sufficient to provide both elastic energy storage and viscous energy dissipation during transient loading.

13. The damping device (40) according to any one of claims 1-3, further comprising a surface texturing or high-friction coatings at regions of contact with the connecting unit (21 , 22) to increase frictional damping.

14. The damping device (40) according to claim 2, wherein the ladder-shaped body (42) includes reinforcement ribs disposed between adjacent apertures (41 ) to control local stiffness and tune deformation under load.

15. The damping device (40) according to claim 3, wherein the compression cylinder (42) includes one or more axial slots or cavities (41 ) configured to collapse progressively under impact to provide staged damping.

16. A patient lifting system (100a, b) comprising: a patient sling (20); a spreader bar (30) configured to connect the patient sling (20) to a patient hoist (200a, b) of the patient lifting system; anda damping device (40) according to any one of claims 1-3 positioned on at least one connecting unit (21 , 22) disposed between the patient sling (20) and the patient hoist (200a, b); wherein the damping device (40) is configured to reduce an impact load transmitted to the patient lifting system by dissipating kinetic energy upon a patient fall.

17. The patient lifting system (100a, b) according to claim 16, wherein the damping device (40) configured to adjust the engagement length and / or routing of the at least one connecting unit (21 , 22) through at least one aperture (41 ).

18. The patient lifting system (100a, b) according to claim 16, wherein the damping device (40) is configured to limit a peak impact load to, at or below a predetermined safe working load of the patient hoist (200a, b).

19. The patient lifting system (100a, b) according to any one of claim 16 to 18, wherein the patient lifting system is a ceiling lift (100a) movable along a track or a floor lift (100b) having a wheeled base.

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