The invention relates to medical appliances, and more specifically to devices for supporting and transferring a paraplegic or quadriplegic patient.
Currently, increasing requirements are being imposed on hospitals, convalescent homes and home care agencies to assure quality and safety of care for both patients and medical practitioners. Care giver shortage, worker injuries and an aging workforce have led to renew emphasis on care giver injury prevention. In the United States and abroad legislation has been proposed to eliminate manual lifting and transferring of patients.
Prior art patient lifts rely on fabric slings upon which the patient must be progressively rolled and lifted, or that need to be slid under the invalid. The installations of these slings usually requires a great deal of exertion on the part of multiple care givers, and are often the cause of occupational injuries to the care givers as well as potential injuries to the invalid.
A major additional problem with slings is their limited life and unknown strength condition. Although they may appear serviceable, the material ages with time and its ability to carry a load deteriorates. Its exposure to improper washing and drying environments (including harsh chemicals, high temperatures, etc.) which may vary substantially among different users is a critical factor. A chemically or thermally altered sling material may lose a significant portion of its load carrying capability and be unsafe for use, while still appearing serviceable.
Current practice with fabric slings is to discard them early in their potential useful life. They demand special washing and drying procedures, and are often discarded after a single use. All of these procedures and options result in increased costs.
Therefore, there is a need for a patient lifting apparatus which addresses some or all of the above identified inadequacies.
The principal and secondary objects of the invention are to provide an improved patient lift apparatus. These and other objects are achieved by a lift which is fitted with comfortable grasping members that curl around the individual.
In some embodiments the curling fingers grasp the upper and lower parts of the patient from above then lift the whole limp body and reposition it into either a supine or a seating position.
In some embodiments the present invention addresses the above-mentioned deficiencies in the prior art patient lifts, and furthermore allows a mobility-challenged patient to effectuate transfers from bed to wheelchair and back without care giver assistance.
In some embodiments there is provided a cradle for lifting and moving a limp body which comprises: a first support frame; a grasping member extending from a first edge of said support frame; said member comprising: a plurality of horizontal, elongated cantles sequentially linked to one another along their longer sides and concomitantly orientable into an arcuate configuration of said member; and a curling mechanism for concurrently rotating said cantles.
In some embodiments said member further comprises a flexible first flat surface; and, wherein said curling mechanism comprises: a series of spaced-apart segments of progressively diminishing height projecting from said first flat surface; and, each of said segments comprising a base and an opposite side; and a driving mechanism for simultaneously rotating said segments about axes parallel to said cantles.
In some embodiments said curling mechanism further comprises a resilient stiffener acting against said driving mechanism.
In some embodiments said resilient stiffener comprises a resiliently bendable member connected to at least one adjacent pair of said segments.
In some embodiments the cradle further comprises: a second support frame rotatively attached to said first support frame; a second of said grasping member extending from said first edge of said second support frame; and a driving device for rotatively folding said second support frame toward said first support frame.
In some embodiments the cradle further comprises a third of said grasping member and curling mechanism extending from an opposite second edge of said first support frame.
In some embodiments the cradle further comprises a fourth of said grasping members and curling mechanism extending from a second edge of said second support frame opposite the third of said grasping members.
In some embodiments said driving mechanism further comprises a first tensioning member for haling said segments toward one another.
In some embodiments said opposite side has a channel defined therein and parallel thereto, housing said member.
In some embodiments each of said segments further comprises: a spur projecting from a first lateral edge substantially perpendicular to said base; an opposite second lateral edge having a slot shaped and dimensioned to receive a linking one of said spur associated with an adjacent segment; and a fastener rotatively securing said linking one of said spur into said slot.
In some embodiments said driving mechanism further comprises: a rotatable shaft; a cam centrally mounted on said shaft and having a first peripheral area; a first rocker linking said first peripheral area to said tensioning member; a rotator coupled to said shaft; wherein said tensioning member comprises a cable acting upon said segments.
In some embodiments said driving mechanism further comprises: a second of said tensioning member; said first and second tensioning members running through longitudinally opposite regions of said cantles; and a second rocker linking said second tensioning member to a second peripheral area of said cam astride said shaft.
In some embodiments said rotator comprises: a lever perpendicularly connected to said cam; a motor; and a clutch selectively coupling said motor to said cam.
In some embodiments said driving mechanism further comprises a modular housing mounted on said support frame and holding said shaft, rotator, cam and rockers.
In some embodiments said housing comprises: a plurality of enclosing walls; and a pair of linking elements, each having a proximal end secured to one of said rockers and a terminal end having a releasable connector accessible through one of said walls.
In some embodiments each of said grasping members and curling mechanism further comprise: a rotatable shaft; a cam centrally mounted on said shaft and having a first peripheral area; a first rocker linking said first peripheral area to said tensioning member; a rotator coupled to said shaft; wherein said tensioning member comprises a cable acting upon said segments.
In some embodiments each of said driving mechanisms further comprises: a second of said tensioning member; said first and second tensioning members running through opposite longitudinal regions of said cantles; and a second rocker linking said second tensioning member to a second peripheral area of said cam astride said shaft.
In some embodiments each of said rotators comprises: a lever perpendicularly connected to said cam; a motor; and a clutch selectively coupling said motor to said cam.
In some embodiments each of said curling mechanism comprises a modular housing mounted on one of said support frames and holding said shaft, motor, cam and rockers.
In some embodiments said rotator comprises: a lever perpendicularly connected to said shaft; a motor; and a clutch selectively coupling said motor to said shaft.
In some embodiments each of said segments comprises at least one trapezoidal block.
In some embodiments said grasping member further comprises a bendable sheet slidingly capping said distal sides.
In some embodiments said grasping member further comprises a flexible second flat surface astride said segments with said first flat surface, said second flat surface being slidingly connected to said segments.
In some embodiments said member further comprises a flexible second flat surface astride said segments with said first flat surface, said segments being hingedly connected to said flat surfaces and parallel to said cantles.
In some embodiments said cradle further comprises at least one form-fitting sleeve made from a flexible sheet material.
The original text of the original claims is incorporated herein by reference as describing features in some embodiments.
Referring now to the drawing, there is shown in
The control of such a device may be through a series of switches and levers mounted within reach of the patient or on a wireless or cable-connected console operable by an assisting person or by the patient.
The lift comprises two quasi-identical pivotally connected grabbing structures, the first 12 adapted to encompass and lift the pelvic portion of the body, and the second 13 adapted to encompass and lift the torso. Each structure comprises a parallelogrammic support frame 14 from which extend along opposite lateral edges a pair of grasping members 15,16 dimensioned and positioned to move along each side of the load either the pelvis and thigh area 17 or the torso 18 of the patient 19 as illustrated in
Each grasping member can be caused to curl inwardly toward the other and to gently slide and penetrate under or around the patient's body. Each member can include a series of independent, parallel, rigid, longitudinal tying members in the form of slats or cantles 20 supported outwardly by two transversal articulated ribs 21,22 secured at their upper extremities to the frame 14. Each slat can be securely riveted or bolted in a latitudinally spaced apart manner to a rib segment on each of the two transversal ribs. Alternately, the slat and one or more of the contacted rib segments can be molded as a unitary component. Alternately, the slats as a group can be formed by a unitary sheet of durable, rigid sheet material such as plastic having longitudinal creases to delineate the cantles and to form hinges between them. These operationally equivalent alternate versions result in cantles sequentially linked to one another along their longer sides.
It should be noted that the device can be implemented with a single grasping member or two members on a single side for use in shoving a patient into a different position.
As illustrated in
The innermost of the upper and lower channels is capped by one of the slats 20 and houses an oblong, flexible, but substantially inelastic tensioning member such as a steel ribbon or a pull cable 32 running from the most distal and smallest segment 33, over a pulley 34 mounted on the support frame 14, to a toggling mechanism 35 that pulls and locks the cable and thus forces the rib and slats to curl inwardly in a grasping motion and remain in this locked, load-carrying position until the mechanism is reversed out of the toggled position. A resilient stiffener such as a leaf spring 36 engaged into the outer channel 31 of the segments provides a resilient force against the pull of the cable and returns the rib to a straight configuration when the pull of the cable is released.
As illustrated in
It shall be understood, as shown in
The pelvic and torso structures are rotatively connected by a hinge 44 and their respective orientation is controlled by a driving device formed by a pair of Acme thread screws 45 driven by either a hand crank or a motor 49 mounted on one of the frames, and having its distal section engaged into a nut 46 mounted on the other frame. Accordingly, the relative position of the structures can be adjusted between a supine position and a seated position of the patient.
For sanitary reasons, each of the grasping members can readily be inserted into a disposable or washable form-fitting sleeve 111 made from fabric, plastic or other flexible sheet material.
A chain 47 attached to one or both of the grasping members can be used to suspend the device to a ceiling winch or a transfer carriage. Handle bars 48 at the top of the torso structure can be used by the patient to rock and wag the grasping members in order to facilitate their insertion around his or her body. The handle bars can also provide a convenient location for mounting controls. Either structure may me extended to provide support for the head, legs and feet with additional supporting ribs. A single head-to-toe structure can be provided to simplify lifting a supine body.
The pulling cable 32 can be made of stainless steel. Its tension need not exceed about 500 kgs (1,100 lbs), considering the tension necessary to rotate each and all the segments of a rib under a 100 kgs (220 lbs) load.
As illustrated in
This embodiment contemplates a 0.624 cm (⅛ in) steel cable and a rib compressive load of 34 atmospheres (500 psi). A four rib assembly can carry a load of 340 kgs (800 lbs). The pivot points of the segments can be located near the outside edges of the ribs so that the weight of the grasping members tends to bias the structure inward.
The general operation and basic design parameters of an individual rib can be more fully understood by looking at a simple force and moment diagram of the most distal segment of a typical rib. The end segment generally is the most critical since it is desirable to have it as thin as possible at the same time as it is carrying the most extreme potential load 52 at its tip 53.
Since ribs are generally configured in pairs and two pairs are used to hold the slats that support the upper body and two pairs are used for the lower body, it is expected that eight ribs will be used to support a patient. If each rib supports 45.45 kgs (100 lbs), the gross lifting capability for an eight rib patient lift would be 363.6 kgs (800 lbs). As shown below, this value can be readily increased by varying the design conditions.
As shown in
F1 (52)—The vertical load on the end of the rib segment.
L1—The horizontal length between the load and the pivot point.
F2 (32)—The tension in the cable pulling at the angle of the adjoining segment.
A—The angle between adjoining rib segments.
L2—The vertical distance between the cable and the pivot point.
The cable forces acting on the segment can be further broken down as those acting along the axis of the segment, (i.e. Fx), or perpendicular to the axis of the segment, (i.e. Fy).
Summing the moments around the pivot point results in the following simple design relationship:
(F1)(L1)=(Fx)(L2)
L2=(F1/Fx)(L1)
for:
F1=45.45 kgs (100 lbs)
F2=454.5 kgs (1000 lbs)
A=25 degrees
L1=5 cms (2 in)
then:
Fx=(F2)(cos A)=(454.5)(cos 25)=(454.5)(0.906)=412 kgs (906 lbs).
and:
L2=(45.5/412)(2)=0.558 cm (0.22 in)
A 0.624 cm (⅛ inch) diameter cable can carry tension loads up to about 910 kgs (2000 lbs). Unit compressive loads at the pivot point are dependent on the materials used and the pivot area, but are easily handled by expanding the length and diameter of the pivot area and the use of industrial strength plastics. The design limitations are projected to be associated with the restraint of the lateral cable force, Fy. For the values shown in this embodiment, this force is approximately 192 kgs (423 lbs) and would tend to peel the slats off the rib segment at the point where the cable turns at 25 degrees. In this embodiment, this force is easily contained by sturdy attachment of the slats to the rib segment. Heavier lifts may incorporate rib segments that are formed in the shape of an inverted U cross-section. In this case the lateral loads are contained directly in the segment.
Thus, it can be understood that for reasonable engineering values and sizes, a rib can be designed that will readily meet the design requirements. Even with a worst case load entirely at the tip of the last rib segment, the tension loads and depth of the segment are modest. As one moves up the rib segments, an increase in the L2 dimension (in order to compensate for the effective increase in the L1 dimension), requires that the depth of the ribs increase at approximately 6 degrees. This produces a general rib design that has balanced loads along its length and can be long and slender and narrow at its tip. Typical maximum depths at the lowest pivot point are on the order of 1.25 cm (0.5 in) and grow to approximately 3.8 cm (1.5 in) at the top of the last rib segment.
The lift can be lowered around the patient until it rests completely on the bed. When it is lowered further the grasping members will automatically begin to curl before the pulling of the cables. Armpit pads 6 can be added for comfort along the upper longitudinal edge of the torso structure.
Vibrations may be induced into each grasping member by a motor mounted on each frame and rotating an eccentric load. The vibrations facilitate insertion of the slats under the patient.
Referring now to
As more specifically illustrated in
A section of another version of the curling structure is illustrated on
In each of the three above-disclosed embodiments of the grasping members 15, 16, 61 and 71, the length is approximately 12 inches (30 cm) and the width approximately 10 inches (25 cm). The overall thickness at the root is approximately 1.5 inches (4 cm). All suggested dimensions are intended to accommodate patients weighing up to about 500 pounds (225 kgs). It should be understood that these parameters can be adjusted to support heavier and more bulky individuals or other loads.
As illustrated in
One of such housing operates each grasping member. The manual operating lever 86 outside the housing is radially connected to a distal portion 87 of the cam protruding through a circular window 88 in the front wall of the housing. The cam is preferably circular rather than oblong as in
While the exemplary embodiments of the invention have been described, modifications can be made and other embodiments may be devised without departing from the spirit of the invention and the scope of the appended claims.
This application is a continuation of U.S. patent application Ser. No. 16/293,402, filed 2019 Mar. 5, U.S. patent Ser. No. 11/147,727, issued 2021 Oct. 19, which is a continuation of U.S. patent application Ser. No. 15/023,646, filed 2016 Mar. 21, U.S. patent Ser. No. 10/238,565, issued 2019 Mar. 26, which is a 371 of International Application No. PCT/US2015/052504, filed 2015 Sep. 25 which claims the benefit of U.S. Provisional Patent Application Serial Nos. 62055132, filed 2014 Sep. 25 and 62207863, filed 2015 Aug. 20 all of which are incorporated herein by reference.
Number | Date | Country | |
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62207863 | Aug 2015 | US | |
62055132 | Sep 2014 | US |
Number | Date | Country | |
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Parent | 16293402 | Mar 2019 | US |
Child | 17503627 | US | |
Parent | 15023646 | Mar 2016 | US |
Child | 16293402 | US |