Single step wheelchair transfer device

[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 60/741 203, filed Dec. 1, 2005, which is incorporated herein in its entirety.

[0002] The invention relates to patient transfer devices for moving a patient from a recumbent position to a seated position.

[0003] Patients often require assistance in moving from a hospital bed to a wheelchair, or require assistance in moving from the hospital bed to a toilet. An attendant rendering assistance is subject to injury in assisting the patient without mechanical assistance. Patient transfer devices can still require excessive bending and lifting by an attendant, increasing the likelihood of injury to the attendant or patient. In the alternative, some patient transfer devices, such as an overhead lift, can make the patient feel like freight due to the lack of any personal contact by an attendant.

[0004] It would be advantageous to provide a patient transfer device that gives an attendant the mechanical advantage necessary to move a patient without injury, and that maintains the close personal contact between the patient and the medical attendant.

[0017] Certain terminology will be used in the following description for convenience and reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the arrangement and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.

[0018] Referring to FIGS. 1-3, the device 100 includes a rolling base unit 105 and an upper unit 110. The rolling base unit 105 includes a pair of caster wheels 112, 114 and a pair of dual height roller wheels 116, 118. An adjustable height stanchion 120 projects upwardly from the rolling base unit 105. The upper unit 110 is secured to an upper end 122 of the stanchion 120. FIGS. 1-2 provide perspective views of the device 100 with the upper unit 110 in an upright seating position. FIG. 3 is a side view of the device 100 with the upper unit 110 in a prostrate position.

[0019] The rolling base unit 105 further includes an adjustment mechanism 124. The adjustment mechanism 124 selectively rotates the dual height roller wheels 116, 118 from a raised position (FIG. 1), wherein the base unit 105 is supported on the rolling surfaces of the wheels 116, 118, to a lowered position (FIG. 10) offset from the raised position by 90 degrees, wherein the base unit 105 is supported by a roller bearing 126 mounted in the center of each roller wheel 116, 118. This operation is described in greater detail in commonly owned U.S. Ser. No. 11/354 801, filed Feb. 15, 2006, which is incorporated herein by reference in its entirety.

[0020] The upper unit 110 includes a frame support member 200 that is secured to the upper end 122 of the stanchion 120. The frame support member 200 supports a pivot pin 205 defining a pivot axis 210. A pivoting wheelchair frame 215 is pivotally mounted to the frame support member 200 by the pivot pin 205 and is configured to pivot about the pivot axis 210.

[0021] The frame 215 is formed of two major components, a seat frame 220 and an upper torso support frame 225. The seat frame 220 and the upper torso support frame 225 are each independently pivotally mounted to the support member 200 to rotate about the pivot axis 210.

[0022] The seat frame 220 is formed of a generally U-shaped tubular member 230 having inner and outer legs 232, 234. The inner leg 232 is pivotally connected to the support member 200. A transverse seat support member 236 is attached at the uppermost extent 238 of the outer leg 234.

[0023] The upper torso support frame 225 is attached to the support member at an inner end 240. The frame 225 includes an upturned outer end 242. A transverse seat support member 244 is attached to the frame 225 at the outer end 242. A flexible seat body 250 extends between the transverse seat support members 236, 244.

[0024] The seat frame 220 and the upper torso support frame 225 are joined by an attitude fixing mechanism 260. The attitude fixing mechanism 260 is pivotally mounted at a first end 262 to the seat frame 220 by a pivot pin 264. A second end 266 of the attitude fixing mechanism 260 is selectively fixable on the upper torso support frame 225. The frame 225 includes a yoke 268 having a through-pin 270. The second end 266 of the attitude fixing mechanism 260 includes a plurality of recesses 272. The attitude fixing mechanism 260 is receivable within the yoke 268 in such a manner that the pin 270 is positioned to selectively engage one of the plurality of recesses 272. The fixing mechanism 260 further includes a spring clip 275 positioned proximate the second end 266 and configured to bear against the frame 225 for urging the fixing mechanism 260 away from the frame 225, and thus urging the pin 270 into a respective one of the plurality of recesses 272.

[0025] A second frame support member 280 is rigidly attached to the stanchion 120. The support member 280 supports a drive mechanism 290. The drive mechanism 290 is pivotally connected to the support member 280 at a lower pivot 295 and to the upper torso support frame 225 at an upper pivot 300. In the illustrated embodiment, the drive mechanism 290 is an electric drive mechanism, but hydraulic, pneumatic or other mechanical drive types are also anticipated.

[0026] The drive mechanism 290 is electrically connected to a controller/battery module 310 by a control cable 312. The controller/battery module 310 is suspended from the support member 280. A remote control switch panel 320 is provided and is shown mounted on the upper torso support frame 225. The remote control switch panel 320 is further electrically connected to the controller/battery module 310 by a further control cable 322.

[0027] A knee-board 330 is mounted to the upper torso support frame 225. The knee-board 330 is rigidly mounted to the frame 225 and is mounted parallel thereto.

[0028] Referring to FIG. 4, the seat portion 220 has been rotated counterclockwise 90 degrees about the pivot axis 210. As the seat portion 220 rotates counterclockwise about the pivot axis 210, independent of the upper torso support frame 225, the fixing mechanism 260 is drawn through the yoke 268. The recesses 272 sequentially line up with the pin 270, enabling the seat portion 220 to be selectively locked in multiple angular positions with respect to the upper torso support frame 225. As the seat portion 220 reaches the 90 degree rotation shown in FIG. 4, the endmost recess 272 reaches the pin 270 in the yoke 268. With the pin 270 lodged in the endmost recess 272, the seat portion 220 is secured in a 90 degree relationship to the upper torso support frame 225.

[0029] Referring now to FIGS. 5-6, the device 100 is shown with the upper unit 110 in the upright seated position. The upper torso support frame 225 and the seat portion 220 are rotated together into the upright position. In this position, the seat portion 220 is supported by the frame support member 200 on the stanchion 120. The upper torso support frame 225 is supported in the upright position by the drive mechanism 290. As shown in FIG. 5, the drive mechanism 290 is in an extended condition. Since the drive mechanism 290 pivots about the lower pivot 295 and the upper pivot 300, which are offset from the pivot axis 210, the extension of the drive mechanism 290 forces the upper torso support frame 225 to pivot about the pivot axis 210.

[0030] Operation

[0031] The device 100 is configured for raising a patient from a reclining position to a seated position. Referring first to FIG. 7, the device 100 is positioned adjacent to a bed 400 with the upper unit 110 in the prostrate position. In this position, the seat body 250 is horizontal and is positioned at the height of the patient support surface 405 of the bed 400 using the adjustable height stanchion 120. As necessary, the dual height wheels 116, 118 are placed in the low profile position to roll under the base of the bed 400, and the device 100 is rolled to the bed 400 so that the seat body 250 overlies a portion of the patient support surface 405. In the configuration of the single step wheelchair transfer device 100 illustrated herein, the device 100 is rolled to the “left” side of the bed 400; the patient's head is also to the left as viewed from beside the bed 400. In a further configuration (not shown), the device 100 is configured to roll to the “right” side of the bed 400; this is advantageous where access to the left side of the bed 400 is restricted, or where the patient is laying with his head to the right from the perspective of the device 100. In a further embodiment, the device is capable of being selectively configured in either the “left” side or “right” side configurations, thereby providing the attendant with the flexibility to operate in different room and equipment layouts using one single step wheelchair transfer device 100.

[0032] Typically, the patient will be rolled away from the device 100, and the device 100 rolled over the portion of the patient support surface 405 previously occupied by the patient. The patient is then rolled back onto the positioned device 100. The patient is then further rolled toward the device 100 until the patient is lying on his side on the seat body 250. The patient's legs are then drawn outward until the patient's knees and lower legs are resting on the knee-board 330.

[0033] Referring now to FIG. 8, the seat portion 220 of the upper unit 110 is rotated upwardly until it reaches the upright position, 90 degrees from the patient support surface 405. The seat portion 220 is automatically locked in the 90 degree position as the fixing mechanism 260 slides through the yoke 268 until the pin 270 engages the last recess 272 on the fixing mechanism 260. With the seat portion 220 in this position, the seat body 250 contacts the buttocks and the backs of the upper thighs of the patient.

[0034] The device is now ready to be moved to the upright seated position. An attendant will use the remote control switch to activate the drive mechanism 290. As the drive mechanism 290 is activated and drives from a retracted position to an extended position (see also FIG. 5), the upper unit 110 rotates from the prostrate position to the upright seated position shown in FIG. 9. The knee-board 330 is fixed to the upper torso support frame 225 and rotates therewith, supporting the patient's knees and lower legs through the rotation cycle as the upper unit 110 comes to the upright position. The patient is now raised to the position of sitting on the edge of the patient support surface 405.

[0035] FIGS. 10-11 illustrate the movement of the device 100 away from the bed 400. Safety belts (not shown) can be provided to secure the patient to the device 100, who is otherwise closely attended by an attendant. In FIG. 10, the dual height wheels 116, 118 are in the low profile position for maneuvering under the base of the bed. In FIG. 11, the dual height wheels have been rotated to the high profile position, better suited for transporting a patient over longer distances or uneven surfaces. In this configuration, the device can be used directly as a wheelchair for special purpose movement, such as for transporting a patient to the bathroom. The device 100 can also be made waterproof for use directly in the shower, eliminating the need to lift or move the patient again once the patient has been lifted and carried by the device 100.

[0036] While the invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the scope of the appended claims.