Patent Publication Number: US-6986181-B2

Title: Patient positioning device

Description:
FIELD OF THE INVENTION 
   The invention relates to an apparatus used to position a patient into the supine position. This invention also relates to a system that positions a patient and applies traction to the spine, such as physical therapy and chiropractic treatment. 
   BACKGROUND OF THE INVENTION 
   The practice of applying traction to the spine of a patient for therapeutic purposes is commonly prescribed by physicians, physical therapists and chiropractors. When professional judgment calls for a patient to be placed in a supine position, a harness is normally attached to the patient by encircling the lower abdomen with a harness that consists of a belt which must be attached by straps to a traction head. The Saunders Group, Incorporated of Chaska, Minn. sells harnesses of this type including its harness model # 46210. The belt portion which encircles the abdomen must be cinched tightly enough to capture the pelvis of the patient and thus transfer the traction force from the traction head through the belt to the pelvis and in turn to the lower spine. When applying traction, the upper part of the body is similarly captured by a thoracic harness. Thoracic harnesses including that designated as model no. 46205 can also be obtained from The Saunders Group, Incorporated of Chaska, Minn. 
   In order to place a patient in the supine position, the clinician first places the patient on a treatment table with the patient&#39;s back resting on the table and with the patient&#39;s legs extended straight and essentially level. The clinician then assists the patient in raising his/her legs onto a stool that is placed on the table between the patient&#39;s lower legs and the table such that the upper legs are close to vertical and the lower legs are parallel to the plane of the table. Stools are available from the Chattanooga Group, Inc. The clinician can then adjust the patient&#39;s lower legs&#39; elevation by loosening and then retightening a vertical adjustment clamp while supporting the patient&#39;s legs so the stool does not collapse to its minimum height. 
   Difficulties arise with this treatment method in the case of obese, elderly or pregnant patients. With obese patients, for instance, the harness belt is frequently difficult to tighten sufficiently to capture the pelvis, which results in the force from the traction head being distributed through the soft tissues throughout the pelvis. This results in (1) discomfort to the patient; (2) slippage of the belts; and (3) uncertainty as to the actual spinal treatment force. 
   This invention relates to a patient positioning device for controlling the movement of a patient into the supine position. This invention also relates to a system for positioning a patient into the supine position and applying traction to the patient. 
   SUMMARY OF THE INVENTION 
   The patient positioning device of this invention can be readily transported and attached to a horizontal or inclined surface such as a patient treatment table. The patient positioning device can be attached by straps and clamps or the like to the table surface. The patient positioning device of this invention rotates from a lowered position to an elevated position. In the lowered position, a patient&#39;s lower legs, the portion below the knees, are rested on the patient positioning device. The patient positioning device is then rotated to the elevated position in which the patient&#39;s feet and lower legs are elevated. The patient positioning device has a motor and an actuator that can be used to move the device between the lowered and raised positions. The motor powers the actuator to move the positioning device. In a preferred embodiment, the motor has a remote controller that permits a patient or attendant to power the motor. Once in the elevated position, traction or other therapy can be applied to the patient. 
   The portable patient positioning device preferably includes a bottom support frame, a leg support, and vertical support members that couple the bottom support frame to the leg support. Attached to the bottom support frame may be a pivot and a stationary bar. The pivot bar and the stationary bar are, in a preferred embodiment, parallel. 
   The patient positioning device&#39;s actuator preferably includes a threaded cylinder coupled to the stationary bar o the bottom support and a screw disposed in the threaded cylinder and attached to a vertical support member. When the motor is powered, the motor rotates the screw in and out of the cylinder. When the screw rotates out of the cylinder, the screw pushes on the vertical support member to push the vertical support member in a rotary manner about the bottom frame pivot. As the vertical support member rotates the leg support, which is coupled to the vertical support, also rotates to the elevated position. Conversely, when the screw is rotated into the cylinder, the screw pulls the vertical support and the leg support in a rotary manner into the lowered position. 
   The leg support may be mounted to the device so that it can move laterally relative to the device. Preferably, the leg support moves laterally with a rail system and locks in place in a desired position that is best for a patient&#39;s anatomy. In a preferred embodiment the locking system includes a pin that fits into a hole. There are preferably a series of holes and the pin is placed in the hole that corresponds to the desired location, thereby locking the leg support in place. The pin may be spring loaded in order to hold the pin in the hole. 
   The patient positioning device may also have a pad, which is preferably a thigh support pad, that is coupled to the leg support. The thigh support pad can be moved laterally with the leg support so that it can be moved behind a patient&#39;s thighs. This pad provides comfort to a patient&#39;s legs as it provides a stationary force absorbing fulcrum for the moment arm if traction is to be employed. Preferably, the leg cushion is coupled to the pad, so that the leg cushion moves laterally with the rails and the pad. As described above and below, the tracks and rails permit the thigh support pad and the leg support to be moved to a position that fits a particular patient&#39;s anatomy. 
   This invention can also be used as a therapeutic or passive exercise device. In particular, the support can be rotated between the lowered and elevated positions. One such application where the device could be used as a passive exercise device is after a patient has had hip surgery. 
   This invention also includes a system for treating a patient&#39;s back by applying traction to the back. The system includes the patient positioning device including any of the embodiments described above and below and a device for applying the patient in traction. The traction device is preferably includes a femur board, a cable, and a traction unit. The femur rests on the front of the patient&#39;s thighs, and the cable extends from the femur board to the traction unit. Once the patient&#39;s lower legs are elevated with the positioning device, the femur board is placed across the thighs, and the traction unit pulls on the cable and the femur board, placing the patient in traction. Except where so expressly limited in the claims, the patient positioning device can be used with a variety of traction devices, including harness type devices such as those described above. 
   This invention also includes methods of positioning a patient&#39;s legs with the patient positioning device, and methods of treating a patient with the patient positioning device and the device for applying traction. 
   Other features of the invention are described below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a patient positioning device according to a preferred embodiment of this invention; 
       FIG. 2  is a side view of the preferred embodiment of  FIG. 1  disposed on a treatment table and in an elevated position; 
       FIG. 3  is a side view of the preferred embodiment of  FIG. 1  disposed on a treatment table and in a lowered position; 
       FIG. 4  is a view along line  4 — 4  of  FIG. 2 ; 
       FIG. 4A  is an assembly drawing of a preferred embodiment of the thigh pad of FIG.  1 &#39;s connection to the patient positioning device of  FIG. 1 ; and 
       FIG. 5  is a cross-section taken along line  5 — 5  of FIG.  4 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   The patient positioning device  10  is portable and can be easily transported and adapted to a patient&#39;s treatment table  8  or any other suitable surface. The treatment table may, but need not be, a Triton Table available from the Chattanooga Group, Inc. The surface may be inclined. As described below, the patient positioning device  10  can be rotated from a lowered position to an elevated position. A perspective of an embodiment of the patient positioning device  10 , that is partially cut away at the top, is shown in FIG.  1 .  FIGS. 2 and 4  illustrate the patient positioning device  10  in an elevated position, and  FIG. 3  depicts the patient positioning device  10  in a lowered position. ( FIG. 2  depicts the device  10  in an elevated position, but not fully elevated, and  FIG. 4  depicts the device  10  in a fully elevated position so that the details of the device are better understood.) 
   As shown in  FIG. 1 , the patient positioning device  10  includes a bottom frame  11 . The bottom frame  11  can have any number of configurations, and in the preferred embodiment shown, it is generally rectangular. Additionally, the bottom frame  11  can be constructed from any suitable material, but it is preferably metal. In the preferred embodiment shown, the bottom frame  11  has four bars  12 ,  14 ,  16 ,  18 . The bars  12 ,  14 ,  16 ,  18  may be attached by any suitable means including but not limited to mechanical fasteners and welding. 
   Attached to the bottom frame  10  are a pair of vertical support members  20 ,  22 . The vertical supports  20 ,  22  are depicted in  FIGS. 1-3 . Any number of vertical support members  20 ,  22  can be used, and they are preferably metal, but any suitable material can be employed. Vertical support member  20 , as shown in  FIGS. 2 and 3 , may have an angular shape in order to accommodate the raising and lowering of the device  10  so as not to interfere with the upper portion of the device in the lowered position. 
   In the preferred embodiment show, the vertical support member  20  is coupled to a cross-bar  21  that extends between bottom support members  16  and  18 , and the vertical support member  22  is coupled to a cross-bar  23  which also extends between bottom support members  16  and  18 . The cross-bars  21 ,  23 , which are shown in  FIG. 1 , are rotatably mounted to the bottom support members  16  and  18  with a bearing or the any suitable means. The vertical support members  20 ,  22  are attached to the cross-bars with welds and support plates  25 , which are shown in FIG.  4 . Other attachment means such as mechanical fasteners may be used. The preferred embodiment is exemplary, and other vertical supports may be used. For instance, a pair of vertical supports attached to each of the sides may be employed. As described in more detail below, because the cross-bars  21 ,  23  are rotatably mounted, the vertical support members  20 ,  22  can rotate with the cross-bars to move the device  10  from the lowered position of  FIG. 3  to the elevated position of FIG.  3 . 
   The vertical support members  20 ,  22  are preferably attached to the cross-bars  21 ,  23  such that they are off-set from the center line, as shown in FIG.  4 . This provides a stable support for the device. Any number of support members can be used, and they can be attached to the bottom and top frames by any suitable means in any locations. The embodiment shown is the preferred embodiment. 
   The patient positioning device  10  also includes a top frame  26 , which is also shown in  FIGS. 1-5 . In the preferred embodiment shown, the top frame  26  is stationary and includes a substantially c-shaped support member  28 , which is shown in  FIGS. 1 ,  4  and  5 . Extending between the sides of the support members are two cross-bars  29 ,  31 . The cross-bars  29 ,  31  are rotatably mounted to the side support members by any suitable means including for example bearings. Each of the cross-bars  29 ,  31  is attached to one of the vertical support members by welding. Optionally, support plates  33 ,  35 , which are best shown in  FIG. 4 , can be used to support the vertical members. Other means such as mechanical couplings and fasteners can be used. 
   The stationary top frame  26  also includes a stationary guide  37 , which is best shown in the cross-section of FIG.  5  and the perspective cut away of FIG.  1 . The leg support  30  of  FIG. 1  has been cut away to expose the guide  37 , which has also been cut so that the cross-section of the guide  37  can be exposed. The stationary guide or track is substantially T-shaped as shown in the end view of FIG.  4  and the perspective of FIG.  1 . Disposed within the stationary guide  37  are a series of holes  39 . Each of these holes  39  is for receiving the pin  41  as shown in FIG.  5  and as described in more detail below. The guide  37  is mounted on the support member  28  by mechanical fasteners (not shown) or any suitable means. 
   The device  10  further includes a leg support  30  that is in a preferred embodiment a pad or cushion. The leg support  30  is preferably any suitable cushioning material. Preferably, vinyl  43  covering a foam cushion  45  or the like is used. The leg pad  30  may have a relatively rigid back  47  such as wood or metal. The leg support  30  is mounted on a c-shaped rail  49 , which has a channel  51 , as shown best in  FIG. 4 , that surrounds the stationary T-shaped guide  37  so that the rail  49  and the attached leg support  30  can slide over the T-shaped guide  37  and move laterally relative to the base and top frames as shown in  FIG. 2  with the phantom lines and the solid lines. The support  30  can be attached to the rail  49  by any suitable means. Together the leg support  30 —including the cover  47 , the cushion  45 , and the backing  47 , and the c-shaped rail  49 —form a moveable piece that moves on the guide track  37 . The c-shaped rail  49  is also shown in  FIG. 1  where the leg support  30  has been cut away. The rail  49  has also been cut away to show the guide  37  and the channel  51  defined by the rail  49 . 
   Other means may be used to mount the leg support  30  so that it can move laterally relative to the top frame  26 . For example, a torsion spring and a rod (not shown) or other rail and track systems may be used. 
   The leg support  30  may have a locking system for locking the leg support  30  in place after it has been moved laterally relative to the bottom and top frames. The locking system may include the pin  41 , the guide track  37 , and bracket  61 . Bracket  61  is mounted to the leg support  30  by screws  59  or fasteners as best shown in FIG.  5 . The screws  59  thread into the bracket  61 , the leg support  30 , and the leg support backing. The pin  41  is mounted in a pin housing  65 , which is mounted to the bracket  61  with any suitable means so that the housing  65  can move up and down relative the bracket  61 . 
   The pin  41  can be spring loaded downward as viewed in  FIG. 5  by spring  63 . Spring  63  is mounted within pin housing  65 . Knob  67  is coupled to the pin housing  65 . The pin  41  is spring loaded so that it fits within one of the guide holes  39 , as shown in FIG.  5 . The knob  67  can be pulled upward to pull the pin housing  65 , which lifts the pin  41  upward against the pressure of the spring  63  and out of the hole  39 . The pin  41  is what retains the leg support  30  and prevents the leg support  30  from moving once it has been positioned; thus, it defines a preferred embodiment of a locking system. 
   As best understood with reference to  FIGS. 2 and 5 , the leg support  30  can be positioned laterally relative to the top or bottom frames by lifting the pin  41  against the pressure of the spring  63 , sliding the leg support  30  laterally relative to the bottom and top frames as shown by comparing the phantom lines and the solid lines in FIG.  2 . 
   The patient positioning device  10  also includes a pad  44  that cushions the upper leg just above a patient&#39;s knees, as best understood with reference to  FIGS. 2 and 5 . Like the leg pad  30 , the pad  44  can be any suitable cushioning material, preferably vinyl  44   a  covering foam  44   b  with a stable backing  44   c  such as wood, reinforced plastic, or metal. The pad  44  is preferably coupled by a hinge bracket  44   d  to the top frame support member  28 , as best shown in FIG.  4 A. Preferably, the hinge  44   d  is relatively rigid such that it can hold the pad  44  in place. In another embodiment not shown, the pad  44  may be rigidly connected to the top frame. 
   The pad  44  is preferably mounted so that the pad  44  can move laterally relative to the top and base frames. The hinge bracket  44   d  is connected to bracket  44   e  with fasteners  44   h  as shown in FIG.  4 A. The top  44   f  of the bracket  44   e  is connected to the leg support  30  with fasteners  44   g  or the like as shown in  FIGS. 4 and 5 . Because the pad  44  is mounted to the leg support  30  the pad  44  moves with the leg support  30 . 
   In order to support the leg support  44  and the pad  30 , the device  10  may further include a pair of c-shaped rails  53  which are attached to the side portions  44   j  of bracket  44   e  with fasteners or any suitable means as best shown in FIG.  4 A. The c-shaped rails  53  ride on a series of wheels  55 , three in the preferred embodiment, as best understood with reference to  FIGS. 4 and 5 . The wheels  55  are preferably mounted to the top frame member  28  with brackets  57 , which are preferably c-shaped. 
   When the leg support  30  and the pad  44  move laterally, the rails  53  ride over the wheels  55 . The lateral moveable pieces of the device  10  include the leg support  30 , the pad  44 , the hinge  44   d , the bracket  44   e , the rails  53 , and the rail  49 . The stationary pieces include the guide  37 , the wheels  55 , the brackets  57 , and the top support member  28 . The leg support  30  rail  49  moves over the guide  37 , and the rails  53  move over the wheels  55  in order to move the leg support  30  and the pad  44  laterally. 
   The patient positioning device  10  also includes a motor  34  for moving the patient positioning device  10  between a lowered and an elevated position. The motor  34  may be any suitable motor and is selected based on the patient positioning device&#39;s intended use. If the patient positioning device  10  is intended to be used for lifting a patient&#39;s lower legs in preparation for applying therapeutic traction, then a motor having a relatively low duty cycle rating can be selected. In contrast, if the patient positioning device is intended to be used repetitively as a passive exercise device, then a motor with a high duty cycle rating should be employed. 
   The motor  34  powers an actuator  36  to move the patient positioning device  10  between the elevated and lowered positions of  FIGS. 2 and 3 . In the preferred embodiment shown, the actuator  36  includes a screw  38  disposed in a cylinder  40 , as best shown in FIG.  3 . The screw may be a ball screw. The screw  38  is connected to one of the vertical support members  20 , and the cylinder  40  is hinged to the bottom frame  11  by fasteners  70  and brackets  72  or any other suitable means. Thus, when the motor  34  powers the screw  38 , the screw  38  moves relative to the cylinder  40 . As the screw  38  moves, it drives the patient positioning device including the vertical support  20 , the top frame  26 , and the leg support pad  30  to rotate about the cross bars  21 ,  23 . Additionally, the top cross bars  29 ,  31  rotate relative to the top frame  26  to change the angle of the vertical supports  20 ,  22  relative to the top frame. Further operation of the motor  34  and the system is provided below. 
   The motor  34  may have a remote control  34   a  so it can be powered by the patient, therapist, or other care provider. In the case of passive exercise, the remote controller provides patient control over movement to the supine position, which permits the patient to control the level of pain. Other actuators may be used, such as a linear motor, rotary actuator, hydraulic piston, or any suitable means for rotating the patient positioning device  10 . 
   Although the preferred embodiment preferably uses a motor, a manual device such as a screw and hand-crank could be employed in place of the motor and actuator. Furthermore, hydraulic or pneumatic pistons can be used as well. 
   The patient positioning device can be used alone to support a patient&#39;s legs or with a traction device. Although any suitable traction device can be used, in a preferred embodiment a traction device  80  which includes a femur board  82 , a cable  84 , and a traction unit  86 , which are shown in FIG.  2 . The femur board  82  extends across the front of a patient&#39;s thighs, and the cable  84  extends from the femur board  82  to the traction unit  86 . Although not shown, straps, belts and the like may be used to couple the femur board to the table  8 . For example, a belt could extend from either lateral side of the femur board and extend down beneath the table and attach together to hold the femur board in position. The belt prevents the femur board from sliding out of a preferred position. 
   The cable  84  can be attached to the femur board  82  by any suitable means. The patient positioning device  10  preferably has an opening  64  through which the tension cable  84  can be threaded. In the preferred embodiment, this opening  64  is defined by the space between the bottom  11  and top frames  26 . The cable  84  threads between them. 
   The traction unit  86  applies tension to the cable  84  to pull the femur board  82  and apply traction to the patient. Other traction devices such as harnesses can be used with the patient positioning device. The traction device could be any of a number of suitable devices, but is preferably a traction unit made by Chattanooga Group, Inc. Even more preferably, the traction unit is a Triton traction unit and could be the MP-1 Digital Traction Unit. 
   Except where expressly stated in the claims, the traction device could be any number of devices. For example, any number of harness systems including those referenced above can be used. The femur board system is, however, preferred. 
   Operation of the patient positioning device can best be understood with reference to  FIGS. 2 and 3 . The portable patient positioning device  11  can be placed on a patient&#39;s treatment table or other flat area including an inclined surface. If desired the patient positioning device  10 , can be coupled to the treatment table  8  by one or more straps  88  and buckles  90  or other mechanism as shown in FIG.  3 . When placed on the surface, the patient positioning device  10  is in the lowered position of FIG.  3 . The patient places his feet and lower legs on the leg pad  30 , as shown in FIG.  3 . 
   Preferably, the support pad  30  and the pad  44  are first positioned laterally, so that the support  30  is positioned to fit a patient&#39;s anatomy and the pad  44  is in close proximity with the patient&#39;s upper legs just above the patient&#39;s knees, and locked in placed in the extended position. The angle of the extension pad  44  can be adjusted by adjusting the hinge  44   d . Alternatively, these lateral and hinge adjustments can be done after the patient positioning device  10  is moved to the elevated position. 
   In order to adjust the lateral position of the leg support  30  and the pad  44 , the knob  67  of the locking system is pulled to pull the pin  41  against spring pressure and out of the hole. The support pad  30  is then slid laterally by pulling or pushing the pad  30  so that the c-shaped rail  49  moves over the t-shaped guide  37  and the rails  53  move over the wheels  55 . Once the leg support  30  is in the desired position that fits a patient&#39;s anatomy, the knob  67  and pin  41  are released, and the pressure of the spring  63  moves the pin  41  into the corresponding hole  39  in the guide  37 . The pin  41  then retains the leg support  30  in position until the pin  41  is moved to move the leg support  30 . 
   The patient positioning device  10  is moved to the elevated position, by operating the motor controller  34   a . This can be done by the patient, which is advantageous in controlling any patient discomfort and permitting the patient to find the best semi-fowler position that fits the patient&#39;s anatomy. When powered, the motor  34  powers the actuator  36 . In the preferred embodiment shown, the screw  38  is rotated relative to the cylinder  46  and moves away from the cylinder  46  in a typical ball screw/lead screw arrangement. As the screw  38  extends further out from the cylinder  46 , the vertical support members  20 ,  22  are pushed upward to rotate, and the cross bars  21 ,  23 ,  29 ,  31  rotate relative to the respective bottom and top frames. Thus, the top frame, the leg support  30 , and the vertical supports  20 ,  22  are rotating about the cross-bars  21  and  23 , which defines pivots, to move the leg support  30  to the elevated position of FIG.  3 . Additionally, the rotatably mounted cross-bars  21 ,  23 ,  29 ,  31  rotate relative to the bottom and top frames to adjust the angle at which the vertical supports extend from the bottom and top frames. The motor  34  is powered until the patient positioning device  10  is moved into the desired elevation position, which is in most instances the elevated position, as shown in FIG.  3 . If desired, the support  30  and the pad  44  can be adjusted laterally once the patient positioning device  10  is in the elevated position of  FIG. 2  as described above. All of this movement can be controlled by the patient or clinician with the controller  34   a.    
   If desired, traction can then be applied with any traction apparatus, including but not limited to the femur board  82 , as shown in FIG.  2 . This can be done by powering the traction unit  86  to place a tension on the cable  84 . The cable  84  pulls on the femur board  82  to provide the traction. The reverse steps can be performed to move the patient positioning device from the elevated position to the lowered position. 
   One benefit, but not the only benefit, of the patient positioning device of this invention is that it is a portable support. It can be readily transported, and used on almost any horizontal surface. Thus, it is particularly suited for use hospitals, patient care facilities, or home care situations. Another benefit of an embodiment of this invention is that the patient positioning device rotates between the lowered and elevated positions, as opposed to translating vertically. The rotational movement of the leg support is beneficial because without the device  10  vertical movement requires a secondary lateral adjustment of the patient or the support for the lower legs after elevation is achieved, and such adjustment can aggravate some back injuries or cause pain. Rotational movement is preferred because it imitates the normal articulation of the leg around the hip joint. These benefits of the device are not intended to limit the claims except where so stated in the claims. 
   The patient positioning device can also be used as a passive, therapeutic exercise device. By cycling the patient positioning device between the lowered and elevated positions, the patient positioning device can apply a therapeutic force to the lower body. Although this cycling has many applications, one such application is as a passive exercise device for a patient recovering from a hip-joint replacement. Movement of the hip soon after surgery is important but painful. The patient positioning device of this invention makes movement of the joints more comfortable and permits the patient to control the movement. 
   It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.