Abstract:
A patient handling system comprising a patient support apparatus having a patient support surface, a component, and a force generating device inducing movement or assisting in movement of the component, and a sheet for covering at least a portion of the patient support surface, and the sheet coupled to the component wherein when the force generating device is operated to induce movement or assist in movement of the component, the movement induces the sheet to move relative to the patient support surface.

Description:
[0001]    This application claims the benefit of Provisional App. Ser. No. 62/161,340, entitled PATIENT REPOSITIONING APPARATUS, which is incorporated by reference herein in its entirety. 
     
    
     TECHNICAL FIELD AND BACKGROUND OF THE INVENTION 
       [0002]    The healthcare industry has endured a long history of problems with caregiver injuries, especially back injuries. One of the many activities that can cause these injuries includes patient lifting, transferring, and repositioning. 
         [0003]    In an attempt to remedy these problems, some states and institutions have implemented a no lift policy. Often times, these policies dictate the use of powered mechanical devices to move and/or reposition patients. Despite the existence of numerous powered and non-powered mechanical devices to help caregivers move patients, back injuries continue. 
         [0004]    Patients may require repositioning for a number of reasons. For example, for comfort, many patients are placed or place themselves in a position with the backrest of the bed raised. This is also a common position for patients with respiratory conditions, where the backrest is placed at a 30° angle to facilitate breathing. As a result, gravity has a tendency to cause a patient to migrate down the backrest and toward the foot end of the bed. Therefore, caregivers often have to move patients back up the backrest toward the head end of the bed, which is commonly referred to as “boosting” a patient. For ICU patients, this may occur multiple times each day. 
         [0005]    Current boosting methods include placing the deck of the bed in a horizontal position (e.g. lowering the backrest if raised) and positioning a caregiver on each side of the bed, who then grasp the existing sheet to manually move the patient to the head end of the bed using a sliding motion. Thereafter, the backrest can then be returned to its raised position. As noted, this process can be repeated over and over again during the course of a day, especially for ICU patients. 
         [0006]    The mechanical boosting systems that currently exist include overhead hoists that are external to the bed or winching devices that are mounted at the head end of the bed, which engage sheet and then pull the sheet towards the head end of the bed. 
         [0007]    Overhead hoists require separate handling, tracking, and storing and are, therefore, not ideal to use. While some of the winching devices have been incorporated into beds, they tend to operate the same way that caregivers operate in that they slide the patient across the bed support surface, thereby potentially exposing the patient&#39;s skin to shear forces. For patients that have been on a bed for an extended period of time, or for patients with fragile skin subject to developing pressure ulcers, these shear forces may increase the risk of injury. 
       SUMMARY OF THE INVENTION 
       [0008]    Accordingly, a patient repositioning apparatus is provided that can reduce shear forces on the patient&#39;s skin when the patient is being repositioned. Further, the patient repositioning apparatus may be configured to be incorporated into a patient support apparatus, such as a bed, stretcher, cot, table, or chair, or the like, so that it may be moved from a stowed position to a deployed position for use and then returned to its stowed position. 
         [0009]    In one embodiment, a patient handling system includes a patient support apparatus having a patient support surface, a component, and a force generating device inducing movement or assisting in movement of the component. The system further includes a sheet for covering at least a portion of the patient support surface. The sheet is configured to be coupled to the component wherein when the force generating device is operated to induce movement or assist in movement of the component, the movement of the component induces the sheet to move relative to the patient support surface. 
         [0010]    In one aspect, the patient support comprises a bed. For example, the component may comprise a rail, such as a side rail, and the force generating device comprising a spring for assisting in moving the rail. A suitable spring may include a gas spring. 
         [0011]    In yet another aspect, when the rail comprises a side rail, the side rail includes an engagement structure for releasably coupling the sheet to the side rail. For example, the engagement structure may comprise a clamp or anchor. 
         [0012]    In another embodiment, a patient handling system includes a patient support apparatus having a patient support surface, a component, and a device inducing movement of the patient support surface relative to the component. The system further includes a sheet for covering at least a portion of the patient support surface. When the sheet is coupled to the component and when the force generating device is operable to induce movement or assist in movement of the patient support surface relative to the component, the movement induces the sheet to move relative to the patient support surface. 
         [0013]    In one aspect, the patient support comprises a bed. For example the patient support apparatus may include a mattress for forming the patient support surface. In addition, the bed includes a mattress support, with the force generating device comprising a motor for raising the mattress support relative to the component. 
         [0014]    In one aspect, the component comprises a base of the patient support apparatus, including a wheeled base. 
         [0015]    In another aspect, the bed includes a headboard, and the sheet is coupled to the component through the headboard. 
         [0016]    In yet another aspect, the sheet may be coupled to the component via a tether. 
         [0017]    In yet further aspects, the mattress support supports a guide to direct the tether in a path from the sheet to the component. For example, the guide may comprise a pulley or roller. 
         [0018]    In another aspect, the tether is coupled to the sheet via a clamp. Optionally, the sheet may be coupled to the component via a pair of tethers. 
         [0019]    Accordingly to yet another embodiment, a method of moving a patient supported on a patient support apparatus that includes a sheet overlying at least a portion of the patient support surface of the patient support apparatus and includes a component movable relative to the patient support surface. The method includes coupling the sheet to the component and moving the component, with the moving inducing movement in the sheet to thereby move the patient relative to the patient support surface. 
         [0020]    In one aspect, moving the component includes moving the component using a powered force producing device or an assist force producing device. 
         [0021]    In another aspect, moving the component includes raising the component relative to the patient support surface, with the raising including lifting at least a portion of the sheet relative to the patient support surface. 
         [0022]    In another aspect, moving the component includes translating the component relative to the patient support surface, wherein the translation translates the sheet across the patient support surface. 
         [0023]    In a further aspect, moving further includes raising the component relative to the patient support surface, with the raising including lifting at least a portion of the sheet relative to the patient support surface. 
         [0024]    For example, raising lifts at least a portion of the sheet relative to the patient support surface before translating the sheet across the patient support surface. 
         [0025]    In yet another aspect, moving the component includes moving the component using a powered force producing device. 
         [0026]    In another embodiment, a method of moving a patient supported on a patient support apparatus is provided. The patient support apparatus includes a component, a patient support surface, and a sheet with a head end overlying at least a portion of the patient support surface. In addition, the patient support surface is movable relative to the component. The method includes coupling the head end of the sheet to the component, and moving the patient support surface relative to the component, wherein the moving induces movement in the sheet relative to the patient support surface to thereby move the patient relative to the patient support surface. 
         [0027]    In one aspect, moving the component includes moving the component using a powered force producing device, such as a motor. 
         [0028]    In another aspect, moving the component includes raising the patient support surface relative to the component. 
         [0029]    According to yet another embodiment, a method of moving a patient supported on a patient support apparatus is provided. The method includes reducing the patient&#39;s weight applied to the patient support apparatus at least in the region of the patient&#39;s center of gravity, such as the patient&#39;s sacral region, and sliding the patient across the patient support apparatus after the weight is reduced to thereby reduce at least some of the shear forces on the patient&#39;s skin. 
         [0030]    In one aspect, reducing the weight includes lifting the patient at or near the patient&#39;s sacral region. 
         [0031]    In a further aspect, lifting includes lifting the patient with a component of the patient support apparatus. For example, lifting may include lifting the patient with a powered component of the patient support apparatus or a spring assisted component of the patient support apparatus. 
         [0032]    Before the embodiments of the invention are explained in greater detail, it is to be understood that the invention is not limited to the details of operation or to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention may be implemented in various other embodiments and practiced or carried out in alternative ways not expressly disclosed herein. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. Further, enumeration may be used in the description of various embodiments. Unless otherwise expressly stated, the use of enumeration should not be construed as limiting the invention to any specific order or number of components. Nor should the use of enumeration be construed as excluding from the scope of the invention any additional steps or components that might be combined with or into the enumerated steps or components. 
     
    
     
       DETAILED DESCRIPTION OF THE DRAWINGS 
         [0033]      FIG. 1  is a side elevation view of a patient support apparatus incorporating a patient repositioning apparatus; 
           [0034]      FIG. 2  is a perspective view from the head end of the patient support apparatus of  FIG. 1 ; 
           [0035]      FIG. 2A  is a perspective view of another mounting arrangement of a patient repositioning apparatus; 
           [0036]      FIG. 2B  is a side view of the patient repositioning apparatus of  FIG. 2A ; 
           [0037]      FIG. 2C  is a similar view to  FIG. 2A  with the bars of the patient repositioning apparatus of  FIG. 2A  raised to a handle position; 
           [0038]      FIG. 2D  is a similar view to  FIG. 2A  with the tethers extended; 
           [0039]      FIG. 2E  is a similar view to  FIG. 2A  with the bars shown in a stowed position; 
           [0040]      FIG. 3  is an elevation view of another embodiment of a patient support apparatus incorporating a patient repositioning apparatus; 
           [0041]      FIG. 4  is a fragmentary plan view of the patient support apparatus of  FIG. 3 ; 
           [0042]      FIG. 5  is an enlarged side view of the head end side rail of the patient support apparatus; 
           [0043]      FIG. 5A  is an enlarged cross-section view taken through the side rail of  FIG. 3 ; 
           [0044]      FIG. 6  is a fragmentary enlarged view of the mounting arrangement of the side rail in  FIG. 4 ; 
           [0045]      FIG. 7  is a side elevation view of yet another embodiment of a patient support apparatus incorporating a patient repositioning apparatus; 
           [0046]      FIG. 7A  is a similar view to  FIG. 7  with the side rail removed for clarity; 
           [0047]      FIG. 8  is a fragmentary plan view of the patient support apparatus of  FIG. 7 ; 
           [0048]      FIG. 9  is an enlarged partial fragmentary view of the mounting arrangement of the side rail; 
           [0049]      FIG. 10  is a fragmentary view of a clamp of the patient repositioning apparatus of  FIG. 9  illustrating the clamp in a closed position; 
           [0050]      FIG. 11  is a similar view to  FIG. 10  illustrating the clamp in an open position; 
           [0051]      FIG. 12  is another embodiment of a clamp of the patient repositioning apparatus of  FIG. 7 ; 
           [0052]      FIG. 13  is a fragmentary side elevation view of another embodiment of a patient support apparatus incorporating a patient repositioning apparatus; 
           [0053]      FIG. 14  is a side elevation view of the side rail of  FIG. 13 ; 
           [0054]      FIG. 15  is a cross-section taken through the side rail of  FIG. 14 ; 
           [0055]      FIG. 16  is a perspective view of the side rail of  FIG. 13  where the patient repositioning apparatus is mounted inside the side rail; 
           [0056]      FIG. 17  is a perspective view of another embodiment of a side rail incorporating a patient repositioning apparatus; 
           [0057]      FIG. 17A  is a front elevation view of the side rail of  FIG. 17  illustrating a drive assembly and a release mechanism to release the drive assembly; 
           [0058]      FIG. 18  is a similar view to  FIG. 17  with the sheet engaging portion of the patient repositioning apparatus in a lowered position; 
           [0059]      FIG. 19  is a similar view to  FIG. 18  illustrating a sheet extended through the side rail over the sheet engaging portion; 
           [0060]      FIG. 20  is similar to  FIG. 19  illustrating the sheet engaging portion being moved to a raised position to thereby engage and clamp the sheet; 
           [0061]      FIG. 21  illustrates the steps of boosting a patient using the side rail and the patient repositioning apparatus; 
           [0062]      FIG. 22  is a perspective fragmentary view of another embodiment of a side rail incorporating a patient repositioning apparatus; 
           [0063]      FIG. 23  is an elevation view of the side rail of  FIG. 22  with the sheet engaging portion of the patient repositioning apparatus shown in the engaged and clamping position; 
           [0064]      FIG. 24  is a similar view to  FIG. 23  showing the sheet engaging portion moved to a lowered, disengaged position; 
           [0065]      FIG. 24A  is a fragmentary side elevation view illustrating another embodiment of an actuator assembly or driver for moving the frame; 
           [0066]      FIG. 24B  is a fragmentary side elevation view illustrating another embodiment of an actuator assembly for moving the frame; 
           [0067]      FIG. 24C  is a side elevation of a side rail incorporating a release mechanism for releasing the side rail from a raised position to a lowered position; 
           [0068]      FIG. 24D  is an enlarged view of one embodiment of a release mechanism for releasing the side rail from a raised position to a lowered position; 
           [0069]      FIG. 24E  is an enlarged view of another embodiment of a release mechanism for releasing the side rail from a raised position to a lowered position; 
           [0070]      FIG. 24F  is an enlarged view of yet another embodiment of a release mechanism for releasing the side rail from a raised position to a lowered position; 
           [0071]      FIG. 25  is a perspective of another embodiment of a patient repositioning apparatus shown in a starting position prior to boosting; 
           [0072]      FIG. 26  is an enlarged perspective view of one side of the patient repositioning apparatus of  FIG. 25 ; 
           [0073]      FIG. 27  is a side elevation view of the patient repositioning apparatus of  FIGS. 25 and 26 ; 
           [0074]      FIG. 28  is another perspective view of the patient repositioning apparatus of  FIG. 25  illustrating the patient positioning apparatus in an ending or boosted position; and 
           [0075]      FIG. 29  is an enlarged perspective view of one side of the patient repositioning apparatus of  FIG. 28 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0076]    Referring to  FIG. 1 , the numeral  10  generally designates a patient support apparatus. As will be more fully described below, patient support apparatus  10  incorporates a patient repositioning apparatus  12  that facilitates boosting of a patient—in other words, moving the patient up towards the head end of the patient support apparatus—while reducing the strain on a caregiver. Patient support apparatus  10  may take on a number of different forms including a bed, such as a hospital bed, a stretcher, a cot, an operating room table, or a chair, or any other structure used to support a patient in a health care setting or home care setting or the like. 
         [0077]    Patient support apparatus  10  includes a base  14  and a patient support surface  16 . Patient support surface  16  may be formed by a frame  18  and an articulable deck  20 , which supports a pad or mattress  22 . Frame  18  is supported on base  14  by lift mechanisms  24 , which are configured to raise and lower patient support surface  16  relative to base  14 . A number of different suitable lift mechanisms may be used, including, for example, the lift mechanisms described in U.S. Pat. Nos. 5,063,624; 5,343,581; 6,822,571; 7,055,195; 7,836,531; and 8,006,332, which are commonly owned by Stryker Corporation of Kalamazoo, Mich. and which are incorporated by reference herein in their entireties. 
         [0078]    Referring again to  FIG. 1 , patient repositioning apparatus  12  is configured to engage a sheet or a pad S (herein after reference will be made to sheet S) placed on patient support surface  16  to selectively pull on sheet S to boost a patient supported thereon. As will be described in more detail, patient repositioning apparatus  12  is configured to couple sheet S to a component of patient support apparatus  10  so that when the component is moved relative to the patient support surface, the component induces the sheet to move. 
         [0079]    In the illustrated embodiment, patient repositioning apparatus  12  includes at least one clamping device, such as a sheet clamp  26 , and at least one tether  28 , which is anchored to base  14 . A suitable sheet clamp is described in U.S. Pat. Nos. 7,591,030 and 8,156,582, which are commonly owned by Stryker Corporation of Kalamazoo Mich. and incorporated by reference herein in their entireties. Thus, when lift mechanisms  24  raise patient support surface  16  relative to base  14 , tether  28  will pull on clamp  26 , and clamp  26  in turn will pull on sheet S to move the patient in the direction indicated by the arrow in  FIG. 1 . To selectively operate patient repositioning apparatus  12 , tether  28  or clamp  26  may include a release to release the sheet so that the sheet is only pulled when the patient needs boosting. Accordingly, patient repositioning apparatus  12  itself may be a non-powered device, but may selectively leverage the power of lift mechanisms  24  of patient support apparatus  10 . As described in the referenced patents and published applications, the lift mechanisms may include linear actuators, such as electric motors or pneumatic or hydraulic cylinders, or the like. Thus, patient repositioning apparatus  12  is able to leverage the force of the force generating device (or devices) that raise the patient support surface relative to the base to move the sheet and the patient supported thereon. 
         [0080]    To facilitate guiding sheet S along the path of tether  28 , patient repositioning apparatus  12  may include a guide  30 , for example, a roller or pulley mounted at the head end of patient support surface  16 . Optionally, guide  30  is mounted in a fixed arrangement, for example, to the deck  20  or frame  18 . Further, guide  30  may be mounted so that its upper guide surface is generally parallel with upper surface  16   a  of patient support surface  16 . Alternately, guide  30  may be positioned so that it or at least its guide surface is above upper surface  16   a  of patient support surface  16  so that when tether  28  is anchored to base  14  and lift mechanisms  24  are actuated, guide  30  directs tether  28  to lift sheet S off patient support surface  16  to thereby reduce the shear forces on a patient&#39;s skin being boosted. For example, guide or guides  30  may be mounted at an upper end of the headboard (described below), including at the upper edge of the headboard, or on a wall positioned behind the headboard of patient support apparatus  10 . Furthermore, the position of the guide or guides may be adjustable. 
         [0081]    Referring to  FIG. 2 , as noted above, patient repositioning apparatus  12  is located at the head end of patient support apparatus  10 . Further, patient repositioning apparatus  12  may include a pair of tethers  28 , with each tether anchored to base  14  and further each tether including a sheet clamp  26  associated therewith. To prevent migration of the clamps toward each other when patient repositioning apparatus  12  pulls on sheet S, sheet clamps  26  may be mounted to and thereby joined by a spacer, such as a rigid beam, rod, or plate, that facilitates maintaining them in their spaced relationship. 
         [0082]    Optionally, patient support apparatus  10  includes a footboard  40 . In the illustrated embodiment, patient repositioning apparatus  12  is located adjacent and beyond footboard  40 . Footboard  40  may comprise a conventional footboard that is modified to include a transverse passageway  42  through which sheet S and/or tethers may extend so that tethers may be anchored to base  14 . Alternately, footboard  40  may be especially configured to incorporate patient repositioning apparatus  12 , for example, to house guide  30  so that at least a portion of patient repositioning apparatus  12  is then integrated into footboard  40 . The guide or guides may be located at the lower end of the headboard or at a medial portion or at the upper end of the headboard. 
         [0083]    Alternately, referring to  FIGS. 2A-2E , tether or tethers  28  may be coupled to a driver, such as a winch, including a motorized winch to power the patient repositioning apparatus  12  independent from patient support apparatus  10 . For example, the driver may comprise a self-contained power enclosure  60  that may be mounted to the head end of the patient support apparatus. Furthermore, at each end of the enclosure  60 , a bar  62  may be provided in a horizontal position (at the level of the mattress) and may protrude from the head end toward the foot end of the bed. Sheet clamping mechanisms  64  are provided at the end of each of the bars and coupled to the tethers  28 , which extend through the bars to the winch and couple to the sheet clamps. Optionally, bars  62  may be mounted to rotate 90° up to a vertical position so that the arms can be moved to raise the tethers and the clamps. Thus, when the sheet is clamped onto the clamping mechanisms  64 , bars  62  may then be rotated to their vertical position thus boosting the patient. Optionally, the bars may be telescoping to reach further to an incontinence pad. In one embodiment, the telescoping bars may be powered to extend or retract and then rotated to their vertical positions. In addition, such as shown in  FIG. 2E , the bars can double as pushing handles and then stowed by being rotated 90° toward the center of the bed. 
         [0084]    Optionally, as seen in  FIG. 2B , enclosure  60  includes a transverse shaft  60   a  to which bars  62  are mounted. Shaft  60   a  may be driven by a separate driver  66 , which is mounted, for example, below patient support surface  16  or may be driven by a motor in enclosure  66 . Driver  66  may comprise a linear driver, such as a cylinder or electric motor that includes an extendible rod  66   a  that is coupled to shaft  60   a , for example, by a link so that as driver  66  extends or contracts rod  66   a , shaft  60   a  will rotate to raise or lower bars  62 . Once raised, then tethers  28  and/or bars  62  can be retracted to pull on the sheet or pad supporting the patient. 
         [0085]    In any of the aforementioned embodiments, patient support apparatus  10  may include one or more sensors for detecting the position of a patient on patient support surface  16 , which generate a signal or signals that can be used to determine when a patient may need boosting. For example, patient support apparatus  10  may comprise a patient support apparatus that includes sensors and a control system for monitoring and controlling various features of the patient support apparatus, including providing communication with a remote device, such as EMR, nurse call station, Admission, Discharge, and Tracking (ADT), a server, or the Internet, such as disclosed in U.S. Pat. Nos. 7,836,531; 8,006,332; 8,689,376; and 8,413,271; and pending applications 61/932,574 (Attorney Docket P-413B); and Ser. No. 14/578,630 (Attorney Docket P-451), which are commonly owned by Stryker Corporation of Kalamazoo Mich. and incorporated by reference herein in their entireties. 
         [0086]    Further, the control system may monitor and use the sensor signals to either generate a local or remote alarm to let a caregiver know that the patient needs boosting or take action based on the sensor signals. For example, the control system may be used for local or remote control of the patient support apparatus. Optionally, the control system may be in communication with the sensor (or sensors) and, as noted, generate alarm condition either locally or remotely to indicate that the patient needs to be boosted. Alternately or in addition, the control system may be in communication with the sensor and control the operation of the patient support apparatus in response to signals from the sensor. For example, based on the signals from the sensor, the control system may determine that the patient needs to be boosted and actuate the lift mechanism or the driver that moves patient repositioning apparatus  12 . Optionally, the control system may actuate the lift mechanism or driver incrementally to assure that the patient is not moved too far along patient support surface. 
         [0087]    In one embodiment, the control system includes a second sensor, which also is positioned to detect the location of patient on patient support surface  16 . For example, the second sensor may be used to determine when the patient has been boosted to a predefined position along the patient support surface to reduce the likelihood of a patient being boosted too far along the patient support surface. The control system may then be configured to receive signals from the first sensor that indicates a patient needs boosting and drive the lift mechanism or driver and then use the signals from second sensor to stop actuation or discontinue operation of the lift mechanism or driver once the control system determines that the patient is sufficiently boosted. 
         [0088]    It will be understood that, in at least some embodiments, the patient repositioning apparatus, or at least a component or components of the patient repositioning apparatus, may be removable and used on another patient support apparatus. In one embodiment, the patient support apparatus is equipped with a sensor to detect the presence and identity of an individual on the patient support apparatus. Optionally, the sensor may also detect the use of the patient repositioning apparatus so that the use of the apparatus may be associated with the patient and be charged to the individual patient using the patient repositioning apparatus. In another embodiment, the sensor may be used to track use of the apparatus for compliance purposes and/or to determine its efficacy. A suitable tracking and/or transaction system to monitor the use and/or generate billing is described in copending application 62/081,744 (Attorney Docket No. P-443), which is commonly owned by Stryker Corporation of Kalamazoo Mich. and incorporated by reference herein in its entirety. 
         [0089]    Referring to  FIG. 3 , the numeral  110  generally designates another embodiment of the patient support apparatus. Patient support apparatus  110  is also configured to facilitate boosting the patient while reducing the strain on a caregiver. As will be more fully described below, patient support apparatus  110  uses the motion of a component of the patient support apparatus, such as a side rail, to lift a patient, or at least partially lift the patient, and then move the patient, for example, toward the head end of the bed, to reduce the shear stresses on the patient&#39;s skin. 
         [0090]    Patient support apparatus  110  similarly includes a base  114  and a patient support surface  116 . Patient support surface  116  optionally includes a frame  118  and a deck  120 , such as a deck with articulating deck sections, to support a pad or a mattress  122  for supporting a patient thereon. Further, patient support surface  116  is supported on base  114  by lift mechanisms  124  that are configured to raise and lower patient support surface  116  relative to base  114 . 
         [0091]    Patient support apparatus  110  also includes side rails, for example, head end side rails and foot end side rails  126 ,  128 , which are mounted to patient support surface  116 . Side rails  126 ,  128  may be mounted to deck  120  so that the side rails will move with the articulating deck sections to provide a barrier regardless of the positions of the deck sections. Each side rail  126 ,  128  includes a side rail body  126   a ,  128   a , which are mounted to deck  120  by mounting assemblies  130 . Mounting assemblies  130  move side rail bodies  126   a  and  128   a  between a lowered position (such as shown in reference to the foot end side rails  128 ) and a raised position (such as shown in reference to the head end side rails  126 ). 
         [0092]    In the illustrated embodiment, mounting assemblies  130  include a pair of arms  130   a ,  130   b , which are pivotally mounted at their upper ends to the respective side rail body  126   a ,  128   a  and at their lower ends to a transverse mounting member  130   c , which mounts to the respective deck section. In this arrangement, the arms, the side rail body, and the mounting member form a four-bar linkage, which when moved moves the respective side rail body in a curvilinear path when moving the respective side rail body between its lowered and raised positions. The curvilinear path is generally shown by the dashed arrowed line in  FIG. 3 . Suitable side rails and/or mounting assemblies  130  are described in U.S. Pat. Nos. 7,712,166; 7,412,734; 7,836,531; and 8,006,332 which are commonly owned by Stryker Corporation of Kalamazoo Mich. and incorporated by reference herein in their entireties. For example, as described in the reference patents, mounting assemblies  130  may include springs, such as gas springs and/or coiled springs to lower the amount of force needed to raise the side rail body. 
         [0093]    To facilitate boosting of the patient, each head end side rail  126  includes a clamp  132  for clamping a portion of sheet S overlying patient support surface  116  to the respective head end side rail. In this manner, when the side rail bodies are moved between their lowered and raised positions, the sheet will be at least partially lifted off patient support surface  116  (or at least the weight of the patient on the support surface will be reduced), and then further moved towards the head end of the patient support apparatus. By at least initially partially lifting the sheet off patient support surface  116  (or at least reducing the weight of the patient on the patient support apparatus), the friction generated by sheet S moving relative to patient support surface  116  will be reduced thereby reducing the shear stresses on the patient&#39;s skin. Thus, patient repositioning apparatus  112  is able to leverage the force of the force assist device or devices of the side rails to move the patient. Alternately, the side rails may be powered to move between their respective positions. For example, the arms for each side rail may be driven by a motor or motors. The motor or motors may be housed in the side rail bodies or mounted in the deck of the support apparatus. 
         [0094]    Referring to  FIGS. 5 and 5A , side rails  126  may include clamp  132  at a central upper portion of the side rail body  126   a . For example, a suitable clamp  132  may comprise a C-shaped body  134  with a concave downwardly facing surface  134   a  for frictionally engaging sheet S between clamp  132  and upper end  126   b  of side rail body  126   a . Clamp  132  may be mounted for movement between a clamping position, such as shown in solid lines in  FIG. 5A , and a non-clamping position, such as shown in phantom lines in  FIG. 5A . 
         [0095]    Optionally, side rail body  126   a  includes a recess  126   c  ( FIG. 5A ) in which clamp  132  is mounted and is supported for pivotal movement by, for example, one or more pins that extend into and pivotally mount the clamp between the side walls forming the recess, so that when clamp  132  is moved to its non-clamping position, clamp  132  may be at least partially recessed and stowed within side rail body  126   a . Optionally, recess  126   c  is sized to allow clamp  132  to be fully recessed in side rail body  126   a . Furthermore, side rail body  126   a  may include a removable door or cover to enclose, and optionally, hide clamp  132  in side rail  126 , which may facilitate cleaning. 
         [0096]    Referring again to  FIG. 5 , clamp  132  may be formed by a pair of C shaped arms  140 , which are spaced apart and pivotally mounted to side rail body  126   a . Arms  140  support a transverse clamping member  142  that forms the concave inwardly facing surface  132   a  for engaging sheet S between clamp  132  and side rail body  126   a . Optionally, side rail body  126   a  includes a pair of recesses in which arms  140  are pivotally mounted and further adapted to receive arms  140  (when claim  132  is moved to non-clamping or its stowed position), and optionally a larger recess to receive transverse clamping member  142  so that again clamp  132  may be at least partially or fully recessed in side rail body  126   a.    
         [0097]    In either embodiment of the clamp, the inwardly facing surface  132   a  may include a high friction surface to enhance the gripping of the sheet. For example, the high friction surface may be formed in the surface or applied to the surface. A suitable high friction surface may include a knurled surface or ridges formed on clamp  132  or a surface applied to clamp  132  formed from a material with a high coefficient of friction, such as rubber, to thereby increase the retention of sheet in the clamp. 
         [0098]    Referring to  FIG. 4 , each side rail  126  may also be mounted for linear movement relative to patient support apparatus  110  so that in addition to the curvilinear motion of the respective side rail bodies, mounting assemblies  130  may also translate linearly relative to patient support surface  116 . In this manner, when sheet S is clamped onto a respective head end side rail  126  and its respective side rail body  126   a  is moved to its raised position, additional motion of the sheet in the direction of the head end may be obtained by linearly moving mounting assemblies  130  relative to patient support surface  116 . 
         [0099]    In the illustrated embodiment, side rails  126  may be mounted on screw drives formed by threaded driven rods  150 , which are mounted for rotation in deck  120  and which are optionally driven, for example, by one or more motors  152 . In the illustrated embodiment, a single motor is provided whose output shaft  154  is coupled to a drive rod  156 . Drive rod  156  includes threads at least at its opposed ends to engage and drive the respective driven rods  150 . As noted above, each mounting assembly  130  includes a mounting member  130   c , which includes a threaded sleeve  158  to receive a respective threaded driven rod  150 , so that when motor  152  is driven and driven rods  150  are rotated about their longitudinal axes, side rails  126  will move linearly with respect to patient support surface  116  to thereby increase the range of motion of clamps  132 . Optionally, referring to  FIG. 6 , each mounting member  130   c  may be mounted in the side  120   a  of deck  120 , for example, in a longitudinal opening  120   b  that forms a channel that provides a guide for mounting member  130   c , which may provide additional support to the respective side rail. 
         [0100]    Alternately, a manual driver, such as a handle may be coupled, for example, by way of a similar drive rod, to driven rods  150 . Further, in lieu of driven rods  150 , mounting assemblies  130  may be mounted to deck  120  on linear bearings (not shown), which can provide manual linear movement of the respective side rails relative to the patient support surface (or driven linear movement by way of a linear driver, such as a linear motor, coupled to the side rail). Optionally, one or more detents or locking mechanisms may be included to define preset positions for the side rail along the bearings. 
         [0101]    Referring to  FIG. 7 , the numeral  210  generally designates another embodiment of the patient support apparatus. Similar to the previous embodiments, patient support apparatus  210  includes a patient repositioning apparatus  212 , which may be integrated into patient support apparatus  210 , to boost a patient. 
         [0102]    Patient support apparatus  210  includes a base  214  and a patient support surface  216 , which is supported on base  214  by lift mechanisms  224 . As described in reference to the previous embodiments, patient support surface  212  may include a frame  218  and a deck  220  with articulatable deck sections, which support a pad or mattress  222 . Mounted to the side of patient support surface  216  are side rails  226 , which may include head end side rails and foot end side rails (not shown). For examples of suitable side rails  226 , reference is made to U.S. Pat. Nos. 7,712,166; 7,412,734; 7,836,531; and 8,006,332, which are commonly owned by Stryker Corporation of Kalamazoo, Mich. and incorporated by reference herein in their entireties. 
         [0103]    Referring to  FIG. 7 , patient repositioning apparatus  212  is mounted adjacent patient support surface  216  between the side rail  226  and patient support surface  216 . As will be more fully described below, patient repositioning apparatus  212  is configured to engage a sheet S (or incontinence pad) overlying patient support surface  216  and at least partially raise sheet S above patient support surface  216 , and further move sheet S toward the head end of patient support apparatus  210 , in a similar manner described in reference to the previous embodiment, to thereby boost a patient supported on patient support apparatus  210 . 
         [0104]    In the illustrated embodiment, patient repositioning apparatus  212  includes a pair of clamps  232  that are mounted on the opposed sides of patient support apparatus  210  independently of the movement of the side rails. In the illustrated embodiment, each clamp  232  is mounted to patient support apparatus  210  by a pair of arms  240 . Arms  240  are pivotally mounted at their upper ends to clamp  232  and pivotally mounted at their lower ends to a carrier or mounting member  242 , which is mounted to patient support surface  216 . For example, mounting members  242  may be mounted below deck  220  at frame  218  or mounted to deck  220 . Each arm  240  of the pair of arms is spaced apart and generally parallel to form a four-bar linkage with clamp  232  and mounting member  242 . Thus, when the pair of arms  240  rotates, clamps  232  are raised or lowered in a curvilinear path similar to clamps  132 . 
         [0105]    Mounting members  242  may also be mounted for linear movement relative to patient support surface  216 . For example, mounting members  242  may be mounted to screw drives in the form of driven threaded rods  250 , similar to driven rods  150  described in reference to patient support apparatus  110 . In the illustrated embodiment, driven threaded rods  250  may also be driven by a single motor  252  (which is mounted in patient support surface for example in frame  218  or deck  222 ) with an output shaft  254  that drives a drive rod  256 . It should be understood, just as in the case of patient repositioning apparatus  110 , that more than one motor may be used to drive driven rods  250 . Drive rod  256  includes threaded portions, for example threaded ends, to engage and drive driven threaded rods  250 , such as shown in  FIG. 8 . Mounting members  242  similarly include threaded sleeves to receive and engage threaded rods  250  so that as the threaded rods are rotated about their respective longitudinal axes, mounting members  242  and clamps  232  will be moved linearly along the respective threaded rod. 
         [0106]    As the threaded rods  250  are driven to move clamps  232  forward toward the head end of the patient support apparatus, the weight of the patient on the sheet S will resist, which causes clamps  232  to raise up. As clamps  232  raise up, the weight of the patient on patient support surface  216  will be reduced to thereby reduce the friction between sheet S and patient support surface  216  to thereby reduce shear forces on the patient&#39;s skin. Referring again to  FIG. 7A , the motion of clamp  232  is up and forward as driven rods  250  are rotated so that the sheet is initially at least partially lifted off patient support surface  216  before it is moved toward the head end of patient support apparatus  210 . Optionally, the motion of clamps  232  may be coupled to a motor or motors so that clamps  232  are directly driven by a motor or motors, which may be more suitable for heavier patients. 
         [0107]    Referring to  FIGS. 10-12 , clamps  232  each include a clamping arm  236  and a base  234  to which arms  240  are pivotally mounted. Each clamping arm  236  is pivotally mounted, for example, at one end thereof to base  234  and movable between a closed position, such as shown in  FIG. 10 , and an open position such as shown in  FIG. 11 . Optionally, each clamping arm  236  includes a latch  238  for engaging base  234  when arm  236  is in its closed position. For example, latch  238  may comprise a spring biased latch that engages an engagement structure provided on base  234  and is biased in a normally latched position. Alternately, latch  238  may comprise a flexible finger with a snap-fit arrangement that engages a corresponding detent structure on base  234  or simply provides a frictional coupling between arm  236  and base  234 . Alternately as shown in  FIG. 12 , a suitable latch  238 ′ may include a cam lever style latch where a hook engages a detent on base  234 , and the lever is repositioned so that the cam goes over center to become secured in place. 
         [0108]    Referring again to  FIG. 10 , when a portion of sheet S is positioned between clamping arm  236  and base  234 , clamping arm  236  may be moved to its closed position to thereby engage sheet S between the downwardly facing surface  236   a  of clamping arm  236  and upwardly facing surface  234   a  of base  234 . Optionally, one or both of the respective facing surfaces  236   a ,  234   a  may include a high friction surface either formed or applied thereon. For example, a suitable high friction surface may comprise a knurled surface or ridges formed in the respective members or a rubber surface applied thereon, including by injection molding. In this manner, sheet S is frictionally engaged by clamp  232 , when clamping arm  236  is moved to its closed position. 
         [0109]    Alternately, clamps  232  may each include a track, for example, a driven track to pull sheet S forward to the head end of the patient support apparatus. Optionally clamps  232  may include upper and lower driven tracks, for example, on clamping arm  236  and on base  234  to thereby pull the sheet S. Further, the sheet may include a rope or cord structure so that the sheet does not get pulled through. 
         [0110]    As noted above, patient repositioning apparatus  212  may be located between patient support surface  216  and side rail  226 . For example, patient repositioning apparatus  212  may be sandwiched between the head end head section of deck  220 , namely the Fowler, and the side rail. Furthermore, apparatuses  212  may be housed in the Fowler and, therefore, can be used when the Fowler is in a raised position. Thus, boosting may be achieved when a patient is in an inclined position. 
         [0111]    Alternately, patient repositioning apparatus  212  may be stowed below patient support surface  216  or may be incorporated into pad or mattress  222 . For example, pad or mattress  222  may include a recess or relief area in its sides into which clamps  232  (and optionally arms  240 ) may be moved when in their inoperative or stowed positions. To move the clamps (and arms), each clamp  232  and/or arms may include a camming assembly that laterally translates the respective clamps (and optionally arms) so they move outwardly when moved to their deployed positions but then move inwardly into the respective recess or relief in pad or mattress  222  when in their stowed positions. For example, the camming assembly may be provided on arms  240  at their pivotal connection to mounting members  242 . An example of a suitable lateral translation device, reference is made to U.S. Pat. No. 7,784,125 which is commonly owned by Stryker Corporation of Kalamazoo, Mich. and incorporated by reference herein in its entirety. 
         [0112]    With the clamp arrangement of the present embodiment, the range of motion of clamps  232  may be increased over at least some of the clamps in the previous embodiments. For example, the range of motion of clamps  232  may extend to reach and engage an incontinence pad, which may be used to translate the patient along the patient support surface  216 . 
         [0113]    Although illustrated as moving in a curvilinear path, clamps  232  may be configured to move vertically upward, then laterally, and then vertically downward. 
         [0114]    Referring to  FIG. 13 , the numeral  310  generally designates yet another embodiment of a patient support apparatus. Patient support apparatus  310  similarly includes a patient repositioning apparatus  312  that is incorporated into patient support apparatus  310 . Similar to the previous embodiments, support apparatus  310  includes a base  314  and a patient support surface  316 , which is mounted to base by lift mechanisms  324  that are configured to raise or lower patient support surface  316  relative to base  314 . Patient repositioning apparatus  312  is configured to facilitate boosting of a patient on patient support surface  316  and, in the illustrated embodiment, is incorporated into the side rails  326 . As will be more fully described below, similar to patient repositioning apparatus  112 , the motion of the side rails is used to move the sheet S to reposition the patient on patient support surface  316 . 
         [0115]    In the illustrated embodiment, patient repositioning apparatus  312  is configured to translate relative to side rail body  326   a  and, further, may be mounted to the outwardly facing side  326   b  of said side rail body  326   a  or inside side rail body  326   a , as described below. Patient positioning apparatus  312  includes clamps  332  that are mounted to side rails  326  and are configured to engage a sheet S positioned on patient support surface  316  and to pull sheet S toward the head end of patient support apparatus  310  when side rail  326  is moved between a lowered position (not shown) and a raised position shown in  FIG. 13 . Optionally, clamps  332  are supported for linear movement along the respective side rail body  326   a  of each side rail  326  by a drive screw  350 , such as a threaded rod, which are mounted to the surfaces  326   b . In this manner, clamps  332  may have a greater range of motion, for example, than clamps  110 . 
         [0116]    Each drive screw  350  may be driven by a motor  353  ( FIG. 14 ), which is also mounted to side rail body  326   a , so that clamps can be selectively translated relative to the side rail bodies. For example, motor  352  may be controlled by a patient support apparatus based control system described above, including based on sensor signals received from sensors located at patient support apparatus  310 . For further details of suitable sensors that may be used in combination with patient repositioning apparatus  310 , reference is made to above description. In addition to detecting when a patient requires boosting and to detecting the position of the patient, sensors may be provided to detect the position of the clamp relative to the side rail body so that the control system may provide discrete adjustments or adjustments in defined increments to the position of the sheet relative to the patient support surface  316 . 
         [0117]    Referring to  FIG. 14 , clamps  332  may be positioned in an opening or window  326   c  formed in side rail body  326   a  so that the clamps may extend through the respective side rails  326  to engage the opposed edges or sides of sheet S positioned on the patient support surface  316 . As best seen in  FIG. 15  opening  326   c  extends through side rail body  326   a . Alternately, where the patient repositioning apparatus  312  is located inside the side of body, opening  326   c  may extend through inwardly facing side  326   d  of the side rail body  326  only so that the patient repositioning apparatus is not viewable from the outwardly facing side of the side rail. 
         [0118]    Furthermore, drive screw  350  may be located inside side rail body  326   a  so that it is positioned between inwardly facing side  326   d  and outwardly facing side  326   b  of side rail body  326   a . As best seen in  FIG. 15 , clamps  332  may be mounted on drive screw  350  by one or more mounting members  340 , which include sleeves  340   a , namely threaded sleeves, for receiving and engaging drive screw  352  so that when drive screw  350  is rotated about its longitudinal axis, mounting member(s)  340  and clamp  332  will translate along drive screw  350 . 
         [0119]    Referring to  FIG. 13 , side rail body  326   a  is mounted to patient support surface  316  by a pair of arms  330 . Arms  330  are pivotally mounted at their upper ends to side rail body  326   a  and pivotally mounted at their lower ends to a mounting member  331 , which is adapted to mount side rail  326  to deck  320  or frame  318 . In this manner, arms  330 , side rail body  326 , and mounting member  331  form a 4 bar linkage, similar to the previous embodiments. When mounted to deck  320 , side rail  326  will move with the deck so that side rail  326  will provide a continuous barrier (when raised) regardless of the angle of the deck sections (in this case the head section or “Fowler”). 
         [0120]    In the illustrated embodiment, arms  330  are pivoted by an actuator  370 . For example, actuator  370  may comprise an electric linear actuator with an output shaft  370   a  that extends and contracts to drive the motion of the side rail. For example, the output shaft  370   a  may be coupled to a link  372  that is coupled, e.g. eccentrically mounted, to one of the arms  330  to rotate the respective arm  330  about its pivot connection to mounting member  331 , and thereby raise or lower side rail body  326   a.    
         [0121]    In any of the above embodiments, the patient support apparatus may include a control system that incorporates a pinch detection system to detect when a sheet is pinched in the patient repositioning apparatus. For example, a pressure sensitive strip may be incorporated into the clamp to detect the presence or absence of a sheet and proper positioning of the sheet in the clamping device. 
         [0122]    While several forms of the invention have been shown and described, it should be understood that features of one embodiment may be combined with features of another embodiment. Further while not specifically noted in each case, the various components forming the patient repositioning apparatus may be made from metal, plastic, or hybrid materials, including reinforced plastic. Furthermore, while a standard sheet may be used in conjunction with the patient repositioning apparatuses described herein, a sheet with a low friction surface may be used including sheets formed from Tyvek, and as noted may be a pad, including an incontinence pad. In addition, in the embodiments that provide additional linear travel for the clamps, the clamps may have a travel in a range of approximately 8-24 inches, 12-20 inches, and optionally in a range of 14 to 18 inches. Furthermore, the size of the clamps may vary. A suitable clamp length may be in a range of 10-16 inches long, and optionally 12-14 inches long. Additional features that may be incorporated into any of the above patient repositioning devices include a quick release device. For example, a quick release mechanism may be included in any of the actuators or the clamps themselves for emergency situations or anywhere in the mounting assemblies. 
         [0123]    Accordingly, patient support apparatuses and patient repositioning apparatuses are described that can reduce the stress on a caregiver when trying to boost a patient. Further, in some embodiments, the patient support apparatuses and patient repositioning apparatuses can reduce the patient&#39;s weight applied to the patient support apparatus, at least in the region of the patient&#39;s center of gravity, such as the patient&#39;s sacral, and slide the patient up the patient support apparatus to boost the patient after the weight is reduced to thereby reduce at least some of the shear forces on the patient&#39;s skin. 
         [0124]    In any of the embodiments, one or more components of the patient repositioning apparatus may be removed for use on another patient support apparatus or stowed away, for example, in a recess in the patient support apparatus, including in the side rails or the patient support surface. Additionally, the entire patient repositioning apparatus may be removed and used on another patient support apparatus. 
         [0125]    Referring to  FIGS. 17-21 , the numeral  412  generally designates another embodiment of a patient repositioning apparatus incorporated into a patient support  410 , such as a hospital bed, a stretcher, a cot, an operating room (OR) table or the like. In the illustrated embodiment, patient support  410  comprises a hospital bed with movable side rails  426 . As will be more fully described below, patient repositioning apparatus  412  is incorporated into side rails  426  of the patient support  410 , for example, the head end side rails ( FIG. 21  shows both head end side rails), and allows a caregiver to couple the sheet on a mattress  422  to the side rails  426  so that the motion of the side rails  426  can be used to move the sheet toward the head end of the mattress  422 . Thus, when the side rails are moved from a lowered position, or an intermediate raised position, to their upper raised position (such as shown in  FIG. 21 ), the sheet will be lifted and then moved toward the head end of the bed  410 . In this manner, the side rails may be used to boost the patient supported on patient support  410 . By at least partially lifting the sheet off the mattress, the frictional forces and shear on the patient&#39;s skin can be reduced. For examples of suitable side rails  426 , reference is made to U.S. Pat. Nos. 7,712,166; 7,412,734; 7,836,531; and 8,006,332, which are commonly owned by Stryker Corporation of Kalamazoo, Mich. and incorporated by reference herein in their entireties. 
         [0126]    As best seen in  FIGS. 17-20 , patient repositioning apparatus  412  includes a frame  430 , which is movably mounted to each side rail  426  to move from a fully raised or clamping position, such as shown in  FIG. 17 , to engage a sheet S, such as shown in  FIG. 20 , and lowered or disengaged positions, such as shown in  FIGS. 18 and 19 . For ease of description, reference will be made to one of the side rails. It should be understood that the same details are applicable to the other side rail. 
         [0127]    Frame  430  may be mounted to the inwardly facing side  432  of side rail  426 , or may be mounted in side rail  426 , as described below. Each side rail  426  includes a side rail body  434 , for example, formed from a perimeter frame member  436  that is covered by plastic, such as by overmolding outer and inner panels  438  and  440 , or by securing thereto preformed outer and inner panels  438  and  440 . In the illustrated embodiment, frame  430  is mounted inside body  434  between outer and inner panels  438  and  440 . Additionally, side rail body  434  is formed with one or more through openings  442 ,  444 , and  446 , which extend from the inwardly facing side to the outwardly facing side of side rail body  434 . Openings  444  and  446  form hand holds, while opening  442  forms an access window for receiving sheet S there through so that sheet S can be engaged and clamped by frame  430 . As described more fully below, frame  430  is mounted to translate in opening  442 , when frame  430  is moved between its lowered position and its engaged position, such as shown in  FIGS. 17 and 20 , to thereby clamp the sheet in side rail  426 . 
         [0128]    Side rail body  434  may be formed with a cavity  448  for receiving frame  430 . For example, cavity  430  may be sized so that frame  430  can be fully lowered into cavity  448  when moved to its fully lowered or lowermost, disengaged position. Further, frame  430  is mounted for vertical movement in cavity  448  such that the upper end  450  of frame  430  ( FIG. 18 ) can be moved to a position so that it is flush or beneath the lower edge  452  of opening  442  when frame  430  is moved to its fully lowered position within the side rail body  434  (not shown). When frame  430  is moved to its fully extended or clamping position, upper end  450  of frame  430  abuts or is extended into an upper portion  454  of frame member  436  of side rail body  434  to thereby clamp sheet S between the upper end  450  and upper portion  454 . In the illustrated embodiment, upper portion  454  includes a recess that extends along its length to receive upper end  450  of frame  430 . However, it should be understood that the upper portion  454  may have a solid continuous lower facing side (no recess), with upper end  450  of frame  430  clamping against the lower facing side of upper portion  454 . 
         [0129]    In the illustrated embodiment, frame  430  comprises an open frame formed by an outer perimeter frame member  460  and an intermediate frame member  462 . Intermediate frame member  462  joins upper and lower portions  464  and  466  of outer perimeter frame member  462  to thereby reinforce outer perimeter frame member  460 . Further, intermediate frame member  462  defines two openings  464  and  466 , which may be equal in size, to form finger clearances in frame  430 . Optionally, frame  430  may be sized to provide gaps  468  and  470  on either side of outer perimeter frame member  462  between frame  430  and side rail body  434 , also to provide finger clearances on either side of frame  430 . 
         [0130]    Frame  430  is moved between its non-engaged positions and its clamping position by an actuator assembly. For example, a suitable actuator for the actuator assembly includes a linear actuator, such as an electric, pneumatic or hydraulic actuator. In one embodiment, the actuator comprises one or more motors that drive a rack and gear assembly. For example, as best seen in  FIGS. 17 and 17A , toothed racks  472 ,  474  may be mounted in cavity  448  on opposed ends of frame  430 , with gears  476  and  478  mounted to the lower opposed ends of frame  430  for engaging racks  472 ,  474 . For example, gears  476 ,  478  may be powered by one or more motors  476   a ,  478   a  mounted in frame  430 . Alternately, a four-bar linkage assembly or X-frame may be positioned beneath frame  430  in cavity  448 , and optionally coupled to frame  430 , which may be driven to extend or retract by an actuator, such as a linear actuator or a driven gear, such as a cycloidal gear and motor, to thereby raise or lower frame  430 . 
         [0131]    In another embodiment, frame  430  may be raised or lowered one or more drive screws, which may be driven to extend or retract frame  430  by a gear, such as a cycloidal gear, and motor, mounted, for example, in side rail body  434 . For example, the drive screws may extend into frame  430 , with frame  430  coupled to the drive screws by followers so that when the drive screws are driven to rotate about their longitudinal axes, the followers will raise or lower frame  430  relative to the drive screws. 
         [0132]    Optionally, each side rail  426  incorporates a quick release mechanism  480  to decouple the motive power of the actuator from frame  430  to allow frame  430  to move to its non-engaged or lowered position and thereby release the sheet S from engagement with the side rail. For example, once decoupled from the actuator, frame  430  may return to its non-engaged or lowered position under the force of gravity or under the force of a spring, for example, mounted to frame  430  and located in cavity  448  of side rail body  434 . For examples of several other quick release mechanisms, reference is made to  FIGS. 24D-F . Alternately, as described below, the quick release mechanism may be incorporated into the side rail mounting mechanism to allow quick lowering of the side rail from its raised position, for example, in a “Code” situation where the side rails must be lowered very quickly and caregivers have maximum access to the patient. 
         [0133]    In the illustrated embodiment and as best seen in  FIG. 17A , quick release mechanism  480  comprises a handle  480   a  that is pivotally mounted to side rail body  434  and which is coupled to the actuator or gear, for example, via a link  482 . Optionally, link  482  may comprise a cable  482   a  or linkages or a combination of both. When handle  480   a  is pivoted, link  482 , which is coupled to gears  476 ,  478 , disengages gears  476 ,  478  from their driving positions (i.e., engaged with racks  472 ,  474 ) and allow frame  430  to return to its disengaged or retract position. 
         [0134]    In one embodiment, cable  482   a  comprises a Boden cable (a push-pull cable). Further, as best seen in  FIG. 17A , gears  476  and  478  may be coupled to a linkage assembly  484 , which is mounted in frame  430 . For example, gears  476 ,  478  may be mounted to frame  430  on movable shafts or the gears may be movably mounted on their respective drive shafts, which allows each gear  476 ,  478  to move between an extended, engaging position for engaging racks  472 ,  474  and a retracted, non-engaging position. Gears  476 ,  478  may be biased into their engaging positions, for example, by springs mounted about the respective shafts. 
         [0135]    In the illustrated embodiment, linkage assembly  484  may include a spring biased crank arm  486 , which is rotationally mounted about its medial portion to frame  480  and eccentrically coupled to linkages  488  of linkage assembly  484 . Cable  482   a  is coupled to crank arm  486  so that when cable  482   a  is pulled, crank arm  486  will rotate about its rotational axis. In this manner, when crank arm  486  is rotated about its rotational axis by cable  482   a  (when handle  480  is pulled as shown in  FIG. 18 ), crank arm  486  will rotate in a counterclockwise direction as viewed in  FIG. 18  and thereby pull on links  488  (which are coupled to the shafts of the gears) to disengage gears  476  and  478  from their respective tracks  472 ,  474 . Once the handle  480  is return to its stowed position, such as shown in  FIGS. 17 and 20 , cable  482   a  pushes on crank arm  486  to rotate crank arm  486  in a clockwise direction, and thereby push the linkages  488  to push the respective gears  476 ,  478  to their engaging positions for re-engagement with their respective rack  472 ,  474 . 
         [0136]    Optionally, handle  480   a  is mounted to an end of side rail  426 , for example to the head end of side rail  426 , so that it is accessible by a caregiver. Further, handle  480   a  may be configured to generally follow the contour of the side rail body  434 , such as shown in  FIGS. 17 and 18 . 
         [0137]    Referring again to  FIGS. 18-20 , when frame  430  is lowered, a portion of sheet S may be extended through opening  442 . Once the portion of sheet S is extended into opening  442 , frame  430  may be moved to its extended, clamping position to thereby clamp sheet S between frame  430  and upper portion  454 . Optionally, upper end  450  of frame  430  and/or the underside of upper portion  454  includes an enhanced gripping surface  490  to thereby enhance the clamping of sheet S there between. Gripping surface  490  may be formed by ribs, ridges, knurling, or a high friction material, such as a material with a soft durometer, including a gel, which is coupled or applied to or formed with frame  430  and/or upper portion  454 . For example, the ribs may extend longitudinally along the respective surface or the ribs may extend laterally across the respective surface, and further cooperate with ribs formed on the opposing surface, such as shown and described in reference to  FIGS. 22-24 . 
         [0138]    Referring to again  FIG. 21 , after sheet S is coupled to side rails  426  by patient repositioning apparatus  412 , side rails  426  may be raised to their upper raised position to thereby lift the patient off the mattress  422  and then shift or lift the patient toward the head end of patient support  410  to thereby “boost” the patient. Once the patient has been boosted, the side rails can be returned to their lowered or intermediate position adjacent mattress  422 , and the sheet may then be decoupled from the side rail. Alternately, one of the side rails may be raised to its raised position so that one side of a patient is lifted, which can assist in turning a patient. 
         [0139]    Referring to  FIGS. 22-24 , the numeral  512  designates yet another embodiment of a patient repositioning apparatus, which is also mounted in side rails  526  (only one shown, see previous embodiments for illustrations of how the side rails can be used together). As will be more fully described below, patient repositioning apparatus  512  includes an enhanced gripping surface in the form of ribs on its movable frame  530 , as well as on a stationary member  531  supported in side rail body  534  of side rail  526 . Similar to the previous embodiment, each frame  530  is movably mounted in a respective side rail  526  to move from a fully raised or engaged, clamping position, such as shown in  FIG. 22-23 , for engagement with a sheet, similar to such as shown in  FIG. 20 , to lowered or disengaged positions, such as shown in  FIG. 24 . 
         [0140]    In the illustrated embodiment, frame  530  is mounted in side rail body  534  of side rail  526 . As best seen in  FIG. 22 , side rail body  534  is formed from a perimeter frame member  536  that is covered by plastic, such as by overmolding or by securing preformed inner and outer panels (not shown) to frame member  536 . Frame member  536  includes an upper portion  536   a  for supporting stationary member  531  of clamp  530  and a lower portion  536   b  ( FIG. 23 ), which is reinforced to mount side rail  526  to a patient support  510 . Additionally, in the illustrated embodiment, side rail body  534  is formed with one or more through openings  552  and  554 , which extend through side rail body  534 . Opening  554  forms a hand hold, while opening  542  forms an access window for receiving sheet S there through so that sheet S can be engaged by frame  530 , similar to the previous embodiment. Frame  530  is mounted to translate vertically in opening  542  so that frame  530  can move between its lowered position and its engaged, clamping position, such as shown in  FIGS. 22 and 23 . 
         [0141]    Side rail body  534  may also include a cavity  548  for receiving frame  530 . In the illustrated embodiment, cavity  548  is defined between a pair of vertical mounting members  548   a  and  548   b  and above horizontal mounting member  538   c , which are secured to frame member  536 , for example by fasteners or welding, or the like. Mounted to the inwardly facing sides of mounting members  548   a  and  548   b  are rails  572  and  574 . Rails  572  and  574  guide frame  530  between its raised or engaged, clamping position ( FIG. 22 ) and its lowered or disengaged positions ( FIG. 24 ). 
         [0142]    To move frame  530  between raised its engaged, clamping position and its lowered or disengaged positions, side rail  526  includes an actuator assembly  575 . In the illustrated embodiment, actuator assembly  575  includes a handle  580  pivotally mounted to side rail body  534  about a rotational axis  581  and a link  582 , which is coupled on one end to handle  580  and coupled at its other end to a carriage  586 . Link  582  translates the rotational motion of handle  580  into linear motion of carriage  586 , which in turn raises or lowers frame  530  along rails  572  and  574 . Optionally, link  582  comprises a rigid linkage, but it should be understood that a push-pull cable could be used instead, such as a Boden cable. 
         [0143]    For example, handle  580  may include an arm or a lobed portion  584  about its rotational axis to which link  582  is anchored at one end. Furthermore, handle  580  may include a spring that biases the handle, for example, in a clamping position where carriage  596  is moved to a position shown in  FIG. 22 ) that corresponds to the frame  530  being its raised or clamping position. Carriage  586  is coupled to the other end of link  582  and movably mounted on transverse mounting member  548   c , which is secured between frame member  536  and mounting member  548   b . Carriage  586  translates along mounting member  548   c  when handle  580  is pivoted about its rotational axis  581  (between its non-clamping position and clamping position) to thereby form a driver to push or pull on frame  530 , as more fully described below. 
         [0144]    In the illustrated embodiment, carriage  586  comprises a pair of spaced apart plates  588 ,  590 , which support a pair of rollers  592 . Rollers  592  are guided by ramps  530   a ,  530   b  provided on frame  530 . In the illustrated embodiment, ramps  530   a ,  530   b  are formed by adjacent or side-by-side elongate openings or slots provided in frame  530 . To translate the linear motion of carriage  586  into vertical motion in frame  530 , the openings are angled upwardly on one end. Carriage  586  also may include one or more rollers  594  that guide link  582  through carriage  586  to its anchor point on carriage  586 . For example, when handle  580  is rotated upward about its pivoted axis, link  582  will pull on carriage  586 , which will cause carriage  586  to translate along transverse mounting member  548   c . As carriage  586  moves along member  548   c , rollers  592  will pull or push on frame  530 . 
         [0145]    As would be understood, when handle  580  is lifted and pivoted about rotational axis  581 , link  582  pulls on carriage  586 , which causes rollers  592  to translate along ramps  530   a  and  530   b  to the right as viewed in  FIG. 22 . Consequently, as carriage  586  is moved to the right as viewed in  FIG. 22 , frame  530  will lower. In contrast, when handle  580  is pivoted downwardly about its rotational axis  581 , such as shown in  FIG. 22 , link  582  will push carriage  586  to the left as viewed in  FIG. 22  to return carriage  586  to its lifting position where rollers  592  of carriage  586  return to the lowered ends of the ramps  530   a ,  530   b  and thereby raise frame  530  to its engaged, clamping position. 
         [0146]    In the illustrated embodiment, frame  530  comprises a plate  596  with transverse openings  596   a ,  596   b  that form ramps  530   a ,  530   b . However, it should be understood that frame  530  may have different constructions, such as an open frame construction with the ramps formed sub-frames within the open frame. Similar to the previous, frame  530  may be sized to provide gaps (not shown) on either side to provide finger clearances between frame  530  and side rail body  534 . 
         [0147]    As noted above, upper end  598  of frame  530  includes an enhanced gripping surface  600  to enhance the clamping of sheet S. In the illustrated embodiment, enhanced gripping surface  600  comprises a plurality of spaced, apart ribs  600   a . Ribs  600   a  run transversely across frame  530  and are configured to engage corresponding recesses  604   a  formed by an enhanced gripping surface  604  provided on stationary member  531 . Stationary member  531  is mounted to frame member  536  of side rail body  534  at the upper end of opening  552  beneath the upper portion  536   a  of frame member  536 . Further, in the illustrated embodiment, ribs  600   a  and recesses  604   a  are formed by mirror image undulating surfaces provided or formed on frame  530  and stationary member  531 . Further, one or both undulating surfaces may include a high friction surface applied thereto, for example, by coating or during the forming process (e.g., co-injection molding of frame  530  and stationary member  531 ). High friction surfaces may be formed from a high friction material, such as a material with a soft durometer, including a gel, which is coupled or applied to or formed with frame  530  and/or stationary member  531 . 
         [0148]    Optionally, handle  580  is also mounted to an end of the side rail  526 , for example to the head end of side rail  526 , so that it is accessible by a caregiver. Further, handle  580  may be configured to generally follow the contour of the side rail body (outer surface may be similar to side rail body  434 ). 
         [0149]    Optionally, carriage  586  is guided along transverse member  548   c  by a pair of rails  548   d , which are mounted to either side of transverse member  548   c . Rails  548   d  are secured to member  548   c  by fasteners or welds, or may be integrally formed with member  548   c  to thereby form a track along which carriage  586  may slide or roll (carriage may also include additional rollers or bearings to roll along upper side of member  548   c  between rails  548   d ). 
         [0150]    As noted above, patient repositioning apparatus  512  may be used in a similar manner as patient repositioning apparatus  412 . Accordingly, reference is made to the previous embodiment for a description of how apparatus  512  may be used. 
         [0151]    Referring to  FIG. 24A , the numeral  575 ′ designates another embodiment of an actuator assembly that may be used to move frame  530  between its lowered position and its clamping position. In the illustrated embodiment, actuator assembly  575 ′ includes an X-frame  575   a  and an actuator  575   b , which comprises a linear actuator, such as electric, pneumatic, or hydraulic actuator. X-frame  575   a  includes one fixed pivot axis  575   b  at the lower end thereof and mounted in cavity  548 , for example, to mounting member  548   c , and a movable pivot axis  575   c  mounted in a track or slotted opening provided in the mounting member  548   c . Actuator  575   b  coupled to the X-frame at or near the movable pivot axis to thereby extend or contract X-frame  575   a . The upper ends of X-frame  575  optionally also include one fixed pivot axis and one moving pivot axis mounted to frame  530  or may include two moving pivot axes  575   d, e  that when X-frame  575   a  is extended or contracted so there is sufficient play to accommodate the movement of the X-frame arms. 
         [0152]    Referring to  FIG. 24C , the numeral  575 ″ designates another embodiment of an actuator assembly that may be used to move frame  530  between its lowered position and its clamping position. In the illustrated embodiment, actuator assembly  575 ″ includes a gear  576 ″ and a motor (not shown) and a tooth rack  578 ″, which is either formed or mounted to frame  530  and driven by gear to raise or lower frame  530 . In addition, actuator assembly  575 ″ includes one or more rollers  574 ″, which are mounted to the opposed side of frame  530 , to guide frame  530  when it is moved between its raised and lowered positions. 
         [0153]    It should be understood that the frames described above may be raised or lowered by any number of actuator assemblies or actuators, including the actuator assemblies and actuators described above, or combination thereof. 
         [0154]    Referring to  FIGS. 25-29 , the numeral  712  generally designates another embodiment of a patient repositioning apparatus. Patient repositioning apparatus  712  is configured to mount to a patient support  710 , such as a hospital bed, stretcher, EMS cot, Operating Room (OR) table, or the like. 
         [0155]    Similar to the previous embodiments, patient repositioning apparatus  712  includes a pair of sheet clamps  730  mounted to opposed sides of patient support  710  closer to the head end of patient support  710  than the foot end so that it generally aligns with the torso of the patient. In the illustrated embodiment, each sheet clamp  730  is mounted to patient support  710  by a four-bar mechanism  770 , with the sheet clamps forming part of the four-bar mechanisms. In the illustrated embodiment, each four-bar mechanism  770  comprises a manually driven four-bar mechanism that is driven by a crank arm  772  with a handle  774 . The fixed bar or link of each four-bar mechanism  770  is provided by a mount  776 , for example a structural angle, that is mounted to patient support  710 , for example, to the deck  714  that supports the mattress  722 . 
         [0156]    In the illustrated embodiment, each four-bar mechanism  770  includes two follower arms  778 , which are pivotally mounted at their lower ends to mount  776  and are driven by crank arm  772 . Sheet clamp  730  comprises a plate  782 , which is pivotally mounted to the opposed upper ends of follower arms  778  to thereby form the four-bar mechanism. 
         [0157]    As noted above, each four-bar mechanism  770  may be manually driven by crank arm  772 , which includes a gear  784  that engages toothed portions  778   a ,  780   a  of follower arms  778 ,  780 , respectively so that when handle  774  is pushed or pulled and crank arm  772  is rotated about is rotational axis  781  (in the counterclockwise direction as viewed in  FIGS. 26 and 29 ), follower arms  778 ,  780  will rotate about their respective rotational axes  778   b ,  780   b  in a clockwise direction (as viewed in  FIGS. 26 and 29 ) to thereby move clamp  730  in an arcuate path toward the head end of patient support  710 . 
         [0158]    Optionally, each four-bar mechanism  770  may include a crank arm  772 , but the rotational shafts that rotatably couple the lower ends of each follower arm  778 ,  780  to its respective mount may be shared by the four-bar mechanism on the opposed side of the patient support so that both four-bar mechanisms may be operated from a single crank arm. However, it should be understood that the four-bar mechanisms may be independently driven, which would, however, require two operators to boost a patient. When independently driven, one of the four-bar mechanisms may, therefore, be used to assist in tilting a patient. 
         [0159]    As best seen in  FIGS. 26 and 27 , each plate  782  of each sheet clamp  730  includes an elongated opening  790  and a plurality of cams  792  and associated lock plates  794 , which are mounted about opening  790 . The number of cams and lock plates may be varied. In the illustrated embodiment, cams  792  comprise wedge shaped cams that are pivotally mounted about an upper edge  790   a  of opening  790 , while lock plates  794  are mounted on a lower edge  790   b  of opening  790 . Optionally, cams  792  may be pivotally mounted to plate  782  by brackets  791 , which locate the respective cams in recesses provided at upper edge  790   a  of opening  790 . 
         [0160]    In this manner, when a sheet is inserted into the opening  790  from the patient support facing side  730   a  of clamp  730 , the cams  792  will pivot outwardly from the outwards facing side of clamp  730  so that the sheet can slide over lock plates  794  and be pulled through the opening  790  from the outwardly facing side  730   b  of each clamp  730   a . Cams  792 , however, grip the sheet tightly when the sheet is pulled in the other direction. Thus, when a sheet S is inserted into openings  790  and then four-bar mechanisms  770  are operated to raise clamps  730 , the patient&#39;s weight on the sheet will cause the cams  792  to grip harder on the sheet as the load increases. 
         [0161]    Optionally, cams  792  and/or lock plate  794  may include enhanced gripping surfaces formed thereon or applied thereto, such as ribs, ridges, knurling, or high friction material to thereby increase the performance of the clamps. 
         [0162]    Accordingly, with the patient repositioning apparatus  710 , a sheet that is under a patient may be pulled through sheet clamps  730  and held tightly while the four-bar mechanisms  770  are rotated so that the sheet is lifted and then moved toward the head end of the patient support  710 . Similar to the previous embodiments, by lifting and then moving the sheet toward the head end, the shear on a patient&#39;s skin is reduced. 
         [0163]    As noted above, four-bar mechanisms  770  are manually driven, but it should be understood, that gears  734  may be driven by a motor or another actuator. Furthermore, depending on the size of follower arms  778 ,  780 , crank arms  772 , and gear ratios, the amount of force to move a patient can be greatly reduced. For example, with a sufficient lever arm and gear ratio, the mechanism can move a patient who weighs 250 pounds with 20-lbs of effort. This allows a single caregiver to boost a patient with less effort, causing less stress than other conventional methods. 
         [0164]    Referring to  FIG. 24C , as noted above, any of the above the side rails or patient repositioning apparatuses may incorporate a quick release mechanism to allow the side rail (or patient repositioning apparatus) to lower quickly, for example, in the event of a “Code” situation where the side rails must be lowered very quickly so that caregivers have maximum access to the patient. For ease of description, reference will be made to a side rail application; however, it should be understood that the same or similar mechanism may be used for any of the above patient repositioning apparatuses that are mounted directly to the patient support. 
         [0165]    Referring again to  FIG. 24C , the numeral  926  generally designates a side rail for a patient support, such as a hospital bed. Side rail  926  includes a side rail body  934  and a mounting mechanism  936 , which includes a pair of mounting arms  938 . Mounting arms  938  are pivotally mounted at their upper ends to side rail body  934  and at their lower ends to an articulating deck for frame (which supports the deck)  914 . 
         [0166]    Optionally, one or more of the pivot connections  940  that mount the lower ends of the mounting arms to deck  914  may incorporate a quick release mechanism  980 , which allows the side rail body  934  to be quickly lowered. 
         [0167]    Referring to  FIG. 24D , one or both lower pivot connections  940  of side rail mounting arms  938  may include a clutch  941  to allow the side rail body  934  to quickly pivot about pivot connection  940 . Clutch  941  is mounted to a driven shaft  942  (e.g., a shaft driven by a motor mounted to deck or frame  914 ) and includes a fixed disc  944 , which is fixedly mounted to driven shaft  942 , and a floating disc  946 , which is movably mounted to shaft  942  and fixedly mounted to side rail mounting arm  938 , which together form the clutch  941 . Each disc  944 ,  946  may comprise a gear disc with spaced teeth on their faces at their perimeters, which when mated together couple the two discs together and thereby drivingly couple the respective mounting arm to its associated driven shaft  942  for selective rotation with the driven shaft  942 . This type of connection is often referred to as a hirth joint. 
         [0168]    The slope (pressure angle) of the teeth on disc  944 ,  946  may be symmetrical so that the discs rigidly couple the side rail mounting arm  938  to the driven shaft  942  in both rotational directions (i.e., clockwise and counterclockwise). Alternately, the slope of the teeth may be asymmetrical, and further such that the slope on one side of the teeth allows the two discs to slip passed each other if a minimum threshold of a downward force is applied to side rail body  934 . The slope on the other side is sufficiently steep to lock the two discs together unless the discs are separated, as described below. Therefore, it should be understood that the quick release mechanism may be configured as a slip joint at pivot connections  940  to allow the side rail body  934  to lower by simply applying sufficient downward force on the side rail body to allow the two discs to slip by each other. 
         [0169]    As best seen in  FIG. 24D , in one embodiment, quick release mechanism  980  includes an actuator  982  to separate the two discs. In the illustrated embodiment, actuator  982  comprises a cable  982   a . When cable  982   a  is pulled, cable  982   a  separates disc  946  from disc  944 . Cable  982   a  is coupled to disc  946  and is supported so that it can rotate with the disc  946  when the side rail body lowers. For example, cable  982   a  may include a bifurcated end  982   b  to couple to disc  946  radially outward from its central axis  940   a  at equidistant points from axis  940   a  and at points 180 degrees apart. 
         [0170]    In this manner, when cable  982   a  is pulled (for example, by a handle provided on side rail body  934 ), discs  944  and  946  will separate to decouple side rail body  934  from the motive power of the motor that drives pivot connection  940 . It should be understood that one or both pivot connections  940  may be driven and include quick release mechanism  980 . 
         [0171]    Referring to  FIG. 24E , the numeral  1080  designates another embodiment of a quick release mechanism. Quick release mechanism  1080  includes a frame or housing  1080   a , which is coupled to disc  946 , and a spring  1080   b  that is mounted about shaft  942  and captured between a shoulder  1080   c  formed or provided in frame  1080   a  and a shoulder  942   a  formed or provided on shaft  942 . In this manner, when frame  1080   a  is pushed toward disc  944 , spring  1080   b  will compress. When frame  1080   a  is released, spring  1080   b  will urge disc  946  to separate from disc  944 . To urge frame  1080   a  and disc  946  toward disc  944  to engage disc  944 , quick release mechanism  1080  includes an actuator  1082 . 
         [0172]    In the illustrated embodiment, actuator  1082  includes a threaded shaft  1082   a  and a handle  1082   b , which is coupled to shaft  1082   a . Shaft  1082   a  is supported in side rail body  934  by a bracket  1082   c  with a threaded opening  1082   d , through which shaft  1082   a  extends to engage and push on the end of frame  1080   a . Thus, when handle  1082   b  is turned in the clockwise direction, for example, as viewed in  FIG. 24E , shaft  1082   a  will urge frame  1080   a  toward disc  944  so that discs  946  and  944  will be engaged. When discs  944  and  946  are engaged, side rail body  934  is coupled to the motive power of the motor (or motors) that drives one or both pivot connections  940 . When handle  1082   b  is turned in the opposite direction, for example, in the counterclockwise direction as viewed in  FIG. 24E , spring  1080   b  will urge frame  1080   a  to the right as viewed in FIB.  24 E so that disc  946  will separate from disc  944  with a sufficient distance to disengage the two discs  944 ,  946  from each other. 
         [0173]    It should be understood that, alternately, the spring may be mounted relative to disc  946  so that spring  1080   b  urges disc  946  into engagement with disc  944 . In this configuration, frame  1080   a  is decoupled from disc  946  and configured to compress or reduce the spring force applied by spring  1080   b  on disc  946  to allow the two discs to slip when a downward sufficient force is applied to the side rail body. Again, the position of frame  1080   a  can be controlled by actuator  1082 . 
         [0174]    Referring to  FIG. 24F , the numeral  1182  designates another embodiment of an actuator that may be used to urge frame  1080   a  (with or without disc  946  as noted above in reference to the modification noted above) toward disc  944 . In the illustrated embodiment, actuator  1082  comprises a cam actuator with a cam disc or body  1182   a  that is adjacent to the end of frame  1080   a . Cam disc  1182   a  is mounted for rotation about a rotational axis  1182   b  offset from the center of the disc and is driven about axis  1182   b  either manually or by a powered actuator. For example, a manual actuator may include a handle that is mounted to cam disc and accessible at side rail body  934  for use by a caregiver. A powered actuator may include a motor and gear that engage the cam disc, for example, engages gear teeth mounted to the perimeter of cam disc  1182  or to a cylindrical member  1182   c  mounted to cam disc  1182   a  about axis  1182   b.    
         [0175]    In this manner, as cam disc  1182   a  is driven about axis  1182   b , cam disc  1182   a  will push on frame  1080   a  to thereby either push disc  946  toward disc  944  against the spring force of spring  1080   b  or will increase the spring force applied by spring  1080   b  on disc  946  to urge disc  946  toward disc  944  (in the modified version described above). If the cam disc  1182   a  is rotated in the opposed direction so that it moves away from disc  944 , spring  1080   b  will either push on frame  1080   a  to pull disc  946  away from disc  944  or the spring force exerted by spring  1080   b  on disc  946  will be reduced to allow the two discs to slip when sufficient downward force is applied to the side rail body  934  (as described above in reference to the modified version of quick release  1080 ). 
         [0176]    It should be understood that any of the quick release mechanisms described above, and shown in  FIGS. 24D-24F , may be used to decouple frames  430 ,  530  from the motive force of the motors that drive the frames  430 ,  530  up and/or down. 
         [0177]    In any of the above, patient positioning apparatuses, the surface or surfaces (and other surfaces) that contact the sheet may be cleared by on board methods or by extend methods. For example, any of the surfaces of the patient repositioning apparatuses that make contact with or could make contact with bodily fluids or the like may incorporate antimicrobial additives, such as Microban. For example, the antimicrobial additives may be applied to coatings on the various surfaces or may be incorporated into the material forming the surface, such as disclosed in U.S. patent application Ser. No. 13/673,393, entitled MEDICAL EQUIPMENT WITH ANTIMICROBIAL COMPONENTS AND/OR SYSTEM, which is commonly owned by Stryker Corporation of Kalamazoo Mich. and incorporated by reference herein in its entirety. 
         [0178]    In other embodiments (or in addition), UV light may be used to clean the patient repositioning apparatuses. In the case of patient repositioning apparatus that are built-in to the side rails, the side rails may incorporate one or more UV lights, such as UV LED lights, that are powered and controlled by a bed-based control and power supply system. Further, the powered actuators described above may be powered and controlled by a bed-based control and power supply system, and optionally controlled by user input devices, such as buttons, located on the side rail or user input devices located the headboard or footboard. 
         [0179]    A suitable method of use of some of the patient positioning apparatuses described herein includes lowering the side rail to a location so the clamping device or clamps are at appropriate level for engaging a sheet supported on the mattress. The sheet is then engaged by a clamping device. Side rails on both sides are raised to a higher position to thereby lift or at least reduce the weight (or immersion) of the patient on the patient support surface. The side rails are then further moved to pull on the sheet to boost the patient. After the patient is boosted, the side rails then can be lowered to gently lower the patient back on to the patient support surface. The sheet at that point can then be released from the clamps. The patient reposition apparatuses, as noted, may also be used to the tilt or assist in tilting the patient by operating just one side of the apparatus. 
         [0180]    The above description is that of various embodiments of the invention. Alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to claim elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular.