Abstract:
A patient support is disclosed having an adjustable length deck and a mattress positionable on the deck. The mattress includes a foot portion having an adjustable length.

Description:
[0001]     This application is a continuation of U.S. patent application Ser. No. 11/315,665, filed Dec. 22, 2005, which is a continuation of U.S. patent application Ser. No. 10/770,721, filed Feb. 3, 2004, now U.S. Pat. No. 7,000,272, which is a continuation of U.S. patent application Ser. No. 09/755,583, filed Jan. 5, 2001, now U.S. Pat. No. 6,496,993, which is a divisional of U.S. patent application Ser. No. 09/120,125, filed Jul. 22, 1998, now U.S. Pat. No. 6,212,714, which is a continuation-in-part of U.S. patent application Ser. No. 08/901,840, filed Jul. 28, 1997, now U.S. Pat. No. 6,151,739, which is a continuation of U.S. patent application Ser. No. 08/367,829, filed Jan. 3, 1995, now U.S. Pat. No. 5,666,681.  
         [0002]     U.S. Pat. No. 6,212,714 is also a continuation-in-part of U.S. patent application Ser. No. 09/018,542, filed Feb. 4, 1998, now U.S. Pat. No. 6,163,903; which is a continuation of U.S. patent application Ser. No. 08/511,711, now U.S. Pat. No. 5,715,548.  
         [0003]     U.S. Pat. No. 6,212,714 also claims the benefit of U.S. Provisional Patent Application No. 60/059,772, filed Sep. 23, 1997 with respect to common subject matter. The disclosures of the above patent applications are expressly incorporated by reference herein. 
     
    
     BACKGROUND AND SUMMARY OF THE INVENTION  
       [0004]     The present invention relates generally to adjustable beds and more specifically to a bed having an improved adjustable foot section.  
         [0005]     There are many known bed designs that have adjustable foot sections. On beds that convert from a planar bed configuration to an upright chair configuration, the foot section is generally shortened as the foot section rotates from a horizontal to a vertical position. There are also beds having adjustable lengths wherein an attendant physically repositions the head or foot section of the bed to the desired length. These designs include a sliding telescopic foot section as well as a folding foot section equivalent to a “lazy boy” design. It is also known to deflate the foot section of the mattress when converting from a bed to a chair. For short occupants, there exists a need for adjustment of the foot prop or board in the chair position shorter than that attended by adjusting the length of the foot section.  
         [0006]     The ability to adjust the length of the foot section independent of converting from a bed to a chair is also important. This would assist in maneuvering the bed in a confined locations during patient transport. It also allows the bed length to be customized to a patient&#39;s size. If a foot prop is provided at the end of the foot section, the adjustment of the foot section and the prop would prevent patient migration across the support surface of the bed. It would also provide support for the feet to thereby improve the patient&#39;s feeling of security. It could also be used in the prevention of peripheral neuropathy (“foot drop”). Positioning the end of the mattress relative to the patient substantially increases the ability to provide heel management. Heel management is wherein the heel is supported by the thigh and the calf and the heel has reduced pressure contact with the mattress.  
         [0007]     Certain individuals who are confined to bed for an extended period of time are vulnerable to skin breakdown on the back of the heel. Protection of the skin in this area is important if initial indications of tissue failure are observed. If the breakdown process has progressed to a point of ulceration, protection of the heel area of the patient is essential to healing.  
         [0008]     Reducing or eliminating the time an individual spends in a supine position will protect the heel area, although it may increase the risk of skin failure on other areas of the foot and body. The current practice for protecting the heel area of a patient while in the supine position utilizes foot support to reduce or eliminate pressure and shear on the back of the heel. Such support is often provided by placing an ordinary pillow or folded towel under a calf area of the patient&#39;s legs. Several different foam boot designs are known that strap to the leg or foot to reduce the effects of heel pressure. In addition, a conventional mattress is known in which removable sections are provided in a foot area.  
         [0009]     All of these conventional support methods require a caretaker to add or remove components from the bed in order to control pressure on the heels of the patient. Components which are removed from the bed have the potential to get lost or mislaid. Components that are added to the bed provide an extra cost associated with the purchasing, cleaning, and disposal of the added components. There is also a cost in time for the caregiver who must go through multiple steps to initiate and maintain the support of the device.  
         [0010]     According to the present invention, a patient support having an adjustable length deck is provided. The patient support includes a deck support frame, a deck, a head board positioned adjacent a head end of the deck, and a foot board positioned adjacent a foot end of the deck. The deck includes a first section connected to a remainder of the deck, a second section movable in a common plane with the first section, and a first actuator directly connecting the first and second sections.  
         [0011]     According to one aspect of the present invention, a patient support having an adjustable length deck is provided. The patient support includes a deck support frame, a deck, a patient rest surface configured to support a patient thereon, and a plurality of siderails configured to block egress of a patient from the patient rest surface. The deck includes a first section connected to a remainder of the deck, a second section movable in a common plane with the first section, and a linear actuator connecting the first and second sections and configured to move the second section relative to the first section between an extended position and a retracted position.  
         [0012]     According to another aspect of the present invention, a patient support is provided including a mattress support and a mattress. The mattress support includes a main section and an extendable section movable relative to the main section between extended and retracted positions relative to the main section. Movement of the extendable section to the extended position exposes an exposable portion of the mattress support. The mattress has a main portion positioned over the main section of the mattress support and an extension portion positioned over the exposable portion of the mattress support when the extendable section is in the extended position. The extension portion has a width that is substantially equal to a width of the main portion adjacent to the extension portion.  
         [0013]     According to another aspect of the present invention, a patient support is provided that includes a mattress support and mattress. The mattress support includes a main section and an extendable section movable relative to the main section between an extended position and a retracted position. The mattress support has an extended length when the extendable section is in the extended position. The mattress support has a retracted length when the extendable section is in the retracted position. The extended length is greater than the retracted length. The mattress has a main portion positioned over the main section and an extension portion movable between a first position positioned on the extendable section when the extendable section is in the extended position and a second position spaced apart from the extendable section when the extendable section is in the retracted position with the main portion positioned over the main section. The extension portion of the mattress has a thickness less than a thickness of the main portion.  
         [0014]     According to another aspect of the present invention, a patient support is provided including a mattress support, a mattress supported by the mattress support, and a plurality of siderails positioned to block egress of a patient from the mattress. The mattress support includes a main section and an extendable section positioned adjacent to the main section. The mattress support has an extended length when the extendable section is in an extended position. The mattress support has a retracted length when the extendable section is in the retracted position. The extended length is greater than the retracted length. A segment of the main section of the mattress support supports the mattress at a first elevation relative to a floor when the main section is substantially horizontal. The extendable section of the mattress support is configured to support the mattress at a second elevation relative to the floor when the extendable section is substantially horizontal. The second elevation is greater than the first elevation.  
         [0015]     Other features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     A detailed description particularly refers to the accompanying figures in which:  
         [0017]      FIG. 1  is a schematic view of a patient on a bed with the foot section/portion fully extended;  
         [0018]      FIG. 2  is a schematic view of a patient on a bed with the foot section/portion adjusted and illustrating the heel management according to the principles of the present disclosure;  
         [0019]      FIG. 3  is a bottom view of the foot section of a mattress according to the principles of the present disclosure;  
         [0020]      FIG. 4  is a perspective top view of the foot section of the deck according to the present disclosure and connected to the remainder of the deck;  
         [0021]      FIG. 5  is a bottom exploded view of a foot section of the deck of  FIG. 4 ;  
         [0022]      FIG. 6  is a bottom perspective view of 180° with respect to the respective view of  FIG. 5  of one section of the deck of  FIG. 5 ;  
         [0023]      FIG. 7  is a top perspective view of the detail of the foot prop socket and safety switch according to the principles of the present disclosure;  
         [0024]      FIG. 8  is a perspective view of the rotating mechanism according to the principles of the present disclosure;  
         [0025]      FIG. 9  is an exploded perspective view of a mattress according to the principles of the present disclosure;  
         [0026]      FIG. 10  is a perspective view of a foam foot portion of a mattress according to the principles of the present disclosure;  
         [0027]      FIG. 11  is a bottom view of the foot portion of  FIG. 10 ;  
         [0028]      FIG. 12  is a side view of the foot portion of  FIG. 10  with a cover according to the principles of the present disclosure;  
         [0029]      FIG. 13  is a bottom view of the foot portion of  FIG. 12 ;  
         [0030]      FIG. 14  is a partial perspective view of the foot end of a ticking for a mattress according to the principles of the present disclosure;  
         [0031]      FIG. 15  is a perspective view of the foot section of the deck and a foot prop;  
         [0032]      FIG. 16  is a perspective view of a modified foot section of the deck with a pair of foot prop sockets;  
         [0033]      FIG. 17  is a view of the foot section of the deck shortened and the mattress foot section folded;  
         [0034]      FIG. 18  is a schematic of the fluid controlled circuit for the foot angle actuator;  
         [0035]      FIG. 19  is a perspective view of the bed showing the deck in a chair configuration;  
         [0036]      FIG. 20  is a diagrammatic view of the bed showing the deck in the chair configuration.  
         [0037]      FIG. 21  is a sectional view of a side rail according to the principles of the present disclosure; and  
         [0038]      FIG. 22  is the side rail of  FIG. 21  shown being moved away from and stored underneath the deck (in phantom). 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0039]     As illustrated in the Figures, the bed will be discussed with respect to a deck  10  and a mattress  20  thereon. As illustrated in  FIG. 4 , the deck  10  includes a seat section  12 , a thigh section  14  and a foot section  16  mounted to a frame  18 . The deck would also include, but not shown, a head section also connected to the frame  18 . Since the present disclosure is directed specifically to the foot section  16 , the other portion will not be described in detail. The foot portion  16  may be used on any deck structure.  
         [0040]     The retracting foot section of the present disclosure can be retracted while the bed is in its horizontal bed position. This pennits the caregiver to adjust the overall length of the bed in either the bed position or the chair position as shown in  FIGS. 19 and 20 . The overall bed length can be shortened by about 12-14 inches to facilitate transport of the bed. In other words, the retracting foot section reduces the bed length so that the bed can fit into smaller elevators. The shorter bed also has a smaller turning radius. The foot section can also be moved to its retracted position to save space during storage of the bed.  
         [0041]     The retracting foot section of the present disclosure also decreases patient migration since the foot prop location may be adjusted to the height of the patient. Therefore, the bed size can be customized for the patient. The bed also includes a shearless pivot linkage disclosed in copending application Ser. No. 08/511,711, filed Aug. 4, 1995, the specification of which is incorporated herein by reference. The combination of the shearless pivot with the retracting foot section and foot prop reduces patient migration toward the foot end of the bed as the bed articulates.  
         [0042]     The mattress  20  illustrated in  FIGS. 1 and 2  includes a body support portion  22  and a foot portion  24 . The foot section  24  includes a calf portion  26  which is variable in length and thickness and a heel portion  28  which is variable in thickness. One preferred embodiment of the mattress foot portion  24  is illustrated in  FIGS. 1-3  as including a plurality of bladders. A plurality of variable thickness bladders  30  are separated by variable length bladders  32 . The heel bladder  28  is separated from one of the variable thickness bladders  30  by a variable length bladder  32 . The uniaxial variable bladders are produced by gussets in the bladders.  
         [0043]     Referring to  FIG. 3 , a control line  34  is connected to the foot mattress portion  24  and by line  36  to the first variable thickness bladder  30 . A line  38  at the other end of the first bladder  30  is connected to the second bladder  30 . Line  40  at the opposite end of the second bladder  30  connects the second bladder  30  to the third bladder  30 . A control line  42  is connected to line  44  of the foot portion  24  which is connected at its other end to the heel bladder  28 . A control line  46  is connected to the first variable length bladder  32 . All of the variable length bladders  32  are connected about the periphery of the foot portion  24 . A cover  48  for the foot portion is held together by snaps  50 . Preferably, the cover  48  is a slip or a shear promoting material, for example, 30 denier ripstop nylon which aids the movement of the foot section in the mattress ticking. This removes the shearing between the occupant and the ticking as the length of the mattress is changed. A strap  51  is secured to the cover  50  by the snaps which are rivets and ties the foot section to an adjacent section  22  of the mattress.  
         [0044]     The control lines  34 ,  42  and  46  are connected to a control module which selectively inflates and deflates the bladders. An example of the control module is that in U.S. Pat. No. 5,666,681 which is incorporated herein by reference. From the connection, all of the variable thickness bladders  30  are inflated and deflated simultaneously, all of the variable length bladders  32  are also inflated or deflated simultaneously. Alternatively, each of the variable length bladders may be individually controlled with additional control lines or other flow control mechanisms. All three types of bladders are independently controlled.  
         [0045]     The foot section  16  of the deck includes a first section  52  connected to the frame  18  and the remainder of the deck and a second section  54  movable along the plane of the section  52 . A foot prop  56  is mounted to the second foot section  54  and extends transverse to the plane of the foot sections  52  and  54 .  
         [0046]     To size the bed to the patient and provide heel management, an occupant is placed on the top surface of the mattress  20  as illustrated in  FIG. 1  with the calf of the patient resting on the foot mattress portion  24 . The foot deck section  54  is retracted onto the deck foot section  52  until the foot prop  56  is adjacent the foot of the occupant as illustrated in  FIG. 2 . Simultaneously, the length adjusting bladders  32  are deflated so that the length of the portion  26  of the mattress is decreased, placing the heel of the patient above the heel bladder  28 . The heel bladder  28  is then deflated, decreasing its thickness such that the interference pressure on the heel of the patient is reduced. By independently controlling the length of the foot section of the deck, the length of the foot portion of the mattress and the thickness of the heel portion of the mattress, appropriate adjustment of the length of the bed is possible as well as heel management.  
         [0047]     The foot section  16  of the deck may be pivotally connected to the frame so as to allow the foot section to drop and to be used in various styles of beds or chair beds as shown in  FIGS. 19 and 20 . A separate and distinct actuator would be provided for the pivotal movement as well as the articulation of the other deck sections. This allows adjustment of the foot section for the length of a patient and heel management independent of articulation of the deck and mattress as well as reducing the length and thickness of the foot portion of the mattress as the deck is converted to a chair.  
         [0048]     The foot section  16  of the deck will be explained with respect to  FIGS. 4-8 . The first foot section  52  includes a top wall  58  and a pair of opposed lateral side walls  60 . Mounted to the bottom surface of top wall  58  by welding for example, are a pair of guide tubes  62 . An intermediate guide tube  64  is telescopically received with tube  62  and an end guide tube  66  is telescopically received in intermediate guide tube  64 . As will be discussed below, the end guide tube  66  is secured to the second foot section  54 . The pairs of telescopic guide tubes  60 ,  64  and  66  guide the relative movement of foot section  54  with respect to foot section  52 . Plates  68  are connected between the guide tubes  62  and the bottom surface of the top plate  58 . Thus, the foot section  52  has a trapezoidal shape. This trapezoidal shape with the larger of the two parallel surfaces being the top wall  58 .  
         [0049]     Also mounted to the under surface of the top wall  58  of the foot section is a hinge plate  70  which mates with a hinge plate  72  mounted to the deck frame  18 . This pivotally mounts the foot section  16  of the deck to the frame  18 . Mounted between the guide tube  62  are a pair of spaced end walls  74  and  76 .  
         [0050]     The second foot section  54  includes a top wall  78 , a pair of side walls  80  extending therefrom and a pair of bottom walls  82  extending from side walls  80 . The top, side and bottom walls are made from one continuous piece of material. The second foot section  54  is generally U-shaped with bottom flanges  82  forming a C-channel with the side walls  80  and top walls  78 . Thus, the top and side walls of the foot section  54  encompass or surrounds a portion of the top and side walls of the foot section  52 . The foot section  54  includes an end wall  84  connected to the top wall  78 , the side walls  80  and the bottom walls  82 . Tube mounting assembly  86  mounts one end of the guide tube  66  to the end wall  84  of the foot section  54 .  
         [0051]     The end wall  76  of the foot section  52  includes openings  87  and  88 , best seen in  FIGS. 4 and 6 , between the guide tube  62 . An actuator  89  shown in phantom in  FIG. 5  is connected to end wall  74  and has an input connections. The actuator  89  is preferably an air cylinder, and mounting connection  90  on end wall  74  is connected to a control line (not shown). The other end of actuator  89  is secured to wall  76  by bracket  92  in the opening  88 . Arm  94  extending from actuator  89  is secured to wall  84  of the second foot section  54  by bracket  96 . The actuator  89  is between the guide tubes  62 ,  64  and  60 . The pair of guide tubes  62 ,  64  and  66  provide uniform distribution of forces. Also, the guide tubes support the weight of the occupant&#39;s feet and minimizes friction between the walls of the foot section  52  and  54 . This prevents binding and rubbing between the foot section  52  and  54 .  
         [0052]     Plastic wipers  98  are also connected to the underside of top wall  78  of the foot portion  54  to protect the sliding joint between the foot sections  52  and  54  and also to prevent the sheet and mattress from intrusion into the joint and jamming the foot section adjustment.  
         [0053]     The foot section  54  includes lateral extensions  100 . Bushing  102  mounts a bumper or roller  104  to the lateral extension  100 . Socket  106  which receives the foot prop  56  is also included in the lateral extension  100 . Alternatively, a pair of sockets  106  and  107  may be provided on each extension  100  as shown in  FIG. 16 . A switch  108  is mounted to the socket  106  by fastener  110  as illustrated in  FIG. 7 . Switch  108  indicates the presence of the foot prop in the end of the bed and is part of the control system. Alternatively, the switch  108  may be designed to also sense the presence of pressure on the foot prop produced by the foot of the occupant of the bed engaging the foot prop of the occupant of the bed.  
         [0054]     Handles  128  are conveniently provided at the foot of the bed connected between the lateral extensions  100  and the foot section  54 . A cover  150  is mounted to the end wall  84  of the foot section  54  as shown in  FIG. 5 . Slots  154  in the top of end wall  84  receives a stop  156  when the foot portion  24  of the mattress is made of foam as illustrated in  FIGS. 10-13 .  
         [0055]     The width W 1  of the foot sections  52  and  54  is substantially the width of the frame  18  and smaller than the width W 2  of the frame  18  with its support surfaces. This accommodates side rails (not shown) mounted on the frame  18  in their lowered or tucked position as the foot section  16  pivots down. Width W 3  of the foot section  16  with the lateral extensions  100  may be substantially equal to the width W 2 , since the extensions will pivot below the side rails.  
         [0056]     The length of the foot deck section  16  as well as the angle of the foot section  16  with respect to the frame  18  are determined by length sensor  114  and angle sensor  116  mounted to the first foot section  52  at tube  62  by bracket  112 . A sensor crank  118  is mounted to the length sensor  114  at one end and its other end is mounted to sensor link  120 . The sensor link  120  extends through the opening  87  in the wall  76  and is connected at its other end to a pivotal connection  122  to the end wall  84  of the foot section  54 . The length sensor  114  may be for example, a potentiometer wherein the crank  118  and link  120  rotate the potentiometer with a change of the length of the foot section  54  with respect to foot section  52 .  
         [0057]     A link  124  is connected to the angle sensor  116  at a first end by crank  123  and is pivotally connected at the second end to pivot leg  126  (shown in  FIG. 6 ) mounted to hinge plate  72  ( FIG. 4 ) which is connected to the deck frame  18 . The angle sensor  116  may also be a potentiometer to determine the pivotal position of the foot section  16  with respect to the deck frame  18 .  
         [0058]     A pair of links  130  are pivotally mounted at one end to bracket  132  which is mounted to end wall  76  of the first foot section  52 . The other end of links  130  are pivotally connected between brackets  134  and  136  mounted onto rod  138 . The other end of brackets  136  is pivotally connected by brackets  140  to end wall  142  of the frame  18 . Brackets  144  in the midsection of rod  138  connect rod  146  of actuator  148  to the rod  138 . The other end of the actuator  148  is connected to the frame  18 . A cover  150  has one end (not shown) connected to the frame  18  and its other end connected to brackets  152  which are mounted on end face  142  of the frame  18 .  
         [0059]     The actuator  148  determines the articulation or angular position of the foot section  16  of the deck. The actuator  148  illustrated in  FIG. 18  includes rod  146  connected to piston  147 . A pump  210  is connected to the opposite sides of piston  147  by raising valve  212  and lowering valve  214 . Connected between the pump  210  and the valves  212  and  214  are filters  216 , restriction  218  and check valves  220 . Check valves  220  prevent the pressurized fluid in the actuator  148  from flowing back towards pump  210 . The other side of piston  147  is connected to reservoir  222  by lowering return valve  224  and raising return valve  226 . Filter  228  connects the reservoir  222  to the return valves  224  and  226  and a filter  230  connects reservoir  222  to the pump  210 .  
         [0060]     To extend the rod  146 , electrical valves  212  and  226  are actuated to connect the respective sides to the pump  210  and reservoir  222 . This raises the foot section  16 . To lower the foot section  16 , and retract the rod  146 , electrical valves  214  and  224  are activated to respectively connect the opposite sides of the piston  147  to the pump  210  and reservoir  222 . As a safety feature, relief valve  232  is connected between the output of pump  210  and the reservoir  222 . Thus, if the pressure at the output of the pump builds up to an unsafe level, relief valve  232  provides a flow back to the reservoir  222 .  
         [0061]     As another safety feature, a relief valve  234  is connected between the output of valve  214  and the reservoir  222 . Since valve  214  provides the output of the pump to the piston  147  to lower the foot section, if the pressure in the lowering should exceed the setting of relief valve  234 , the excess pressure will be relieved back to reservoir  222 . This is a safety feature in that if the foot section  16  engages an object in its lowering, the piston  147  and rod  146  will stop moving and pressure will build up on that side of the piston. To prevent crushing of an object or a person or part of a person, relief valve  234  will operate. As an alternative to the relief valve  234 , a pressure sensor may also be provided and the valve  214  may be closed or valve  226  opened. By way of example only and not by way of limitation, whereas the relief valve  232  for the pump may be set at 900 PSI, the relief valve  238  for the actuator  148  may be set at approximately 180 PSI.  
         [0062]     The electronics portion  160  of the controller as illustrated in  FIG. 4  is mounted to the frame  18  below the seat section  12  and the thigh section  14  of the deck. The controller  160  is connected to the length sensor  114  by wire  162 , to angle sensor  116  by wire  164  and to the prop sensor switch  108  by wire  166 . The sensor crank  118  and sensor link  120  are hollow or U-channel and the wire  166  for the prop traverses the foot section  116  through the channel in the sensor crank  118  and sensor link  120 . As the length sensor  114  sense the position of the end of the bed or it&#39;s length, the appropriate inflation or deflation of the bladders is made to adjust the length of the foot portion of the mattress. The angle sensor  116  in combination with the foot prop sensor  108  does not allow the foot section to pivot to an angle, for example in the range of 65° to 90° degrees from the horizontal, which will allow egress from the end of the bed without removal of the foot prop. This prevents the occupant from standing on the foot prop. Any angle less than this range will provide foot support in a chair position which is not selected for ease of egress.  
         [0063]     Details of the mattress  20  is illustrated in  FIG. 9 . Ticking  170  receives the body portion  22  and a foot portion  24 . Two examples of each portion is illustrated. The body portion  22  could include a foam seat portion  172  and a foam back portion  174 . Alternatively, it may include a bladder seat section  176  and a bladder back section  178 . The foot section  24  could include a foam foot portion  180  or the bladder foot portion  28 ,  30  and  32  of  FIG. 3 . The control lines  34 ,  42  and  44  have a bend which corresponds to the juncture of the back and seat section of the mattress where a majority of the bending of the mattress occurs. Any combination of feet section may be used with any combination of seat and back section.  
         [0064]     The body portion  22  and the foot portion  24  fit within the ticking  170 . The ticking  170  is a stretchable, breathable thermal plastic which is impervious to bacteria. The seams of the outer ticking of the mattress are formed by continuous ultrasonic welding. Therefore, the seams do not require any stitches which can permit fluid leakage. The ultrasonically welded seams are impermeable to fluids and bacteria so that the seams of the ticking prevent leakage into an interior region of the mattress.  
         [0065]     Magnets  182  are provided at the foot end and the head end of the ticking  170  in interior pockets  184  as illustrated in  FIG. 14 . These magnets secure the foot and head end of the bed to the frame or deck. If the frame is metal, no additional magnets are needed. If not, magnets are also provided on the supporting deck or frame.  
         [0066]     The details of the foam foot portion  180  is illustrated in  FIGS. 10-13 . A foam core  186  is corrugated along its length or longitudinal axis. Preferably, the foam is low-ILD, visco elastic foam. Its ILD is in the range of 8-12 and is preferably 10. The length of the foam foot portion  186  may be, for example, 27 inches and is capable of being shortened to 13.5 inches. This is an example of one foot portion. The corrugation allows the foot portion to diminish in length. Also, the load-ILD allows the foot portion to compress upon the weight of the patient. This will help reduce the pressure on the heel. Also, by providing one of the valleys adjacent to the foot end of the foot portion  186 , the heel may rest in the valley and therefore offer a valley or decreased area under the heel.  
         [0067]     A portion of the foam  186  adjacent to the remainder of the deck is tapered at  188 . This mates with a tapering  173  of the foam seat portion  172 . This is to accommodate articulation between the foot portion and the seat or thigh portion. The foot end of the foam  186  has tapered corners  190 . This allows them to lay adjacent to the foot prop  56 .  
         [0068]     Bonded to the bottom of the core  186  adjacent to the deck end is a torque plate  192 , as illustrated in  FIG. 11 . Prior to bonding, half of a male/female snap rivets  194  are inserted through the torque plate  192 . An attachment plate  196  is also bonded to the bottom of the core  186  adjacent to the foot end. Only the cross-half section is bonded and the ends are left free as flaps.  
         [0069]     The core  186  is provided within a slip cover  198  which includes a zipper  200  as illustrated in  FIGS. 12 and 13 . The cover  198  preferably is a shear promoting material, for example, 30 denier ripstop nylon which aids the movement of the foam foot portion in the ticking  170 . The flaps of attachment plate  196  extend through slots  202  in the bottom of the slip cover  198 . This secures the foot end of the core  186  to the slip cover  198 . The other end of the core  186  is secured within the cover  198  by snap rivets  206  extending through straps  204  and to be received in the mating snap  194  of the torque plate  192 . The straps  204  secure the foam of the foot portion  180  to the adjacent seat portion of the mattress within the ticking  170 . The flap ends of the attachment plates  196  extending through the cover  198  are also received in slots  208  of pockets  184  as are the magnets  182  of  FIG. 14 .  
         [0070]     As illustrated in  FIG. 15 , the foot prop  56  has opposed foot support surfaces  55  and  57 . The general shape of the foot prop  56  is trapezoidal in cross-section. The distance D between the parallel surfaces  55  and  57  may be, for example, 2½ inches. A pair of rods  59  extend from the bottom surface of the foot prop  56  and are received in sockets  106  in the second foot section  54 . Although the foot section  16  is shortened or retracted when the deck rotates from its flat or planar position to the chair position, for very short occupants, the foot prop  56  would still not provide support for the feet of the short occupant. In such a case, the foot prop  56  can be rotated 180° with respect to that shown in  FIG. 15  such that the planar surface  57  would be the foot support surface. It would be  2  inches closer to the patient than if surface  55  was the foot support surface.  
         [0071]     As an alternative, a pair of sockets  106  and  107  spaced along the length of the foot section may be provided in each extension  100  as illustrated in  FIG. 16 . The distance E between the sockets  106  and  107  again, may be, for example, 2½ inches. This will allow the foot prop  56  to be moved from sockets  106  to sockets  107  and thereby shortening the end by 2½ inches. Rotating the foot prop  56  such that the surface  57  becomes a support surface, would shorten it an additional 2 inches. Thus, an adjustment of 4½ inches can be obtained using the configuration of  FIG. 16 . Additional sockets may be provided to give additional adjustments.  
         [0072]     It should also be noted that although the cross section of the foot prop  56  is shown as trapezoidal, any cross sectional configuration which provides a differential between the two opposed supporting foot surfaces may be used.  
         [0073]     It is important that the foot prop  56  has the parallel surface  55  as a support surface when the deck is in its planar position and that it is in sockets  106 . Otherwise, it would overlap the mattress and prevent the end section from inflating to the appropriate height. Sensors and controls can be provided in the sockets  106  and  107  as well as some sensible indicia on  59  to indicate which socket it is in and which surface,  55  or  57  is adjacent the foot. Once this is sensed, the inflation of the foot section would be prevented until either the foot prop  56  has been removed or it is in socket  106  with surface  55  being the foot support surface. Also, as previously discussed, the control should not allow the foot section to rotate beyond, for example, 65° with respect to the horizontal if the foot prop is mounted in either of the sockets  106  or  107 . This allows the foot prop to be available when the foot section is in a chair position while preventing it from being used when the foot section is lowered to permit egress.  
         [0074]     Another method of changing the position of the foot support surface of the foot prop  56  greater than that achieved by the adjustment of the foot section  16  of the deck is illustrated in  FIG. 17 . While the foot section  16  is adjusted from its extended to its contracted shortened position, the mattress foot portion  24  is not shortened nor made thinner. The non-shortened portion of the foot portion  24  of the mattress then extends up one of the support surfaces of the foot prop  56  and forming a foot support surface. If the thickness of the foot portion  24  of the mattress  20  is, for example, five inches, this will shorten the length of the foot section by five inches. Also, if the reversible foot prop, as illustrated in  FIGS. 15 and 16  is used, this would add an additional 7½ to 9½ inches of adjustment.  
         [0075]     Although  FIG. 17  illustrates further decreasing the length of the deck in the planar or total horizontal position, the same adjustment can be made as the foot section of the deck and mattress are rotated down from the horizontal position towards the chair position. The controller would have to be modified so as to not simultaneously adjust the height or length of the foot section of the mattress  24  during the rotational and shortening of the foot section of the deck.  
         [0076]     Although the present invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only, and is not to be taken by way of limitation. The spirit and scope of the present invention are to be limited only by the terms of the appended claims.