Abstract:
A folding, lightweight, portable, and rugged surgical operating platform apparatus that can be erected quickly under adverse conditions at any location and without tools other than the users hands and without the need to attach any loose pieces to form the unitary platform. As needed, the surgical platform will hold, support, elevate, move, and tilt a stretcher (or litter in military terms) bearing a wounded person and the portable surgical support equipment such as IV poles, surgical instrument trays, armboards, wrist restraints, leg stirrups, light poles, and other equipment that a surgeon needs to treat major injuries and save lives. In the folded position, the platform takes up limited, uniform space for ease of portability by a single individual. Different users have different applications and requirements for how the platform is supported using stationary supporting legs or wheels when rolling capability are required.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to and the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 61/856,898 filed Jul. 22, 2013, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to an apparatus to be used in the provision of medical services, particularly surgical procedures within adverse field environments. 
         [0003]    When a person suffers a major injury, the immediate next hour is the “Golden Hour” in that the medical treatment received in the first sixty minutes to stabilize the injury and prevent further complications is usually critical in preventing loss of life or limb. 
         [0004]    For soldiers, sailors, and airmen injured in battle, the initial medical treatment is usually “care under fire” provided by a medic or Navy corpsman as close as possible to the time and place of injury with whatever medical equipment the medic or corpsman carries on their person. The medic or corpsman&#39;s critical task is to stabilize the wound and assist in getting the wounded soldier to the nearest medical facility where doctors and surgeons provide more extensive treatment of the wound and stabilization of the wounded soldier before transferring them to a hospital. 
         [0005]    In modern warfare, military doctors and/or forward surgical treatment units are located even closer to the battlefield to stabilize major wounds and save soldiers&#39; lives as soon as possible after the time of injury. In Iraq and Afghanistan today, this often means a surgeon operating on a wounded soldier in a house, hotel, commercial building, tent, or even in the open at or near the time and place of injury. For a surgeon to work effectively on wounded soldiers under such conditions and save as many soldiers&#39; lives as possible, the surgeon needs a platform to hold the stretcher (or litter in military terms) on which the wounded soldier is brought to them. This platform would function as an operating table in a hospital in raising or lowering the patient to whatever height the surgeon requires, tilting the stretcher as needed for various medical procedures, and supporting required equipment such as intravenous poles, surgical instrument trays, lights, patient arm boards, stirrups for lower extremity wounds, and other surgical equipment. 
         [0006]    Thus it can be seen that there is a need for this means a portable, light-weight operating platform that can be carried by one person and erected quickly under adverse conditions at any location to allow surgeons to treat the wounded soldier as quickly and effectively as possible to stabilize their wounds and save their life. 
         [0007]    A similar need exists in the non-military world in situations of mass casualties in natural or man-made disasters. Under normal situations when a civilian suffers major injury, they can be rushed by ambulance or helicopter to a nearby hospital for emergency shock trauma treatment. However, in the event of a mass casualty, roads can be impassable, local hospitals can be overwhelmed, and medical evacuation helicopters insufficient by the sheer number of injured people. In non-military mass casualty disasters as in warfare, the need is for a portable, light-weight operating table or platform than can be carried by one person and erected quickly under adverse conditions at any location to allow surgeons to treat critically injured people as quickly and effectively as possible to stabilize wounds and save lives. 
         [0008]    Another critical problem and need is in the event of biological or chemical attack or “spill.” In this situation, hospitals with formal operating rooms in close proximity may be available, but to prevent contamination of hospitals and surgical operating theaters it will almost certainly be necessary to perform life-saving surgical procedures in a variety of buildings, tents, or other facilities away from the hospitals and other patient treatment facilities. 
         [0009]    The objective of the present invention is to provide a novel apparatus for a portable, light-weight operating platform that can be carried by one person and erected quickly under adverse conditions at any location. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    Among the several objects of this invention may be noted the provision of an apparatus for, as described and shown herein, a folding, lightweight, portable, and rugged surgical operating platform that can be erected quickly, in one embodiment in less than one minute, under adverse conditions at any location and without tools. The basic platform includes no loose pieces that would require assembly or risk being lost in the field. In one embodiment, the platform weighs approximately thirty-four pounds and the platform and its parts and attachments can be folded up to dimensions of approximately 41 inches by 12 inches by 15 inches so that it can be carried by one person. It will hold, support, elevate, move, and tilt as needed a stretcher carrying a wounded person weighing well in excess of at least 400 pounds, including any desired portable surgical support equipment such as IV poles, surgical instrument trays, armboards, wrist restraints, leg stirrups, light poles, and other equipment that a surgeon needs to treat major injuries and save lives. For example, the platform is designed to allow IV poles to be mounted into all four corners of the platform and the platform side rails accept all surgical table accessories that mount on 5/16 inch by 1⅛ inch rails. In the medical field, rail mounted accessories are designed to be compatible with standard rails with these measurements as such the side rails provided will accommodate most standard accessories. 
         [0011]    The platform provides a stable platform for surgery in a wide variety of emergencies and other situations where in-hospital surgical facilities are not readily available. Different users have different applications and requirements for how the platform is supported using the support members, which are outward-canted to provide strength and stability, such as whether or not wheels and rolling capability are required. For some users the need for ultimate lightweight portability combined with maximum platform stability dictates rigid mounted legs, and wheels and rolling capability are not required in such embodiments. In other embodiments, rigid mounted legs can be switched to wheels or vice versa without tools in less than 10 seconds per leg. Where mobility is required, mounting holes in the rigid mounted legs are drilled off-center so that when mounted on the outward-canted support members, caster spindles are vertical so that the casters function properly. 
         [0012]    The height of the stretcher may, in one embodiment, be adjusted from 28 inches to 36 inches without tools to meet the surgeon&#39;s preference by moving the yolk arms up or down with the locking pin. The legs are individually adjustable, such that the platform can be height-adjusted and tilted from end to end, with up to about a 15 inch change in elevation from end to end. Likewise, legs may be adjusted from side to side if on a sloping surface. Preferably, adjustments may be made in less than five seconds using the mounting knob. Having the ability to tilt the platform from side-to-side toward the surgeon makes it easier for a surgeon to work on a wounded soldier or injured person without having to lean over the platform, and should reduce surgeon physical fatigue in day-long mass casualty situations. 
         [0013]    In a preferred embodiment, all swiveling, sliding, and folding aluminum connections between structural elements are separated by ultra-low coefficient of friction virgin polytetrafluoroethylene (or Teflon®) or ultra-high-molecular-weight (UHMW) polyethylene spacers to prevent aluminum self-galling and seizing of mating surfaces, incorporate oil-impregnated bronze bushings, and are held together with stainless steel bolts and deformed-thread self-locking nuts tightened to prevent play. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings in which: 
           [0015]      FIG. 1  is a side perspective view of an embodiment of a portable surgical platform according to the present invention in an unfolded, operational configuration carrying a litter in a substantially level position. 
           [0016]      FIG. 2  is a side perspective view of a portable surgical platform according to the present invention in a fully folded, upright configuration. 
           [0017]      FIG. 3  is a side perspective view of the portable surgical platform of  FIG. 1  in an unfolded operational configuration carrying a litter in the “Trendelenburg” position. 
           [0018]      FIG. 4  is a side perspective view of another embodiment of the portable surgical platform of the present invention in an operational configuration showing the attachment of a number of optional, standard operating table attachments. 
           [0019]      FIG. 5  is an end perspective view of a portable field surgical platform according to the present invention in a partially unfolder configuration. 
           [0020]      FIG. 6  is a detailed perspective view of the folding cross-bars between the support members and the locking brace of an embodiment of the portable surgical platform. 
           [0021]      FIG. 7  is a detailed perspective view of a yoke and yoke arm of a portable surgical platform according to the present invention having a stretcher pole of the litter secured to the yoke. 
           [0022]      FIG. 8  is a detailed perspective view of a yoke arm housing about a yoke arm wherein the spring-loaded pin is positioned within the yoke arm housing in a first vertical position to prevent movement of the yoke arm. 
           [0023]      FIG. 9  is a detailed perspective view of a yoke arm housing about a yoke arm wherein the spring-loaded pin is positioned within the yoke arm housing in a second horizontal position to allow movement of the yoke arm. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]      FIG. 1  is a side perspective view of one embodiment of a portable field surgical platform  118  according to the present invention in an unfolded, operational configuration. Portable surgical platform  118  comprises a rigid support structure, such as a pair of collapsible sides, such as elongated horizontal beams  109 ,  110  (parallel horizontal beam  110  shown better in  FIG. 4 ), supported by a plurality of support members  32  connected to and supporting the horizontal beams. The plurality of support members  32  are preferably arranged in corresponding, opposing pairs  32   a - 32   b , and  32   c - 32   d  spaced apart along the length of the substantially parallel horizontal beams  109 ,  110 . 
         [0025]    When the platform  118  is erected for use, opposing pairs of support members  32   a - 32   b , and  32   c - 32   d  are preferably connected to and rigidly braced apart by a pair of folding, pivotably connected cross-bars  3 ,  4 , said cross-bars  3 ,  4  held rigidly in place by means of a two piece locking brace  2  connected at either end to both of the cross-bars  3 ,  4 , the two pieces of the locking brace  2  joined together, such as by a connecting link  1 . Connecting link  1  may be pulled to straighten the two pieces of the locking brace  2  between the cross-bars  3 ,  4 . The cross-bars  3 ,  4  connect to opposing support members  32  at either end, thereby connecting each pair of support members  32   a - 32   b  and  32   c - 32   d  together and acting as a brace to force the support members  32  apart and maintain the horizontal beams  109 ,  110  substantially in parallel when the platform  118  is assembled for operation. 
         [0026]    The horizontal beams  109 ,  110  are both comprised of two or more submembers  111 ,  112 , such as a first submember and second submember, each submember having an inboard and outboard end, connected by a pivoting hinge  114  that is held rigidly in either an open or unfolded position (shown in  FIG. 1 ) or a folded position (shown in  FIG. 2 ) by a locking means, such as a locking knob  115  or pins or other suitable means. When the platform  118  is unfolded and in its assembled configuration for operation, the pivoting hinge  114  allows the inboard ends of the submembers  111 ,  112  to meet and align such that submembers  111 ,  112  are substantially coplanar and form substantially straight horizontal beams  109 ,  110 . As shown in  FIG. 2 , when the platform  118  is folded into its folded or carrying configuration, pivoting hinge  114  allows submembers  111 ,  112  to lie substantially parallel to each other, and defines an internal space between the submembers  111 ,  112 , leaving room into which the support members  32  may also be folded substantially parallel to the submembers  111 ,  112 . 
         [0027]    Returning to  FIG. 1 , when in operational position, the submembers  111 ,  112  of horizontal beams  109 ,  110  are substantially parallel and are axially aligned, i.e. have a common or substantially common longitudinal axis. In one embodiment, the pivoting hinge  114  is configurable to lock in the folded position, the unfolded operational position, or, preferably, both. The locking means  115  can be automatic, e.g. spring loaded, or manual. In another preferred embodiment, the pivoting hinge  114  is configured to lock automatically in the operational position via releasable internal spring loaded hooks. In one embodiment, releasable, manual latching clamps may be suitably used, such latching clamps (not shown) having a mechanical stop to prevent any unwanted reversal of the mechanism under strain, which locks the submembers  111 ,  112  in position relative to each other. 
         [0028]    As shown in  FIGS. 5 and 6 , the “scissor” action of the pivotably-connected cross-bars  3 ,  4  between the support members  32  allows the platform  118  to unfold for operational use, maintaining the beams  109 ,  110  in parallel, and fold for carrying without the use tools (other than the users hands) or the need to connect any loose pieces to form the unitary platform  118 . Cross-bars  3 ,  4  are connected at a centrally-located pivot point  26 . Portions  27 ,  28  of the cross-bars  3 ,  4 , are also have a hinge point  29 ,  30  to allow the opposing pairs of support members  32   a - 32   b , and  32   c - 32   d , to be pushed together inwardly, collapsing the cross-bars  3 ,  4  until, as shown in  FIG. 2 , the cross-bars  3 ,  4  lie substantially parallel with each other and with the support members  32  and submembers  111 ,  112  of the beams  109 ,  110 . 
         [0029]    In one embodiment, an untrained person can erect the platform from the folded up stage to the operational position ready to receive the stretcher, and with only minimal instruction, the surgical platform of the present invention may be erected from the fully folded, carrying position to the operational position in about 60 seconds or less. 
         [0030]    As shown in  FIG. 6 , each support member  32  is unfolded and locked in position with cross-bars  3 ,  4 . To provide additional stability, a two-piece locking brace  2  and connecting link  1  are provided to brace the support members  21  apart. In one preferred embodiment, the outer opposing ends of the locking brace  2  are connected at the hinge point  29 ,  30  of the portions  27 ,  28  of the cross-bars  3 ,  4 . Connecting link  1  may be pulled to straighten the two pieces of the locking brace  2  between the cross-bars  3 ,  4 . Preferably, connecting link  1  is snugly snap fit about the locking brace when in the straightened, locking position, but may be unsnapped by hand when the platform  118  is to be folded. 
         [0031]    When locked in position, support members  32   a - 32   b  and  32   c - 32   d  are canted outward away from each other from the opposing ends  107 ,  108  of the platform  118 . Support members  32   a - 32   b  and  32   c - 32   d  are preferably positioned at an angle Ω relative to the submember to which it is hingedly connected, said angle being greater than 90 degrees, but less than about 105 degrees from the corresponding submember  111 ,  112 , which range includes all values and subranges therebetween. In the preferred embodiment shown in  FIG. 1 , the individual support members  32   a - 32   b  and  32   c - 32   d  and submembers  111 ,  112 ,  98 ,  99  (shown in  FIG. 4 ) to which it is connected are locked at an angle, for the operational position, at an angle Ω of about 95 degrees relative to one another. This has the desirable result that pushing the platform  118  from one end will not allow the support members  32  to fold up because the outward slant of the support member  32  causes the platform  118  to lift rather than the support members  32  fold inward. As such, the heavier load on the platform  118 , the greater the resistance to the platform support members  32   a ,  32   b ,  32   c ,  32   d  inadvertently folding up. 
         [0032]    A two piece locking brace  2  having a connecting link  1  is connected between the individual support members  32   a ,  32   b ,  32   c ,  32   d  and the outboard end of its corresponding submember  111 ,  112 ,  98 ,  99 . Of course, alternate locking means (not shown), such as a tightening knob or pin, may be provided at the joint or pivot point at which a support member  32   a ,  32   b ,  32   c ,  32   d  is connected to its corresponding submember  111 ,  112 ,  98 ,  99 . 
         [0033]    As shown in  FIG. 1 , support members  32  may be adapted to receive an interchangeable base, such as non-skid, self-leveling feet  55 , wheels  58 , casters (not shown), or a combination thereof. For example, all or only two of the support members  32  may have self-leveling feet  55 , or all or only two of the support members  32  may have wheels  58 . In the embodiment shown in  FIG. 1 , the two support members  32   a ,  32   b  at one end of the platform  118  have wheels  58  affixed, and the two support members  32   c ,  32   d  at the opposing end have self-leveling legs  55  affixed to allow the platform  118  to be moved by a single individual from one end like a wheelbarrow. In the alternate embodiment shown in  FIG. 4 , non-skid, self-leveling feet  55  have been affixed to all support members  32 . 
         [0034]    Where wheels  58  are desired, as best shown in  FIG. 3 , they may be mounted to the support members  32  by means of a releasable connecting device, such as a mounting knob  57 . Wheels  58  may also comprise a break, such as foot-operated break lever  104 , and a swivel lock, such as locking knob  106 , or other control mechanism. Wheels  58  may be formed from any suitable material, but to achieve the desired reduction in weight, the wheels  58  are preferably constructed of expanded foam. 
         [0035]    In a preferred embodiment best shown in  FIG. 4 , support members  32  further comprise leg extensions  43 ,  44 ,  45 ,  46  which may be used to adjust the length of support members  32  (and thus the height of the platform  118 ) as desired. 
         [0036]    Connected to the platform  118  proximate to each corner  100 ,  101 ,  102 ,  103  of the platform  118  is a yoke  48 ,  49 ,  50 ,  51  to adapted to receive the litter or stretcher poles  67  and lock the stretcher  113  to the platform  118 . In the preferred embodiment, a yoke  48 ,  49 ,  50 ,  51  is carried upon a corresponding yoke arm  68 ,  69 ,  70 ,  71  which is pivotably attached proximate to each outboard or distal end of the horizontal beams  109 ,  110  so that the yoke arm  68 ,  69 ,  70 ,  71  may be pivoted to a first position flat, lengthwise along the beam  109 ,  110  when the platform  118  is in the folded position, or pivoted to a second position substantially perpendicular to the beam  109 ,  110  when the platform  118  is unfolded to the operational position. As best illustrated in  FIG. 7 , which is a close-up view of yoke  51 , yoke arm  70 , yoke arm hinge  66 , and a distal end of beam  109 , a yoke arm hinge  66  provides the pivot point for the attachment of yoke arm  70  and is configured so that the yoke arm  70  may only be pivoted when the end of the yoke arm  70  attached to the yoke  51  is fully extended away from the pivot point inside yoke arm hinge  66 . When the yoke arm  70  is pivoted to the second, perpendicular position relative to the beam  109 , the yoke arm  70  may then be adjusted by raising and lowering it vertically, to adjust the height of the yoke  51  relative to the beam  109 . 
         [0037]    As better illustrated in  FIGS. 8 and 9 , in order to place the yoke  48 ,  49 ,  50 ,  51  in operational position, the user will lift the yoke arms  68 ,  69 ,  70 ,  71  to the second position and secure them in place with a securing device, such as a cotter-pin (not shown) or a key ring  14  which engages a spring-loaded pin  18  that extends within the housing  19  of the yoke arm hinge  66  and that is sized to engage with any one of a plurality of slots  23  through the yoke arm  68 . For storage and shipping yoke arms  68 ,  69 ,  70 ,  71  are pivoted to the first position and secured to the horizontal beams  109 ,  110  with releasable connectors, such as snaps  8  (shown in  FIG. 1 ), straps (not shown), latches (not shown) or mating pressure points (not shown). 
         [0038]    As shown in  FIG. 7 , the yokes  51  are suitably designed to accommodate and securely hold in place a stretcher poles  67  having a variety of thicknesses and/or geometrical cross-sections, with the standard stretcher pole  67  diameter being 1.5 inches and having a roughly circular cross-section viewed along the longitudinal axis. The yoke  51  may further comprise a hook (not shown), over-center latch clamp (not shown), or a strap  73  made of nylon, polypropylene, rubber, silicone, canvas or similar high-strength webbing, depending on user preference and requirements. 
         [0039]    As best shown in  FIG. 4 , the platform  118  is configured for the attachment of a wide variety of standard operating table attachments, such as, but not limited to, one or more telescoping IV pole  80 , armboard  90 , surgical instrument trays  62 ,  63   77 , a folding lower shelf  36  (shown in  FIG. 1 ), a fluid containment sheet  61  (shown in  FIG. 1 ), and other surgical or medical equipment. Optionally, on each end of the horizontal beams  109 ,  110  is a mounting fixture, such as hole  79  designed receive and adjustably secure a standard 0.5 inch or other diameter IV pole, light pole, or other 0.5 inch. One or a plurality of holes  79  having other diameters sized to receive any desired post (not shown) may also be provided about the perimeter of the platform  118 . In one embodiment, on the side of the horizontal beam  109 ,  110  in communication with hole  79  is a threaded thumbscrew mounting bracket  78  that may be tightened or loosened to lock the IV pole  80  or other pole rigidly in place with a securing knob  82 , such as in case of an abrupt upward or downward movement of the platform  118  while being transported in a land vehicle or aircraft. In another embodiment, stainless steel tie downs (not shown) are located at each corner, individually rated to approx. 8,000-pound tensile strength. 
         [0040]    Standard operating table attachments, such as folding equipment tray  62  may be mounted on in holes  79  provided about the perimeter of the platform  118 , or may be proved with a slide rail shuttle  34  that engages with slotted side rails  117  formed or attached substantially along the length of the horizontal beams  109 ,  110 . Attachments are held in place using holes  79 , a tightening knob  88  on the slide rail shuttle (shown in  FIG. 1 ), mounting arms  84 , or on brackets (not shown) at the head end of the platform  118 , or a combination thereof. One embodiment of the tray  62  is configured to support anesthetist&#39;s equipment  77  equipped with adjustable arms that are locked in place with a securing knob  83 . Trays  62 ,  63 ,  77  may be configured to fold at a hinge  86  as desired to both conserve space and prevent damage when being transported before attachment to the platform  118 . Trays  62 ,  63 ,  77  may desirably be made from stainless steel or other metal or reusable fiberglass trays. Brackets (now shown) may be provided to support a piece of medical equipment, such as, but not limited to, a ventilator, a vital signs monitor, a surgical piece of equipment, or an anesthetist piece of equipment. 
         [0041]      FIG. 4  also shows optional armboards  90 , which may be attached to the platform  118  in the same manner as trays  62 ,  63 ,  77 . Preferably, armboards  90  are mounted on slide rail shuttles  34  and readily slide on the side rails  117  on the horizontal beams  109 ,  110 , and optionally lock in position with a threaded screw knob  89 . The armboards  90  can be oriented flush in line with the longitudinal axis of the platform  118  as shown in  FIG. 1 , or swivel outward or inward as shown in  FIG. 4  at an angle relative to the beams  109 ,  110  utilizing a pivoting mechanism  92 . A pivoting mechanism  92  allows the armboard  90  to be angled relative to the platform, between 0 and 180 degrees to support the patient&#39;s arm at whatever angle the surgeon wishes, or by swiveling out the surgeon&#39;s way entirely. This range includes all values and subranges therebetween. The armboard  90  may also be configured to angle up or down relative to the plane of the stretcher  113  using a sliding collar  94  adjustment. The armboard  90  may also be contoured to cradle the patient&#39;s arm. Optionally attached to each armboard  90  is, depending on use preference, either a VELCRO-type hook and loop fastener or a latching strap to restrain the patient&#39;s arm onto the armboard  90 . 
         [0042]    As shown in  FIG. 1 , a fluid containment sheet  61  made of PVC-coated fabric or comparable non-porous fabric may be suspended between the beams  109 ,  110  below the stretcher  113  on hooks attached proximate to each corner  100 ,  101 ,  102 ,  103  of the platform  118 . The fluid containment sheet  61  contains bodily fluids and other materials spilling through the stretcher  113  before and during surgery. In a preferred embodiment shown best in  FIG. 3 , the fluid containment sheet  61  further comprises a drain  60  through which all such fluids are funneled into a collection container (not shown), such as a pan, tank, bag, or, preferably, a disposable bag filled with a mass of absorbent crystals. 
         [0043]      FIG. 1  shows one embodiment of a folding lower shelf  36 , which may be optionally attached to the platform  118 . Folding lower shelf  36  may be configured such that it also acts as a reinforcing brace and structural member of the platform  118  when attached. Folding lower shelf  36  comprises an opposing pair of shelf bars  39  connected between support members  32 , preferably connected longitudinally between support members  32  on the same side of opposing ends of the platform  118 . The shelf bars  39  of the lower shelf  36  may be suitably made of 1 inch diameter aluminum tubing. Shelf bars  39  have a connecting link or hinge  52  and, similar to the two piece locking braces  2 , serve to hold the opposing support members  32  rigidly in place. The folding lower shelf  36  further comprises a tear-resistant, flame retardant polymer fabric  37 , such as double-extruded polyester fabric, stretched tightly between the shelf bars  39 . Use of a fabric  37  to form the lower shelf  36  allows the fabric to be more easily carried as a folded or rolled fabric, rather than having a relatively large and cumberson rigid lower shelf (not shown) to span the space created between the shelf bars  39 . When disconnected from the support members  32  and folded in half at the hinge  52 , the shelf bars  39  and fabric  37  can be rolled up together for transport or storage. The lower shelf  36  unfolds as shown and is attached by any suitable means, including a mounting bolt  38  in each of the four corners to a receiver bracket  42  with a retaining knob  47  on the inside of the support members  32  of the unitary platform  118 . Steel inserts may be suitably installed in the receiver brackets  42  such that the mounting bolts  38  of the folding lower shelf  36  thread into steel rather than relatively soft aluminum, thus avoiding deformation caused by overtightening. The lower shelf  36  may be configured to desirably support up to approximately 500 pounds, including all values and subranges therebetween. 
         [0044]    The configuration of the platform  118  may vary significantly. In one embodiment, horizontal beams  109 ,  110  may be 1 inch by 2 inch by ⅛ inch think aluminum tubing, such that it should be sufficiently rugged to stand up to heavy use in the field. The beams  109 ,  110  may have any cross section, such as, but not limited to, square, rectangle, I-beam, trapezoidal, hexagonal, triangular, oval, circular, rounded, or any combination thereof. Although any cross section is possible, it has been found that beams  109 ,  110  having rectangular or I-beam cross sections provide the best strength and nesting capabilities, while allowing for significant amounts of material to be removed as a weight-saving measure without sacrificing the requisite strength of the beams  109 ,  110 . Material may be removed (and weight thereby reduced) by having a plurality of openings  12  in not only beams  109 ,  110 , but also in substantially all structural elements of the platform  118 , including beams  109 ,  110 , submembers  111 ,  112 ,  98 ,  99 , support members  32 , leg extensions  43 ,  44 ,  45 ,  46 , yoke arms  48 ,  49 ,  50 ,  51 , cross-bars  3 ,  4  and locking braces  2 . In one embodiment, the platform  118  will support at least 400 pounds without damage or permanent deflection. This range include all values and subranges therebetween. In one embodiment the platform  118  has been successfully test-loaded with over 600 pounds without damage or permanent deflection. 
         [0045]    Any or all structural elements of the platform  118 , including beams  109 ,  110 , submembers  111 ,  112 ,  98 ,  99 , support members  32 , leg extensions  43 ,  44 ,  45 ,  46 , yoke arms  48 ,  49 ,  50 ,  51 , cross-bars  3 ,  4  and locking braces  2  may be made from any suitable material so long as it is sufficiently durable and operates as shown and described herein. Some exemplary materials include, but are not limited to, aluminum, steel, titanium, bronze, composite alloys or other sturdy metals, polymers, carbon fiber, plastic, ceramics, material composites and combinations thereof. In one embodiment, any or all of the structural elements of the platform  118 , including beams  109 ,  110 , submembers  111 ,  112 ,  98 ,  99 , support members  32 , leg extensions  43 ,  44 ,  45 ,  46 , yoke arms  48 ,  49 ,  50 ,  51 , cross-bars  3 ,  4  and locking braces  2  are resistant to corrosion. Additionally, all swiveling, sliding, and folding aluminum connections may be separated by ultra-low coefficient of friction virgin polytetrafluoroethylene (or Teflon®) or ultra-high-molecular-weight (UHMW) polyethylene spacers to prevent aluminum self-galling and seizing of mating surfaces, incorporate oil-impregnated bronze bushings, and held together with stainless steel bolts and deformed-thread self-locking nuts tightened to prevent play. 
         [0046]    To facilitate the purpose of portability over large distances by a single individual which is a primary object of the invention, the platform  118  is preferably constructed from lightweight materials providing sufficient strength to be used as an operating table. Preferably, the unitary platform  118  weighs as little as possible. A preferred embodiment weight as little as about 45 pounds. When the unitary platform  118  is supplemented by the addition of optional equipment such as a lower shelf  36 , armboards  90 , and surgical instrument support trays  62 ,  63 ,  77 , the combined weight of the platform  118  and optional standard operating table attachments may weigh only up to about 60 pounds. As already noted, the platform  118  and any of its components may be suitably made from any material, including metal aluminum, steel, titanium, bronze, allow composite, polymer, carbon fiber, plastic, or combinations thereof. 
         [0047]    In one embodiment, the platform  118  is readily and quickly height-adjustable to provide a comfortable working height for surgeons of various heights and personal operating preferences. In one embodiment, the height of the platform  118  may be adjusted over a range of about 6 to 28 inches from the lower end of the support members  32  to the yokes  48 ,  49 ,  50 ,  51 , which range includes all values and subranges therebetween. The height may be adjusted by adjusting the connection of leg extensions  43 ,  44 ,  45 ,  46  to support members  32  by making such connection at any one of the plurality of adjustment slots  96  positioned incrementally along the length of the leg extensions  43 ,  44 ,  45 ,  46 . Any one of the support members  32  may be independently height adjustable from the other support members  32 . The height of the platform  118  may be adjusted such that the entire platform may be raised or lowered uniformly (i.e., all support members  32  and leg extensions  43 ,  44 ,  45 ,  46  connected to have the same length), or one end may be raised or lowered, or one side may be raised or lowered as appropriate. Any means of making connections for the height adjustment may be used so long as it is sufficiently durable and has a raising and lowering function. Exemplary but non-limiting examples of height adjustment means include clamp, knob, friction fit, self-leveling ratchet type, screw type spring pin, and the like. 
         [0048]    As discussed above in connection with  FIGS. 7 ,  8  and  9 , in addition to the height adjustment using the support member, the platform  118  may suitably include an independent adjustment means to allow for the raising or lowering of the stretcher  113 . Independent adjustment members such as yoke arms  68 ,  69 ,  70 ,  71 , allow for the adjustment of the height of either end of the stretcher  113  above the beams  109 ,  110 . By raising the height of the yoke arms  68 ,  69  on one end of the platform  118  to a first height, but leaving the opposing yoke arms  70 ,  71  at a different second height, the stretcher  113  may be tiled up to 25 degrees from end to end independently of the platform  118 , which range include all values and subranges therebetween. This independent adjustment suitably allows the movement of the patient into the “Trendelenburg” position, a common critical surgical procedure in which the patient is tiled head-down such that the patient&#39;s heart is higher than the brain. 
         [0049]      FIG. 2  shows a side view of a portable field surgical platform  118  in a folded, upright configuration, according to the present invention. In this configuration, the platform  118  folds to fit into the space of a cube approximately 41″ by 12″ by 15″, but the present article should not be limited by size, so long as it is sufficient to support a stretcher  113 . This folded-up position is one position that allows for easy transport and stowage, for example, as it would be carried by one person manually, or in a land vehicle, emergency vehicle, ship, or aircraft. 
         [0050]      FIG. 7  is a detailed view of one embodiment of a portable field surgical platform  118  wherein yoke  51  and yoke arm  70  are in a raised position. The stretcher  113  is dropped into place, and a metal hook (not shown) or folding strap  73  is placed over the stretcher pole  67  and fitted into a retaining bracket (not shown) on the back side of the yoke  51 . In cases where of a metal hook is used (not shown), the latch clamp locks in an over-center position with a force that may, for example, be adjustable by self-locking nuts (not shown) on the clamp. This clamp can also be spring-loaded to automatically spring open when unlatched or closed when receiving the stretcher pole  67  should surgeons so desire.  FIG. 7  shows one embodiment of the platform with the stretcher  113  locked in place using a strap  73 , which may include one or more eyes, openings, or grommets to receive and engage a hook or post or it may include a VELCRO type closure, snaps, or buckle, or any combination thereof. 
         [0051]    Although this invention has been disclosed and described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms is only by way of example and that numerous changes in the details of operation and in the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.