Abstract:
The invention employs the principle that the force of buoyancy received by a body immersed in a liquid is determined by the density of the liquid and the extent or depth of immersion in the liquid and is unrelated to the displacement of the liquid by the body, thereby reducing the total size and weight of devices providing buoyant support. Buoyant support is provided to bodies in a manner that permits devices to be made for the measurement of both small and large weights and for support of the human body for the purpose of relieving the pressure induced trauma and skin abrasion otherwise incurred by bedridden patients, such as burn victims and those requiring extended or continual bed rest. A tub-like cavity that closely conforms in size and shape to the part of the body to be immersed is made to contain and float a human body on a volume of liquid that equals only a fraction of the body&#39;s weight. Buoyancy may thus be increased by increasing the density of the liquid without undue expense and it also becomes both practical and convenient to add soothing emollients, as well as more specifically prescribed topical medications, to the supporting liquid for automatic distribution and application. Restricted range of movement and the minimal presence of liquid permits an immersed patient to be left relatively unattended without the usual drowning hazard.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    Continuation in part of my application Docket D-7211(1156), Ser. No. 09/496,467 entitled “Buoyancy Devices Using Conformal Cavities”, filed Feb. 2, 2000 
     
    
     
         [0002]    A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.  
         STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0003]    Not applicable  
         REFERENCE TO A “MICROFICHE APPENDIX.” 
         [0004]    Not applicable  
         BACKGROUND OF THE INVENTION  
         [0005]    1. Field of the Invention  
           [0006]    This invention relates to devices made for the liquid immersion of bodies in order to obtain the buoyant support of the immersing liquid, and more particularly to the applicant&#39;s devices made to function with a quantity of immersing liquid that weighs less than the supported body without loss of buoyant force. Embodiments include devices that determine the weights of items added to the weight of the supported bodies and a device made for the immersion and beneficial buoyant support of the human body.  
           [0007]    2. Background Information  
           [0008]    Background information pertinent to the applicant&#39;s invention includes the applicant&#39;s published observation that:  
           [0009]    A body, placed in a liquid, is buoyed up by a force equal to the weight of the volume of liquid it displaces in a space not closely confined, and buoyed up by the same force within a cavity having a close horizontal spacing from the body, wherein displacement of a lesser amount of the liquid is made to immerse the body to the same extent.  
           [0010]    The above is one of the applicant&#39;s several revisions of the standard or conventional statements which have long represented the buoyancy laws. Such conventional statements typically read “A body placed in a liquid is buoyed up by a force equal to the weight of the liquid it displaces.” 
           [0011]    The fact that a floating body displaces its weight of the liquid in which it floats, in a majority of circumstances, wherein sufficient liquid exists, appears to have led to a wide belief that such a displacement is essential, which it is not. This common equality of body and displaced liquid weights has led to the somewhat overly simplified and misleading formulation of statements which represent the buoyancy laws, as they have been so widely taught. The truth of the matter is that a body placed in a liquid can be buoyed up by a force that greatly exceeds the weight of the displaced liquid, given the proper circumstances and that the weight of liquid displaced by an immersed body can be unrelated to the force of buoyancy it creates. This relatively unsuspected and rarely appreciated fact has an ignored utility, not only in applied physics of design but in explaining geophysical phenomena. The applicant has vigorously sought to make the statements of buoyancy law more factually representative.  
           [0012]    While the applicant&#39;s determinations, regarding the herein described exception to the established statements of buoyancy law, were the result of independent observation, he was subsequently made aware of an article entitled “CONCEPTUAL EXAMPLE 9 * How Much Water Is Needed to Float a Ship?” in the publication “Physics”, 4th Edition, Volume 1, page 321, published in 1997. This had the effect of making the applicant&#39;s contentions, which were previously regarded as violations of physical law, far more credible. The article also made it evident that the physical principle was considered remarkable.  
           [0013]    The Physics article indicated an understanding of the principle employed by the applicant in his invention. However it apparently failed to convey this understanding in the included example. The Physics article makes a great point of the fact that a “very small volume” of liquid that could “fit into a single glass” could be used to float the depicted ship in the canal (Part c of FIG. 11. 21 ) when the walls of the canal and the sides of the ship are closely spaced. However, there is no such limitation to a “very small volume” of supporting water in this depicted scenario. While the close spacing of the canal sides would certainly limit the volume of water between the ship&#39;s hull and canal sides, the bow and stern, which are integral parts of the ship&#39;s immersed hull structure, have access to virtually unlimited volumes of supporting water. The total volume of liquid responsible for the floating of the ship is not limited to a “very small volume” as the physics article states. This may have been confusing to anyone trying to justify the article&#39;s broad statements in light of its explanations regarding the illustration. In short, the vessel is obviously floating on a great deal more than would “fit into a single glass.”. This article fails to disclose the applicant&#39;s conformal cavity which would surround the entire ship and which would be required to permit such a phenomenon.  
           [0014]    A dictionary defines a cavity as “an unfilled space within a mass” or as “a space hollowed out” and a canal as “an artificial waterway for navigation or for draining or irrigating land.” Two opposing sides of a canal cannot define a cavity. Any fore and aft canal end walls, if any could be thought to be present, could not be expected to exist except in a distant and remote sense. Side walls alone cannot provide the function of creating a condition that will permit the ship to be supported by a volume of liquid that weighs less than the vessel, much less than that which would “fit into a single glass.” 
           [0015]    Perhaps the article should have described a lock, rather than a canal, but none was disclosed, inferred or suggested. A lock-like conformal cavity containing a ship is shown in the applicant&#39;s drawings. The drawings could represent a large ship, as the included spectator family figures would suggest, but also a small toy-size ship and cavity made for use in demonstrating the applicant&#39;s principle based on revised buoyancy law.  
           [0016]    In a conformal cavity, water can be seen to rise rapidly and very markedly about the body when immersed. This would be an excellent visual evidence that a conformal cavity is neither depicted nor described in the article. The immersion of the ship in a typical canal could be expected to have little perceptible effect on its water level.  
           [0017]    The principles of buoyancy can be attributed to, and otherwise explained as simply the effects of hydraulic pressure, applied by the liquid as a result of liquid density related to depth, but the observable conformal cavity effect is that of a hydro-mechanical advantage. For example, the fact that a small weight at the long end of a fulcrum supported lever can lift a larger one at the short end of the lever is readily appreciated, but the advantage given to a small weight of liquid, working within a conformal cavity to lift the larger weight of a floating body, is not readily understood or appreciated.  
           [0018]    The applicant&#39;s inventions involving conformal cavities, have most frequently been considered to violate natural law. When a buoyant body is placed inside its conformal cavity before adding liquid, its seems incredible that a small fraction of the body&#39;s weight of liquid added to the cavity can be shown to flow down, under the body and lift it into a fully floating position.  
           [0019]    Perspective is important to understanding, as we can see in the following instructional experiment. A smaller bowl is placed inside a slightly larger one of similar shape, with the smaller bowl being made capable of floating low enough in water to bring the bowl surfaces close together when the smaller one floats inside the larger. If the larger one is filled with water to the overflowing level and the smaller vessel is then carefully inserted, the smaller floating bowl will be found to have have displaced its own weight in the water that overflows, in accordance with Archimedes&#39; principle, when the smaller bowl has sunk to its floating level.  
           [0020]    At this point, the displaced water is known to have a weight equal to the weight of the floating bowl, flotation has occurred and all may seem quite in keeping with conventional statements of the buoyancy law. However, the weight of water that equals that of the floating bowl is no longer in the bowl and can no longer be considered to be a factor in the matter of the buoyant effect.  
           [0021]    If the floating bowl is now removed, it can be seen that a comparatively small amount of water remains in the larger bowl, an amount far less than the amount that overflowed and therefore much less than that which would equal the bowl weight, yet this was the small weight of water which was able to support the larger weight of the bowl within the conformal cavity created by the larger bowl when the larger amount was eliminated.  
           [0022]    When the smaller bowl is reinserted into the larger, it will be noted that the smaller bowl floats as before. However, this time it will be very apparent that the smaller bowl has not displaced its weight in water, since such an amount is not available to be displaced. Displacement of the lesser weight of water in the confined space between the walls of the smaller and larger bowls has enabled it to rise rapidly to the flotation level of the smaller bowl and thereby to support the greater weight of the smaller bowl.  
           [0023]    In this perspective at least, it now appears that we can achieve flotational buoyancy by either displacing a volume of water equal to the weight of the floating body or by creating a condition that duplicates the condition that would exist after such a weight of water has been displaced, if it had been available for displacement, without actually requiring its presence or its displacement.  
           [0024]    In the instance of a body floating in an abundance of liquid, under comparatively unrestricted circumstances, it can now be shown that the greater quantity of liquid, that exists beyond a thin surrounding layer, and which would including the body&#39;s weight of displaced liquid, actually offers only a physical support that can be replaced by substantially rigid walls such as those forming a conformal cavity.  
           [0025]    A conformal cavity efficiency value CCE, expressing the effectiveness of its horizontal confinement, can be calculated by dividing body weight minus immersed body weight BW-IBW, by weight of the immersing liquid LW.  
                         
 
           [0026]    with a higher number indicating a greater efficiency.  
           [0027]    Where densities and liquid level permit flotation, IBW=0 and LW should be taken as the value of least liquid required for flotation. Where denser bodies are fully immersible, LW should be taken as the weight of the least liquid required to fully envelop the body.  
           [0028]    It is evident that the applicant&#39;s revised law of buoyancy may provide considerable insight into the physical laws governing geophysical mechanics.  
           [0029]    When fragments and masses of ice, and/or soil, are recently separated they may frequently occupy naturally conformal cavities by virtue of their separation, and their narrowly spaced surfaces may then become further separated by intrusive water and the resulting buoyant effect. The law of buoyancy, as revised by the applicant, provides for the possibility of buoyancy afforded by minimal water contained within such conformal cavities, and may provide explanation for many unexpected instances of ice and soil looseness and motility, that are not otherwise adequately explained. Where the discrete segments of a multi-fractured mass become separated by narrow water-filled crevices, the segments may have complex functions, and be both contained and containing, both confined and confining, in the effect that such buoyancy has on the whole of the mass, in accordance with the applicant&#39;s buoyancy law revisions.  
           [0030]    Such flotation processes may occur within the earth&#39;s crust, at subterranean levels, in the presence of water or even oil, and also below the earth&#39;s crust, where such flotation may occur within fracture created conformal cavities with molten material as the liquid.  
           [0031]    Since a maximum buoyant force can be exerted by a minimal, marginal quantity of liquid within the conforming walls of fissures, it may be expected to contribute greatly to the destruction of geological masses, although evidence may not always be exhibited to readily identify the cause. A considerable amount of conformally augmented lift may occur and have effect, but body density may be too great to permit flotation and some body-like sections may function as bodies in this respect, reacting to buoyant force before becoming fully detached and independent and thus hastening their detachment.  
           [0032]    Much more can be understood about the processes of wet avalanche once the applicant&#39;s revised law of buoyancy is fully understood and applied; once it is realized that the force of buoyancy is related only to the extent of immersion and that the amount of the liquid required to achieve it is irrelevant. The bodies involved in the mass of an avalanche expectedly reside on a slope and benefit from the run-off that the incline provides, not normally achieving a simultaneous extent of water immersion that would afford them the contribution to motility that a mutually achieved and substantial loss of weight would provide, most particularly when the bodies are discrete and have an appreciable degree of separation. However, if an upper level portion of the mass should begin a downward movement and push the bodies of the next level closer together, all of this changes. A relatively rapid “crowding” of the bodies in successively lower levels will result and materially contribute to the motility of the whole as a result of the following. The space between the bodies is suddenly reduced and the small amount of water in such interstices is thus made to rise to temporarily high levels that increases their extent of immersion, perhaps to the extent of submersion for a maximum weight loss, before the water can flow away. Such bodies will thus be much more easily moved against those at the immediately lower level and the wave of sequential crowding that ensues will provide a surprisingly powerful facilitating force of an increased buoyancy effect in the avalanche process.  
         BRIEF SUMMARY OF THE INVENTION  
         [0033]    The applicant&#39;s invention includes conformal-cavity embodiments that provide a simplified way to measure weight and that can be economically made in especially large sizes. One such embodiment can measure weight without appreciable downward deflection of the buoyant body when such weight is added to that of the floating body, while another employs such downward deflection as a means of measuring such added weight.  
           [0034]    The applicant&#39;s invention also includes an embodiment in which a lightweight tub-like conformal-cavity structure provides the buoyant support of a human body with a minimal requirement of liquid, so that lighter materials may be used in the tub structure and no more than normal bed space need be required for an entire support assembly. This makes it practical for buoyant support to be provided on an extended basis, as might be required in the care of burn victims, or on a continual basis as might be beneficial for comatose patients. The use of a minimal amount of liquid also makes it economically practical to add various salts to the liquid for the purpose of increasing its density and thus its force of buoyancy. It also makes it economically practical to include soothing emollients in the composition of the liquid and to use the liquid as a medium for the distribution of more specifically prescribed medications to the immersed portions of the body so that the patient&#39;s skin need not be disturbed by touching.  
           [0035]    The benefits of a liquid immersion, that provides the benefits of buoyant support is well known and widely employed in rehabilitation of the injured and those suffering from any debilitating condition that is exacerbated by the gravitational effect of body weight. Such benefits are normally obtained by immersion in liquids contained in relatively large pools or tubs which hold an excess of liquid. The weight of such excesses of liquid, in addition to the body weight of the patient, make strong containment structures necessary and this adds more to the total weight.  
           [0036]    Many physically handicapped patients must be continually assisted when placed in structures containing an excess of water and even the more able patients must be carefully monitored to prevent drowning. If they cannot tolerate the physical contact necessary for assistance and/or are comatose or otherwise unable to control their own body positions to any appreciable degree, they are not likely to receive the benefit of a buoyant immersion.  
           [0037]    While buoyant support does not remove the downward pressure effects of gravity, it does distribute the pressure of its support to such a degree as to simulate much of the effect of a weightless condition.  
           [0038]    While visco-elastic foam materials have provided improved support when related to other resilient materials they fall far short of the distribution of support that is automatically afforded by buoyancy in a liquid immersion. However gentle the physical contact of a solid or semi-solid surface, it can still have an abrasive effect on sensitized skin. There is a need for a relatively small and lightweight device that can contain a human body and the liquid necessary for buoyant support, that also eliminates the need for continual patient handling and the careful monitoring required to prevent drowning.  
           [0039]    A common object of the invention&#39;s embodiments is to provide a force of buoyant support that is equal to the weight of a volume of supporting liquid that is equal to the volume of the immersed portion of the body while using a volume of the liquid that weighs far less, so that the total size and weight of the embodiments can be minimized and made less than devices that use volumes of liquid that equal or exceed the volume of the immersed portion of the body.  
           [0040]    Another common object of the invention&#39;s embodiments is to provide buoyant support with a reduced requirement of liquid to make the use of liquids of greater density economically practical for the purpose of increasing buoyant support,  
           [0041]    Still another common object of the inventions embodiments is to provide devices that have a practical utility and can also be conveniently used to demonstrate the buoyancy principle they employ.  
           [0042]    An object of two specific embodiments is to provide simplified, nearly frictionless devices that measure weight, require little maintenance and can be economically made in very large sizes.  
           [0043]    Another object of a specific embodiment is to provide a simplified device for the measurement of weight that avoids the need for any substantial downward deflection of the buoyant support body in order to obtain its measurements.  
           [0044]    A further object of a specific embodiment is to provide a buoyant support for the human body that substantially eliminates the friction and pressure effects on skin and subcutaneous tissues that can be caused by contact with solid or even semi-solid surfaces.  
           [0045]    A still further object of a specific embodiment which provides such support, using a minimal amount of liquid, is to make it economically feasible to add salts to the support liquid to increase its density and obtain increased buoyant support and to add emollients and topical medication to the support liquid that will soothe and otherwise benefit the tissues of immersed body surfaces.  
           [0046]    Following the applicant&#39;s independent recognition that bodies immersed in a liquid within closely spaced conformal cavities can receive a buoyant force that greatly exceeds the weight of the liquid, he has devised several novel employments of this principle which were considered impossible by those led to believe, by the conventional wording of buoyancy laws, that a body must displace its weight of liquid in order to float.  
           [0047]    While there may have been a severely restricted recognition of the unstated buoyancy law that underlies the applicant&#39;s employed principle, there appears to have been no known utilization or practical application nor any notable appreciation of its value as applied to explanations and predictions of geophysical occurrences, prior to informations internationally disseminated by the applicant. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0048]    The objectives and principles of the invention and the embodiments thereof will best be understood by reference to the accompanying drawings wherein:  
         [0049]    [0049]FIG. 1 and FIG. 2 depict a generic ship afloat within a conformal cavity using a cross-section and a longitudinal-section respectively. The inclusion of a spectator family simulation in the drawing infers its size to be at least the equivalent of an ocean-going vessel.  
         [0050]    [0050]FIG. 3 and FIG. 4 depict a simple flotation device that can be used to demonstrate the employed buoyancy principle. The device is shown using a longitudinal-section and a cross-section respectively. Beyond its value as a simple tool to demonstrate the applicant&#39;s employed buoyancy principle, its self-leveling platform can be used to as a mount for such things as a, magnetic compass or a laser leveling device.  
         [0051]    [0051]FIG. 5 and FIG. 6 depict a relatively narrow vertical column consisting of an outer conformal cavity column and an inner buoyant body column in which weight additions to that of the buoyant body can be measured by varying the water level and without requiring appreciable downward deflection of the buoyant body. This device is also shown using a longitudinal-section and a cross-section respectively.  
         [0052]    [0052]FIGS. 7 through 10 depict a tub-like cavity that is made or formed to closely conform to the shape of a human body for the purpose of providing a floating support for the body when placed in a supine position. The device is shown in a longitudinal-section in FIG. 7 and three cross-sections, FIGS. 8.  9  and  10 , which are representative of sections taken at intervals along the length.  
         [0053]    [0053]FIG. 11 and FIG. 12 depict a relatively broad vertical column consisting of an outer conformal cavity column and an inner buoyant body column in which weight additions to that of the buoyant body are measured using downward deflection of the buoyant body. This device is also shown in the figures using a longitudinal-section and a cross-section respectively. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0054]    [0054]FIG. 1 shows a cross-section of a ship  15  of generic design, which is afloat on water  16  in a cavity  17  that is embedded in the earth and has been made or formed to closely conform to the immersed portion of the ship&#39;s hull. The small simulated figures of a family of spectators are included to indicate relative size. This drawing is included to illustrate the fact that the principle is not limited by the size of the involved structures. However, the combination of the depicted ship and cavity may also be miniaturized and employed as a colorful toy-like demonstration device.  
         [0055]    [0055]FIG. 2 is a reduced longitudinal-section view of the same ship  15  shown in FIG. 1, showing that the conformal shaping of cavity  17  extends to the fore and aft portions of the ship&#39;s hull as well as the sides. The conformal cavity  17  must surround the immersed body to provide its function.  
         [0056]    [0056]FIG. 3 is a vertical-section view of an embodiment that provides a platform topped buoyant body  18  which is automatically maintained in a self-leveling attitude, in conventional fashion, by virtue of its flotation, but with the advantage of having a greatly reduced propensity for liquid wave perturbations in its leveling motions due to having its buoyancy generated by a thin layer of liquid  21  between the body  18  and the inner cavity surface  19  of cavity support structure  20 .  
         [0057]    [0057]FIG. 4 is a horizontal cross-section of the embodiment shown in FIG. 3, taken just below the level of liquid  21 .  
         [0058]    NOTE! The spacings between the buoyant bodies and the walls of their respective conformal cavities, which are ideally minimal, have been exaggerated for clarity in the drawings.  
         [0059]    One of the many beneficial attributes of conformal cavities, lies in the ability to greatly increase the buoyancy of a floating body without the usual increase in downward deflection. For example, under open water conditions, if a cylinder is partially immersed to a depth of one foot, it can double its buoyant force by doubling the extent of immersion which requires descending another foot. When the body is immersed within a conformal cavity doubling the extent of immersion may only require that the body descend a fraction of this amount, perhaps one or two inches. Where the spacing between body and cavity walls remains constant at differing levels of body descent, the efficiency of the combination remains constant but if the walls tend to move closer together with body descent, efficiency increases and the liquid rises to increase immersion at an ever increasing rate.  
         [0060]    When enough liquid is present within the conformal cavity to achieve flotation of a contained body, small amounts of additional liquid may raise the body only slightly more. However this availability of this small amount of excess liquid can represent a large amount of potential buoyancy force. If the weight of the floating body is increased, a slight descent within the conformal cavity can cause a relatively great increase in extent of immersion since only a small amount of liquid is required to fill the space between the body and the cavity.  
         [0061]    A weight measurement embodiment employing a descent of the buoyant body, and calibrated to indicate weight according to descent, is shown in FIGS. 11 and 12. However, in the instance of an embodiment permitting liquid to be added and/or removed from the cavity, no appreciable downward deflection is required to accomplish weight measurement. An embodiment such as this is shown in FIGS. 5 &amp; 6. In this embodiment, enough liquid  30  is added to the conformal cavity  23  of column  22  to lift the buoyant body  28  to a position that brings it into a gentle contact with the upper limiting walls of  22  at aperture  25 , and this water level registered as equal to a zero reading on scale  24 .  
         [0062]    The space between the buoyant body  28  and cavity  23  within cavity support column  22  is then further filled to the maximum level limited by air vents  26  and  27  to increase buoyant force, with the body restrained against further lift by the upper limiting walls of the cavity support structure  22  at its aperture  25 . Weights added to that of the body  28 , by positioning on its included platform  29 , that do not exceed the capacity of the device and cause immediate deflection, can then be measured by removing liquid through inlet-outlet  31  until a downward deflection begins. The liquid level at this point can be made to represent the added weight and a series of known weights can be used to empirically generate a series of representative liquid levels to determine the calibration of scale  24  for its use in subsequent measurement. Such a series could also be mathematically determined for calibration using a constant that reflects the body-conformal-cavity efficiency characteristic of the device.  
         [0063]    The conformal cavity support column  22  is shown resting on an optional support block  45 , but in very large installations, such as would be designed to measure vehicular weights, the conformal cavity column  22  would be embedded in the earth, with or without such a support  45  and to the extent that platform  29  would be substantially located on-grade or at ground level.  
         [0064]    In use, this embodiment could employ a reversible pump to remove liquid to obtain a measurement and then to replace it in preparation for the next measurement. However a means to accomplish this without the use of a pump requires only that an expendable liquid such as water be added through one of the air vents,  26  or  27  at the top of conformal cavity  22  to prepare for measurement and be gradually removed to accomplish measurement by draining through inlet-outlet  31  using a valve release mechanism or other known means of controlling the flow from inlet-outlet  31 .  
         [0065]    Numbered scale  24  shown as part of FIG. 5, would not be visible in such a sectional view, but is an image superimposed upon the sectional view in the approximate position that it would occupy on either the outer surface of buoyant body  28  or the inner surface  23  of the conformal cavity support column  22 . Scale  24  may also be placed on the exterior surface of  22 , but this is not preferred since it would be at a greater distance from the liquid level to be read and therefore inherently less accurate.  
         [0066]    Whether the scale  24 , by which the water levels are to be read in order to determine weight, is placed on the outer wall of buoyant body  28 , or either the inner cavity surface  23  or the outer surface of cavity support column  22 , at least a portion of the wall of conformal cavity support column  22  will need to be made transparent or otherwise able to transmit an image for a direct reading. However, this does not preclude the reading of the water level by external and indirect means, common to boilers and the like in the past, wherein a narrow, vertically mounted, transparent tube gauge was used for reading the internal water level. In the case of below ground installations, remote reading of the water levels would most likely be employed either by means of video viewing devices or by the use of water level sensors.  
         [0067]    [0067]FIGS. 7 through 10 depict an embodiment that employs a conformal cavity to support a human body. The purpose of this embodiment is to provide improved hydrotherapeutic support for the bodies of patients who have special needs such as burn victims or those who are confined to bed for extended periods, even a lifetime, and who may suffer from physical deterioration of the skin and consequent infections. In addition to beneficial effects for the skin, damage to subcutaneous tissues will be virtually eliminated, particularly those which are traumatized by pressures developed between bone and bed.  
         [0068]    The therapeutic effect of this buoyant support is substantially equal to that obtainable in pools but is provided with a minimal amount of fluid. Since such small amounts are required, it is practical to prepare special solutions that contain salts which may be used to increase liquid density for greater buoyant effect and emollients to soothe the skin while acting as a distribution medium for the application of medications. The greatly reduced need for liquid in a conformal cavity in creating a buoyant support allows for a lightweight cavity structure that can be easily placed and handled in conventional hospital rooms as well as residence bed rooms. The minimal requirements of liquid will also allow patients to be safely left unattended for extended periods without the usual risk of accidental drowning.  
         [0069]    Horizontal tub-like models similar to  33  could be custom formed to the individual. Since such small amounts of liquid  34  would be required, the patient whose body is shown as  32  could sleep in such supportive conformal-tubs without the hazard of tub-drowning. The shape of the tub-cavity inhibits turning and when the person is not in the tub the small amount of liquid tends to form small, very shallow, non-hazardous pools in the lower areas. Placing the patient into the tub will cause the liquid in these lower areas to quickly rise about the body to create the desired extent of immersion and thus generate the desired buoyancy.  
         [0070]    While most persons will have a body density low enough to cause the torso to be fully floated within the cavity, some may not, even with a liquid of increased density. However, those having a greater body density will still lose a majority of their body weight when immersed, just as they would in a pool, but without the risk of sinking below the surface or being otherwise subjected to the aforementioned drowning hazard.  
         [0071]    It is anticipated that most instances of need will require use of a horizontal body cavity to support the body in a supine position. This would be particularly useful for comatose patients or to provide improved rest for those who are paraplegic or otherwise physically handicapped. While this is shown as a preferred embodiment, it should be understood that a vertical, conformally shaped body enclosure is well within the scope of the invention. Such vertical cavities would take up little floor space and be desirable in some cases, most probably for ambulatory patients needing rehabilitation or simply those individuals who have relatively little medical need but who would desire the use of the horizontal and/or the vertical cavities as a means of increasing relaxation and comfort during rest periods.  
         [0072]    Since some cavities of general shape and size might be found suitable for more than one individual, and could be employed without modification in emergency instances, direct use of such generalized tub devices is not to be precluded. However, it is anticipated that such sizes and shapes should be customized for greater efficiency when time permits. Since little more than the patient&#39;s body weight need be supported, lightweight conformal-cavity tubs could be made from materials such as fiberglass.  
         [0073]    The process of customizing the more generalized conformal cavities for efficiency might include placing the patient&#39;s body in a larger but similarly shaped cavity and then filling the excess space in the cavity with a quick hardening polymer foam such as that used to fill compartments in boats. In a process like this, care should be taken to make sure that any heat, generated by the hardening foam, is not excessive, and to take steps to prevent adherence of the foam to the patients skin.  
         [0074]    The combination of patient, liquid and conformal cavity support requires less than the width of a standard single bed. The patient will rest unclothed, with catheters and intravenous attachments and the combination be simply covered with a sheet or blanket. Equipment can be provided, as part of the cavity assembly, to keep the liquid at body temperature, or at whatever temperature is considered beneficial to the patient.  
         [0075]    In the longitudinal-section of FIG. 7, a human body  32  is shown in a supine position, immersed in liquid  34 , with both body  32  and liquid  34  contained within a conformal cavity structure  23 . While not particularly representative of a typical patient, a well developed male figure was chosen for depiction because contour differences are extreme and more clearly defined  
         [0076]    The fact that parts of the body vary in density has been taken into consideration. While the density of the liquid  34  may be adjusted to equal or exceed that of the torso of the body  32  and effectively cause it to float, the liquid is contiguous and substantially uniform in density within the cavity during immersion and while the limbs  35  and  36  will be greatly reduced in their effective weight, their expectedly greater density may cause them to sink below the level of the liquid  34  and to rest gently against the bottom of cavity structure  33 . This is shown in the cross-section views of FIGS. 8 and 9. The cross-section view in FIG. 10, including the body  32  without limbs  34  and  35 , shows the approximate shape of the torso at maximum upper body depth. The view in FIG. 8, including arms  36  shows the approximate shape of the body  32  just above the waist and the approximate shape of the arms  36  just below the elbow. The view in FIG. 9, excluding the torso and including legs  35  shows the approximate cross-sectional shape of the legs  35  just below the knee.  
         [0077]    The major effect of this embodiment of the applicant&#39;s invention is that human body  32  immersed in liquid  34  within conformal cavity structure  33 , is relieved of the major pressures associated with support by means that require contact of the skin with relatively solid, non-liquid surfaces. Even foam materials, which distribute such pressures more evenly, must have some solid contact which can irritate sensitized skin. As a liquid,  32  can also contain density increasing salts for the generation of increased buoyant force and has additional value in that it can be made to contain skin soothing emollients which will be continuously applied and be made to serve as a readily available distributing medium for the application of more specifically prescribed topical medications so that that the patient need not be disturbed by touching.  
         [0078]    A buoyant body and conformal-cavity combination such as that depicted in FIGS. 11 and 12 can be used to demonstrate the principle of the conformal-cavity-buoyancy effect and to form a weighing scale by including a numbered scale  42  against which the user can read the changes in water level or body height caused by additions to weight of buoyant body  38  and relate them to a system of weight measurement. As in FIG. 5, this scale would not be visible in a sectional view and is an image that is superimposed upon the sectional view in the approximate position it would have on either the outer surface of buoyant body  38  or the inner surface of conformal cavity structure  37 . If the scale is placed on the immersed buoyant body  38 , the scale will move with the body, relate its reading of water level to the extent of body immersion in liquid  39 , and benefit slightly from being a more expanded, and therefore slightly more accurate reading. If the numbered scale  42  is placed on the inner wall of cavity  37 , it may benefit slightly by being stationary and will relate its slightly compressed reading of water level to the rise in liquid level within the cavity.  
         [0079]    If reading is to be directly made from the level of liquid  39  and the numbered scale  42  is mounted on the outer wall of immersed body  38 , or the inner or outer wall of cavity structure  37 , a transparent section needs to be included in the wall of cavity structure  37 . Although not shown, it should be understood that the liquid level could be read and equivalent weight representation determined by using a conventional external transparent tube device like those once used to read water level in boilers or storage tanks, by use of remote video viewing or by the use of liquid level sensors.  
         [0080]    Liquid  39  is shown at the level corresponding to the number  3  on numbered scale  42  to indicate the weight of the generic weight  43  which rests on weighing pan  41 . Since no limitations are stipulated, the number three on the scale  42  could indicate a weight of  3  grams, ounces, kilograms, pounds, or even tons. The horizontal cross-section is squared to resist any tendency to turn the numbered scale  42  away from the viewer, if affixed to buoyant body  38 .  
         [0081]    How much a body needs to descend to increase its immersion depends on two factors: the space between the body and cavity walls and the diameter of the cavity. Obviously a very large diameter device would need to descend very little to displace a large quantity of liquid and a device with minimal wall spacing would provide a maximum immersion increase for the amount of liquid supplied by such displacement.  
         [0082]    As more weight is added to the weighing pan  41  the buoyant body  38  will displace more of the excess liquid  44  that exists below it in conformal cavity structure  37 . A relatively slight descent can displace enough of the excess liquid  44  to cause a marked increase in effective immersion and consequent buoyant force due to the small spacing between the vertical walls of body  38  and conformal-cavity structure  37 . The space  40  that surrounds the buoyant body  38  at the top of conformal-cavity structure  37  must be retained to allow for the entrance and exit of air with the rise and fall of buoyant body  38  and level of liquid  39 .  
         [0083]    The body and conformal-cavity combination shown in FIGS. 5 and 6 and that shown in FIGS. 11 and 12 represent simple and virtually frictionless means of determining weight, means that avoid the use of complex mechanisms that experience wear and require lubrication. They are readily adaptable to being made in varying sizes and are therefore more adaptable to the economical measurement of very large weights than most other weight measurement means.  
         [0084]    While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art, without departing from the true spirit of the invention. It is intended therefore, by the appended claims, to cover all such modifications and changes as fall within the true spirit and scope of the invention.