US 3670347 A
A bed for reducing the effective weight of a body is disclosed having a cavity contoured to the approximate shape of the body of a person to occupy the bed. The bed includes a fluid within the cavity and may have a fluid impervious sheet draped over the cavity upon which the person lies and is floated.
Description (OCR text may contain errors)
United States Patent 51 June 20, 1972 Weinstein  THERAPEUTIC BED AND BATH  Inventor: Bernard Weinstein, Spring Valley, NY.
 Assignee: DePuy, lnc., Warsaw, Ind.
 Filed: July 26, 1965 21 Appl. No.: 474,617
 US. Cl ..5/348, 5/60, 5/83, 128/376, 4/177  Int. Cl ..A61g 7/10, A476 27/08, A47C 27/18  Field of Search ..128/365, 369, 376,5/60, 348
 References Cited UNITED STATES PATENTS 743,025 11/1903 Von Orth ..128/369 3,085,568 4/1963 Whitesel1..... ...128/33 3,092,101 6/ 1963 Kinney ..128/66 3,108,293 10/1963 King ..5/348 Spence ..5/348 Staudt..... .4/185 L Jadkowski ..4/173 Miyakawa ..4/ l 73 Mizrach ..4/177 Treand McDaniel ..4/177 Primary Examiner-Casmir A. Nunberg Attorney-Lee C. Robinson, Jr.
ABSTRACT 8 Claims, 8 Drawing Figures THERAPEUTIC BED AND BATH -My invention relates to sleeping, bathing and medical treatments involving both bed and bath care. I have discovered how to apply the principle of Archimedes to certain medical and other problems and have a combination bed and bath,
possessing the features oflightness, economy, compactness and medical therapeutic benefit.
In the treatment of decubiti (bedsores), both preventive and therapeutic, in all cases involving long bed rest, it is an object of medical care to overcome the problem of skin breakdown due to the pressure of body weight. This pressure, when exceeding capillary blood pressure of mm. Hg for a period of time, causes restriction of circulation and tends to create skin breakdown, exacerbating already existing problems of disability. Devices commonly used to work with this problem operate either by distribution of pressure areas through elastic compression (e.g., sponges, lambs wool, etc.) or by frequent turning of the patient, relieving the pressure on one area by substituting pressure on another. The treatment of burned skin or large wounds presents many of the same problems as the treatment of decubiti and such injuries are therefore treated in the same way. i
1. It is an object of my invention to reduce skin pressure below '25 mm. Hg on a continuing basis, to do this by the medium of weight displacement, eliminating both elastic compression and turning as treatments. This is done by floating the patient in a fluid medium on a thin film of some waterproof material. The method here used is based on an application of Archimedes principle.
ON BUOYANCY The buoyancy of any body is a function of the density of the body and the density of the medium in which it is to float. Density refers to the mass per unit volume. Therefore, the buoyancy of the body increases linearly as the density of the body decreases or as the density of the fluid increases.
For a body of density equal to or less than the density of the medium, the body will displace a quantity of the medium equal in weight to itself (W mg). While displacing this quantity of medium, the body will sink into the medium to a depth such that the volume submerged is proportional to the ratio of the densities.
In finding its level of submergence the body may have to compensate for its shape and form. It will, therefore, seek a stable position with regard to its center of mass and center of gravity. Portions of the body of greater density will be submerged to a deeper level than smaller density portions. The body will not necessarily float with the water line and the centerline coincident or parallel.
The pressure actually applied to the body is a function only of depth of the medium at each level. This can be computed from the surface downward knowing the density of the medium and the pressure at the surface. In most cases, the surface pressure will be the normal atmospheric pressure of 14.75 lbs/in. and can be treated as a zero level. The increase downward for non-compressible fluids will be linear. Since the rate of increase for fresh water is approximately one atmosphere per ten meters depth or 1.0345 gms/cm /cm of depth, a simple measurement and calculation can give the pressure at any discrete depth.
lnterposing of a plastic sheet between the body and the fluid has the effect of increasing the volume while not significantly altering the mass. For a straight-sided body, this amounts to 0.0687 inP/in. of perimeter at the water line. (Since the body we are discussing is so close to the density of the water, the buoyancy can be calculated by using the weights of water.) For bodies with less than straight sides, an addition or subtraction will have to be made. (For the human body, the figure, can be approximately doubled.)
2. It is another object of my invention to relieve the pain of patients with burned areas, arthritis or other disabilities such as, but not restricted to, back problems, who have pain in a resting position. By reduction of effective body weight through dry flotation, the pressure of the weight of the patient is relieved from stress areas.
3. It is another object of my invention to provide a device, either inflatable or of foamed plastic, or of a shaped plastic or metal or other material, whose shape will provide flotation for a patient or other person with a minimum of fluid.
4. It is another object of my invention to provide a device whose lightness may, by material and method of composition and design of using minimal fluid for flotation, provide a bed and bath, easily transportable, capable of being supported on such light structures as an ordinary table, cot or other support with a floor loading of as little as 15 lbs per sq. ft.
5. It is another object of my invention toprovide a device whose lightness and compactness provide a way of providing a full bed bath to persons who cannot be easily moved, and where this can be done with an economical amount of liquid.
5. It is another object of my invention to provide all this through a variant of three forms of combination bed and bath:
a. A tube formed of foamed fire-resistant plastic whose interior dimensions are easily modifiable by the operator, usually a nurse or other medical person.
. An inflatable tub formed of fabricated rubber, vinyl, or other flexible cloth or plastic materials whose shape is preformed in original fabrication and which may only be modified by variation of air pressure in separate air chambers. Such a unit will be collapsible and foldable to a small size.
. A tub formed to body contours as described below, of such materials, but not confined to them alone, as shaped metals, fiberglass, etc., whose shape will be rigidly determined by the great strength of the forming material. Such rigidity may be modified where a semi-elastic material such as molded rubber is used. Such a tub may also be used on an uneven surface by being supported on legs.
All such units serving as bathtubs are capable of being fitted with a loose, flexible, waterproof cover made of vinyl, polyethylene, rubber or similar material. I prefer to use a sheet of vinyl film approximately 0.008 in. thick. The person to be rested on this unit is deposited on the sheet of plastic so as to fit loosely within the formed depression. The depression fitting the body cavity is formed in any of the three ways described above, though not necessarily restricted only to them. The size of the body cavity is preferably such as to require the minimal amount of fluid to float the individual on the plastic sheet.
By flotation, the individual is supported by a fluid or semifluid medium, and the pressure of his body on his skin surface and the capillary blood vessels becomes a function of the depth of flotation, the residual air in the plastic cover and other material being rested on, and the density of the flotation liquid.
In an example used to illustrate the principle involved, the following pressures were obtained. A man resting on a sheet of 0.004-in. polyethylene, separated from the plastic by a cotton blanket and sheet, floated 20 cm deep along his trunk. He floated higher elsewhere. At this depth, floating in fresh water, maximum pressure was, at the point of deepest immersion, the pressure of 20 cm of water, or 20 gramslcmi". This is 4/5 capillary pressure, and skin circulation functioned so well that a large skin area, treated by plastic surgery, was kept under this pressure for 23 hours a day, without turning or special medication, and successfully healed.
7. It is a further object of this invention, that by this method of dry flotation, temperature control of the fluid can, in a formed plastic or other insulating tub material, be kept relatively constant, without elaborate apparatus of any type. Over a continued period of time, body temperature will tend to maintain the fluid at close to body temperature level. By the use of radiation fins, or ice, or changing fluid, further heat reduction can be achieved. This will allow control of body perspiration in an easily controllable manner.
This nonnative control of fluid temperature is a valuable, but not essential, aspect of the dry flotation method. For special cases, only an economical amount of fluid needs to be heated and cooled.
8. It is a further object of this invention to provide a variety of media of support to achieve other purposes.
Transportation of severe burn cases or other types of disability where body configuration is a problem, in ambulances, by air, etc., is possible where the fluid is replaced by high viscosity materials such as grease, oils, gelatins or even bread doughs. The use of these special materials is part of the object of my invention. While I prefer water for ordinary use for purposes of heat conduction, price, density, etc., I believe these special high viscosity materials are useful for transportation, or relief of fearfulness by providing a medium of resistance and for other purposes.
9. A further object of my invention is the use of high or low density fluids or semi-solids to provide variable immersion depths and provide medically desired pressure distribution or provide for problems of special body positioning. An example among many would be the use of salt or barium chloride to raise the patients flotation level, so that a peculiar crouch or other fixed position will be provided with proper support or non-support, but with desired exposure to air.
10. A further object of my invention is to provide a painless simple method of bathing a person in such a bed where transfer to a tub or shower is not desirable or obtainable. Such a case would be a burned person or a bedbound person unable to reach a bathroom. It could be used in a military or civil defense situation where water is difficult to obtain and all facilities are under emergency conditions. By merely submerging one end of the waterproof film, the person sinks in the supporting fluid and can be bathed. The waterproof film can then be slid out from under the person or left with the linen and the bath proceed on top of it. At the conclusion, the person climbs out or is lifted to a dry area, dried, may receive medication, may proceed to other activity or be returned to a dry cover for further rest. The dirty water may be left or changed, with or without the tub being occupied.
l I. It is a further object of my invention that where lifting and handling a person is a problem, to simplify and reduce the problem in the following way:
a. By reducing transfers for bathing purposes, as described above. This reduces by half, ordinary nursing transfers of a patient.
b. By the use of a regular stretcher or manual lifting where desired, but preferably by the use of a netting supporting the patient in his natural body contour, or, if desired, supporting him by specially shaped rods, inserted in the netting to maintain desired body position. This netting could be left, but need not be, in the tub, under or over the plastic supporting the patient, and is instantly available for lifting.
12. It is a further object of my invention to reduce the hazard of drowning by shaping this formed tub with a head rest, either integrally shaped with the tub or formed of a plastic cushion.
13. It is a further object of my invention that by the nature of fabrication, this device is easily storable and, in its inflatable form, can be stored easily in a small space. Such devices would provide mass hospital beds in the event of a natural or manmade disaster or war. It is easily carried by campers or kept by homeowners for guests. For yachts, transports and shipping, it provides easily stored bedding which may double as emergency flotation equipment.
14. Another object is to provide without transfer, a level, dry flotation device, which, in its inflatable form, mounted on a hospital bed or other device, can, when drained, allow tilting of the patient without physical transfer to another unit. This is often medically desirable.
l5. Another object of my invention is that it provides a simple foundation on which to mount sterile plastic tents for antiseptic purposes in burns. It may also provide the foundation for exercise devices as indicated medically.
16. Another object of my invention is that when used as a bed, it is not possible for a person to set himself on fire through poor use of cigarettes. The use of self-extinguishing plastic, in the waterproof film, can only result in a small hole, extinguishing the fire through water leakage.
With reference to the drawings, I shall now describe the best mode contemplated by me for carrying out my invention.
FIG. 1 is a cross-sectional view in vertical section illustrating the basic purpose of the floating bed, showing the patient floating with a minimum of fluid in a foamed or other block of plastic.
FIG. 2 shows a three-dimensional view of the floating bed, with a loose sheet of waterproof film laying over the body cavity.
FIG. 3 shows an inflatable model of the tub.
FIG. 4 shows a formed shell model of the tub.
FIG. 5 shows a male plug for FIG. 2 or FIG. 4.
FIG. 6 shows a method of lifiing the patient using the net stretcher with poles and spreaders (optional).
FIG. 7 shows details of the net stretcher.
FIG. 8 shows an inclined version of the stretcher.
In FIG. 1 we see a cross-sectional view of a form of my invention, embodying in one of its preferred fonns the basic principles involved.
The structure is a block of light material; balsa, foamed plastic, or other similar type of material. I prefer, but do not restrict for this purpose, foamed polystyrene or foamed polyethylene.
In the example shows, the shape A is that of a body lying supine. Using a shape similar to but larger than that of the body to be immersed, there is provided a space for fluid which, by being form-fitting is economical of fluid. The exact size or allowance for fluid is a compromise between the desired economy of fluid and the need for space to handle the body and the materials involved in its care. I have found an allowance of space varying from 2 to 4 inches to be the most efficient, but recognize that in the variety of uses possible, a variation of space may be desirable.
FIG. 2 shows the same device in a three-dimensional view.
The size of the block is exaggerated in certain aspects to emphasize certain points of information. In the use of the large block method of fabrication, there is no limitation on block sizes beyond the uses of utility. While I prefer to have the edges of the bath to be made of an insulating material of substantial thickness, I believe there are times when economy of size and strength can be effected by making one or more faces or edges of sheet aluminum, angle iron, or fiberglass and resin, plywood, or other materials.
FIG. 2 refers to a drain pipe 2 draining from the bottom of the tub. This drain will fasten to any convenient drainage device 3, such as garden hose, bucket, tank, etc. The section of tubing or pipe between drain pipe 2 and drainage device 3 is flexible and can be either valved or fastened above the water level of the tank so there is no undesirable leakage.
The waterproof film 4 in FIG. 2 is laid on the tub. This film is waterproof plastic, rubber or other material. For medical purposes, it should be as thin as possible. I prefer to use 0.004 polyethylene or 0.008 vinyl, but other materials may be used. The film is put in the cavity of the bath so that, with the body in it, it floats freely and is not under tension. The edges of the film are outside the tank and line 4 represents wrinkles showing the lack of tension in the sheet. The film edges may nonetheless be fastened so the edges are not lost into the fluid unless so desired. Line 5 represents one type of pin or grommet which can be used.
Line 6 is an overflow safety pipe, used in case the body is submerged below the desired level and prevents water flowing from over the top of the tank in a disorderly fashion.
The netting 16 is used for lifting and is described below. It has a series of grommets or other holding devices similar to that identified by line 5.
FIG. 3 refers to the second type of preferred model of the bed bath. This model is inflatable and can serve also as a bed bath for ordinary purposes, or as emergency bedding and bathing equipment.
In FIG. 3, line 7 indicates the inflatable nature of the device. It can easily be formed of inflatable tubes as are air mattresses or childrens swimming toys. It shows one type of inflatable method for making the sides.
In FIG. 3, line 8 indicates the slight body shaping of the bottom, which is also inflatable. The bottom unit is made of several chambers whose inflatation under various pressures, at valves 9, allows additional shaping. Drainage valve 10 allows water to be drained as in the manner shown in drain pipe 2 and drainage device 3, of FIG. 2.
FIG. 4 shows a variant on the basic two models outlined above. A model may be constructed by forming the sheets of such material as aluminum, fiberglass, plywood or other material to conform to the same body shape as given in FIGS. 2 or 3. FIG. 4 shows a split leg model, which is an example of possible medical need. Line 1 l is the drainage valve; line 12 is the overflow valve; line 13 is the legs which may be added as in the purpose of a bath tub. Such legs would be adjustable in length and removable, to serve purposes of versatility;
FIG. 5 is a plug 14. Where the tub in FIG. 2 is made from foamed plastic, I find it useful, though not always required, to make the tub from a series of sheets of foamed polystyrene. These sheets are commercially available in 4-in. thicknesses. By cutting the body profile out with a knife or thin bladed saw, I am able to quickly and easily fabricate this type of tub. Where speed of fabrication and variety of body shape are required, this method is preferable. The cut out pieces of plastic foam are glued together to form a plug for the tub, or for the tub in FIG. 4 (though these pieces may have to be fabricated from new material).
When the patient is removed and the water is drained, the plug is inserted, providing a light adequate table on which to rest the patient or do other tasks. The patient may be turned on this table, dressings changed, etc. The hole shown is a sample of a type of hole made where the patient has a fixed elbow that makes turning almost impossible with any other equipment.
FIG. 5 is possible with model FIG. 3, though this is more easily done with inflatable air mattress and other inflatable devices.
FIG. 6 represents the method of lifting out of the bath where it is used as both therapeutic bed and bath. Where the device is used for a floating bed, it may be used also as a bath.
In the care of patients unable to help themselves, the floating bed may also be used to bathe patients and re-store them to the floating bed again or to a wheelchair.
BATI-IING PROCEDURE AND DEVICE- When the patient is to be bathed, he will ordinarily be resting on a net sheet, blanket and waterproof film. This is the present desirable procedure, but is subject to medically prescribed variations. To bathe the patient without physical transfer to another area, the patient has, previously inserted under or over the waterproof film, a sheet of netting (see FIGS. 2, 6 and 7. This netting may be of a wide variety of materials and mesh. I prefer nylon mosquito or laundry bag netting in one or two thicknesses, or polypropylene netting of the type used to prevent children from falling into swimming pools. This material is fine mesh and has no knots to irritate the skin or damage the waterproof film. It is not water absorbent and will not be hurt by antiseptics, yethas great strength.
When the patient is to be lifted, the netting has poles inserted into the edges. These edges 15 (shown in FIGS. 2 and 5) may be rolled over to form a tube or be sewn with a cloth or other strong material. The poles may be wood or metal. They may be fitted with a link 17 (shown in FIG. 6) in the middle, or overlapping plastic or metal, which allows the poles to be broken in two for final seating of the patient into the wheelchair.
The bathing procedure follows these steps:
a. Waterproof film is loosened from the grommets and is submerged on one side so the body submerges in the tank.
b. The waterproof film and associated bedding is gently withdrawn from under the patient by pulling from one side. The bedding and film are then laundered or autoclaved or other desirable medical procedure.
. On conclusion of patients bath, which may include a refill for rinsing, the netting is rigged with poles along the edge. Using a standard lifting device, such as a chain hoist or portable patient lift, the poles are connected to the lift and the patient lifted out. While lifted, the patient is dried and has fresh dressings applied. In FIG. 6 cutout 18 indicates where it may be desirable to leave an area exposed for medical, nursing or other attention. The netting offers little or no absorbency and the body may be dried through it. The procedure may be modified by putting the netting next to the patients skin and the waterproof film merely removed by lifting the patient in the net. This would be done as medically desired.
d. The patient is then lowered to a wheelchair. Where the body is to be reclined, it is lowered directly to the reclining wheelchair. Where the body must be lowered in a fixed bent position, as in the case of an arthritic fixed in a wheelchair position, the patient may be lowered, the poles collapsed so he is seated and the netting tucked around the patient and left under him for when he must be lifted again. If it is necessary to lower the body again .into a floating bed, the floating bed is prepared for the person as in normal procedures. Another net is laid in the bath, the waterproof film next and then the desired bedding. The patient is then lowered into the bath and left on the netting on top of the bedding.
This is the procedure I prefer, but it does not prohibit such other procedures as may be desired. This is the one that represents, I believe, the least laborious and least painful method of procedure.
f. Attached to all models FIGS. 2, 3 and 4 are the pockets marked 20. These storage devices which may be built in or added, allowing a convenient place to store poles, dressings, medication, bottles, etc.
I do not wish in any way to imply that the forms of the device are fixed in any shape beyond the therapeutic principles involved. This is particularly apt as regards the outside shape of the bed and bath unit which, in order not to resemble a coffin, must be varied in shape, color and other aspects of design.
Although I have described preferred embodiments of my novel invention, many variations and modifications will now be obvious to those skilled in the art, and I prefer, therefore, to be limited not by the specific disclosure herein but only by the appended claims.
What is claimed is:
l. A therapeutic bed for reducing the effective weight of a human body and for uniformly supporting the entire length of the body, said bed comprising,
a fluid-tight bed bath having a cavity therein defined by internal surfaces of said bed bath for the reception and containment of liquid;
said internal surfaces of said bed bath surrounding said cavity being contoured, both horizontally and vertically, to conform approximately to the shape of a person who is to be placed on said bed;
a fluid impervious, flexible sheet draped loosely over said cavity above the liquid to be received within said cavity;
whereby said sheet maintains the person lying thereon in a state of dry flotation on the liquid contained within said cavity, and whereby the proximity of said internal surfaces defining said cavity to a body floating on said sheet materially reduces the amount of liquid necessary to float the body.
2. The therapeutic bed of claim 1, having a body positioned on the sheet thereof and floating over said liquid in said cavity;
said body being spaced from said internal surfaces of said cavity by a distance ranging between 2 and 4 in.
3. The apparatus of claim 1 wherein said bed bath is constructed from a block of lightweight plastic material, the interior portion of which is removable to form said cavity.
4. The apparatus of claim 3 wherein said plastic material is foamed polystyrene.
5. The apparatus of claim 3 wherein said interior portion is removably replaceable in said cavity to form a flat surface upon which a body may be rested.
6. The apparatus of claim 1 wherein said bed bath is an inl I '4 F