Pressure Garment

Abstract

A garment to provide pulsating pressure to a lower human extremity for aiding blood circulation in the extremity and having an outer nonelastic plastic envelope sealed to an internal relatively soft envelope providing an air space therebetween for the application of pulsating pressure uniformly to a limb inserted within the inner envelope. The inner envelope has a common seam along part of its length with the outer envelope to prevent inflation pressure from displacing the two envelopes. A system of apertures in the inner envelope provide for a limited gaseous passage of air from the pressurized space between the two envelopes to the surface of a limb encased within to provide breathing air for the skin.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to pressure garments for aiding blood circulation and in particular to those for use on animal extremities to provide pulsating pressures urging venous blood from the limb and thereby encourage introduction of arterial blood.

Description of the Prior Art

In the mid "30's" there was some recognition of the fact that thrombotic occlusion sometimes occurs as a result of poor blood circulation in the human extremities. See, for example, U.S. Pat. Nos. 2,134,646 and 2,142,689. However, there was no widespread acceptance of devices for improving the circulation. In the last few years, investigations have shown that an unexpectedly large percentage of post-operative deaths have been a direct result of embolic occulsion and a good deal of this embolic occlusion is attributed to the enforced bed rest of the patients. Blood circulation in the lower extremities of a confined person is notoriously poor. It is now recognized fact that it is desirable to have a patient up and about as soon as possible after an operation in order to obtain the most favorable prognosis. But only relatively recent studies have demonstrated that the greatest benefit of this is probably due to the reduction in thrombotic occulsion.

Early pressure garments tended to use a single pressurized envelope with seals to the skin of the patient at the open end or ends. Since these seals were somewhat tricky in manufacture and usually cause a certain amount of irritation in use, more recent pressure garments have used double envelopes in which pressure between the two envelopes forced the inner envelope against the patient's skin. U.S. Pat. No. 2,747,570 to Jobst and U.S. Pat. No. 3,391,692 to Spielberg describe pressure garments which are designed to provide greater pressure at the lower portion of the enclosed limb graduated to lesser pressure at the upper enclosed portion of the limb. It can be expected that such a pressure gradient would help to promote an undirectional flow of blood. It has been demonstrated, however, that even with blood veins in poor condition, such that the undirectional valves of the veins function inadequately, that light pulsating pressure over a large portion of a lower extremity will increase blood flow through the extremity. Accordingly, U.S. Pat. No. 3,083,708 to Gottfried discloses a pressure garment completely encasing the lower extremity up to the thigh for the application of light pulsating pressures without a gradient.

Most of these prior art devices have used lacings or zippers or some arrangement of air pockets resulting in complexity and increased cost. Another difficulty in prior art devices has been the use of inner envelope material uncomfortable to the skin or producing an air seal against the skin such as to prevent the skin from perspiring freely. Blocking the evaporation of skin vapors hinders the human system from controlling the skin temperature and generally causing discomfort.

SUMMARY OF THE INVENTION

Now, in accordance with the present invention, a pressure garment for the animal extremities is provided which has an outer relatively stiff, nonelastic envelope supporting an inlet stem for the application of pulsating gaseous pressure. An inner soft plastic envelope has an open end sealed to the open end of the outer envelope and is further bonded along the longitudinal line to the outer envelope. The inner envelope further has a plurality of breathing pores to provide for the passage of applied gaseous media past the inner envelope and along the skin of the wearer to enable natural breathing of the skin.

Thus it is an object of the invention to provide a novel pressure garment for improving blood circulation in animal extremities.

It is a further object of the invention to provide a double envelope pressure garment carrying breathing pores in its inner envelope for the passage of air along the skin of the wearer.

It is a further object of the invention to provide a novel pressure garment for an animal extremity comprising an outer nonelastic plastic envelope and an inner soft plastic envelope sealed to said outer envelope so as to provide a pressurizable pocket therebetween.

It is a further object of the invention to provide a pressure garment for the lower limb consisting of inner and outer envelopes, each closed at one end and sealed together at their open end being further bonded together along their length from the open end extending towards the closed end.

Further objects and features of the invention will become apparent upon reading the following description together with the drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a left side elevation of a garment according to the invention with a portion of the outer envelope cut away at the toe.

FIG. 2 is a right side elevation of the garment of FIG. 1.

FIG. 3 is a left side elevation with a portion of the outer envelope cut away of a second embodiment of the invention.

FIG. 4 is a side elevation of a third embodiment of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS

A boot-like garment for providing pulsating pressures to the foot and lower leg is depicted in FIG. 1. The garment has outer envelope 10 made of clear semirigid 8 mil vinyl plastic. Envelope 10 is made of first sheet 11 and second sheet 12 (FIG. 2) acting as left and right sides thermally bonded together all around their perimeters except at open end 14. Other materials may be used and may be sealed together by other methods. The material need not be transparent, but it must be impermeable to most fluids and resistant to stretching to permit an internal pressure equal to at least 40 mm of mercury at sea level.

Inner envelope 15 is made of soft elastic 4 mil matte vinyl. Envelope 15 is made of third sheet 16 and fourth sheet 17 acting as left and right sides thermally bonded together all around their perimeters except at open end 14. Again other materials may be used and may be sealed together by other methods. The material should be sufficiently soft and compliant to mold itself under pressure to a foot and lower leg without producing discomfort by way of nonuniformity in contact pressures. Materials that are insufficiently soft and compliant will frequently develop relatively stiff wrinkles and resultant nonuniformity in contact.

At open end 14, sheets 11 and 16 are thermally sealed together and sheets 12 and 17 are thermally sealed together. This forms a completely enclosed space or pocket in between envelopes 10 and 15.

Because the outer envelope is semirigid, there would be a loss of free movement of the enclosed limb if the inner and outer envelopes were secured together along their entire perimeters. However, on the application of pressure between the envelopes, inner envelopes 15 is urged to extrude from outer envelope 10. This is avoided by bonding envelopes 10 and 15 together along part of a longitudinal seam. In the boot-like configuration of FIGS. 1 and 2 this is accomplished by thermal bonding of the rear seams of envelopes 10 and 15 together from open end 14 to heel portion 18. The remainder of foot portion 20 of envelope 15 remains free floating inside envelope 10.

Envelope 10 carries port 21 for applying and withdrawing fluid or for applying elastic waves to a contained fluid. Port 21, as depicted, consists of a reinforcing element 22 and stem 24 of tubing supported by and sealingly connected to element 22. Element 22 and stem 24 may be made of metal, rubber or plastic with element 22 clamped, or otherwise bonded tO envelope 10.

A plurality of small apertures or "pores" 25 are located near the foot portion 20 of envelope 15 for the passage of fluid inside of envelope 15 as a source of ventilation. It will be recognized that a usual fluid for pressurizing the inventive garment is air. When pores 25 are provided in envelope 15, port 21 is preferably in the proximity of pores 25 which in turn are preferably near the toe (or closed end) of the garment. Having pores 25 near the closed end allows fluid passing therethrough to effect ventilation along the entire length of the garment. By having port 21 near pores 25, any significant pressure gradient due to fluid flow through pores 25 is avoided.

Pores 25 must have a total combined area less than the inside diameter of port 21. This is necessary so that fluid can be readily provided through port 21 at a rate faster than it exhausts through pores 25.

FIG. 3 depicts a boot-like garment similar to that of FIGS. 1 and 2 except that apertures 25 are replaced by a separate source of ventilating gas. A soft flexible tube 26 from outside of the garment, extends through the open end to foot portion 20. Tube 26 lies inside of inner envelope 15 and preferably is bonded to the envelope along its length so as to avoid interference with the insertion or withdrawal of a limb. Tube 26 has an open end 27 in the vicinity of foot portion 20 for releasing ventilating gas.

In order to provide a pressure gradient from the closed end toward the open end of the garment, apertures 28 in either inner envelope 15 or outer envelope 10 may be provided. Apertures 28 similar to apertures 25 should have a total combined area less than that of port 21. With a continuous pressure maintained between envelopes 10 and 15, flow through apertures 28 will cause a pressure drop along the length of the garment resulting in a pressure gradient. This gradient can be controlled as desired by the size of envelope 10, the relationship between effective areas of port 21 and apertures 28 and the location of port 21 and apertures 28.

A garment useful over a fore limb is depicted in FIG. 4. Outer envelope 30 made similar to envelope 10 of FIG. 1 is generally rectangular in shape and carries inner envelope 31 much the same as envelope 15 of FIG. 1 except for shape. The outer envelope is bonded to the inner envelope at open end 32 and along seams 34 to wrist position 35. Port 36 is provided for connection to a source of fluid under pressure and series of apertures 37 near the closed end of envelope 31 are provided for ventilation. Means for providing an independent ventilation source or a pressure gradient such as described with relation to FIG. 3 are contemplated.

While the invention has been described with relation to a specific embodiment, various other configurations are contemplated. For example, the boot-like garment of FIGS. 1 through 3 can be made in various lengths covering less or up to the entire length of the limb. Similarly a garment such as in FIG. 4 for a fore limb may be made in various lengths and may have more conformance in shape than that shown. Thus it is intended to cover the invention within the full scope of the following claims.

Claims

We claim:

1. In a garment for an animal body extremity consisting of inner and outer envelopes forming a pocket therebetween for the periodic application of fluid pressure to stimulate flow of vascular fluids, the combination in said inner envelope comprising:

a. A soft compliant envelope material readily moldable to an animal body under light pressure;

b. An open-ended proximal portion to said inner envelope;

c. A closed distal portion to said inner envelope;

d. A fluid impermeable seam connecting the open end of said proximal portion to said outer envelope;

e. A longitudinal seam along the length of said proximal portion connected to said outer envelope; and,

f. A complete separation between the distal portion of said inner envelope and said outer envelope whereby the distal portion of said inner envelope has freedom of movement within said outer envelope.

2. In a garment according to claim 1 the combination in which said distal portion is perforated by a plurality of small apertures for allowing a gaseous flow between said inner envelope and along the surface of said animal body.

3. In a garment according to claim 1 the combination in which said distal portion is shaped to accomodate a foot.

4. In a garment according to claim 1, the combination with said inner envelope of a flexible tube extending from the exterior through said open ended proximal portion and extending into the proximity of said closed distal portion whereby to provide a flow of ventilating gas between said first envelope and said limb.

5. A garment for enhancing blood circulation in an animal body comprising:

a. A first envelope of soft compliant synthetic resin open at one end and closed at the other for insertion of an animal limb;

b. A second envelope of semirigid synthetic resin exterior to said first envelope and sealed to said first envelope at said open end to form a pocket therebetween;

c. Port means connected to said second envelope for introducing gas between said second envelope and said first envelope so as to compress said first envelope against said limb; and,

d. A plurality of pores in said first envelope in the proximity of the closed end for providing a ventilating flow of gas between said first envelope and said limb, the total area of said pores being less than the area of said port means.

6. A garment having an open end and a closed end for enhancing blood circulation in an animal body comprising:

a. A first envelope of soft compliant synthetic resin open at one end and closed at the other for insertion of an animal limb;

b. A second envelope of semirigid synthetic resin exterior to said first envelope and sealed to said first envelope at said open end to form a pocket therebetween;

c. Port means connected to said second envelope proximate to said closed end for introducing gas between said second envelope and said first envelope so as to compress said first envelope against said limb; and,

d. A plurality of apertures located in said garment proximate to said open end, whereby on the application of fluid pressure at said port means, fluid flow through said apertures provides a pressure gradient entending from a relatively high pressure at said closed to a relatively low pressure at said open end.