Disposable hyperbaric oxygen chamber

A disposable hyperbaric oxygen chamber includes a polyethylene bag which is substantially the length of a patient's leg and which is placed around the entire leg and thigh with the excess bag at the top thereof being folded over the thigh in order to fit snugly thereon without compression. A length of nonstretchable tape seals the top of the bag around the upper thigh just below the inguinal ligament. Another circumferential layer of tape is applied to the top of the bag to attach the same to the patient's pants to prevent displacement of the bag as the patient moves around. In an alternative embodiment, the bag may be preformed into the leg of a pair of disposable shorts to be worn by the patient. Oxygen is fed to the bag through the use of a hose connector secured to the bag. After the bag has been inflated with oxygen, the tubing may be clamped off and removed so that the patient can move about freely.

BACKGROUND OF THE INVENTION 
The present invention is directed toward hyperbaric apparatus for applying 
oxygen to leg wounds and, more particularly, to a disposable, inflatable 
hyperbaric chamber and to a method of applying and utilizing the same. 
As is well known in the art, hyperbaric chambers are devices which create 
sealed and pressurized environments for the treatment of lesions and 
wounds on a patient's body. It has been well established that hyperbaric 
oxygen is an effective treatment for wounds as the same induces the growth 
of new blood vessels or neovascularization necessary for stimulating the 
growth of new tissue in order to close defects in wounds. 
Devices have been proposed in the past for treating leg ulcers or other leg 
wounds utilizing hyperbaric oxygen. These prior devices are comprised 
essentially of a rigid chamber having an opening at one end through which 
the leg can be inserted. Such prior hyperbaric chambers are described, for 
example, in U.S. Pat. No. 4,003,371 to Fischer and U.S. Pat. Nos. 
4,296,743 and 4,432,353 to Lasley. 
The prior art hyperbaric oxygen chambers such as those proposed by Fischer 
and Lasley are relatively expensive and are difficult to sterilize, 
thereby creating cross-infection between patients using the same chambers 
for therapy. Furthermore, these prior art chambers were relatively large, 
rigid and immovable. Accordingly, during treatment, the patient was 
required to lie in a prone position at all times. 
In an article published by Heng et al. in Arch Dermatol in 1984, a 
technique for administering hyperbaric oxygen is disclosed which utilizes 
a disposable polyethylene bag. This technique has the advantage of being 
substantially simpler than more complex hyperbaric oxygen chambers and is 
less likely to cause cross-infection. The technique previously proposed by 
Heng et al., however, is still believed to be deficient in the manner in 
which the bag is closed and secured to the patient and in the inability to 
allow the patient to be ambulatory while receiving treatment. 
A similar problem exists with the apparatus shown in U.S. Pat. No. 
5,029,579 to Trammell. Trammell discloses an arrangement which utilizes a 
flexible disposable bag but which must be continuously connected to a 
pulsating oxygen source. As a result, the patient can not be ambulatory. 
Furthermore, in both the Heng et al. and Trammell arrangements, there is 
no easy and convenient way of securing the flexible bag to the patient's 
leg. 
SUMMARY OF THE INVENTION 
The present invention overcomes the deficiencies of the prior art described 
above and provides a hyperbaric oxygen chamber for treating leg wounds 
which is disposable and which, if desired, allows the patient to be 
ambulatory while treatment is being applied. The chamber is comprised 
essentially of a disposable polyethylene bag which is substantially the 
length of the patient's leg and which is placed around the entire leg and 
thigh. 
The excess bag at the top is gathered into two pleats on the medial and 
lateral side of the thigh and these pleats are folded over in front of the 
thigh to cause the bag to fit snugly but without compression over the 
thigh. Tape seals the top of the bag around the upper thigh just below the 
inguinal ligament. The tape is placed circumferentially around the bag and 
is positioned to fall within the inguinal triangle which is the space 
bounded by the inguinal ligament superiorly, rectus femoris laterally and 
obturator muscles medially. Another circumferential layer of tape is 
applied to attach the top end of the bag to the patient's pants to prevent 
displacement of the bag as the patient moves around. 
Alternatively, the bag may be preformed onto the leg of a pair of 
disposable short pants to be worn by the patient. The bag can be secured 
to the leg with a circumferential layer of tape or the shorts can be made 
of an air impermeable material and include an adhesive waistband and 
adhesive band at the bottom of the other leg. Oxygen is fed to the bag 
through the use of a hose or tubing connector welded or otherwise secured 
to the bag or to the shorts. After the bag has been inflated with oxygen 
to the proper pressure level, the tubing can be clamped off so that the 
patient can move about freely.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings in detail wherein like reference numerals 
have been used throughout the various figures to designate like elements, 
there is shown in the figures a disposable hyperbaric oxygen chamber 
constructed in accordance with the principles of the present invention and 
designated generally as 10. In one form of the invention shown in FIGS. 
1-5, the disposable hyperbaric oxygen chamber 10 is comprised of an 
elongated and disposable polyethylene bag 12 having its upper open end 14 
heat welded or otherwise secured to the open pant leg of a pair of 
disposable shorts 16. It should be understood, however, that this is by 
way of example only. An aspect of the invention can also be practiced 
utilizing only the polyethylene bag 12 without the disposable shorts 16. 
As shown in FIGS. 1 and 3-5, the bag 12 is large enough to totally enclose 
the entire leg 18 of a patient 20. Bag 12 is also preferably made to be 
transparent so that a doctor can observe the healing process of the wound 
being treated. Attached to the lower end 22 of the bag 12 is a hose or 
tubing connector 24 which allows a source of oxygen under pressure (not 
shown) to communicate with the interior of the bag 12 through appropriate 
tubing assembly 26 as shown in FIG. 1. The tubing assembly 26 preferably 
includes a Y-connector 28 which allows one branch 30 of the tubing to be 
connected to the bag 12 while the other branch 32 of the tubing can be 
connected to a pressure gauge 34 or the like. In lieu of the pressure 
gauge 34, the connector 24 or some other portion of the bag 12 may be 
provided with a built in pressure gauge or indicator. Devices are known 
which, for example, emit an audible sound or automatically close when a 
predetermined and preset pressure level is reached. 
For the reasons which will become clearer hereinafter, the connector 24 may 
also include a one-way valve therein. That is, it may include a valve 
which allows oxygen under pressure to enter the bag 12 but which prevents 
oxygen from escaping therethrough. Such valves are, per se, well known in 
the art as shown in U.S. Pat. No. 2,168,611 to Thompson. 
The disposable hyperbaric oxygen chamber 10 described above is used in the 
following manner. First, the leg bandages are removed from the patient so 
as to expose the ulcer or other wound being treated. The polyethylene bag 
12 is then placed around the entire leg and thigh. If the embodiment of 
the invention utilizing the combined bag and shorts 16 is utilized, this 
is accomplished by having the patient put the shorts on and pull them up 
to the proper position. 
Whether or not the shorts 16 are utilized, the upper end of the bag is 
pulled up against the buttocks as high as possible. The top open end of 
the bag (again with or without the shorts attached) is stretched laterally 
and the excess width is gathered into two pleats 36 and 38, one on the 
medial side and one on the lateral side of the thigh. The pleats 36 and 38 
are then folded over in front of the thigh to cause the top of the bag 12 
(whether or not already attached to the shorts 16) to fit snugly, without 
compression, over the thigh and tape is utilized to keep the pleats in 
place. The top end of the bag 12 is then sealed around the upper thigh 
just below the inguinal ligament. This is accomplished utilizing a length 
of nonstretchable tape 40 that is placed circumferentially along the top 
of the open end 14 of the bag 12 and over the pleats. 
The layer of tape 40 must be arranged so that it falls within the inguinal 
triangle which is the space bounded by the inguinal ligament superiorly, 
rectus femoris laterally and the obturator muscles medially. The tape 
should be sufficiently tight so as to provide a substantial seal in order 
to prevent excessive leakage of oxygen from the bag 12 during therapy. 
However, because of the specific placement of the tape, blood flow to and 
from the leg is not restricted. 
With respect to the embodiment of the invention which does not utilize the 
bag 12 permanently secured to the disposable shorts 16, a second 
circumferential layer of tape is preferably applied in order to attach the 
top end 14 of the bag 12 to the patient's shorts or other clothing. 
Attaching the top of the bag to the shorts 16 or by the use of an 
additional layer of tape to the patient's normal clothing prevents 
displacement of the disposable hyperbaric oxygen chamber when the patient 
moves around during treatment. 
The bag 12 is then filled with oxygen through tubing assembly 26 utilizing 
either a conventional oxygen delivery system or a specially designed 
single use source. When the bag is substantially full, the pressure of the 
oxygen is regulated to be between approximately 25-30 mmHg for arterial 
ulcers, burns and pyoderma gangrenosum and preferably between 18-20 mmHg 
for venous ulcers. The bag is then depressed slightly to check for leaks 
so as to be certain that the interior pressure is substantially 
maintained. If no leaks are sensed, the tube 30 can be removed from the 
connector 24 if the connector includes a one-way valve therein. If such a 
valve is not utilized, then the tubing 30 can be clamped off and removed 
from the Y-connector 28. In any case, the patient is then free to move 
about. 
It has been found that the best results are obtained if the hyperbaric 
oxygen therapy is applied for four to six hours per day. This is done on 
four consecutive days during each week with a three-day rest period and is 
continued for three to six weeks. 
The bag 12 is preferably made of polyethylene or a similar material which 
is impervious to fluids (particularly oxygen) so as to maintain the oxygen 
pressure within the bag at the desired level. There may be times, however, 
when it may be desired to lower the pressure within the bag or reduce the 
amount of oxygen. To this end, the disposable hyperbaric oxygen chamber 10 
may include a bleed valve 42. 
In its simplest form, bleed valve 42 is comprised of a plurality of small 
holes 44 formed in a portion of the bag 12. The holes 44 are normally 
covered by a flap of material 46 having a releasable adhesive backing 
thereon. The flap 46 normally covers all of the holes 44. However, if it 
is ever desired to reduce the pressure in the disposable hyperbaric oxygen 
chamber, the flap 46 can be pulled back to expose some or all of the holes 
44 to allow some of the oxygen to escape. When the proper pressure is 
reached, the flap 46 is resealed. 
In order to eliminate or substantially reduce odors that may form within 
the bag during the treatment period, the bag may be made from or lined 
with a deodorant material. Finely ground carbon powder, for example, 
coated on the inside of the bag will absorb foul odors. Other materials 
and other means of eliminating odors may also be used. 
Another embodiment of the disposable hyperbaric oxygen chamber is shown in 
FIGS. 6, 7 and 8. The embodiment shown therein is similar to the previous 
embodiment except that the shorts 116, to which the bag 112 is attached, 
are made of an air impermeable material. The waistband 148 of the shorts 
and bottom 150 of the free leg 152 have adhesive on the inner surface 
thereof as shown at 154 and 156, respectively. In the manner well known in 
the art, the adhesive bands 154 and 156 are normally covered with a 
release strip which can be removed to expose the adhesive. Since the 
shorts 116 are also made of an air or oxygen impermeable material, the 
hose or tubing connector 124 can be attached directly thereto. 
Located on the back of the bag 112 are a plurality of inflatable pillows 
such as show at 158 and 160. These pillows are preferably formed 
integrally with the bag although it is possible to attach them after the 
bag is formed. In any case, the pillows 158 and 160 are filled with air or 
oxygen. There may be small passages formed between the interiors of the 
pillows and the bag 112 so that the pillows are inflated as the bag is 
filled with oxygen. Alternatively, the pillows may be prefilled with air 
or can be provided with separate fill valves. 
The embodiment of the invention shown in FIGS. 5-8 is used in a manner 
similar to the first embodiment described above. It is not necessary, 
however, to seal the top of the bag 112 around the patient's thigh. 
Rather, after the patient puts the shorts 116 on, the release material is 
removed and the adhesive 154 and the waistband 148 is then firmly sealed 
around the patient's waist. Similarly, the adhesive 156 is exposed and the 
lower end 150 of the leg 152 is sealed around the patient's leg that is 
not being treated. Oxygen is then introduced through the connector 124 
above. 
It should be readily apparent that the embodiment of the invention just 
described can also be used to treat sores and the like on a patient's 
buttocks or lower abdomen since oxygen will also fill the shorts 116. 
Furthermore, it is not beyond the scope of the invention to provide the 
shorts 116 with two bags, one for each leg. With such an arrangement, the 
shorts would be provided with adhesive only at the waistband. In either 
case, the shorts and the bag or bags can be formed separately and later 
joined together or they can be formed in a single piece. 
The present invention may be embodied in other specific forms without 
departing from the spirit or essential attributes thereof and accordingly 
reference should be made to the appended claims rather than to the 
foregoing specification as indicating the scope of the invention.