U.S. patent application number 15/043158 was filed with the patent office on 2016-06-09 for methods for ambulatory oxygen therapy.
The applicant listed for this patent is Oxyvive, Inc.. Invention is credited to Amir Belson, James J. Leary.
Application Number | 20160158084 15/043158 |
Document ID | / |
Family ID | 43900876 |
Filed Date | 2016-06-09 |
United States Patent
Application |
20160158084 |
Kind Code |
A1 |
Belson; Amir ; et
al. |
June 9, 2016 |
METHODS FOR AMBULATORY OXYGEN THERAPY
Abstract
The present invention provides a topical oxygen therapy system
for treating chronic non-healing wounds. The system is configured
to be extremely portable, allowing patients to be completely
ambulatory during treatment. The topical oxygen therapy system
includes an oxygen source and a wound dressing capsule. The oxygen
source includes a miniature compressed oxygen cylinder and a
miniature pressure regulator that delivers oxygen through an outlet
tube to the interior of the wound dressing capsule. The oxygen
source may be attached directly to or integrated into the wound
dressing capsule. Alternatively, the oxygen source and wound
dressing capsule may be separate modules connected by a flexible
tube.
Inventors: |
Belson; Amir; (Los Altos,
CA) ; Leary; James J.; (St. Louis, MO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Oxyvive, Inc. |
Los Altos |
CA |
US |
|
|
Family ID: |
43900876 |
Appl. No.: |
15/043158 |
Filed: |
February 12, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13441574 |
Apr 6, 2012 |
9283131 |
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15043158 |
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PCT/US2010/002832 |
Oct 25, 2010 |
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13441574 |
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61279624 |
Oct 23, 2009 |
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61516952 |
Apr 11, 2011 |
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Current U.S.
Class: |
604/23 |
Current CPC
Class: |
A61P 17/02 20180101;
A61G 10/04 20130101; A61H 23/0236 20130101; A61H 2201/5058
20130101; A61F 13/00 20130101; A61G 7/05784 20161101; A61H 23/0245
20130101; A61H 2201/0207 20130101; A61F 2013/0017 20130101; A61H
23/02 20130101; A61H 33/14 20130101; A61H 2033/143 20130101; A61H
2201/0214 20130101; A61M 35/30 20190501 |
International
Class: |
A61G 10/04 20060101
A61G010/04; A61F 13/00 20060101 A61F013/00 |
Claims
1. A method for ambulatory oxygen therapy for treating a patient
wound, said method comprising: placing a capsule over the wound to
form an interior space; and delivering a controlled amount of an
oxygen-containing to the interior space to promote healing; wherein
the oxygen-containing gas is delivered from a pressurized source
which is worn by the patient without interfering with normal
ambulation.
2. A method as in claim 1, wherein the source comprises: a gas
cylinder containing compressed oxygen-containing gas; and a
pressure regulator having an inlet and an outlet, the inlet of the
pressure regulator connected to the gas cylinder and the outlet
opening to the interior space.
3. A method as in claim 2, wherein the gas cylinder and the
pressure regulator are integrated into the capsule as a single
wearable unit.
4. A method as in claim 2, wherein the gas cylinder and the
pressure regulator are connected to the capsule by a tube.
5. A method as in claim 1, wherein placing a capsule over the wound
comprises sealing a rim of the capsule to the patient's skin.
6. A method as in claim 1, wherein the oxygen-containing gas is
delivered continuously to the interior space.
7. A method as in claim 1, wherein the oxygen-containing gas is
delivered intermittently to the interior space.
8. A method as in claim 1, further comprising adjusting the flow
rate of the oxygen-containing gas in the range from 0 to 10
m/hr.
9. A method as in claim 1, wherein a pressure of the
oxygen-containing gas within the capsule over the wound is
maintained in the range from 0-20 PSI.
10. A method as in claim 8, wherein the flow rate of
oxygen-containing gas is adjusted while the patient is wearing the
capsule.
11. A method as in claim 1, wherein the oxygen-containing gas is
selected from the group consisting of oxygen, heliox, and
nitrox.
12. A method as in claim 2, further comprising periodically
replacing the gas cylinder containing compressed oxygen-containing
gas while the capsule remains in place over the wound.
13. A method as in claim 1, further comprising releasing the
oxygen-containing gas from the interior of the capsule when
pressure within the interior of the capsule exceeds a predetermined
level.
14. A method as in claim 1, wherein the wound dressing capsule is,
impermeable.
15. A method as in claim 1, wherein the wound dressing capsule is
permeable.
16. A method as in claim 1, wherein the wound dressing capsule is
semipermeable.
17. A method as in claim 1, further comprising strapping the
capsule over the wound a portable topical oxygen therapy system of
claim 1, wherein the wound dressing capsule is permeable.
18. A method as in claim 1, further comprising cycling pressures in
the interior of the wound dressing capsule between hyperbaric,
isobaric and/or hypobaric pressures according to a predetermined
treatment regimen.
19. A method as in claim 1, further comprising pulsing pressures in
the interior of the capsule.
20. A method as in claim 1, further comprising manually
pressurizing the interior of the wound dressing capsule.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/441,574 (42995-703.301), filed Apr. 6,
2012, (now U.S. Pat. No. ______), which is a continuation of
International Application No. PCT/US2010/002832 (Attorney Docket
No. 42995-703.601), filed Oct. 25, 2010, which claims the benefit
of Provisional Application No. 61/279,624 (Attorney Docket No.
42995-703.101), filed Oct. 23, 2009, and Provisional Application
No. 61/516,952 (Attorney Docket No. 42995-703.102), filed Apr. 11,
2011, the entire contents of which are incorporated herein by
reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates to a topical oxygen therapy
system and a method for treating chronic non-healing wounds. The
system is configured to be extremely portable, allowing patients to
be completely ambulatory during treatment.
[0003] The U.S. Centers for Disease Control and Prevention estimate
that chronic non-healing wounds affect about 5.7 million patients
per year in the U.S. at a total treatment cost of approximately $20
billion annually. Chronic non-healing wounds are often the result
of diabetic ulcers, venous stasis ulcers, decubitus ulcers (bed
sores, pressure sores), post-surgical infections and gangrenous
lesions. Chronic wounds such as these can go for many months
without healing. Amputation of a limb is a last resort treatment
for chronic wounds that have become life threatening, for example
because of infection or gangrene. Various therapies have been
devised for accelerating the healing of chronic non-healing
wounds:
[0004] Hyperbaric oxygen therapy--Patients are treated in a
pressurized hyperbaric chamber, typically at 2 to 3 times
atmospheric pressure, and allowed to breath 100% oxygen. While this
therapy has been shown to be effective at accelerating healing of
wounds, the therapy is expensive, largely because of the cost of
building and operating the hyperbaric chamber. This therapy is also
time consuming and inconvenient for the patient. The patient must
travel to the hospital or clinic several times a week for
treatment, each treatment session typically lasts a couple of
hours, and it may require months of treatment before the wound is
adequately healed.
[0005] Topical oxygen chamber--The affected area of the body is
enclosed within a flexible or rigid chamber and the chamber is
filled with 100% oxygen. The oxygen can be supplied by a compressed
oxygen tank or an oxygen concentrator. This therapy is less costly
than hyperbaric oxygen therapy and it is portable enough that some
patients can undergo treatment at home.
[0006] However, it is still time consuming, requiring four 90
minute session per week, during which, the patient must remain
immobile. Because this therapy is intermittent, it may not be as
effective as it could be if applied more continuously.
[0007] Transdermal continuous oxygen therapy--A battery powered
electrochemical oxygen concentrator supplies 100% oxygen through a
small flexible cannula that is inserted under a bandage placed over
the wound. The electrochemical oxygen concentrator is described in
U.S. Pat. No. 5,578,022 for Oxygen Producing Bandage and Method.
The therapy is continuous for up to 15 days and the oxygen
concentrator is very small allowing the patient to be completely
ambulatory. However, the flow rate of oxygen from the oxygen
concentrator is very low, only 3 ml per hour, and the entire
disposable oxygen concentrator must be replaced every 7 to 15 days,
adding significantly to the cost of the therapy. The current cost
of a 15 day disposable oxygen concentrator is $700 or approximately
$47 per day of treatment.
[0008] Accordingly, it would be beneficial to provide a topical
oxygen therapy system for treating chronic non-healing wounds that
is extremely portable, that allows patients to be completely
ambulatory during treatment, that provides for a variety of
treatment regimens and that has the potential to provide more
economical treatment of chronic non-healing wounds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a cutaway side view of a topical oxygen therapy
system according to the present invention.
[0010] FIG. 2 is a top view of the topical oxygen therapy system of
FIG. 1 with a contoured protective housing removed to show the
oxygen source inside.
[0011] FIG. 3 shows a wound dressing capsule in the shape of a
rigid or semi-rigid dome connected to the oxygen source by a
flexible.
[0012] FIG. 4 shows a low-profile and form-fitting wound dressing
capsule connected to the oxygen source by a flexible.
[0013] FIG. 5 shows a topical oxygen therapy system according to
the present invention attached to a patient's lower extremity by a
plurality of straps.
DESCRIPTION OF THE INVENTION
[0014] The present invention provides a topical oxygen therapy
system for treating chronic non-healing wounds. The system is
configured to be extremely portable, allowing patients to be
completely ambulatory during treatment.
[0015] The topical oxygen therapy system 100 includes an oxygen
source 102 and a wound dressing capsule 104. The oxygen source 102
may be attached directly to or integrated into the wound dressing
capsule 104, as shown in FIGS. 1 and 2. FIG. 1 is a cutaway side
view and FIG. 2 is a top view with a contoured protective housing
148 removed to show the oxygen source 102 inside. Alternatively,
the oxygen source 102 and wound dressing capsule 104 may be
separate modules connected by a flexible tube 106, as shown in
FIGS. 3 and 4. The oxygen source 102, wound dressing capsule 104
and the flexible tube 106 may have luer fittings or quick
connect/disconnect fittings 108 for easy assembly or revision of
the system. The wound dressing capsule 104 can be circular, oval,
square, rectangular, triangular or any convenient shape for
covering the wound or wounds to be treated. The wound dressing
capsule 104 can also be formed or formable into a tubular or
cylindrical configuration to fit around a limb or another part of
the patient's body.
[0016] In one preferred embodiment, the oxygen source 102 includes
a miniature compressed oxygen 1 10 cylinder and a miniature
pressure regulator 1 12 that delivers oxygen through an outlet tube
1 16 to the interior of the wound dressing capsule 104 (optionally
connected via the flexible tube 106). In the current embodiment,
the compressed oxygen cylinder 110 is approximately 2.5 inches long
by 0.73 inches in diameter and contains oxygen compressed to
approximately 3000 psi. Other sizes and pressures of the compressed
oxygen cylinder 1 10 can also be used in the system. The miniature
pressure regulator 1 12 is preferably adjustable for regulating the
pressure to 0-20 psi, such that the oxygen source can supply a flow
rate of 0-10 ml per hour of oxygen at atmospheric pressure or
slightly above. Optionally, the oxygen source may include a
calibrated orifice, an adjustable orifice, a porous flow restrictor
or other flow control device 1 14 downstream from the pressure
regulator 1 12 to control the flow rate of oxygen. Optionally, an
on/off valve may also be included. At the current size, the
compressed oxygen cylinder 1 10 has enough capacity for topical
oxygen therapy over a period of approximately 5 days at a flow rate
of 10 ml per hour, approximately 10 days at 5 ml per hour or
approximately 17 days at 3 ml per hour. The necessary therapeutic
flow rate will be determined primarily by the size of the wound
dressing capsule needed to cover the wound or wounds being
treated.
[0017] In an alternate embodiment, the oxygen source may utilize a
fixed-pressure regulator. Coupled with a calibrated orifice, the
fixed-pressure regulator will be able to deliver a reliable preset
flow rate of oxygen.
[0018] The oxygen source with the compressed oxygen cylinder is
small enough that it can be attached directly to or integrated into
the wound dressing capsule, as in FIGS. 1 and 2. If the oxygen
source is in a separate module, as in FIGS. 3 and 4, it can be
placed in a protective housing 146 and it can be attached to the
body adjacent to the wound dressing capsule or it can be clipped to
the patient's belt or pinned to the patient's clothing. The entire
treatment system weighs just a few ounces so the patient is free to
walk around, work or exercise while the topical oxygen therapy is
taking place on a continuous or intermittent basis. Keeping the
patient ambulatory is especially important for maintaining
circulation, which is important for the wound healing process,
particularly in the lower limbs. It also reduces the overall cost
of medical care because the patient can remain active and
productive and does not need to interrupt his or her regular
routine to receive therapy.
[0019] The compressed oxygen cylinder would typically be replaced
approximately every 5 to 17 days, depending on the flow rate of
oxygen used, but could be replaced more or less often if desired.
Alternatively, two or more compressed oxygen cylinders may be
provided in the oxygen source to provide longer therapy and/or
higher flow rates. A hollow, tubular spike 1 18 connected to the
pressure regulator pierces the tip of the compressed oxygen
cylinder to connect to the interior of the cylinder while
simultaneously creating a seal around the spike. Optionally, an
O-ring or other sealing member 122 may be provided to help form a
seal between the cylinder 1 10 and the tubular spike 1 18.
Preferably, a mechanism 120 such as a screw, cam, lever or toggle
is provided to increase the mechanical advantage for piercing the
tip of the compressed oxygen cylinder. The mechanism can either
move the cylinder toward the spike or the spike toward the
cylinder. For safety, the mechanism also prevents the compressed
oxygen cylinder from being detached from the spike while there is
still pressure in the cylinder. One option is to configure the
mechanism with an intermediate position where the pressure from the
cylinder is allowed to safely vent before the cylinder is
released.
[0020] Optionally, the oxygen source may be configured to mix the
oxygen with ambient air to achieve oxygen levels in the range of 20
to 100 percent.
[0021] Optionally, the oxygen source may be configured to deliver
more than one gas to the wound dressing capsule. The gasses could
be mixed or they could be delivered sequentially or alternating.
For example, nitrogen or carbon dioxide could be delivered initial
and/or periodically to provide one or more periods of hypoxia or
anoxia. Hypoxia has been shown to increase the release of tissue
and vascular growth factors, which contribute to wound healing.
Following the periods of hypoxia with periods of high oxygen
concentration will accelerate the wound healing process. Another
option would be to mix or alternate the delivery of oxygen with a
gas that has other therapeutic effects. For example, nitric oxide
can be administered to cause vasodilatation and increase perfusion
of blood to the wound to accelerate healing.
[0022] Alternatively, the oxygen source may utilize a single
cylinder of compressed mixed gas, for example a HELIOX or NITROX
mixture.
[0023] The wound dressing capsule may be made in many different
configurations. FIG. 3 shows a wound dressing capsule 104 in the
shape of a rigid or semi-rigid dome 130 that covers and protects
the wound during treatment. The base of the dome can be shaped to
fit against the surface of a patient's limb, torso or other area to
be treated.
[0024] In one alternative, the dome-shaped wound dressing capsule
may be made of an impermeable elastic material that expands with
the application of hyperbaric pressures, i.e. pressures above
atmospheric pressure. The elastic energy stored in the dome can
help to maintain the pressure within the wound dressing capsule. By
closing an optional stopcock or one-way valve 132 on the inlet to
the wound dressing capsule, the elastic material of the dome can
maintain the internal pressure for an extended period of time, even
when the oxygen source is disconnected.
[0025] The wound dressing capsule may include a pressure relief
valve 124 to prevent overpressurization or the seal 126 may be
configured to act as a pressure relief valve when excessive
pressures are applied.
[0026] Optionally, the wound dressing capsule may be made with a
port or a one-way valve 128 for establishing a connection with the
interior of the wound dressing capsule without having to remove it.
The port or valve can be used for introducing materials, such as
moisture and medications. A syringe needle or a spray device can be
inserted through the port or valve.
[0027] FIG. 4 shows a wound dressing capsule 104 that is lower
profile and more form-fitting so that it can be worn unobtrusively
under the patient's clothing. The wound dressing capsule 104 may be
contoured to fit different body parts or it may be flexible so that
it can be fitted to nearly any part of the patient's body.
Optionally, a flexible wound dressing capsule may have a malleable
member 134, such as an annealed copper or aluminum wire, embedded
along the rim so that the wound dressing capsule can be manually
shaped to fit against the surface of a patient's limb, torso or
other area to be treated. Although this embodiment of the wound
dressing capsule may be flexible, it is preferably not stretchable
at the pressures used for therapy, otherwise the wound dressing
capsule could balloon up conspicuously when pressurized.
Optionally, support members 136, such as metal wires or more rigid
plastic members or molded ribs, across the flexible wound dressing
capsule will help to protect the wound and will help to keep the
flexible wound dressing capsule from overinflating when internal
gas pressure is applied.
[0028] The wound dressing capsule may be configured to allow
application of hyperbaric, isobaric or hypobaric pressures. For
applying different types of pressures, the wound dressing capsule
should be impermeable to gas and should provide a good seal against
the surface of the patient's body. For applying isobaric pressures,
the wound dressing capsule may be permeable, impermeable or
semipermeable and the seal against the surface of the patient's
body is not as critical. For isobaric applications, the wound
dressing capsule should be sufficient to maintain the desired
concentration of oxygen at the wound site for a given flow rate of
oxygen. Thus, there is a balance between flow rate of oxygen and
permeability of the wound dressing capsule for maintaining
effective wound healing therapy.
[0029] A sealing mechanism 126 may be provided for sealing the rim
of the wound dressing capsule 104 against the patient's body
surrounding the wound sufficiently to maintain the desired
therapeutic concentration of oxygen at the wound site. The sealing
mechanism 126 may be configure as a soft elastomeric rim seal, an
elastomeric foam seal, an inflatable rim seal (inflated to a higher
pressure than the treatment pressure), a fluid filled rim seal,
etc. Preferably, the sealing mechanism is attached to the wound
dressing capsule. Alternatively, a separate sealing mechanism may
be used. For example, a sheet of sterile elastomeric foam can be
cut to fit around the wound site, then the wound dressing capsule
can be seated against the foam to provide a seal. For convenience,
the sheet of foam may have contact adhesive on one or both sides.
Alternatively or in addition to these mechanisms, the seal against
the skin may be provided by a gel (solid or semi-solid) or a skin
compatible, hyporeactive adhesive, such as a hydrocolloidal
adhesive of the type used for ostomy devices, or adhesive tape. In
some cases, high strength adhesives may be contraindicated because
many patients with chronic wounds have fragile skin and injuries
from adhesive removal would be slow to heal and could even become
chronic wounds themselves.
[0030] Optionally, a protective layer, such as a hypo reactive
dressing, can be applied to the skin prior to attaching the wound
dressing capsule.
[0031] In an alternate embodiment, the wound dressing capsule may
be a conventional occlusive dressing with the end of the flexible
tube 106 placed under the dressing to deliver oxygen to the wound.
The dressing may be covered with a permeable or semipermeable
barrier layer to limit diffusion of the oxygen away from the wound
area.
[0032] Alternatively or in addition to the attachment methods
described above, one or more straps 140 may be provided to attach
the topical oxygen therapy system 100 or the wound dressing capsule
component of it to the patient, as shown in FIG. 5. Preferably, the
straps would be made of a breathable, elastic material and could
optionally include some foam padding or other cushioning material.
The straps would wrap around the limb or torso of the patient and
distribute the force of attachment so that pressure sores are not
created. The straps may be attached to the wound dressing capsule
or may simply wrap around it to hold it in place. The straps may
attach using hook-and-loop fasteners, snaps, buckles, contact
adhesive or other known fastening mechanisms. Alternatively, an
elastic garment may be donned over the wound dressing capsule. As
another alternative, adhesive tape may be used in place of the
straps. The straps, in combination with a conformable rim seal
and/or an adhesive, will help to hold the wound dressing capsule in
place and to maintain hyperbaric pressures within the wound
dressing capsule.
[0033] Hyperbaric pressures would more effectively drive oxygen
into the tissues by diffusion. However, localized high pressure may
interfere with blood circulation, as well as the migration of
lymphocytes and fibroblasts into the area, therefore localized
hyperbaric pressures should only be used intermittently. The oxygen
source may be made programmable so that cyclic pressures are
applied according to a treatment regimen. Alternating between
hyperbaric, isobaric or hypobaric pressures can be accomplished
using mechanically-actuated or electrically-actuated valves. The
flow and/or pressure may be pulsed, which could improve the
absorption of oxygen into the blood and tissues.
[0034] Alternatively, the wound dressing capsule may be configured
to allow external manual or mechanical pressurization. The wound
dressing capsule may be shaped like a bellows, telescopic structure
or ampule that can be pressurized by pressing on it externally.
Levers or other mechanisms may be used to increase mechanical
advantage. Straps, latches, ratchets, springs or other mechanisms
may be provided to maintain the pressure once it is applied.
Alternatively, a motorized and/or automatic mechanism may be
provided to mechanically increase or decrease the pressure
according to a prescribed treatment regimen.
[0035] A port, reservoir or chamber 142 may be provided in the
oxygen source and/or the wound dressing capsule to introduce
humidity to keep the wound and the dressing moist because the
compressed oxygen is likely to be very dry. Humidity can be
provided in the form of water vapor or a mist introduced into the
wound dressing capsule and or into the incoming flow of oxygen. An
automated humidity control system may be provided with a moisture
sensor, a water reservoir and an injector or evaporator.
[0036] Another port, reservoir or chamber 144 in the wound dressing
capsule can also be used to introduce medication to the wound. The
medication can be sprayed, injected or delivered to the surface of
the wound. Medications can include topical anesthetics,
antiseptics, antibiotics, healing promoters, such as nitric oxide,
and/or tissue growth factors.
[0037] The topical oxygen therapy system can be used for
intermittent or continuous delivery of oxygen and other gasses,
depending on what treatment regimen is desired or found to be most
effective. Typically, the wound dressing capsule will be applied
over an absorbent wound dressing to absorb any exudate from the
wound. Optionally, the absorbent wound dressing can be omitted for
short-term or intermittent use of the topical oxygen therapy system
to allow unrestricted contact between the oxygen and the wound and
to allow observation of the wound during treatment. Optionally, the
wound dressing capsule or a portion of it may be transparent to
allow observation of the wound during treatment.
[0038] Optionally, the topical oxygen therapy system can include an
electronic, mechanical or electromechanical control system to
control and/or vary the pressure, flow rate, composition duration
and timing of the topical oxygen therapy.
[0039] The topical oxygen therapy system can be configured to be
reusable, with only the compressed oxygen cylinder needing to be
replaced periodically. Alternatively, some or all of the topical
oxygen therapy system, including the wound dressing capsule and/or
the oxygen source, can be made disposable. As another alternative,
the compressed oxygen cylinder can be made refillable by adding an
inlet valve on the cylinder or otherwise connected to it so that
the cylinder can be refilled from a larger compressed oxygen
tank.
[0040] Topical oxygen therapy can be combined with other known
modalities, for example subsonic, sonic or ultrasonic vibrations,
photodynamic therapy or low level laser treatment. Optionally, the
topical oxygen therapy system may include features to heat and/or
cool the wound or the surrounding skin. For example, the tissue
could be heated to increase local blood circulation or cooled to
fight inflammation. Optionally, these additional features may be
battery powered to allow maximum patient mobility.
[0041] While the present invention has been described herein with
respect to the exemplary embodiments and the best mode for
practicing the invention, it will be apparent to one of ordinary
skill in the art that many modifications, improvements and
subcombinations of the various features and embodiments,
adaptations and variations can be made to the invention without
departing from the spirit and scope thereof.
* * * * *