U.S. patent application number 09/840416 was filed with the patent office on 2002-10-24 for ultrasonic method and device for wound treatment.
Invention is credited to Babaev, Eilaz.
Application Number | 20020156400 09/840416 |
Document ID | / |
Family ID | 25282320 |
Filed Date | 2002-10-24 |
United States Patent
Application |
20020156400 |
Kind Code |
A1 |
Babaev, Eilaz |
October 24, 2002 |
ULTRASONIC METHOD AND DEVICE FOR WOUND TREATMENT
Abstract
The method and device of the present invention for ultrasound
wound treatment includes a transducer to produce ultrasonic waves.
The ultrasonic transducer has tip with the distal end (radiation
surface). A liquid is directed to the radiation surface throug
central orifice or separate tube wherein an directed atomized
particle spray of the liquid is created upon contact of the liquid
with the radiation surface. The spray directed to the wound from at
least 0.1 inches transmits ultrasound waves trough particles and
has an irrigation, mechanical cleansing, liquid energizing and
bactericide effect.
Inventors: |
Babaev, Eilaz; (Minnetonka,
MN) |
Correspondence
Address: |
CARTER, DELUCA, FARRELL & SCHMIDT, LLP
445 BROAD HOLLOW ROAD
SUITE 225
MELVILLE
NY
11747
US
|
Family ID: |
25282320 |
Appl. No.: |
09/840416 |
Filed: |
April 23, 2001 |
Current U.S.
Class: |
601/2 |
Current CPC
Class: |
A61M 35/30 20190501;
A61M 11/005 20130101; A61M 2205/058 20130101; A61N 7/00 20130101;
B05B 17/063 20130101; B05B 17/0623 20130101 |
Class at
Publication: |
601/2 |
International
Class: |
A61H 005/00 |
Claims
What is claimed is:
1. A method for ultrasound wound treatment comprising the steps of:
(a) producing an ultrasonic spray of liquid particles produced by
the contact of liquid with an ultrasonic nozzle tip operating at a
frequency of 16 kHz to 10.sup.3 MHz, and (b) directing the
ultrasonic spray onto a wound surface while maintaining the tip
surface at a distance of at least about 0.1 inches from the wound
surface.
2. The method of claim 1, wherein the liquid contacts a radiation
surface of an ultrasound tip or instrument to produce a spray from
liquid flow or drops.
3. The method of claim 1, wherein in step (a) the liquid is
supplied to the ultrasound tip or instrument at a different
position, which causes the liquid particles to be energized.
4. The method of claim 3, wherein in step (a) the liquid is
supplied to the ultrasound tip or instrument via a central
orifice.
5. The method of claim 3, wherein in step (a) the liquid is
supplied to the ultrasound tip or instrument via a separate
tube.
6. The method of claim 1, wherein ultrasound waves are directed and
transported to the wound surface through liquid spray.
7. The method of claim 1, wherein ultrasound waves are directed to
the wound surface and transport gas to the wound through liquid
spray.
8. The method of claim 1, wherein ultrasound liquid spray directed
to the wound surface has irrigation, mechanical debridement and/or
cleansing effect.
9. The method of claim 1, wherein ultrasound liquid spray directed
to the wound surface has a blood flow increasing effect.
10. The method of claim 1, wherein the liquid comprises at least
one substance selected from the group consisting of antibiotics,
antiseptics, saline, oil, water, and combinations of two or more
thereof.
11. The method of claim 1, wherein the ultrasound frequency is
modulated.
12. The method of claim 1, wherein the ultrasound frequency is
pulsed.
13. A method for ultrasound wound treatment comprising the step of
driving an ultrasonic tip or instrument with constant frequency to
create liquid spray.
14. A method for ultrasound wound treatment comprising the step of
driving an ultrasonic tip or instrument with sinusoidal ultrasound
wave
15. The method of claim 14, wherein the ultrasound wave form is
rectangular.
16. The method of claim 14, wherein the ultrasound wave form is
trapezoidal.
17. The method of claim 14, wherein the ultrasound wave form is
triangular.
18. A device for ultrasound wound treatment, which comprises: (a)
an ultrasound transducer, (b) an ultrasound nozzle attached to said
transducer, said nozzle having a tip with a radiant distal end, and
(c) a liquid supply in fluid communication with said nozzle distal
end, wherein a liquid spray is generated that can be directed to
the surface of a wound.
19. The device of claim 18, wherein the ultrasound tip of the
sprayer has different modification of distal end (radiation
surface).
20. The device of claim 19, wherein the radial side surface of the
distal end of ultrasound tip has one or more grooves.
21. The device of claim 19, wherein the radial side surface of the
distal end of ultrasound tip has threads.
22. The device of claim 19, wherein the radial side surface of the
distal end of the ultrasound tip has rings.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method of using
ultrasonic waves in wound treatment. In particular, the present
invention relates to a method of spraying a wound surface using
ultrasonic waves for delivering drugs, killing bacteria, cleansing
a surface, increasing blood flow and stimulating healthy tissue
cells.
BACKGROUND OF THE INVENTION
[0002] Ultrasonic waves have been widely used in medical
applications, including both diagnostics and therapy, as well as in
many industrial applications. One diagnostic use of ultrasound
waves includes using ultrasonic waves to detect underlying
structures in an object or human tissue. In this method, an
ultrasonic transducer is placed in contact with the tissue (or
object) via a coupling medium, and high frequency (1-10 MHz)
ultrasonic waves are directed into the tissue. Upon contact with
underlying structures, the waves are reflected back to a receiver
adjacent the transducer. By comparison of the signals of an
ultrasonic wave as sent with the reflected ultrasonic wave as
received, an image of the underlying structure can be produced.
This technique is particularly useful for identifying boundaries
between components of tissue and can be used to detect irregular
masses, tumors, and the like.
[0003] Two therapeutic medical uses of ultrasonic waves include
aerosol mist production and contact physiotherapy. Aerosol mist
production makes use of a nebulizer or inhaler to produce an
aerosol mist for creating a humid environment and delivering drug
to the lung.
[0004] Ultrasonic nebulizers operate by passing ultrasonic waves of
sufficient intensity through a liquid, the waves being directed at
an air-liquid interface of the liquid from a point underneath or
within the liquid. Liquid particles are ejected from the surface of
the liquid into the surrounding air following the disintegration of
capillary waves produced by the ultrasound. This technique can
produce a very fine dense fog or mist. Aerosol mists produced by
ultrasound are preferred because a smaller particle size of the
aerosol can be obtained with the ultrasonic waves. One of the major
shortcomings of inhalers and nebulizers is that there are no
directed aerosol to the target without an air stream, which
decreases the efficiency of ultrasound.
[0005] Contact physiotherapy applies ultrasonic waves directly to
tissue in an attempt to produce a physical change in the tissue. In
conventional ultrasound physiotherapy, an ultrasonic transducer
contacts the tissue via a coupling medium. Ultrasonic waves
produced by the transducer travel through the coupling medium and
into the tissue. The coupling medium is typically a bath of liquid,
a jelly applied to the surface to be treated, or a water-filled
balloon. Conventional techniques provide ultrasonic waves having an
intensity of from about 0.25 w/cm.sup.2 to 3 w/cm.sup.2 at a
frequency of from about 0.8 to 3 Megahertz. The treatment is
applied to a skin surface for from about 1 to 30 minutes, two or
three times a week. The coupling medium can provide a cooling
effect which dissipates some of the heat energy produced by the
ultrasonic transducer. More importantly, a coupling medium or
direct contact between the tissue and the ultrasonic transducer is
necessary to transmit the ultrasonic waves from the transducer to
the skin surface because ambient air is a relatively poor medium
for the propagation of ultrasonic waves.
[0006] Several beneficial effects have been reported from contact
ultrasound physiotherapy. For example, the following effects have
been associated with contact ultrasound physiotherapy: local
improvement of the blood circulation, heating of the tissue,
accelerated enzyme activity, muscle relaxation, pain reduction, and
enhancement of natural healing processes. Despite these beneficial
effects, current techniques of medical physiotherapy using
ultrasonic waves are limited by the necessity of providing a direct
contact interface between the ultrasonic transducer and the tissue
to maintain an effective transmission of the ultrasonic waves from
the transducer to the tissue. The necessity of direct contact with
or without a coupling medium makes current methods undesirable.
Some tissue conditions may be accessible to contact ultrasound
devices but would be impractical for contact ultrasound treatment.
For example, fresh or open wounds resulting from trauma, bums,
surgical interventions are not suitable for direct contact
ultrasound treatment because of the structural of the structural
nature of the open wound and the painful condition associated with
those wounds. Moreover, conventional contact ultrasound may have a
destructive effect on these types of open wounds due to the close
proximity of an oscillating tip of an ultrasonic transducer
relative to the already damaged tissue surface.
OBJECT OF THE INVENTION
[0007] It is an object of the invention to provide a method and
device for treating wounds.
[0008] It is also an object of this invention to provide a method
and device for treating wounds using ultrasonic waves.
[0009] It is another object of the invention to provide a method
and device for delivering drugs and irrigation to wounds.
[0010] It is a yet another object of the invention to provide a
method and device for the mechanical cleansing and debridement of
wounds.
[0011] It is a further object of the invention to provide a method
and device for increasing blood flow in a wound area.
[0012] It is a yet further object of the invention to treat a wound
by spraying the surface of the wound with an aerosol mist produced
by ultrasonic waves.
[0013] These and other objects of the invention will become more
apparent from the discussion below.
SUMMARY OF THE INVENTION
[0014] The present invention concerns a method and device for
spraying a wound surface to deliver drugs, kill bacteria, or
cleanse a surface by non-contact application of ultrasonic waves.
The ultrasonic waves are applied to the wound without requiring
direct or indirect (via a traditional coupling medium) contact
between an ultrasonic wave transducer and the wound to be
sprayed.
[0015] Ultrasonic sprayers (Sonic and Materials Inc., Misonix Inc.,
Sono-Tek Inc.; U.S. Pat. Nos. 4,153,201, 4,655,393, and 5,516,043)
typically operate by passing liquid through the central orifice of
the tip of an ultrasound instrument. Known applications are
essentially industrial, such as a burner or device for coating of
surfaces. No ultrasound wound or biological tissue treatment
application with such a device has been indicated, with the
exception of ultrasound liposuction.
[0016] According to the present invention a directed spray of
liquid particles produced by contact of the liquid with a free end
surface of an ultrasonic transducer is directed onto a wound. The
ultrasonic waves cause the spray to project outwardly from the
distal end surface, and the particles of the spray provide a medium
for propagation of the ultrasonic waves emanating from the distal
end surface.
[0017] In the method of the present invention, particle spray
created by low frequency ultrasound waves and directed at the
surface of a wound, can deliver drugs, kill bacteria on the wound,
increase blood flow, and/or remove dirt and other contaminants from
that surface (mechanical cleansing). This method of drug delivery
is particularly advantageous on tissues for which local topical
application of a drug is desirable yet contact with the tissue is
to be avoided. Furthermore, the low frequency ultrasound waves used
in the method energize the drug and cause penetration of the drug
below the surface of the tissue. Finally, the bacteria killing
method is effective when applied to the surface whether the liquid
sprayed is a drug (an antiseptic or antibiotic), oil, saline,
distilled water, or the like.
[0018] In a device acording to the invention, a spray is produced
by first delivering liquid to the free distal end surface of an
ultrasound tip through the axial (center) orifice or hose. After
liquid is delivered to the free distal end surface, ultrasonic
waves create the spray, which is directed to a particular targeted
surface such a wound. Simultaneously ultrasonic waves are delivered
to the wound surface through the spray.
[0019] The device must have a nozzle made from a rigid material
such as steel (non-disposable) or plastic (disposable). The nozzle
allows liquid to be delivered to a lateral surface of the
transducer tip or directly to the distal side (radiation surface)
of the ultrasound instrument to be sprayed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of an ultrasonic wound
treatment system for use according to the invention;
[0021] FIG. 2 is a partial cross-sectional view of the distal
portion of an ultrasonic wound treatment device of the invention
with a central orifice;
[0022] FIG. 3 is a partial cross-sectional view of the distal
portion of an ultrasonic wound treatment device of the invention
with no central orifice;
[0023] FIG. 4 is a partial cross-sectional view of the distal
portion of an ultrasonic wound treatment device of the invention
with focused ultrasound;
[0024] FIG. 5 is a partial cross-sectional view of the distal
portion of an ultrasonic wound treatment device of the invention
with a thread on a radial surface;
[0025] FIG. 6 is a partial cross-sectional view of the distal
portion of an ultrasonic wound treatment device of the invention
with a thread in a central orifice;
[0026] FIG. 7 is a partial cross-sectional view of the distal
portion of a device for spraying where fluid is delivered to a
lateral or radiation surface of the transducer tip by tube or
sleeve and gas is delivered through the ultrasound tip's central
orifice;
[0027] FIG. 8 is a partial cross-sectional view of the distal
portion of a device for spraying where gas is delivered to a
lateral or radiation surface of the transducer tip the through
housing or bushing by perimeter of the tip and liquid is delivered
through the ultrasound tip's central orifice;
[0028] FIG. 9 is a view illustrating use of a bushing for better
effect of ultrasound standing waves to treat wounds; and
[0029] FIG. 10 is a partial cross-sectional view of a nozzle for
ultrasound wound treatment using two tubes, one for carrying gas
such a oxygen and another for carrying liquid such as a therapeutic
agent.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention is a method and device, which uses
ultrasonic wave energy to treat wounds. The device comprises a
generator of electrical signals and a handpiece having an
ultrasound transducer tip. The handpiece also comprises a tube for
delivering drug to the radiation surface of the ultrasound tip.
[0031] The invention can perhaps be better appreciated from the
drawings. In FIG. 1, a system 10 according to the invention
comprises an ultrasound generator 12 in operative connection
through cable 14 with an ultrasound handpiece 16. Handpiece 16
comprises an ultrasound nozzle 18 and a transducer 20 and is in
fluid communication through connecting member 22 with liquid
reservoir 24. Liquid dispensed from reservoir 24 contacts the
distal end or radiation surface 26 of nozzle 18, resulting in a
spray 30 that is directed toward the surface 32 of wound 34. In
this fashion liquid is sprayed on the wound surface while
ultrasonic waves are delivered to the wound.
[0032] FIG. 2 is a schematic representation of a cross-section of
an ultrasonic nozzle tip 36 for wound treatment with a central
lumen or orifice 38, as used in a device of the present invention.
Liquid from a reservoir (not shown) is delivered in the direction
of arrow 40 to the distal end 42 of ultrasound tip 36 through
central orifice 38 to create ultrasound mist 44, which is directed
to the surface 46 of a wound 48.
[0033] FIG. 3 is a schematic representation of a cross-section of
an ultrasonic nozzle tip 50 for wound treatment with no central
orifice, as used in a device of the present invention. Liquid from
a reservoir (not shown) is delivered in the direction of arrow 52
to a solid distal end 54 of ultrasound tip 50 through a lumen 55 in
tubing 56, to create ultrasound mist 58. Ultrasound mist 58 is
directed to the surface 60 of a wound 62.
[0034] FIG. 4 is a schematic representation of a cross-section of
an ultrasonic nozzle tip 66 with focused energy for wound treatment
with no central orifice, as used according to the invention. Liquid
68 from a reservoir (not shown) is delivered in the direction of
arrow 68 to the solid distal end 70 of ultrasound tip 66 through a
lumen 71 in tubing 72 to create an ultrasound mist 74 that is
directed to a focal point 76 on the surface 78 of a wound 80.
Ultrasound tip distal end 70 is curved, e.g., elliptical, oval,
etc.
[0035] FIG. 5 is a schematic representation of a cross-section of
an ultrasonic nozzle tip 84 for wound treatment with grooves 86 on
a radial surface 88. Liquid from a reservoir (not shown) is
delivered in the direction of arrow 90 to radial surface 88 through
a lumen 91 in tubing 92, to create an ultrasound mist 94.
Ultrasound mist 94 is directed to the surface 96 of a wound 98.
Grooves 86 can alternatively be threads or rings.
[0036] FIG. 6 is a schematic representation of a cross-section of
an ultrasonic nozzle tip 102 for wound treatment with thread 104 in
a central lumen or orifice 106. Liquid from a reservoir (not shown)
is delivered in the direction of arrow 108 through central orifice
106 to the distal end 110 of ultrasound tip 102 to create an
ultrasound mist 112. Ultrasound mist 112 is directed to the surface
114 of a wound 116.
[0037] FIG. 7 is a schematic representation of a cross-section of
an ultrasonic nozzle tip 120 for wound treatment with a central
lumen or orifice 122. Liquid from a reservoir (not shown) is
delivered in the direction of arrow 124 through a lumen 128 in
tubing 130 to the distal end 132 of ultrasound tip 120 to create an
ultrasound mist 134. A gas such as oxygen is delivered in the
direction of arrow 136 through central orifice 122. Ultrasound mist
134 is directed to the surface 138 of wound 140. Alternatively,
liquid can be delivered in the direction of arrow 136 through
central orifice 122 and gas can be delivered in the direction of
arrow 124 through lumen 128.
[0038] FIG. 8 is a schematic representation of a cross-section of
an ultrasonic nozzle tip 146 for wound treatment with a central
lumen or orifice 148. Liquid from a reservoir (not shown) is
delivered to the distal end 152 of ultrasound tip 146 through
central orifice 148, to create an ultrasound mist 154. Ultrasound
mist 154 also carries a gas such as oxygen, delivered in the
direction of arrow 156 through annular channel 158 formed by
bushing 160. Ultrasound mist 154 contacts the surface 164 of wound
166. Alternatively, gas liquid can be delivered in the direction of
arrow 156 through annular channel 158 and gas can be delivered in
the direction of arrow 150 through central orifice 148.
[0039] FIG. 9 is a schematic representation of a cross-section of
an ultrasonic nozzle tip 168 for wound treatment with a central
lumen or orifice 170 and an expanded bushing 176, which creates
better conditions for standing waves. Liquid from a reservoir (not
shown) is delivered in the direction of arrow 172. Substantially
annular channel 174 is formed by expended bushing 176, and gas such
as oxygen is delivered through annular channel 174 in the direction
of arrow 178. An ultrasound mist 180 created at the distal end 182
of ultrasound tip 168 is directed at the surface 184 of wound 186.
Alternatively, liquid can be delivered in the direction of arrow
178 through annular channel 174 and gas can be delivered in the
direction of arrow 172 through central orifice 170.
[0040] FIG. 10 is a schematic representation of an ultrasonic
nozzle tip 190 with no central orifice, where liquid is delivered
from a reservoir (not shown) in the direction of arrow 192 through
a lumen 194 in tubing 196 to the distal end 198 of tip 190. A gas
such as oxygen is delivered from a gas source (not shown) in the
direction of arrow 200 through a lumen 202 in tubing 204 to tip
distal end 198. An ultrasound mist 206 created at tip distal end
198 is directed to the surface 208 of wound 216.
[0041] The cross-section of the ultrasonic nozzle tip can be
circular, oval, elliptical, rectangular, multi-angular,
trapezoidal, or a combination thereof. The distal end shape of the
ultrasound nozzle tip may be the same or different, such as
rectangular, elliptical, oval, spherical, conical, curved, stepped,
with chamfer, etc. The most preferred shape is rectangular, due to
radiation beams from the ultrasonic nozzle tip surface being fully
directed to the target (wound). With the spherical, elliptical and
oval shaped ends, radiation beams are focussed at a focal point, as
shown, for example, in FIG. 4. With distal ends of other shapes,
some of the radiation beams spread before reaching the target.
[0042] Radial side surface(FIG. 5) of distal end and central
orifice (FIG. 6) of the ultrasond tip may have slot (groove)or
thread for liquid to be directed to the radiation surface, which
increases the liquid pressure.
[0043] Since local tissue oxygenation can stimulate tissue
regeneration and prevent infection in wound treatment, the method
of the present invention includes the mixing and delivery of oxygen
and sprayed liquid (saline, water, therapeutic agent, etc., a
shown, for example, in FIG. 7. In this case the liquid spray
delivers oxygen or another gas to the wound. Gas or liquid can be
delivered via tubing (FIG. 7) or housing (FIG. 8).
[0044] The step of producing the spray can further include
operating the transducer to produce ultrasonic waves having a
frequency of from about 18 to 10000 kHz. Although a frequency of 1
to 18 kHz can be used, this range should be avoided since this
range of sound wave is uncomfortable to the patient and operator.
The preferred range of frequency is from about 30 to 100 kilohertz,
the most preferred frequency being about 40 kHz.
[0045] The distance of separation between the distal free end
surface of the transducer and the surface to be sprayed is
preferably from about 0.1 to 20 inches.
[0046] One of the benefits of the present invention is the use of
the ultrasound standing waves for wound treatment. Ultrasound
standing waves 210 occur when an ultrasound nozzle tip is activated
through the air toward the wound surface as a result of incident
and reflected waves from the wound surface, which creates
ultrasonic radiation pressure. Standing waves 210, actually
ultrasound radiation pressure, occur when the distance between the
distal end of the transducer nozzle tip (as a radiant of ultrasound
waves) and the reflected surface (wound surface) is: n..lambda./2
(.lambda.=wave length, n=integer). To reach this preferred distance
and therefore this effect in wound treatment practice, the
ultrasound transducer or tip must be moved back and forth toward
the wound by the operator.
[0047] The standing waves are more effective in limited space or
area as a tube. In this case use of a bushing 12 (FIG. 9) increases
ultrasound radiation pressure. The bushing may or may not be
disposable part on the distal end.
[0048] The liquid can further include any drug (antibiotic,
anticeptic, etc.), saline, water (distilled or regular), or oil for
application to the tissue.
[0049] In addition, the method of the invention can include
directing the spray onto the surface for from about 1 second to
about 30 minutes, dependant upon the condition and size of the
wound. This can be done on a daily or semi daily basis, or
two-three times per week or month.
[0050] The method of the present invention permits application of
ultrasonic waves to the wound without establishing contact,
directly or indirectly, between the ultrasonic transducer and the
wound. For example, surfaces of the human body especially suited
for treatment with the method of the present invention include
infected and/or inflamed situations in open wounds, including
trauma or gun shut wounds, and fire and chemical bums.
[0051] In addition, the method of the present invention is
particularly suited to directing a spray into orifices or other
body crevices that are difficult to access.
[0052] This method of wound treatment has a several advantages.
First, this method topically applies medicines such as liquid
antibiotics to the wound surface without the need to contact an
infected, inflamed or painful tissue with an instrument. Second, a
significant debridement, cleansing and bactericidal effect can
occur, when spraying a wound surface using the method of the
present invention. And third, aside from the bactericidal effect
and advantages of non-contact treatment, use of the method of the
present invention permits a significant reduction in volume used of
liquid medicine used as compared with traditional methods for wound
treatment. Similarly, this allows for precise dosage of the sprayed
liquid to permit a user, such as a physician to administer the
desired volume of liquid at a desired rate and duration.
[0053] The method of the present invention decreases healing times
for inflammatory and purulent infected wounds, up to 1.5 to 2 times
faster than traditional methods. This effect results from a
bactericidal, blood flow increasing and mechanical cleansing effect
of the atomized spray particles, which have ultrasound energy due
to the ultrasonic waves.
[0054] The ultrasonic spray mechanically scrubs the surface of
tissue to remove dirt, dead tissue, and purulent buildup on the
tissue surface.
[0055] The mentioned healing effect also results of energized and
highly activated antibiotics, drug penetration into the tissue
surface up to 0.5 mm in depth under influence of ultrasound waves.
Additionally, a combination of the low frequency ultrasonic waves
and the sonicated medicines (highly activated by ultrasonic energy)
destroy the surface bacteria to result in a higher disinfecting
property of sonicated liquids as compared to ordinarily applied
liquids. The spray of the present method also stimulates healthy
cell growth to aid in granulization and epithelization of the
healing tissue. Other applications of the method can be directed to
non-medical uses such as cleansing, sterilizing and coating
surfaces of objects and food. The method of the present invention
offers an approach that may re-establish use of some traditional
antibiotics and establish a method fighting bacteria without
antibiotics when necessary.
[0056] The effect of the method of the present invention in highly
activating antibiotics may allow some traditional antibiotics to
overcome bacteria which have become resistant to that antibiotic.
Moreover, independent of the sonication effect of the antibiotics,
the low frequency ultrasonic waves applied in the method of the
present invention physically destroy bacteria. The combination of
the highly activated antibiotics and of the low frequency
ultrasonic waves in the method of the present invention produce a
strong bactericidal effect not found in mere topically application
or orally ingested antibiotics. This combined effect has been shown
to significantly increase the healing of purulent infected
wounds.
[0057] The present method also provides a system of non-contact
drug delivery without using a compression sprayer system. This
simplifies the design of a non-contact drug delivery sprayer and
reduces the weight of the sprayer. More importantly, not using
compression to propel the atomized particles preserves the
ultrasound energy carried by the spray particles.
[0058] The method of the present invention provides a method of
compressionless non-contact drug delivery.
[0059] It is to be understood, however, that other expedients known
to those skilled in the art or disclosed herein, may be employed
without departing from the spirit of the invention or the scope of
the appended claims.
* * * * *