U.S. patent number 3,608,553 [Application Number 04/855,126] was granted by the patent office on 1971-09-28 for ultrasonic method and apparatus for tissue grafting.
This patent grant is currently assigned to Ultrasonic Systems, Inc.. Invention is credited to Lewis Balamuth.
United States Patent |
3,608,553 |
Balamuth |
September 28, 1971 |
ULTRASONIC METHOD AND APPARATUS FOR TISSUE GRAFTING
Abstract
The method and apparatus of grafting tissue, such as tissue in
biological organisms such as humans, by the removal of live
epidermal cells from one area of a body by ultrasonic means, and
then transporting such cells in a suitable isotonic fluid
suspension to the site where the fluidized cells are to find their
new homes and then applying the cells thereto.
Inventors: |
Balamuth; Lewis (New York,
NY) |
Assignee: |
Ultrasonic Systems, Inc.
(Farmingdale, NY)
|
Family
ID: |
25320418 |
Appl.
No.: |
04/855,126 |
Filed: |
September 4, 1969 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
655118 |
Jul 21, 1967 |
3526219 |
|
|
|
Current U.S.
Class: |
606/131; 606/132;
606/169; 601/2 |
Current CPC
Class: |
A61B
17/322 (20130101) |
Current International
Class: |
A61B
17/322 (20060101); A61b 017/00 (); A61b
017/32 () |
Field of
Search: |
;128/303,303.1,305,305.5,24A |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Austenal Laboratories, Inc., Catalogue, March, 1948, p. 20, (copy
in 3/1) .
Taylor, Rennie, Associated Press Article, Oct. 31, 1947, (copy in
3/1).
|
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Howell; Kyle L.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of my copending
application Ser. No. 655,118, filed July 21, 1967, now U.S. Pat.
No. 3,526,219, issued Sept. 1, 1970 and which entire subject matter
of the copending application is incorporated herein by reference as
if fully herein set forth.
Claims
I claim:
1. A method of grafting tissue to a human, comprising the steps
of
A. removing a layer of tissue from a portion of the human in the
form of cells utilizing ultrasonic energy, by
1. vibrating a tool member having an output edge to provide peak
accelerations of at least 50,000 g,
2. engaging said output edge of said vibrating tool member with the
surface of said tissue to transmit said vibrations to the tissue in
engagement therewith, and
3. microchopping said tissue from said human portion by
progressively moving said output edge relative to the surface of
said tissue such that there is a substantial component of relative
motion perpendicular to said edge, whereby said layer of tissue is
removed from said human,
B. forming a fluidized suspension containing said cells, and
C. depositing said cells of said fluidized suspension on a grafting
site to form a new layer of tissue on said human.
2. A method as in claim 1, further including the step of selecting
and maintaining the frequency and intensity of said ultrasonic
energy at a level below which substantial damage will occur to said
cells during removal thereof.
3. A method as in claim 1, further including the step of
transferring said fluidized suspension to said grafting site prior
to depositing said cells thereon.
4. A method as in claim 3, wherein the step of transferring said
cells includes simultaneously applying suction to said
ultrasonically treated portion to remove said fluidized suspension
therefrom.
5. A method as in claim 3, further including the step of draining
the fluid of said fluidized suspension from said grafting site to
leave a substantial concentration of said cells thereon.
6. A method as in claim 1, wherein the step of depositing said
cells includes spraying the fluidized suspension onto the grafting
site so as to obtain a dispersion of said cells thereon.
9. A method as in claim 8, wherein the step of forming said
concentration includes the steps of
a. delivering said fluidized suspension to a reservoir, and
b. extracting from said reservoir said cells at a greater
concentration per given volume than initially pumped into said
reservoir per said given volume in said fluidized suspension.
10. A method as in claim 1, further including the step of first
preparing the grafting site for the application of said cells
thereon to enhance the grafting operation.
11. A method as in claim 1, further including the step of
maintaining the tissue to be removed under tension to obtain a
substantially continuous depth of removal.
12. A method as in claim 1, further including the step of
controlling the depth of removal of said layer of tissue during the
relative movement between said human and tool member.
13. A method as in claim 12, wherein said thickness of tissue
removed is controlled by providing a guard having a bottom end in
substantially parallel spaced relation to the output edge of said
tool member, whereby the thickness of the layer of tissue to be
removed is controlled.
14. A method as in claim 1, wherein said step of forming a
fluidized suspension includes the steps of
a. supplying a treatment fluid to the treated surface so that
contact of said output edge with the treated surface pressurizes
the fluid for enhancing the effectiveness of the liquid in mixing
with the microchopped tissue and forming a suspension thereof,
and
b. simultaneously applying suction to said treated surface adjacent
said tool member to remove said suspension from the surface.
15. A method as in claim 14, wherein the treatment fluid is
supplied to the tissue surface and the suction is applied to the
tissue surface at spaced apart locations between which at least a
portion of the vibrated tool member is interposed so that the
suction induces the treatment fluid to flow between said vibrated
tool member and the tissue surface for ensuring the continuous
mixing and the removal of said suspension.
16. The method of grafting tissue to a human, comprising the steps
of
A. removing a layer of tissue from a portion of a human in the form
of cells utilizing ultrasonic energy, by
1. vibrating a tool member having an output edge to provide peak
accelerations of at least 50,000 g,
2. engaging said output edge of said vibrating tool member with the
surface of said tissue to transmit said vibrations to the tissue in
engagement therewith,
3. microchopping said tissue from said human by progressively
moving said output edge relative to the surface of said tissue such
that there is a substantial component of relative motion
perpendicular to said edge, whereby said layer of tissue is removed
from said human,
4. maintaining the tissue to be removed under tension to obtain a
substantially continuous depth of removal, and
5. controlling the depth of removal of said layer of tissue during
the relative movement between said human and tool member,
B. selecting and maintaining the frequency and intensity of said
ultrasonic energy at a level below which permanent damage will
occur to said removed cells and the surrounding tissue,
C. supplying a treatment fluid to said portion of the human treated
with ultrasonic energy for enhancing the removal of said cells and
forming a fluidized suspension containing a mixture of said cells
and treatment fluid,
D. transferring said fluidized suspension to a grafting site by
applying a suction force to said ultrasonically treated portion to
remove said treatment fluid therefrom, and
E. depositing said cells on said grafting site whereby said grafted
cells form a new layer of tissue on said grafting site.
17. A method as in claim 16, further including the steps of
a. first preparing the grafting site for the application of said
cells thereon to enhance the grafting operation, and
b. extracting from said fluidized suspension concentration of said
cells prior to transferring said cells to said grafting site.
18. A method as in claim 17, wherein the step of depositing said
cells includes spraying said fluidized suspension onto said
grafting site so as to obtain a dispersion of said cells
thereon.
19. A method of grafting tissue from a removal site to a grafting
site of a human, with an ultrasonic instrument having a tool member
with an output edge for engagement with the tissue to be removed,
comprising the steps of
A. supporting said human in a position wherein the removal and
grafting sites are exposed,
B. positioning said ultrasonic instrument in energy transferring
relationship to said removal site wherein said tool member engages
said tissue,
C. removing a layer of tissue from the removal site in
substantially cellular form by progressively moving said ultrasonic
instrument relative to the surface of said removal site, said step
of removing a layer of tissue further includes,
1.
1. vibrating said output edge to provide peak accelerations of at
least 50,000 g,
2. microchopping said tissue from said human by progressively
moving said output edge relative to the surface of said tissue such
that there is a substantial component of relative motion
perpendicular to said edge, whereby said layer of tissue is removed
from said human,
3. maintaining the tissue to be removed under tension to obtain a
substantially continuous depth of removal, and
4. controlling the depth of removal of said layer of tissue during
the relative movement between said human and tool member,
D. forming a fluidized suspension containing said removed cells by
providing a treatment fluid to said work site for forming said
suspension,
E. transferring said suspension containing said cells to a grafting
site adapted to receive said cells thereon, and
F. depositing said cells on said grafting site, whereby the grafted
cells will form a new layer of tissue on said grafting site.
20. Apparatus for grafting tissue to a human, comprising
A. means for ultrasonically removing a layer of tissue from a
portion of a human in the form of cells, said means for
ultrasonically removing a layer of tissue includes
1. a tool member having an output edge for engagement with the
layer of tissue of said portion as it is moved relative
thereto,
2. vibration generating means coupled to said tool member to effect
vibration of the latter at a high frequency and with peak
accelerations of at least 50,000g, so as to microchop said tissue
into particles as the vibrating tool is moved relative to said
tissue surface, and
B. means for forming a fluidized suspension containing said cells,
said means of forming said fluidized suspension includes means for
supplying a treatment fluid to the tissue surface adjacent said
vibrated tool member so that contact of said vibrated tool member
pressurizes the liquid for enhancing the effectiveness of the fluid
in mixing with the microchopped tissue particles and forming said
fluidized suspension,
C. means for transferring said cells in said fluidized suspension
to a grafting site adapted to receive said cells thereon, and
D. means communicating with said transferring means adapted for
depositing a layer of said cells on said grafting site to form a
new layer of tissue thereon.
21. Apparatus as in claim 20, further including means for selecting
and controlling the frequency and intensity of said ultrasonic
means at a level below which substantial permanent damage will
occur to said cells during removal thereof.
22. Apparatus as in claim 20, wherein said means adapted for
depositing said cells includes means for spraying the fluidized
suspension onto said grafting site so as to obtain a dispersion of
said cells thereon to form said new layer of tissue.
23. Apparatus as in claim 22, further including means adapted for
draining the fluid of said fluidized suspension from said grafting
site to leave a substantial concentration of said cells
thereon.
24. Apparatus as in claim 20, wherein said means for forming said
fluidized suspension includes means adapted for supplying a
treatment fluid to said portion of the human adapted to be treated
with said ultrasonic energy for enhancing the removal of said
cells, and forming said fluidized suspension.
25. Apparatus as in claim 24, wherein said means for transferring
said cells includes means adapted for applying suction to said
ultrasonically treated portion to remove said fluidized suspension
therefrom.
26. Apparatus as in claim 20, further including means communicating
with said transferring means for forming a concentration of said
cells prior to depositing said cells on said grafting site.
27. Apparatus as in claim 26, wherein said means for forming said
concentration includes
a. a reservoir for retaining said fluidized suspension, and
b. means for extracting from said reservoir said cells for
transferring to said grafting site at a greater concentration per
given volume than initially pumped into said reservoir per said
given volume.
28. Apparatus as in claim 20, and further including control means
engageable with said vibration generating means for controlling the
thickness of said layer of tissue microchopped from the surface of
the human.
29. Apparatus in claim 28, and further including means adapted for
maintaining the tissue to be removed under tension during movement
of said tool member relative thereto, to obtain a substantially
continuous depth of removal.
30. Apparatus for grafting tissue to a human, comprising
A. means for ultrasonically removing a layer of tissue from a
portion of a human in the form of cells, said means for
ultrasonically removing a layer of tissue includes
1. a tool member having an output edge for engagement with the
layer of tissue of said portion as it is moved relative
thereto,
2. vibration generating means coupled to said tool member to effect
vibration of the latter at a high frequency and with peak
accelerations of at least 50,000 g, so as to microchop said tissue
into particles as the vibrating tool is moved relative to said
tissue surface, and
B. means for selecting and controlling the frequency and intensity
of said ultrasonic means at a level below which permanent damage
will occur to said removed cells and the surrounding tissue,
C. means for supplying a treatment fluid to said portion of the
human adapted to be treated with ultrasonic energy for enhancing
the removal of said cells and forming a fluidized suspension,
D. means for transferring said cells of said fluidized suspension
to a grafting site, including means for applying suction to said
ultrasonically treated portion to remove said fluidized suspension
therefrom,
E. means communicating with said means for transferring said cells
and adapted for depositing same on said grafting site, and
F. means adapted for draining said treatment fluid from said
grafting site to leave a substantial concentration said cells
thereon, whereby the grafted cells form a new layer of tissue on
said grafting site.
31. Apparatus as in claim 30, wherein said means for depositing
said cells includes a nozzle adapted to be moved relative to the
grafting site so as to obtain a dispersion of said cells thereon.
Description
BACKGROUND OF THE INVENTION
This invention relates broadly to grafting of tissue and more
particularly to the method and apparatus for the selective removal
of layers of tissue by ultrasonic means and then transplanting the
cells of the removed tissue to a new location.
Although the principles of the present invention are broadly
applicable to the removal and transplanting of layers of low
compliant materials, the present invention is particularly adapted
for use in conjunction with tissue in humans and hence will be so
illustrated and will be so described.
OBJECTIVES OF THE INVENTION
An object of the present invention is to provide an improved method
and apparatus for grafting of tissue in humans.
Another object of the present invention is to provide an improved
method and apparatus for progressively removing a layer of tissue
from one area of the body and transplanting the removed layer in
the form of viable tissue to another area of the body.
Another object of the present invention is to provide an enclosed
system in which healthy cells are removed in clusters using
ultrasonic energy and transported in a fluid suspension and applied
to another area of the human body.
Another object of the present invention is to provide an improved
method and apparatus for the removal of living organic cells in a
rapid manner with the exertion of a minimum of physical energy and
the depositing of the removed cells on the area requiring
grafting.
Other objects and advantages of this invention will become apparent
as the disclosure proceeds.
SUMMARY OF THE INVENTION
The outstanding and unexpected results obtained by the practice of
the method and apparatus of this invention are attained by a series
of features, steps and elements assembled working together in
interrelated combination.
In my copending application, referred to above, I disclose that
mechanical elastic vibrations of hyperaccelerations of 50,000 g,
properly transmitted to a biological organism in vivo may be
employed to selectively separate living organic tissue from
surrounding tissue without harmful effects to the surrounding
tissue. This new principle has been termed "microchopping" to more
clearly define and illustrate my invention.
I have now discovered that ultrasonic energy, properly controlled,
may remove the epidermal cells of the human body without
substantial damage thereto and that the removed cells may be
deposited on another area for grafting thereof. The essential idea
of this invention is the removal of live epidermal cells from one
area of the body by ultrasonic means, and then transporting such
viable cells in a suitable isotonic fluid suspension through a
conduit to the site where the fluidized cells are to find their new
homes. Preferably the entire operation is self-confined so that no
external means need contact the fluid suspension from the time of
formation to the time of grafting. This is particularly useful for
extensive graft areas such as are required due to burns or diseases
of the skin.
If desired the operation of obtaining the original cells may be
performed with a dermatome, a device for cutting tissue by
nonultrasonic mechanical means, which has precision controls
determining the depth to be "shaved" from the site, and the
fluidized slurry of cells pumped in a hermetically sealed system to
the transplanting or grafting site.
BRIEF DESCRIPTION OF THE DRAWINGS
Although the characteristic features of this invention will be
particularly pointed out in the claims, the invention itself, and
the manner in which it may be made and used, may be better
understood by referring to the following description taken in
connection with the accompanying drawings forming a part hereof,
wherein like reference numerals refer to like parts throughout the
several views and in which:
FIG. 1, is a side elevational view in schematic form illustrating
the invention for grafting skin on a human;
FIG. 2, is a top elevational view of FIG. 1, illustrating the
relationship of equipment;
FIG. 3, is an enlarged view illustrating the related components of
the invention for transporting the removed cells to the grafting
site;
FIG. 4, is a side elevational view, partly broken away and in
section, of the ultrasonic system utilized in accordance with the
present invention;
FIG. 5, is a greatly enlarged view in section of the ultrasonic
tool and associated guard in position during the removal process of
a layer of tissue;
FIG. 6, is an enlarged view in section of the means of depositing
the removed cells on the grafting site;
FIG. 7, is a sectional view of another tool that can be used in
accordance with the invention; and
FIG. 8, is a view similar to FIG. 7, of another tool that can be
used in conjunction with the invention.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring to the drawings in detail and initially to FIGS. 1-6
thereof, it will be seen that the grafting apparatus 10 briefly
includes in assembled relation to each other support means 12
having a plurality of vertical legs 13 and a top 14 on which the
human 15 may be supported during the grafting process for the
removal of the live epidermal cells 17 from a removal site 18 in
the form of individual cells or cell clusters and thereafter
deposited on a grafting site 20, which sites may be on the same or
different humans as in a transplant operation. Removal means 35 is
adapted to remove the layer of tissue from a portion of the removal
site 18 of the human and the forming means 60 cooperating therewith
produces a fluidized suspension 62 (see FIG. 3) containing cells or
cell clusters 17 and a treatment fluid 63 which is continuously
formed and removed from the removal site 18. Continuously or
intermittently transferring means 90 transfers the cells 17 of the
fluidized suspension to the grafting site 20 which is adapted to
receive the cells thereon as by providing a layer or coating 120 of
a medication and the depositing means 105 coupled thereto applies
the cells 17 onto the grafting site 20, such that the grafted cells
will form a new layer of tissue thereon.
Positioning Means
The integrated operating components of the apparatus 10 may be
contained on or associated with positioning means 25 to provide
equipment mobility for a variety of positions without necessitating
changing of the position of the human 15, and includes a base 26
with a plurality of casters 27 for ease of movement and a vertical
leg 28 which extends therefrom for slidable engagement with bracket
29 which has secured thereto shelf 30 in any conventional manner.
The bracket 29 is provided with a vertical bore for receiving the
vertical leg 28 and is provided with a slot 31 having a bolt 32
extending therethrough to clamp the bracket in fixed position to
the vertical leg 28. It is appreciated that other mechanical means
may be employed to produce the desired horizontal and vertical
movement of the operating components to transplant cells from
various portions of the body.
Removal Means
The removal means 35 as illustrated in FIGS. 4 and 5, for
ultrasonically removing tissue from the removal site 18 may include
an oscillation generator 36 mounted on the shelf 30 with a power
cable 37, connected to an ultrasonic motor 41, for effecting the
necessary high frequency vibrations of the tool 43 having a sharp
output edge or surface 45. The ultrasonic motor 41 may be in the
form of a hand piece adapted for being hand held and generally
comprising a tubular housing 44 into which an insert unit 47
supporting the tool 43 may be partially telescoped. The generator
is an oscillator adapted to produce electrical energy having an
ultrasonic frequency and having control knobs 39 and 40 for
respectively selecting and maintaining the frequency and intensity
of the ultrasonic energy at a level below which substantial
permanent damage will occur to the cells 17 during removal
thereof.
The tubular housing 44 is contained in a casing 50 which includes
an upper section 51, a lower section 52, an intermediary flexible
section 53 and a rear wall 54 through which the power cable 37
extends. Treatment fluid supply conduit 66 which forms part of the
fluid supply means 60, and differential pressure conduit 61 which
forms part of the transferring means 90, hereafter discussed in
detail, also extend through the rear wall 54. A flexible sleeve 57
is attached to the rear of the outer casing 50 and permits gross
relative movement with respect to the removal site 18.
To permit relative movement of the tool 43 with respect to
tensioning means 70 to intermediary section 53 is flexible and is
interposed between the upper section 51 and lower section 52, and
may be in the form of a bellows adapted to permit tilting of the
upper section 51 with respect to the lower section 52. The front
end 68 of the lower section 52 is provided with the tensioning
means 70 for maintaining the tissue to be removed under tension in
the direction of arrow 71 (see FIG. 5) during movement of the tool
43 in the direction of arrow 72 (see FIG. 4) to obtain a
substantially continuous depth of removal with minimal injury to
the cells. The tensioning means 70 includes a plurality of
outwardly curved flexible fingers or members 73 in spaced-apart
relation such that its contacting edge 74 grips the tissue 16 and
forces it outwardly in the direction of the arrow 71 to hold it
firm. The tensioning means 70 is not necessary in all instances
since it is dependent upon the portion of the human, the cells are
being removed from as well as the depth of removal, plus the skill
of the operator in performing the grafting operation.
The ultrasonic motor 41 may be one of a variety of
electromechanical types, such as electrodynamic, piezoelectric and
magnetostrictive. The ultrasonic motor for effecting tissue removal
through hand directed tools of suitable configuration which are
interchangeable with other work performing tools in acoustically
vibrated material treating devices may be of the type disclosed in
U.S. Pat. No. Re. 25,033, 3,075,288, 3,076,904 and 3,213,537, and
wherein each work tool is rigidly joined, in end-to-end
relationship to a connecting body or acoustic impedance transformer
and to a transducer which may form an insert unit or assembly which
is removably supported in a housing containing a coil in
surrounding relationship to the transducer and receiving
alternating current for producing an alternating electromagnetic
field.
The transducer in the ultrasonic motor 41 is longitudinally
dimensioned so as to have lengths which are whole multiples of
half-wavelengths of the compressional waves established therein at
the frequency of the biassed alternating current supplied so that
longitudinal loops of motion as indicated by arrow 16, occur both
at the end of the insert unit 47 to which the tool 43 is rigidly
connected. Thus, the optimum amplitude of longitudinal vibration
and hyperaccelerations of tool 43 is achieved, and such amplitude
is determined by the relationship of the masses of the tool 43 and
insert unit 47 which may be made effective to either magnify or
reduce the amplitude of the vibrations received from the
transducer.
Applicant has discovered in accordance with his copending patent
application referred to above, that a tool having a sharp edge,
vibrating ultrasonically, and gently pressed against a highly
compliant substance, such as organic living tissue 16, will
actually penetrate or shatter said substance whenever the peak
acceleration of the sharp edge is above the threshold range of the
treated material. For substances such as human tissue it is found
that if one uses a tool edge where the peak acceleration is well
over the value of 50,000 g, rapid removal of tissue is obtainable.
By simultaneously employing gross motion of the vibratory tool
along a plane substantially parallel to the surface of the very
highly compliant material we obtain a repetition of the
microchopping process so that layers of tissue may be removed.
Applicant is well aware of the art of disrupting biological cells
by means of intensely cavitating liquids such as is obtained by
putting such cells in a liquid suspension and then irradiating the
liquid with a beam of ultrasonic vibration strong enough to produce
vigorous cavitation. In this way blood cells may be hemolyzed in a
very short time by means of cavitating liquid. But, if one takes
the cells in the skin of one's finger and exposes them indefinitely
by rubbing the finger tip against an ultrasonic tool of flat
pistonlike output in the presence of a liquid, one will experience
a tingling, massagelike sensation, which is not unpleasant and all
that happens superficially is the cleaning of the surface of the
skin. Thus, those forces which will disrupt cells in liquid
suspension will have no such effect on live tissue such as human
skin. But, as soon as a tool vibrating at hyperintense
accelerations whose output configuration is in accord with the
teachings herein is brought into direct contact with the tissue,
the interaction between the tool and the tissue causes the said
tissue to be chopped or broken into small clusters and easily
removed without damage to the underlying or surrounding tissue as
well as the removed cellular material.
The hand held ultrasonic motor illustrated in FIGS. 4 and 5, is
employed and the tool 43 moves periodically in a plane
substantially normal to the layer of tissue 16 in the direction of
arrow 72, so that its peak acceleration is well above 50,000 g, and
which tool, when applied to the superficial biological tissue 16,
will actually disintegrate same into small clusters or
substantially individual viable cells 17 by way of the
microchopping action present.
It is important that the operation of cutting be performed without
significant cavitation at the site, so as to avoid "blasting" the
cells into a homogeneous dispersion. The suppression of cavitation
arises chiefly from the sharpness of the vibrating edge and the
direction of vibration, so that practically "zero area" is present
in the cutting edge. In practice, it is the vibrating area which
determines the amount of cavitation.
The tool 43 may be in the form of a relatively flat metal member,
as shown in FIGS. 4 and 5, thereby to provide a relatively long
edge for contact with the tissue or other highly compliant
materials to which the vibrations are to be applied for effecting
the removal thereof by microchopping. The tool 43 may be
permanently attached to the end of insert unit 47, for example, by
brazing solder or the like, or the tool may be provided with a
threaded stud (not shown) adapted to be screwed into a tapped hole
in the end of insert unit 47 for effecting the rigid connection of
the tool to the stem.
Guard means in the form of hood 80, extending from the housing 44
is provided in telescoping relationship to the insert unit 47 and
tool member 43 with its front end 81 in spaced relation a distance
D to the edge 45 of the tool 43. As hereinafter explained this
permits the user to control the thickness of the layer of tissue to
be microchopped into small segments, cell clusters, or individual
cells 17 and removed.
Means for Transferring the Fluidized Suspension
Transferring means 90 provides for the removal of the fluidized
suspension 62 from the removal site 18 to the grafting site 20 and
in turn the depositing of the cells on the grafting site. The
transferring means 90 mounted on the shelf 30 includes a reservoir
91 having a cover 92 for retaining the fluidized suspension 62, and
in which the cells 17 may settle to the bottom 93 thereof to
produce a concentration thereof. Pump means 95 mounted on the shelf
30 is connected to the reservoir 91 by a tube 96 extending through
the cover 92 into the reservoir 91. By maintaining the reservoir
substantially sealed the pump means 95 creates a differential
pressure in the reservoir 91 for obtaining either a pumping in or
out therefrom of the fluidized suspension 62. The pump may have a
two-way switch to connect to pressure or suction outlet. Obviously
other conventional pumping means may be employed.
The conduit 61 is connected to a removal valve 97 which in turn is
connected to inlet tube 98 which extends into the reservoir 91
through the cover 92 a given distance. For the removal of the
fluidized suspension 62 from the reservoir 91 an outlet tube 100 is
provided and extends substantially to the bottom of the reservoir
where a higher concentration of cells 17 are contained. The outlet
tube 100 is connected to applicator valve 101 which in turn through
applicator tube 102 is connected to the depositing means 105.
In order to facilitate the removal of the microchopped tissue from
the removal site 18 the removal valve 97 is opened and the
applicator valve 101 is closed, and a suction force is applied by
means of conduit 61 to the ultrasonic motor 41. The conduit 61 is
connected in any conventional manner (not shown) through the
housing 44 and terminates in the hood 80 so as to apply a suction
force as indicated by the arrow 86 in FIG. 5.
To progressively cover a surface area and remove a layer of the
organic tissue therefrom the ultrasonic motor is moved in the
direction of arrow 72 so as to continually microchop the surface
area and apply a suction force and a treatment fluid to the work
site. The treatment fluid is preferably an antiseptic so that the
surface may be maintained free of germs. The treatment liquid is
pressurized by the tool 43 which enhances the effectiveness of the
liquid in mixing with the microchopped tissue and forming a
suspension thereof. The suspension may flow by means of gravity
from the treated surface or a suction force may be applied and
utilized adjacent the tool.
If desired the flow may be reversed and the liquid supplied by the
pumping means through the opening defined between the inner surface
of the guard means 80 and the tool 43 so as to permit the removal
of the emulsified mixture through at least one of the branches 104
and channel 108. The suction means illustrated in FIG. 3, may be
employed and may be assisted by the ultrasonic pumping means 103
contained in the tool 43. The pumping means consisting of a number
of ridges as in the form of threads actually apply a force in the
direction of arrow 86 which force assists in instantaneously
cleaning the removal site. As such the continuous removal of the
microchopped tissue from the surface may also be accomplished by
combining the ultrasonic pumping action with the suction supplied
through the tool.
Ultrasonic pumping means 103 may be relied upon either alone or in
combination with the suction means to remove the microchopped
material from the removal site. The pumping means 103 is employed
when the channel 108 and branches 104 are utilized as the removal
duct and the ultrasonic pumping means may consist of formations on
the wall of the channel 108, as for example, threads which direct
the microchopped particles away from the removal site.
After a sufficient quantity of cells 17 have been removed from the
tissue 16 the generator 36 is turned off as well as the fluid
supply source 64 such that the removal process is discontinued. It
is appreciated that by the proper arrangement of well known
equipment the continuous depositing of the cells on the grafting
site may be accomplished. As illustrated the removal valve 97 will
be closed and the applicator valve 101 opened to permit the removal
of the fluidized suspension 62 from the reservoir 91 to the
grafting site 20.
Since more treatment fluid might be utilized in forming the
suspension than required in the actual application of the cells 17
to the grafting site 20 means for forming a concentration of the
cells 17 prior to depositing on the grafting site 20 may be
employed. Although various commercial equipment may be employed to
obtain the concentration without injuring the cells, the invention
illustrates a simple means of obtaining this concentration by
positioning the outlet tube 100 close enough to the bottom 93 of
the reservoir 91 so that the cells 17 that have settled close to
the bottom may be removed therefrom to provide a higher
concentration of cells on the grafting site.
Means for Depositing the Fluidized Suspension on a Grafting
Site
Depositing means 105 as illustrated in FIG. 6, is connected by the
applicator tube 102 to the transferring means 90 such that a
continuous supply of fluidized suspension 62 may be continuously or
intermittently applied to the grafting site 18. At the grafting
site 18 it is preferable to maintain a sterile condition to have
the exposed area covered with a preferably transparent cover or
closure. This closure may be flexible so as to permit the spraying
of the fluidized cells uniformly over the grafting site, so as to
"seed" it properly. If conditions require, a rigid cover may
likewise be employed. There exist a number of ways of physically
depositing the fluidized suspension on the grafting site 18 in
accordance with the present invention. One form of which is to form
a spray 106 bypassing the fluidized suspension through a nozzle 107
adapted to be moved relative to the grafting site so as to obtain a
dispersion of the cells 17 thereon.
Since the treatment fluid acts as a carrier for the cells in almost
all cases a degree of treatment fluid will be deposited on the
grafting site. If the cell concentration is sufficiently high the
treatment fluid may be left to run off with a certain percentage of
cells. In contrast, if the fluidized suspension does not contain a
substantial concentration of cells then draining means 110 may be
employed so that a substantial concentration is assured to be
retained thereon. The draining means 110 may be in the form of a
closure 111 having an open end with a peripheral edge 112 for
engagement with the grafting site 18. The peripheral edge 112 is
provided with a series of slits 113 to facilitate the flow of the
treatment liquid 63 from the grafting site. The top 114 of the
closure contains a flexible member 115 which is secured to the
applicator tube 102 to permit relative movement in the direction of
arrow 116 of nozzle 107 while the closure 111 remains in a fixed
position.
The grafting site 18 may be first coated with a layer of medication
120 that serves the purposes of sterilizing and attracting the
cells 17 while the treatment liquid 63 runs off the grafting site
18.
Operation
In accordance with this invention the human 15 is first positioned
in place on the support means 12 with removal site 18 and grafting
site 20 both exposed for the removal of cellular tissue 17 from one
site and transplanting to the other site. The positioning means 25
is brought into position so that the interrelated equipment is
easily controlled to perform the grafting operation.
Initially the generator 36 is turned on and the intensity control
39 and frequency control 40 are adjusted to obtain the proper
degree of vibratory energy in the removal means 35 at the output
edge 45 of the tool 43. The frequency and intensity is selected and
maintained at an energy level below which substantial damage will
occur to the cells 17 during removal thereof. This does not
preclude the fact that a certain small percent of the removed cells
might be damaged and not take at the grafting site. The removal
means 35 is placed in position, as seen with respect to FIGS. 1, 2
and 5, and the tool 43 penetrates the tissue 16 until the front end
81 of the hood 80 engages the surface of the tissue 16. The
tensioning means 70 is then brought into engagement with the tissue
16 and laterally applied forces in the direction of arrow 71
retains the skin under tension to assure a substantially continuous
depth of removal of fluidized suspension through conduit 61 and
inlet tube 98 into the reservoir 90. Means of tensioning the tissue
16 are also contemplated within this invention such as surface
freezing the tissue such that it is less deformable but still may
be microchopped and transplanted in accordance with this
invention.
The depositing of the cells 17 on the grafting site 20 as
illustrated in FIGS. 1, 2 and 6 may be carried on simultaneously
with the removal process or some time thereafter. The time lapse
will depend on a number of factors, for example, if the cells are
removed from one human to be transplanted to another it might be
necessary to first treat the cells in a solution for a period of
time before depositing same on a different human. If the cells 17
had been removed from a "cell bank" and were frozen then time to
let the cells thaw out to room temperature might be required.
Another reason for permitting a period of time to elapse, unless a
centrifuge is used, is the obtainment of a higher concentration of
cells per given volume than is obtained per same given volume when
the cells are removed. By letting the cells 17 settle to the bottom
93 of the reservoir 91 they are then extracted by means of outlet
tube 100 and transferred to the depositing means 105.
In forming the fluidized suspension 62 a treatment fluid 63 is
provided as required from the fluid supply source 60 that travels
through conduit 65 to the removal site 18 and there enhances the
removal of the cells which are microchopped into cell clusters or
cells 17 and form a mixture with the treatment fluid 63.
The fluidized suspension 62 is continuously removed and transferred
via the transferring means 65 to the grafting site 20. This is
preferably accomplished by maintaining a differential of pressure
as by applying a suction force from pump 95 which creates a vacuum
in the sealed reservoir 91 and by having removal valve 97 open and
applicator valve 101 closed. The suction force is transmitted
through conduit which pumps the fluidized suspension into the
reservoir. For removal from the reservoir 91 the valve 97 is closed
and the applicator valve 101 is opened with the cells 17 in the
fluidized suspension 62 exiting from the reservoir 91 by the force
applied by the pump 95. The depositing means 105 may take various
forms and shapes depending on the area of the grafting site 20 as
well as the condition of the patient 15. As illustrated it includes
a nozzle 107 from a spray 106 that includes both the cells 17 and
treatment fluid 63. If a concentration of cells 17 had been formed
by extracting from the reservoir 91 cells 17 at a greater
concentration per given volume than initially pumped into the
reservoir per same given volume then the draining means 110 might
not be required. If the treatment fluid is too great then draining
takes place by providing the closure 111 with fine slits 113 to
permit the exiting of the treatment fluid while leaving a layer of
cells 17 that will form a new layer of tissue on the human 15.
The nozzle 107 may be moved relative to the grafting site 20 until
a complete layer of cellular material is deposited thereon. For
certain applications a layer of medication 120 might first be
placed on the grafting site 20 to assure a proper seeding of the
newly deposited cells thereon. When transplants are to be performed
covering large areas of the body the apparatus may be automated to
the extent that the depositing means and removal means
automatically traverse areas of the body and perform their
functions substantially unattended.
Additional Embodiments of the Invention
FIGS. 7 and 8, illustrate other forms of tools that may be used to
obtain the variety of vibrational motions for the removal of tissue
in various locations without permanent damage to the removed
cellular material.
The tool 43a illustrated in FIG. 7, has a passageway 121a, which
may be of circular cross-sectional area and the output edge 45a of
the tool may be chisel shaped to provide a minimal of contacting
area with the tissue 16a at the removal site 18a, to maintain the
creation of cavitation thereat at a minimum. The hood 80a is in
coaxial alignment with the tool 43a and the front end 81a engages
the tissue 16a to control the depth of cut as the tool is moved in
the direction of arrow 72a. The longitudinal vibratory energy is
applied in the direction of arrow 76a and a routing or planing
action is obtained with the relative movement between the tool and
removal site.
FIG. 8, illustrates a tool 43b having a chisel shaped output edge
45b angularly disposed to the tissue 16b at the removal site 18b,
with the guard 80b having an opening 122b to permit the tool to
extend therethrough a preselected distance. With this tool
arrangement we obtain an ultrasonic microplaning removal of the
tissue 16b as the ultrasonic vibrations are applied in the
direction of arrow 76b and the front end 81b of the guard 80b
engages the tissue 16b to control the depth of cut.
CONCLUSION
From the above disclosure, it is evident that the method and
apparatus of this invention embraces an interrelated series of
devices and instruments which can be advantageously employed for
effectively grafting of tissue. In accordance with the invention we
have the removal of live epidermal cellular tissue from one site on
a person's body and the application of that viable tissue to
another site in the same or different human. The use of the
microchopping principle combined with sterile pumping means,
permits the use of a self-contained system wherein grafting over
large body areas (cases of severe burns, for instance) may be
accomplished readily and easily.
This invention also contemplates the establishment of a "cell bank"
in that the removed cells may remain in solution under controlled
conditions until such time as required and then deposited on the
grafting site. Accordingly, the process of grafting in accordance
with this invention may be on a continuous or intermittent basis
depending upon the schedule of events and the needs of the
patient.
The treatment fluid is preferably an antiseptic solution so that
the work site may remain not only free of microchopped tissue but
sterile at the same time. The liquid is supplied to "float away"
the removed tissue and also maintain the work site at a controlled
temperature as not to overheat the surrounding tissue and possibly
cause permanent damage thereto. The necessity of cooling the
removal or work site will be directly related to the type of tissue
being removed. An additional factor to be considered is the size of
the surface area and thickness of the layer to successive layers to
be removed. If desired the treatment fluid may be supplied at a
preselected temperature just for this purpose.
Although the previously described embodiments of the invention have
all involved the removal of tissue from organic structures, it is
apparent that the method and apparatus embodying the invention may
be employed for removing any other material of relatively low
compliance, by introducing elastic vibrations above the determined
threshold thereof which will generally exceed 50,000 g.
Although illustrative embodiments of the invention have been
described in detail herein with reference to the accompanying
drawing, it is to be understood that the invention is not limited
to those precise embodiments, and that various changes and
modifications may be effected therein without departing from the
scope or spirit of the invention, except as defined in the appended
claims.
* * * * *