US3608553A

US3608553A - Ultrasonic method and apparatus for tissue grafting

Info

Publication number: US3608553A
Application number: US855126A
Authority: US
Inventors: Lewis Balamuth
Original assignee: Ultrasonic Systems Inc
Current assignee: Ultrasonic Systems Inc
Priority date: 1969-09-04
Filing date: 1969-09-04
Publication date: 1971-09-28
Anticipated expiration: 1988-09-28

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.

Description

United States- Patent lnventor Appl. No.

Filed Patented Assignee Continuation-import of application Ser. No.

655,1 18, July 21, 1967, now Patent No. 3,526,219.

ULTRASONIC METHOD AND APPARATUS FOR References Cited Taylor, Rennie, Associated Press Article, Oct. 31, 1947, (copy in 3/1) Primary Examiner-Richard A. Gaudet Assistant Examiner--Kyle L. Howell Attorney-Leonard W. Suroff TISSUE GRAFIING 31 chhmsnnwing Figs ABSTRACT: The method and apparatus of grafting tissue, US. Cl 128/303, such as tissue in biological organisms such as humans, by the 128/24 A, 128/305 removal of live epidermal cells from one area of a body by ul- Int. Cl ..A6lbl7/00, trasonic means, and then transporting such cells in a suitable A6lb 17/32 isotonic fluid suspension to the site where the fluidized cells Field of Search 128/303, are to find their new homes and then applying the cells 303.], 305, 305.5, 24 A thereto.

0 96 60 9\ .95 67 F r' 36 35 L /02 50 755 2 a w H /5 a n In l l l :M 2 I4 /3 25 28 4 PATENI ED SEP28 Ian SHEET 2 [IF 2 INVENTOR. LEWIS BALAMUTH Mu). M

ATTORNEY ULTRASONIC METHOD AND APPARATUS FOR TISSUE GRAFTING CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-impart of my copending application Ser. No. 655,118, filed July 21, 1967, now US. 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.

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 accordancewith 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 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 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 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. 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 3, 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 ones 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 the 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 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 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 1 14 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 removalmeans 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 for a "cell bank and were frozen then time to let the cells thaw out to roomltemperature 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 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 pennit 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 FlGS. 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 122!) 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.

8 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 persons 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 drawings, 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.

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

l. 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

. 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 fluidizedsuspension 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 asto obtain a dispersion of said cells thereon.

7. A method as in claim 1, wherein the'step of forming a fluidized suspension includes the step of 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 said fluidized suspension.

8. A method as in claim 1, further including the step of forming a concentration of said cells prior to depositing said cells on said grafting site to form a concentrated layer of Cells thereon, v H.

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

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,

. 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 humanand 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 theremoval 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. 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,

. maintaining the tissue to be removed under tension to obtain a substantially continuous depth of removal, and

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 graft- 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 b 50,000g, so as to microchop said tissue into particles as municating with said transferring means for forming a concentration of said cells prior to depositing said cells on said grafting site.

ing said concentration includes ill 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 com- 27. Apparatus as in claim 26, wherein said means for forma. 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 29, 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 fonn 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 3, so as to microchop said tissue into particles as the vibrating tool is moved relative to said tissue surface, and

18. 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 applying 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

Claims

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. 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.

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.

3. maintaining the tissue to be removed under tension to obtain a substantially continuous depth of removal, and

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,

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.

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.

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.

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.

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.

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.

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,

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

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.

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

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.