US2366054A - Dermatome - Google Patents

Description

Dec. 26, 1944. r Q 2,366,054

DERMATOME I Filed Aug. 2, 1944 INVENTOR JOHN D. RE E s E BY W T- R-M ATTORNEY .blade may readily be assembled and from Patented Dec. 26, 1944 I UNITED STATES PATENT OFFICE DERMATOME J oh n 0. Reese, Philadelphia, Pa. Application August 2, 1944, Serial No. 547,718

9 Claims. (01. rag-305) This invention relates to surgical instruments, more particularly to instruments known as dermatomes, and has for an object to provide improved devices of this character.

Today most dermatomes in use in this country are of the type disclosed in United States Letters Patent No. 2,283,709, granted July 7,1942, to G. J. Hood,and comprise a body member having a convex outer surface adapted to be coated with an adhesive for temporary retention of a skin graft thereon, together with a skin-cutting blade mounted for rotation and reciprocation relative to the convex surface for separating the skin graft from the body of the patient while the adhesive-coated convex surface is rolled or rocked on the latter.

The dermatomes of this type available commercially during the past half-dozen years, while constituting a very considerable improvement over prior dermatomes, are not entirely satisfactory for several reasons, principal of which are; (1) inaccuraciesin the adjustmentof the skin-cutting blade withrespect to the convex surface of the body member, (2) flexing or twisting of the body member, and (3) flexing of the blade; each of these resulting in the cutting of skin grafts of non-uniform thickf ness or. with holes completely therethrough.

Therefore, another object of the invention is to provide a dermatome which will but a skin graft of uniform thickness throughout.

Yet another object of the invention is to provide a dermatome incorporating novel means for supporting'a skin-cutting bladewith respect to a convex surface'of a body member. l

A further object of theinventionis to provide, in a dermatome of the type wherein a skin-" cutting blade is supported for rotary and reciprocatory movement relative to the convex surface I of a skin-holding body membennovel means for accurately varying the spacing of the blade rela- {tive to the convex surface of :the body member.

. Another objectof the invention is to provide, in a dermatome, a blade holder with which a which it may readily be removed. I Yet another object of the invention is to provide a dermatome having an improved skin-holdingsurface.

' These and other objects are effected by the inventiona's will be apparent from the following description and claims taken in accordance with the accompanying drawing, forming a part of this application, in which:

Fig. 1 is a front elevational view, partially in section, of apparatus embodying the principles of the present invention; s

Fig.2 is an elevational view of the left side of the apparatus, as viewed in Fig.1, with certain elements thereof shown in exploded relation;

Fig. 3 is a verticalsectional view, taken along the line III -III Of Fig. 1, looking in th direction indicated by the arrows;

Fig. 4 isa vertical sectional view, taken along the line IVIV of Fig. 1, looking in the direction indicated by the arrows;

Fig. 5 is a perspective view of a skin-cutting blade member; and

Fig, 6 is a similar view, greatly enlarged as to thickness, of one of the shims appearing in Figs. 1 to 4.

Referring now to thefdrawing more indetail, the reference numerallfl indicates, in its entirety, a body member comprising a pair of spaced, parallel, semi-circular side walls I I and I2, joined along their curved. edges by a bottom curacy, although it will be obvious that it may be'made of separate elements secured together in assembled relation by suitable means, for

example, welding or riveting.

. 0ne diificulty encountered in the use of prior dermatomes of the semi-cylindrical type has been failure of the adhesive coating (applied to the convex surface to hold the skin thereagainst), to adhere to said surface during thegraft-cutting operation, particularly where the skin of the donor area isinfiexibledue to fauna, disease, malnutrition orjother abnormality. To eliminate thisdifficulty the present invention provides a roughened convex surface I4, preferably obtained by making the body member I0, or at least the curved wall I3 thereof, of a relatively soft material, such as brass, and subjecting the outer surface. thereof to asand blasting treatment.

which pits the surface, as at I5, with subsequent porosity enhancing the adhesive properties thereof. H I

A shaft I] is mounted in the bearing I6 for both rotary and reciprocatory movement, and is provided with terminal portions I8 having their ends threaded, as at I9.

A pair of posts 2I and 22 are mounted on,

and extend radially of, the' shaft II, at opposite sides of the body member.

ID, in parallel relation and 'with their outer ends 23 projecting beyond-the outer convex surface M of the body member I6.

Each of the posts 2| and 22 is provided with an opening extending laterally therethrough which has a portion 26 of enlarged diameter to closely receive the main portion of the shaft 11, and a portion 2? of reduced diameter to closely receive the reduced terminal portion I8 of the shaft, with the threadedportion I9 thereof extending beyond the post for reception thereon of a nut 28. Preferably, the post 22 has, substituted for the nut 28 of post 2|, a handle member '29 threaded onto its shaft terminal portion l9, -b y means of which the shaft and its associated structure may readily be reciprocatedand "To--- tated relative to the convex outer surface of the body member, in a manner familiar to those skilled in the art. It will be apparent that -t-i 'ght-' ening of the nut 28 and the handle 29 will securely'clampthe po'sts mancz'ragmnsn movement axially of the shaft I7, Preferably, the

free end of the handle"'29' is provided with a notch 39 against which the little'finger cf the operator may rest, with his "thumb abutting the finger piece 46 and the remaining fingers surrounding the handle. k

In order to prevent r 'tation of "the posts'with respect to the shaft, and to insure parallelalignment of said "posts, the latterareprovide'd with- ,central bores 3| extending axially thereof from end to endfaligned openings '32 alsobei'ng provided in the shaft 11, Where 'it intersects the bores. Dowel pins 93 are closely received'in the upper portions 34 of the bores and in'the aligned openings 32 of the shaft, with the result that rotation of the posts with respect to the shaft,

and hence relative to each othe'rfis positively prevented.

A blade-supporting bar 736 is positioned at the outer'ends23 of the posts, and has 'a "flat upper blade supporting surface 37, lying "in a plane parallel to the axis of the shaft fl'lhdinclined with respect 'to the leng'itudi'nalaxes-of the posts, theout'er ends 'of said posts'likwise being beveled, as at 3'8, 'tojthesarn'e angieas the blade-supporting surface '31. j j

A pair of lugs 39 extend upwardlyfromfthe supporting surface '31 of the bar 36 and are adapted to be telescopically "reeive'd in'eiilarge'd 7 portions 4| of theip'osIt bores'3l. Th'ebar"'36 and posts 2| and 22 are retainedinasseiiibled remtioh by extensions 42, integral withthe dowels 33 and having their terminal portions '43 threadedly received in threade'd'bores '44,"forfnedin the ends of the lugs 39. The upper ends of'the'dowels 33 are providedwith knurledfihger pieces '46, by Which 'the'dowels and their'extensions 42 ma be rotated to inovethe supporting her '36 towards or away from'the posts. A skin-cuttingblade 41, preferably of relatively thick and rigid t'oiol's'teel, and having a hollow-ground 'cuttingedge' 48, is adapted to be bar 36 a material distance (Fig. 4), with the result that the blade likewise projects r'earwardly of the bar, as at 53, thereby providing a surface easily engaged by the fingers of the operator to 'raisethe blade from the bar Without the necessity of touching the cutting edge 48.

For reasons not necessary to discuss here, it

is desirable that the spacing of the cutting edge 48 of the blade from the convex surface [4 of the body member be variable at the option of the operator, so that skin grafts of varying thicknesses may be cut, these thicknesses generally being between 6 and '16 thousandths ofan inch.

In the presentconstructio'n, such adjustment 'of the "spacing is easily and accurately iobtaineii simply by the insertio'nof shims "5'4, of the desired thickness, between the blade-and the outer end surfaces 38 of the posts. Preferably, 'th'e'se shims 54 are *of the shapeshow'nin*Fig.-,6,*vary- 'ing-only in thickness, and are provided withdinger tabs or handles '56, which project rearward'ly when inserted between the "blade'and the posts. The shims are provided with 'nOtch'es-SL- c'o'rre- 'sponding to the notches 4-9 of the blade lL-"a-nd receive the lugs 39 when assembled.

To facilitate the use of this'derfnatome; there is provided a finger grip "in the form-ofa'kriurled rod 58, extending between the "bodyportienside walls H and 12, adjacent 'the straight -edges thereof 'near one end. 'In usingthe-fdevice, the

'operator'will grip the body portion H! 'withorfe or more fingers against-the finger grip 58 and the thumb against the opposite side of "the bearing-1'6, thesurface l-'4 of the bodymember havi-n'g previously beencoa-te'd wi-thasuitable-adhesive. That end-of the-convex surface raw-men is adjacent the finger grip--58- is"pressed against the body of the patient, and-the body member slowly rocked on the convex su-r-fa'ce. The adhesive will cause the skin to be -raised sufii'ci'ently to bereadily cut bythe blade as thelatter is -reciprocated thereagains't by means 6f the -ha'nthe lugs 39 or the "latterextendi'r'i'g through notches '49 formed in the 'cuttingedgefdf the blade. When positioned onthe supportingbar 36, forward movement of the blade is prevented by engagement of the bottdm's of the notches 49.

with the I lugsj39, an'd rearward movement is prevented by contact of the rear edge of the blade with an upstanding rib 5i, providedon the rearwardly-projecting heel 52 of the supporting bar 36 (Fi'g's."1,.2 and 4). 'Ihe blade may be proportienedso as to fit snugly on the bar between other applications,

spirit thereof.

dle 29, moved by the operators-other hand.

While the invention has-beenshewn in -but one form, it will be --obvious to thos'e iskilled i'n the'artthat it is notso-limited, -but isls eepfilble of various modifications and-changes, as wen as without departing frb'in the What is claimed is: i i

1. A dermatome comprising a bodymeniber having a convex outer surface and 'adapted to have a cutting blade associated with 'saidsurface at a predetermined distance therefroin "-fer rotary movement about the axis 0f generation of the surface and for reciprooatory :moveme'rit -parallel to said axis; a bearing carriedxzby and located axially of the body member; a shaft rotatable and. slidably supported in :said abearlng;

-said shaft having terminal portions iof 'redu'c'ed diameter providing outwardly-facing iannulitr shoulders at the junctures of :said reduced. terminal portions with the body of theshaft; a

the ends Of the shaft with the-shaft-wterminal portions at least partially projecting therebeyond, said posts extending radially of the shaft atoppositesides of, and spacedfrom, the @body member in parallelrelfation; nuts threaded on the portions of the shaft which extend beyond theshaft, and dowel pins disposed in said bores and passingthroughth shaft; and a bladesupporting bar secured to the outer ends of the posts and adapted to retain a blade with its cutting edge a predetermined distance from the convex surface of the body member.

2. A dermatome comprising a body member having a semi-cylindrical outer surface; a cutting blade associated with said surface at a predetermined distance therefrom for swinging movement about the axis thereof and for reciprocatory movement parallel to said axis; a hearing carried by and disposed axially of the body member; a shaft rotatably and slidably supported in said bearing; a pair of posts carried by the terminal portions of said shaft and extending radially therefrom in parallel spaced-apart relation with the spacing of said posts being materially greater than the width of the body member, said posts having openings extending transversely therethrough for reception of the shaft terminal portions and said terminal portions having threaded extremities extending beyondthe outer ends of the post openings; nuts threaded on the projecting extremities of the shaft and bearing against the post to prevent axial movement of said posts with respect to the shaft; a blade-supporting bar disposed in close proximity tothe outer semi-cylindrical surface ofthe body member in parallel relation to the shaft; a pair of parallel lugs extending outwardly from one surface :of th blade-supporting bar near opposite ends thereof for connecting said bar to the outer ends of 'the radially-extending posts, said posts having bores extending axially thereof from end to end and adapted to receive the supporting bar lugs, the shaft terminal portions received in the transverse openings of the posts intersecting the bores and being bored in alignment with th post bores; and headed pins extending into said bores from the ends thereof adjacent the shaft and closely fitting the bores in the vicinity of the shaft to prevent relative rotation of the posts with respect to the shaft and with respect to each other, said pins hav- .ing threaded inner ends received in mating threaded sockets in the ends of the supportingbar lugs, whereby said bar may be drawn towards of generation of the convex surface and for reciprocatory movement parallel to said axis, said means comprising a bearing carried by and loicated axially of the body member; a shaft, ro-

tatably and slidably supported in said bearing; a pair of posts carried by the terminal portions of said shaft and extending radially therefrom in parallel relation at opposite sides of and spaced from the body member with their outer ends extending beyond the convex surface of the body member, each of said outer ends having an opening therein; a rigid bar having, a flat inner bladesupporting surface; a pair of lugs extending upwardly from said blade-supporting surface and adapted to be received in the openings in the outer ends of the posts; and means for urging said blade-supporting bar towards the outer ends of the posts, whereby a cutting blade supported on the blade-supportingsurface-of the bar will be clampedagainst said outer ends of th posts,

4; In a dermatome of the type.comprising a bodymember having a convex outer surface and a cutting blade associatecltherewith; means for supporting said blade at a predetermineddistance from said convex surface for swinging movement about the axis of generation ofsaid surface and for reciprocatorymovement parallel to said axis; said means comprising a bearing carried by and positioned axially of the 'body member; atshaft rotatably and slidably supported in said bearing; a pair of posts carried by the terminal portions of said shaft and extending radially therefrom in parallel relation at opposite sides of and spacedfrom the body member with their outer ends extending beyond the convex surface of said body member, said outer ends of the posts lying in a plane parallel to the axis of the body member and inclined with respect to the longitudinal axes of said posts; a

rigid bar having a flat inner blade-supporting surface; a pair of lugs extending upwardly from said blade-supporting surface at an angle thereto corresponding to the angle of inclination of the post outer ends with respect to the longitua dinal axes of the posts, said lugs being adapted to be received in mating axial bores extending through the posts from end'to end thereof; and bolts extending into the post bores from the inner nds thereof and having terminal portions threadedly received in openings formed in the ends of the supporting bar lugs, whereby tightening of said bolts will draw the blade-supporting bar towards the post outer ends to clamp a blade carried on said bar against said post outer ends.

prising a body member having a convex outer surface, a shaft disposed axially thereof, and a surface; a pair of parallel spaced lugs extending upwardly from said surface near the ends thereof with their longitudinal axes inclined at an angle to the perpendicular of said surface in planes at right angles to the longitudinal axis of the bar, said bar having a straight rear edge; a heel projecting'rearwardly from said rear edge for a limited portion of its length with its upper surface continuous with the blade-supporting surface of the bar; and a rib extending upwardly from the rear edge of saidheel and providing a backing for a blade when positioned on the bar between said rib and the lugs with its cutting edge projecting forwardly of the front edge of the bar.

6. Structure as specified in claim 5, wherein the blade-engaging surface of the rib is disposed rearwardly of the rear edge of the blade-supporting bar a material distance, so that ablade sup ported on the bar will have its rear edge overhanging the rear edge of the bar at opposite sides of the rib and heel, whereby said blade may be grasped at itsrear edge by the fingers of the 'user for removal.

7. A dermatome comprising a body member 5. For use in a dermatome of the type combody member; a bladesupporting ibar 'tcarried by the posts at one end 0f the il'attertand bridging fine space therebetweeri; fme'ansfsupporting the pds'ts at their other "ends front-the body member tor-movement 'o'f the bar parsilleiz'to, and atsavpredetenninedvdistanceirom,':the'sldn-enga i isurface of :said body: member; and :means' for urging the blade supporting bar towards the ends of the posts to clamp a blade between saidzbar and said post ends, whereby the rpredeterniined spacing df the bar with respect :to .the skin-engaging surface may be accurately Varied by the insertion of shims 0'1 the desired ithiclmessbetween the bladeand the post/ends.

'8. A dermatome comprising a body "member having a convex skinen'gagin'glsurface; a pairqo'f parallel spaced-apart posts a opposit'e sides of the :body member and-extending radially with respei; :to raid convex surface; :a blade-supporting bar "carried .by the posts :at i one end nf the latter and bridging:theegpasce13herebetween; :means pi-vota'ily tand slidably "supporting \the' posts at their other ends from the body :merriberior movement 16f the bar parallel 'to, :andat a predetermined :distancezfrom, theiconvexsurface; :and means-for drawing' the ldla'deesupporting tbar towards the ends of bhe posts rt'o'clamp a oiadebetween said bar and'-:sai'd .post ends, whereby the :predetermined spacing of the bar, andn henceofthe bmde,

with respect :to the convex-surface may lie-accurately varied by 1;he insertion sof shims of ihe desired thickness between the blade andiiheipost ends. Y

9. Structure as specified 'in'lclaim i=8, wherein the skin-engaging :convex' surface is pitted.

' JOHN DREESE.

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