WO1992003976A1

WO1992003976A1 - Apparatus for implementing a standardized skin incision

Info

Publication number: WO1992003976A1
Application number: PCT/US1991/005908
Authority: WO
Inventors: Robert F. Cusack; Ladislau Biro; Michael D. Mintz
Original assignee: International Technidyne Corporation
Priority date: 1990-09-10
Filing date: 1991-08-27
Publication date: 1992-03-19

Abstract

An apparatus (10) for implementing a standardized skin incision includes a hollow housing (15) and a pivot pin (40) projecting from an interior surface of the housing (15) for pivotally securing thereon a driver member, either a cam (54), or a crankwheel (82) having a crankpin (84) projecting therefrom. The driver member is spring biased from a first position to a second position by a spring member (76). A driven member (56) has a receptacle, either a square cam follower recess (58), or an arcuate crankpin slot (86), for slideably receiving therein at least a portion of the driver member, either the cam (54) or the crankpin (84), as applicable. The cam (54) or crankpin (84) bears upon the receptacle as the driver moves from the first position to the second position. The motion of the driver thus induces a movement of the driven member (56). Cutters (68) are affixed to the driven member (56) and project from an exterior surface of the driven member. The cutters (68) traverse a path at least partially external to the housing (15) for implementing the standardized skin incision as the driven member (56) is moved by the driver member.

Description

Apparatus For Implementing a Standardized Skin Incision

Technical Field

The present invention relates to apparatus for providing a skin incision in order to cause bleeding and more particularly to a disposable device which provides a precisely controlled incision in the skin of a patient.

Background Art

Devices for producing skin incisions to permit observation of the bleeding tine are known in the art. The bleeding time is defined as the time between implementing the incision and the moment when the bleeding stops due to clotting. The process of making an incision and then timing the bleeding time is a well known test to determine the ability of a patient's blood/tissue interaction to stop bleeding from injured vessels. Many techniques have been described in th^ literature as well as in certain prior art devices. Initially, bleeding tests were performed by surgeons or technicians who employed a scalpel to make a relatively shallow, small incision.

Such wounds as implemented by scalpels or lancets produced incisions which were typically 5 to 10 mm long and l to 5 or more mm deep. Generally, incisions such as these are referred to in this specification as standardized skin incisions. The need for devices to automatically produce such incisions was apparent due to the fact that many persons have a fear of scalpels as well as the further fact that the length and depth of manually produced incisions was a pure function of the ability of the practitioner and hence such incisions could vary widely depending upon the skills of the practitioner. Disposability was a naturally desirable attribute for a mechanized incision making device to avoid spreading blood transmitted disease and to avoid the related necessity of sterilizing the device after each use.

To circumvent such problems and satisfy such requirements, a series of devices have been designed which seek to provide a standardized skin incision in order to cause bleeding so as to accurately determine bleeding time. A discussion of such known devices appears in U.S. Patent No. 4,643,189 entitled APPARATUS FOR IMPLEMENTING A STANDARDIZED SKIN INCISION issued on February 17, 1987 to Michael Mintz, one of the applicants herein, which patent discloses a device of that nature. The Mintz 4,643,189 patent depicts an apparatus having a housing with an internal hollow in which is contained a moveable pivot arm. The pivot arm has a pivot pin disposed proximate one end that is held within a pivot slot in the housing. An arcuate cusped cam slot in the housing guides a slide pin disposed on the pivot arm proximate the other end. A spring urges the pivot arm into rotation causing the slide pin to traverse the cam slot which induces the pivot arm into radial and linear motion conforming to the shape of the cusped, arcuate surface. As a result, a cutting blade affixed to the end of the pivot arm is projected through a slot in the hollow housing, renders the incision in the skin of a patient, and the blade is retracted. The apparatus described produces a surgical cut of constant depth which simulates the cut of a surgeon's scalpel, as opposed to an arcuate cut or puncture. The Mintz '189 device produces the cut quickly and at the proper length and depth to assure accurate bleeding time measurements. A further advantage of the apparatus is that it is extremely simple to implement and manufacture. The low cost of the device permits it to be disposable and due to the operation of the device the transmission of communicable diseases through inadvertent exposure to disease carrying blood is prevented.

It is an object of the present invention to provide a device for making multiple incisions simultaneously in a rapid and reliable manner. It is a further object to provide a device capable of making a standard incision as rendered by a scalpel in a simple and economical manner. It is still a further object to provide a device capable of making more than one incision in a reliable and economical manner. Disclosure of the Invention

The present invention relates to an apparatus for implementing a standardized skin incision comprising a hollow housing, a pivot pin projecting from an interior surface of the housing for pivotally securing thereon a driver m tiber. The driver member is spring biased from a first position to a second position by a spring member. A driven member has a receptacle for slideably receiving therein at least a port n of the driver member, this portion of the driver member bearing upon the receptacle as the driver moves from the first position to the second position. The motion of the driver thus induces a movement of the driven member. At least one cutter edge is affixed to the driven member and projects from an exterior surface of the driven member. The cutter traverses a path at least partially external to the housing for implementing the standardized skin incision as the driven member is moved by the driver member.

Brief Description of the Drawings FIG. 1 is a perspective view depicting a patient's arm for describing operation of the apparatus according to this invention.

FIG. 2 is a side view in elevation of the skin incision apparatus according to this invention. FIG. 3A is a bottom plan view of the apparatus.

FIG. 3B is a top plan view of the apparatus.

FIG. 4 is an exploded, perspective view of an embodiment of a hollow housing in accordance with the present invention.

FIG. 5 is a perspective view of plunger or trigger mechanism employed in this invention.

FIG. 6 is an exploded rear perspective view of a earn and a blade carrier having a cam follower recess in accordance with one embodiment of the present invention.

FIG. 7 is a front plan view of the blade carrier depicted in FIG. 6.

FIG. 8A is a front plan view of a first alternative embodiment of the cam depicted in FIG. 6.

FIG. 8B is a front plan view of a second alternative embodiment of the cam depicted in FIG. 6.

FIG. 9 is an exploded front perspective view of a crank wheel and mating slotted blade carrier in accordance with an alternative embodiment of the present invention.

FIGS. 10A through 10D are sequential depictions of a front plan view of a cam and cam follower type blade carrier assembled within one half of the housing of the apparatus in accordance with an alternative embodiment of the present invention and moving from an initial position depicted at FIG. 10A to a final position depicted at FIG. 10D. FIGS. 11A through 11D are sequential depictions of a front plan view of the crank wheel and mating slotted blade carrier assembled within one half of the housing of the apparatus in accordance with an alternative embodiment of the present invention and moving_. from an initial position depicted at FIG. 11A to a final position depicted at FIG. 11D.

FIGS. 12A through 12D are sequential depictions of a front plan view of a cam having an alternative shape from that shown in FIGS. 10A-10D and a cam follower type blade carrier assembled within one half of the housing of the apparatus in accordance with an alternative embodiment of the present invention and moving from an initial position depicted at FIG. 12A to a final position depicted at FIG. 12D.

Best Mode for Carrying Out The Invention

Referring to FIG. 1, there is shown a device

10 for performing a skin incision according to this invention. Before an incision is made, a pressure sleeve or sphygmomanometer cuff 12 is placed about a patient's upper arm. The cuff is then inflated to a pressure of about 40 mm of mercury. The device 10 is placed on the patient's forearm where the incision may be made either parallel or perpendicular to the fold of the patient's elbow. The device 10 contains a trigger plunger 14 which when pressed inwardly releases the cutting edge for making the incision as will be explained. Prior to depressing the trigger plunger 14, the cutting edge is completely contained within the housing 15 of the device 10 and is not exposed in any manner whatever until the trigger plunger 14 is pushed. When the trigger plunger 14 is depressed, at least one cutting edge is projected out of and traverses a slot or slots in the base of the housing which has been placed flush against the patient's skin. An incision of a given length and of a uniform depth is thereby made. The device is relatively small and, is disposable as it is fabricated from inexpensive plastic and metal materials.

Referring to FIG. 2, there is shown a side view of the device 10. The housing 15 bears a plurality of grooves 18 on its exterior for enhancing the ease with which the device 10 may be gripped and for aesthetic purposes. The portions of the trigger plunger 14 visible in the assembled device are shown to include a finger tab 20 and a pushrod portion 22. To activate the device, the finger tab 20 is pushed inwardly in the direction of arrow 24 which action releases a spring loaded cutter blade carrier as will be explained below. The trigger plunger 14 is supported internally in the top portion of the housing 15 in a channel. In order to prevent inadvertent operation, a safety clip 26 is employed. The clip 26 has a U-shaped portion which removably embraces the visible pushrod portion 22 and abuts against the finger tab 20 on one side and the housing 15 on the other preventing the plunger from being depressed as long as the clip 26 remains in place on the pushrod portion.

A typical device in accordance with the present invention has a height A of approximately 1- 1/8", a bottom width B of 1-3/8", a top width C of about 1-1/16" and a depth D (FIG. 3A) of about 7/16". The dimensions can vary of course, but for the purpose of economizing on materials, the unit would typically be as small as can readily be safely and effectively manipulated by the hands of a user. Referring to FIG. 3A, a bottom plan view of the device 10 shows that housing 15 is preferably comprised of two mating halves 16A and 16B which sections are secured together along joint 28 using conventional means such as gluing, welding or with dowel pins. The bottom or base of the device 10 has a pair of elongated slots 30A and 3OB through and across which a corresponding pair of cutting blades are projected and moved during operation, as will be explained. Referring to FIG. 3B, there is shown a top plan view of the device 10 depicting the trigger plunger 14 together with the housing 15 comprised of mating halves 16A and 16B.

Referring to FIGS. 4A and 4B there is shown an exploded perspective view of the housing 15, comprised of mating halves 16A and 16B and depicting the interior of the housing 15 which i *, for the most part, hollow. The housing halves 16A and 16B are preferably molded from a suitable plastic and include a channel 32 for accommodating the trigger plunger 14. The channel 32 has a retainer boss 34 which cooperates with a retaining lip on the plunger 14 to prevent it from being withdrawn from the device 10. A divider rail 36 is one wall defining the channel 32 and supports the trigger plunger 14. The divider rail has a cutout 37 to permit a trigger hook 72 (see FIG. 6) extending upwards into the channel to engage an engagement pawl 52 (see FIG. 5) on the trigger plunger 14. Each half of the housing 15 includes raised, flat slide surfaces 38 for slideably supporting the moving mechanical parts of the device as will be described below. A split pivot pin 40 protrudes from either housing half 16A or 16B and is centered within an annular recess 42 in the flat slide surface 38. Although the pivot pin 40 can be located on the inner surface of either section 16A or 16B, it is shown as projecting from section 16B. A plurality of assembly pins 44 project from mating half 16A towards the viewer.. The assembly pins 44 cooperate with corresponding apertures 46 in mating half 16B when they are assembled into the housing 15, as is common in the art of assembling plastic devices. The slot pair 30A and 3OB are formed by corresponding depressions 48 (A and B) in each of the mating halves 16A and 16B.

FIG. 5 depicts the trigger plunger 14 which includes a finger tab portion 20, a horizontally offset pushrod portion 22 and retainer lip 50 and an engagement pawl 52. The pawl 52 is disposed on the pushrod portion 22 distal to the finger tab 20 and extending perpendicular to the rod portion in a direction opposite to the direction of offset.

Referring to FIG. 6A and 6B, there is pictorially represented a cam 54 and a blade carrier 56. The blade carrier 56, in the embodiment depicted, has a cam follower recess 58 defined by a rear slide surface 60 and an internal peripheral wall 62. The shape of the cam follower recess is generally rectangular having parallel sidewalls with parallel top and bottom walls. The cam 54 is received within the cam follower recess 58 and the internal peripheral walls 62 slideably embrace the cam at four points of contact or near contact at all degrees of angular rotation of the cam about its axis. The cam 54 includes a cylindrical boss 64 with a pivot bore 66 disposed in the center thereof. The boss 64 is dimensioned to be received within the annular recess 42 surrounding the split pivot pin 40 (Fig. 4B) when the cam 54 is installed upon the split pivot pin 40 via the pivot bore 66.

Referring to FIG. 7, the rear surface of the blade carrier 56 is shown, the front surface of which is depicted in FIG 6B. The blade carrier 56 includes a pair of cutter blades 68 affixed to the rear surfc.se thereof by blade retainers 70. The blade retainers 70 may be small meltable bulbs of plastic in continuity with the blade carrier 56 that are flattened under heat and pressure to embrace and restrain the cutter blades 68. Of course, other conventional alternative means for retaining the cutter blades 68 are available, such as, for example, gluing. The blade carrier 56 includes a pair of spacer members 76 to engage the slide surface 38 and frictionally insulate the cutter blades 68 and blade retainers 70 from the slide surface 38. The blade carrier 56 has a trigger hook 72 which releasably cooperates with the engagement pawl 52 of the trigger plunger 14 for controlling the release or restraint of the incision making mechanism as further described and depicted below.

Referring now to FIGS. 8A and 8B the profile of a pair of alternative cam shapes are depicted as can be employed for cam 54. The cam shape of Fig. 8B is a consequence of varying the dimension d~ , the distance from the axis of rotation to the cam engagement surface, around the peripherv of the cam 54. The cylindrical boss 64 projecting from the rear side of the cam 54 (Fig. 6A) corresponds with a recess 74 on the front side. The recess 74 serves as a receptacle for a spring biasing member 76, which, in the embodiment shown, is a coiled spring having an end which is received in a spring grip aperture 78 and the other end of which terminates in a short straight section which is received within one of the slotted grooves of the split pivot pin 40 when the device is assembled. Assembly apertures 80 are provided in the cam 54. to permit a suitable pin shaped tool to be inserted through an assembly aperture in the housing 15 and then through an aligning assembly aperture 80. This allows the spring biased cam to be held under tension while the device is assembled. Referring to FIG. 9 there is shown a crank wheel 82 having a crank pin 84 projecting from the front face thereof. The crank wheel 82 and pin 84 are the functional equivalent of the cam 54 of the previously discussed embodiment and like the cam 54, the wheel 82 has a boss recess 74 and a pivot bore 66. The blade carrier 56 of the embodiment shown in FIG. 9 utilizes an arcuate crankpin slot 86 into which the crankpin 84 is inserted and which translates the rotary motion of the crankpin 84 about the axis of the crank wheel 82 into the desired rectilinear motion which shall be more fully described below. Like the previously described cam 54 and follower 58 embodiment, the blade carrier 56 includes a trigger hook 72. A corner relief groove 88 provides a clearance space for an otherwise motion inhibiting internal protrusion of a portion of the housing 15. The cutter blades 68 may be embedded within the blade carrier 56 on its bottom face rather than being held to the rear face of the blade carrier 56. The arcuate slot in the carrier block may completely penetrate the blade carrier 56 as shown, or may be formed as a groove having a selected depth impressed into the face of the blade carrier 56 that is disposed next to the crank wheel 82. Likewise, the cam follower recess 58 could be configured such that it extends through the entire thickness of the blade carrier 56 in the previously shown embodiment.

Referring to FIGS. 10A through 10D, the relative assembly and cooperative motion of the components of the cam type embodiment of the present invention can be appreciated. FIGS. 10A through 10D depict a series of stop action images of the device as it performs its intended function. The views of the device in Figs. 10A through 10D show the moving parts of the device assembled within one of the mating halves 16A or 16B with the other mating half removed. A detailed depiction of the split pivot pin, spring, spring recess, etc. has been omitted for the sake of clarity in each figure, with the exception of Fig. IOC. Starting at FIG. 10A, the device is shown an instant after being activated by a depression of the trigger plunger 14 which has disengaged the engagement pawl 52 from the trigger hook 72. The spring biasing mean? 6, which are configured to bias the cam 54 in a counter-clockwise direction in the perspective shown, acts upon the cam 54 inducing it to turn in a counterclockwise direction. The cam follower recess 58 slideably embraces the cam 54 and the rotatory motion of the cam causes the cam 54 to impinge upon the internal peripheral wall 62 of the cam follower recess 58, particularly at contact point A, and the blade carrier 56 is forced downward. At the same time, the blade carrier 56 is retrained between the left side wall of the housing 15 and contact point B of the cam 54, thus the blade carrier 56 is maintained in parallel with the housing 15 wall during downward travel. Please note that the housing 15 is slightly bell shaped in the embodiment shown and that a lateral guide 90 for the blade carrier 56 perpendicular to the bottom wall of the housing (and consequently to the patient's skin) is formed from a raised portion of the plastic housing and compensates for the bell shape. Equivalent results could be achieved either by making the side wall perpendicular to the bottom wall or progressively thickening the sidewall to compensate for its external divergence from the perpendicular. In FIG. 10B the blade carrier 56 has bottomed out against the interior surface of the bottom wall of the housing 15 as the cam 54 at contact point C presses it downward. Simultaneously, the blade carrier 56 remains restrained against the housing 15 sidewall by the cam 54 at contact point D. The cutter blades 68 in Fig. 10b are at their leftmost point of travel and are projected through the slot pair 30A and 30B and plunged into the skin of the patient to the maximum (and constant) degree. The incision of fixed length and depth is performed when the cusp of the cam proximate contact point C in Fig. 10b engages the lower right corner E of the cam follower recess. At such time, the cam 54 begins to push the blade carrier 56 laterally across the housing 15, while at the same time restraining the blade carrier 56 between the cam 54 and the housing 15 bottom wall. The incision is completed immediately prior to the aforesaid cusp of the cam reaching the upper right corner F of the cam follower recess as shown in FIG. IOC. When the aforesaid cusp reaches the upper right corner F of the cam follower recess, it pushes the blade carrier 56 up and the cutter blades 68 are retracted within the housing 15 thus preventing accidental injury due to inadvertent exposure to the sharp blades. More importantly, the retraction of the blades 68 is irreversible without disassembling the device, (a procedure which is not contemplated or facilitated) and therefore only a single usage of the device is possible. This prevents exposure to the diseased blood of patients while further preventing injuries which may result from an exposed cutting edge.

The operation of the device may be made extremely rapid as determined by the strength of the spring. Thus the cutting edge may traverse the slot(s) in an extremely short period such as a fraction of a second. The patient awareness of the incision making process is minimized by the rapidity of the action. Furthermore, the incision is of a predetermined minimum uniform depth and length, and hence unnecessary cutting and bleeding is eliminated.

The assembly and motion of an alternative embodiment of the device utilizing a crankwheel 82 & id slotted blade carrier 56 is shown sequentially in

FIGS. 11A through 11D. Starting at FIG. HA the device is shown prior to activation with the trigger plunger 14 partially depressed and with the engagement pawl 52 in the process of slipping beyond the grip of the trigger hook 72. The blade carrier 56 is held high in the housing 15 prior to being activated so that the cutter blades 68 are retracted well into the housing 15. The crankwheel 82 is spring biased in a counter-clockwise direction in this view. The crankwheel 82 is prevented from turning by the crankpin's 84 bearing upon the arcuate slot's 86 internal bearing wall at point G. When the device is activated by a complete depression of the trigger plunger 14, the crankpin 84 is allowed to turn by the downward motion of the blade carrier 56. As the crankwheel 82 turns from its position in FIG 11A to that shown in FIG. 11B, the crankpin's 84 rotary path is resolved into a varying horizontal and vertical component by the varying angle of the slot 86 relative the tangent of the crankpin 84 path at all points. The horizontal force component maintains the carrier in slideable parallel association with the left side housing 15 wall during the downstroke. When the carrier reaches the bottom interior wall surface of the housing 15, the crankpin 84 encounters a section H of the arcuate slot 86 that is more acutely bent upwards so that the rotational path of the crankpin 84 is resolved into purely horizontal movement for a sufficient number of degrees of rotation to propel the blade carrier 56 and cutter blades 68 across the slots 30A and 3OB in a straight line to reach the position shown in FIG. 11C. After the incision has been made, the crankpin 84 enters a further area I of the arcuate slot 86 which translates the rotary motion of the crankpin 84 into a horizontal component for maintaining the blade carrier 56 in contact with the housing 15 right side wall and a vertical component for lifting the blade carrier 56 up and retracting the cutter blades 68 from their previous exposed position projecting from the slots 30A and 3OB at the bottom of the device 10.

With reference to FIGS. 12A-12D, a further alternative embodiment is there depicted having an alternative cam shape than that shown in FIGS. 10A- 10D. The embodiment shown has an operation and function in accordance with the previously described embodiments, in that the rotary motion of the driver portion of the device, here a cam 54, is translated by a suitably shaped receiver in a driven member, here a cam follower recess 58, into movement of the driven member, the blade carrier 56, on a path having a shape which approximates a square "U". It is noted that the cam shown in Fig. 4B and in Figs. 12A-12D has the special property that it may roll in contact with and between opposing parallel planes without affecting the distance between the planes. The profile of the cam is configured to obtain maximum force translation from the spring to thereby assure an optimum incision. It should be noted that the cam 54 is in continuous contact with the interior walls of the cam follower recess, which are, in the embodiment shown, in opposing parallel planes. If the cam follower recess 58 is configured as a square, the motion of the blade carrier within the housing is completely constrained such that the position of the cam 54 at any degree of rotation generates a corresponding unvarying position of the blade carrier 56.

Thus the present invention performs the incision making task quickly, painlessly and dependably. The unit has the further advantage that it is extremely inexpensive to fabricate, as all parts are made from molded plastic, with the exception of the blades 68 and the coiled spring 76.

..nile the above description and dimensions are given by way of example, it will become apparent that there are many alternative techniques which can be employed in modifying the invention as above described. All such techniques shall be deemed to be encompassed within the breadth and scope of the claims appended herewith.

Claims

Claims 1. An apparatus for implementing a standardized skin incision comprising: a. hollow housing means having at least one opening in an exterior surface thereof communicating with said hollow; b. driver means pivotably secured within said hollow housing means; c. biasing means for biasing said driver . means from a first position to a second position; d. driven means having a receptacle for slideably receiving therein at least a portion of said driver means, said driver means portion bearing upon said receptacle as said driver means moves from said first position to said second position, said motion of said driver means inducing a movement of said driven means; e. cutter means affixed to said driven means and projecting from an exterior surface of said driven means, said cutter means traversing a path at least partially external to said housing through said at least one exterior surface opening for implementing said standardized skin incision as said driven means is moved by said driver means.

2. An apparatus in accordance with Claim 1, further comprising control means for releasably restraining said driven means in said first position.

3. The apparatus according to Claim 1, wherein said exterior surface of said housing means is an exterior abutment surface for abutting said apparatus against the skin of a patient, said abutment surface having said at least one external surface opening therein for conducting said cutter means therethrough when said cutter means traverses said partially external path.

4. An apparatus in accordance with Claim 1, wherein a portion of the interior of said hollow housing means constrains the motion and orientation of said driven means as it is moved by said driver means, wherein said first position of said driver means corresponds to a first position of said driven means, said first position of said driven means having said cutter means retracted within said housing means, wherein said second position of said driver means corresponds to a second position of said driven means, said second position of said driven means having said cutter means retracted within said housing means, and wherein the transition from said first corresponding position of said driven means to said second corresponding position of said driven means is non-reversible.

5. An apparatus in accordance with Claim 4, wherein the path traversed by said cutter means is substantially rectilinear.

6. An apparatus in accordance with Claim 4, wherein said received driver means portion is a cam having a lobe extending perpendicular to the axis about which said cam pivots, a contact face being disposed at the periphery of said lobe, wherein said driven means receptacle is a cam follower recess having a peripheral internal wall which is contacted by said cam peripheral contact face as said cam moves from said first position to said second position, wherein said contact induces said driven means to move from said corresponding first position to said corresponding second position.

7. An apparatus in accordance with Claim 6, wherein said cam is substantially continuously slideably embraced by said cam recess internal peripheral wall such that the position of said driven member is a function of the angular displacement of said cam about its axis.

8. An apparatus in accordance with Claim 7 wherein said cam follower recess has a square shape and said cam maintains simultaneous contact, within a given tolerance range, with each of said sides of said recess at all times during the movement of said cam from said first to said second position.

9. An apparatus in accordance with Claim 8, wherein said cutter means path has a square "U" shape, said first position proximate a free end of one upright leg of said "U", said second position proximate a free end of the other upright leg of said "U", the external portion of said at least partially external path corresponding to the connective leg of said "U".

10. An apparatus in accordance with Claim 9, wherein said constraining portion of said hollow housing has a square "U" shape and is substantially parallel to said square "U"-shaped path.

11. An apparatus in accordance with Claim

10, wherein said constraining portion includes a pair of surfaces disposed on either side of said driver means and said driven means, said pair of surfaces residing in planes parallel to that containing said "U"-shaped path.

12. An apparatus in accordance with Claim

11, wherein the pivotal securement of said cam within said housing is upon a pivot pin projecting from an interior surface of said housing! --^'

13. An apparatus in accordance with Claim 11, wherein said cutter means includes a pair of cutting blades and wherein said at least one external surface opening is a pair of apertures permitting said pair of cutting blades to traverse said at least partially external path.

14. An apparatus in accordance with Claim 11, wherein said housing is fabricated as first and second sections which are secured together.

15. An apparatus in accordance with Claim 11, wherein said biasing means is a spring wire having one end secured to said housing and another end secured to said driver means.

16. An apparatus in accordance with Claim 11, wherein said control means includes a moveable member having a first end located outside said housing and a second end located within said housing, said second end releasably supporting said driven means, said control means when moved releasing said driven means to allow said driver means to move under the influence of said spring biasing means.

17. An apparatus in accordance with Claim 16, further comprising safety clip means removeably affixed over said control means preventing said control means from being moved.

18. An apparatus in accordance with Claim 4, wherein said received driver means portion is a substantially cylindrical crankpin extending perpendicularly from said driver means, wherein said driven means receptacle is an arcuate slot having an internal wall surface which is contacted by the side surface of said crankpin as said driver means moves from said first position to said second posit Dn, wherein said contact induces said driven means to move from said corresponding first position to said corresponding second position.

19. An apparatus in accordance with Claim

18, wherein said crankpin is substantially continuously slideably embraced by said internal wall surface such that the position of said driven member is a function of the angular displacement of said driver means about the pivotal axis of said driver means.

20. An apparatus as claimed in Claim 19, wherein said arcuate slot has a region which resolves the rotary motion of said crankpin into a horizontal and a vertical component, said vertical component causing said driven means to be directed toward said at least one cutter aperture, said horizontal component pressing said driven means into said housing means interior constraining portion, said constraining portion maintaining said driven means in an orientation with said cutter means directed downwards, a region which resolves the rotary motion of said crankpin into purely horizontal motion for causing said cutting means to traverse said at least one external surface opening at a fixed vertical depth relative to said skin of said patient, and a region which resolves said rotary motion into an upwardly directed vertical component for retracting said cutter means back into said housing and a horizontal component for pressing said driven means into said housing means interior constraining portion, said constraining portion maintaining said driven means in an orientation with said cutter means directed downwards

21. An apparatus in accordance with Claim 20, wherein said cutter means path has a square "U" shape, said first position proximate a free end of one upright leg of said "U", said second position proximate a free end of the other upright leg of said "U", the external portion of said at least partially external path corresponding to the connective leg of said "U".

22. An apparatus in accordance with Claim 21, wherein said constraining portion of said hollow housing has a square "U" shape and is substantially parallel to said square "U"-shaped path.

23. An apparatus in accordance with Claim

22, wherein said constraining portion includes a pair of surfaces disposed on either side of said driver means and said driven means, said pair of surfaces residing in planes parallel to that containing said "U"-shaped path.

24. An apparatus in accordance with Claim 23, wherein the pivotal securement of said driver means within said housing is upon a pivot pin projecting from an interior surface of said housing.

25. An apparatus in accordance with Claim

23, wherein said cutter means includes a pair of cutting blades and wherein said at least one external surface opening is a pair of apertures permitting said pair of cutting blades to traverse said at least partially external path.

26. An apparatus in accordance with Claim 23, wherein said housing is fabricated as first and second sections which are secured together.

27. An apparatus in accordance with Claim 23, wherein said biasing means is a spring wire having one end secured to said housing and another end secured to said driver means.

28. An apparatus in accordance with Claim 23, wherein said control means includes a moveable member having a first end located outside said housing and a second end located within said housing, said second end releasably supporting said driven means, said control means when moved releasing said driven means to allow said driver means to move under the influence of said spring biasing means.

29. An apparatus in accordance with Claim 28, further comprising safety clip means removeably affixed over said control means preventing said control means from being moved.

30. An apparatus for implementing a standardized skin incision comprising: a. hollow housing means having at least one opening in an exterior surface thereof communicating with said .lollow; b. a cam pivotably secured within said hollow housing means having a lobe extending perpendicular to the axis about which said cam pivots, a contact face being disposed at the periphery of said lobe; c. biasing means for biasing said cam from a first position to a second position; d. a driven means having a cam follower recess with an internal peripheral wall for slideably receiving therein at least a portion of said cam, said contact face bearing upon said internal peripheral wall as said cam moves from said first position to said second position, said motion of said cam inducing a movement of said driven means; e. cutter means affixed to said driven means and projecting from an exterior surface of said driven means, said cutter means traversing a path at least partially external to said housing through said at least one external surface opening for implementing said standardized skin incision as said driven means is moved by said cam.

31. An apparatus in accordance with Claim 30, further comprising a control means for releasably restraining said cam in said first position, wherein said housing means has an exterior abutment surface for abutting said apparatus against the skin of a patient, said abutment surface having said at least one external surface opening therein for conducting said cutter means therethrough when said cutter means traverses said partially external path, wherein a portion of the interior of said hollow housing means constrains the motion and orientation of said driven means as it is moved by said cam, wherein said first position of said cam corresponds to a first position of said driven means, said first position of said driven means having said cutter means retracted within said housing means, wherein said second position of said cam corresponds to a second position of said driven means, said second position of said driven means having said cutter means retracted within said housing means, and wherein the transition from said first corresponding position of said driven means to said second corresponding position of said driven means is non-reversible.

32. An apparatus in accordance with Claim 30, wherein said cam is substantially continuously slideably embraced by said cam recess internal peripheral wall such that the position of said driven member is a function of the angular displacement of said cam about its axis, and wherein said cam follower recess has a square shape and said cam maintains simultaneous contact, within a given tolerance range, with each of said sides of said recess at all times during the movement of said cam from said first to said second position.

33. An apparatus in accordance with Claim 32, wherein said cutter means path has a square "U" shape, said first position proximate a free end of one upright leg of said "U", said second position proximate a free end of the other upright leg of said "U", the external portion of said at least partially external path corresponding to the connective leg of said "U", wherein said constraining portion of said hollow housing has a square "U" shape and is substantially parallel to said square "U"-shaped path, and wherein said constraining portion includes a pair of surfaces disposed on either side of said cam and said driven means, said pair of surfaces re .ding in planes parallel to that containing said "Q"-shaped path.

34. An apparatus in accordance with Claim 33, wherein the pivotal securement of said cam within said housing is upon a pivot pin projecting from an interior surface of said housing

35. An apparatus in accordance with Claim 34, wherein said cutter means incli. as a pair of cutting blades, wherein said at least one external surface opening is a pair of apertures permitting said pair of cutting blades to traverse said at least partially external path, wherein said housing is fabricated as first and second sections which are secured together, wherein said biasing means is a spring wire having one end secured to said housing and another end secured to said cam, wherein said control means includes a moveable member having a first end located outside said housing and a second end located within said housing, said second end releasably supporting said driven means, said control means when moved releasing said driven means to allow said cam to move under the influence of said spring biasing means, and further comprising safety clip means removeably affixed over said control means preventing said control means from being moved.

36. An apparatus for implementing a standardized skin incision comprising: a. hollow housing means having at least one opening in an exterior surface thereof communicating with said hollow; b. driver means pivotably secured within said hollow housing means having a substantially cylindrical crankpin extending from a surface thereof substantially parallel to the pivotal axis of said driver means; c. biasing means for biasing said driver means from a first position to a second position; d. driven means having an arcuate slot for slideably receiving therein at least a portion of said crankpin, said arcuate slot having an internal wall surface which is contacted by the side surface of said crankpin as said driver means moves from said first position to said second position, said motion of said driver means inducing a movement of said driven means; e. cutter means affixed to said driven means and projecting from an exterior surface of said driven means, said cutter means traversing a path at least partially external to said housing through said at least one external surface opening for implementing said standardized skin incision as said driven means is moved by said driver means.

37. An apparatus in accordance with Claim 36, further comprising a. control means for releasably restraining said driver means in said first position, wherein said housing means has an exterior abutment surface for abutting said apparatus against the skin of a patient, said abutment surface having said at least one external surface opening therein for conducting said cutter means therethrough when said cutter means traverses said partially external path, wherein a portion of the interior of said hollow housing means constrains the motion and orientation of said driven means as it is moved by said driver means, wherein said first position of said driver means corresponds to a first position of said driven means, said first position of said driven means having said cutter means retracted within said housing means, wherein said second position of said driver means corresponds to a second position of said driven means, said second position of said driven eans having said cutter means retracted within said housing means, and wherein the transition from said first corresponding position of said driven means to said second corresponding position of said driven means is non-reversible.

38. An apparatus in accordance with Claim 37, wherein said crankpin is substantially continuously slideably embraced by said internal wall surface such that the position of said driven member is a function of the angular displacement of said driver means about the pivotal axis of said driver means.

39. An apparatus in accordance with Claim 38, wherein said arcuate slot has a region which resolves the rotary motion of said crankpin into a horizontal and a vertical component, said vertical component causing said driven means to be directed toward said at least one cutter aperture, said horizontal component pressing said driven means into said housing means interior constraining portion, said constraining portion maintaining said driven means in an orientation with said cutter means directed downwards, a region which resolves the rotary motion of said crankpin into purely horizontal motion for causing said cutting means to traverse said at least one external surface opening at a fixed vertical depth relative to said skin of said patient, and a region which resolves said rotary motion into an upwardly directed vertical component for retracting said cutter means back into said housing and a horizontal component for pressing said driven means into said housing means interior constraining portion, said constraining portion maintaining said driven means in an orientation with said cutter means directed downwards

40. An apparatus in accordance with Claim 39, wherein said cutter means path has a square "U" shape, said first position proximate a free end of one upright leg of said "U", said second position proximate a free end of the other upright leg of said "U", the external portion of said at least partially external path corresponding to the connective leg of said "U", wherein said constraining portion of said hollow housing has a square "U" shape and is substantially parallel to said square "U"-shaped path, and wherein said constraining portion includes a pair of surfaces disposed on either side of said driver means and said driven means, said pair of surfaces residing in planes parallel to that containing said "U"-shaped path.

41. An apparatus in accordance with Claim

40, wherein the pivotal securement of said driver means within said housing is upon a pivot pin projecting from an interior surface of said housing.

42. An apparatus in accordance with Claim 41, wherein said cutter means includes a pair of cutting blades, wherein said at least one external surface opening is a pair of apertures permitting said pair of cutting blades to traverse said at least partially external path, wherein said housing is fabricated as first and second sections which are secured together, wherein said biasing means is a spring wire having one end secured to said housing and another end secured to said driver means, wherein said control means includes a moveable member having a first end located outside said housing and a second end located within said housing, said second end releasably supporting said driven means, said control means when moved releasing said driven means to allow said driver means to move under the influence of said spring biasing means, and further comprising safety clip means removeably affixed over said control means preventing said control means from being moved.