The present invention relates to an apparatus and method for effecting shave biopsies.
In the practice of dermatology, lesions of questionable morphology may be removed and pathologically studied to determine if the lesion is cancerous or benign. There are many methods available to remove a skin lesion, whether for biopsy purposes or simply to excise the lesion from the patient. One common way to remove a skin lesion is by using a technique known as saucerization or “shaving.” This technique removes the lesion and superficial layers of the skin.
The shaving dermatological technique is a relatively simple procedure wherein a single edged blade is used to sever the lesion from the patient. While some doctors use scalpel blades, many instead use a single edged, razor-type blade. The razor type technique utilizes a flexible, flat surgical blade that is placed between a user's thumb and forefinger(s). Slight pressure is applied to the blade to induce the blade to curve away from the user's hand. By varying the finger pressure on the blade, the user can change the curvature of the blade to a certain extent. Commonly, a readily available double edge razor blade is used for this procedure and is snapped in half longitudinally to yield two sharp-edged half-blades for use. The patient's skin is pinched upward to produce a tight mound of skin, with the lesion located atop the mound. The curved edge may then be used in a sawing and/or sliding motion to scoop under the lesion, thus removing the lesion from the skin through use of a typically shallow and wide saucer-like cut.
Many millions of skin lesions are removed every year in the United States by this method. There are currently purpose-built shave blades which use various handles and holders to make the blade more user-friendly. Some, however, choose to use standard consumer razor blades, which are initially nonsterile and coated with a rust-resistant lubricant, and are typically made from 0.004″ thick chrome-plated carbon steel. The user bends the razor blade repeatedly along its long axis (which typically includes a series of mounting apertures, weakening that area of the blade), and eventually the razor blade breaks under the bending stress to create two long, thin, single-edged sharp excision blades. These two halves can then be sterilized and used on a patient.
These makeshift excision blades can present many challenges for the user. The correct blade curvature and cut depth are important to achieving a successful removal of the skin lesion without excessive removal of surrounding non-lesion skin. However, current blades only curve in a natural range of approximately 1″ radius at their tightest curvature, which may be inadequate for certain lesion removal situations. Another problem with the excision blades in current use is that the sharp razor blade edge extends across an entire width of the blade and the broken edges may leave sharp corners and surfaces elsewhere on the excision blade. Hence, the user must be cautious to avoid inadvertently cutting into her own fingertips during the lesion removal, in addition to the attention to the patient's skin required by the actual removal process. Moreover, the razor blades include no ergonomic features to facilitate safe use thereof. Finally, because the excision blades are not intended for bending during use, there may be a tendency for the blades to suddenly invert their curvature (in an “oil can” manner) in response to a slight change of force applied by the user. Such an unexpected shift in the blade configuration could be harmful to the patient and/or the user and could unnecessarily complicate the lesion removal process.
While various holders and guards have been proposed for use with double- or single-edged razor blades or excision blades formed as discussed above, these accessories add complexity and bulk to the lesion removal blade and can be relatively expensive and difficult to sterilize, particularly as compared to the simple, one-piece excision blades currently used.
In an embodiment of the present invention, a unitary shave biopsy blade is described. The shave biopsy blade comprises a first side edge, a second side edge laterally spaced from the first side edge, and a front edge extending laterally between the first and second side edges. A back edge extends laterally between the first and second side edges and is spaced longitudinally from the front edge. At least one of the front and back edges is at least partially sharpened to form a cutting edge. A top surface is defined laterally between the first and second side edges and longitudinally between the front and back edges. A bottom surface is defined laterally between the first and second side edges and longitudinally between the front and back edges and is spaced from the top surface by a blade thickness. At least one of the top and bottom surfaces includes a bend area feature which defines a local reduction in the blade thickness. Another embodiment of the invention involves the construction and use of a kit of differently configured blades.
In an embodiment of the present invention, a method of excising a target area from a surface of a skin tissue is described. A unitary blade is provided, the unitary blade including longitudinally oriented and laterally spaced first and second side edges, laterally oriented and longitudinally spaced front and back edges, and oppositely disposed top and bottom surfaces, at least one of the front and back edges being at least partially sharpened to form a cutting edge spaced apart from both the first and second side edges, and at least one of the top and bottom surfaces including a bend area feature which defines a local reduction in a thickness of the unitary blade. A laterally directed compressive force is applied to the unitary blade to bend the unitary blade into a convex relationship with the surface of the skin tissue. The compressive force is adjusted to place the unitary blade into a predetermined bend profile. A shape of the bend profile is at least partially dependent upon a shape of the bend area feature. The bend profile includes at least a portion of the cutting edge. The target area is excised from the skin tissue through substantially longitudinally oriented motion of the unitary blade.
For a better understanding of the invention, reference may be made to the accompanying drawings, in which:
a and 10b depict an example sequence of operation of the embodiment of
In accordance with the present invention,
The shave biopsy blade 100 includes a first side edge 102, a second side edge 104 laterally spaced from the first side edge, a front edge 106 extending laterally between the first and second side edges, and a back edge 108 extending laterally between the first and second side edges and spaced longitudinally from the front edge. At least one of the front and back edges 106 and 108 is at least partially sharpened to form a cutting edge 110. Each cutting edge 110 may be laterally separated from the first and second side edges, as shown in
A top surface 112 is defined laterally between the first and second side edges 102 and 104 and longitudinally between the front and back edges 106 and 108. As seen in the cross-sectional view of
At least one of the first side edge 102, the second side edge 104, and the back edge 108 may be ergonomically contoured, as shown in
Whether or not an ergonomic contour is present, at least one of the first side edge 102, the second side edge 104, and the back edge 108 may include a friction-increasing feature 120 along at least a portion thereof, for engagement with a digit of a user. For example, and as shown, a plurality of serrations or scallops may serve as a friction-increasing feature 120 and help the user to maintain a firm grip on the shave biopsy blade 100.
As can be seen in both
The bend area feature 120 may be spaced apart from the first and second side edges 102 and 104 and the front and back edges 106 and 108, as shown, or may intersect with one or more of the first and second side edges and the front and back edges. The bend area feature 120 may have a footprint shape operative to facilitate at least one desired bending characteristic in the shave biopsy blade 100 upon application of compressive force in the lateral direction to the shave biopsy blade.
Examples of some possible configurations of footprint shapes of bend area features 120 are shown in FIGS. 1 and 3-9. The bend area feature 120 in
The respective bend profiles of the blades 100 shown in
In
Though the general shape of the shave biopsy blade 100 is the same in all of the depicted configurations, each of the different bend area features 120 shown can facilitate different bending characteristics of the shave biopsy blade as discussed above and shown, by way of example in
Regardless of the shape or configuration of the bend area feature 120, each shape biopsy blade 100 is configured to bend in a lateral direction under compressive force, as shown in
To use the shave biopsy blade 100 to excise a target area (e.g., a skin lesion and small amount of surrounding skin) from a surface of a skin tissue, the user may first select a desired shave biopsy blade 100 from a group of shave biopsy blades having differently configured bend area features 120, with the selection being based at least partially upon the predetermined bend profile of the selected shave biopsy blade (which is facilitated by that blade's bend area feature). For example, the user may wish to choose a shave biopsy blade 100 having a very sharply angled bend profile (
Next, the user grasps the selected shave biopsy blade 100, such as by placing the contacting the first and second side edges 102 and 104 in a substantially perpendicular fashion with the thumb 1022 and forefinger 1024, respectively, possibly with retention assistance by the friction-increasing features 118. The user then applies a laterally directed compressive force to the shave biopsy blade 100, to bend the shave biopsy blade into a convex relationship with the surface of the skin tissue. The compressive force applied by the user will place the shave biopsy blade 100 into a predetermined bend profile, as shown in the sequence of
Since the bend area feature 120 of the depicted shave biopsy blade 100 is substantially in line with the center of the sharpened cutting edge 110, the bend profile of the shave biopsy blade is easily controlled by the user through pressure on the first and second side edges 102 and 104. The sections of the shave biopsy blade 100 which are outside the bend area feature 120 are thicker, and thus stiffer and less yielding, than the bend area feature itself, which does most of the shape contouring. This arrangement assists a user in controlling the cutting depth and shave profile of the shave biopsy blade 100. It should be noted that the bend area feature 120 is not necessarily located in a centered position with respect to the cutting edge 110.
Once the desired bend profile is achieved, the user can then proceed to excise the target area from the skin tissue through substantially longitudinally oriented (into or out of the plane of
Through the motive force applied to at least one of the first and second side edges 102 and the back edge 108, the shave biopsy blade 100 can then be moved substantially longitudinally toward the target area. When the shave biopsy blade 100 has been brought to the desired cutting position, the user may then pass at least a portion of the bend profile (e.g., that portion having the cutting edge 110) through the skin tissue beneath and adjacent to the target area, in order to sever the target area with the cutting edge.
Optionally, the user may somewhat adjust the predetermined bend profile during excision of the target area by selectively varying the laterally directed compressive force exerted on the shave biopsy blade 100. Such adjustment may be desirable, for example, when the borders of the target area to be removed are uneven or the bend profile approaches an anatomical feature of the patient's skin which should remain undamaged.
Once the target area has been severed, the user may move the shave biopsy blade 100 substantially longitudinally away from the target area, though an upward or lifting motion of the shave biopsy blade may also be provided in certain use environments. Regardless of the motions employed, the shave biopsy blade 100 may be removed from the skin tissue once the target area has been removed.
It is contemplated that at least a portion of the shave biopsy blade 100 may include a drug-eluting material and/or feature. “Elute” is used herein to indicate that a therapeutic agent is released, leached, diffused, or otherwise provided to the target tissue. Therefore, at least a portion of the shave biopsy blade 100 could be adapted to elute a therapeutic agent, such as, but not limited to, an anesthetic, anti-inflammatory, coagulant, cauterizing agent, scar-reducing material, or antiseptic fluid, to the wound (not shown) created by removal of the target area from the skin tissue. Additionally, it is contemplated that at least a portion of the shave biopsy blade 100 may be coated with, elute, or otherwise include a lubricant which helps decrease friction of the shave biopsy blade against the patient's skin surface.
As an example of a strip processing procedure, the raw blade material may be treated with a photo-resist as is common in printed circuit manufacturing. The strip of blade material is then passed through progressive acid etching baths to chemically remove material. For instance, the bend area feature 120 could be etched into a portion of the thickness of the strip of blade material in one step, with a subsequent step including full removal of the material between adjacent shave biopsy blades 100. Accordingly, a strip of raw blade material can be transformed into a chain of finished blanks which can be further processed in an in-line grinding process that sharpens the blanks by passing them through grinding machines.
As shown in
While aspects of the present invention have been particularly shown and described with reference to the preferred embodiment above, it will be understood by those of ordinary skill in the art that various additional embodiments may be contemplated without departing from the spirit and scope of the present invention. For example, the shave biopsy blade 100 could be made of surgical steel such as Hitachi Gin 5 or 440C, any other high tensile strength stainless steel, or any other suitable metallic or nonmetallic material, or combinations thereof, capable of sharpening into a cutting edge 110. The friction-increasing features 118 could be integrally formed with the rest of the shave biopsy blade 100 and/or could include an external friction-increasing agent, such as a rubberized coating. The shave biopsy blade 100 could be provided to the user in at least a slightly pre-bent configuration, rather than having the straight resting configurations of various Figures. The shave biopsy blade 100 could be asymmetrical in those areas currently shown in the Figures as being symmetrical. The shave biopsy blade 100 could form the predetermined bend profile through any suitable combination of plastic and/or elastic bending. A portion of the user's body other than the digits could be used to provide any of the described forces to the shave biopsy blade 100, as could an automatic or manual assistance tool. A device or method incorporating any of these features should be understood to fall under the scope of the present invention as determined based upon the claims below and any equivalents thereof.
While the present invention has been illustrated by a description of various preferred embodiments and while these embodiments have been described in some detail, it is not the intention of the Applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The various features discussed herein may be used alone or in any combination depending on the needs and preferences of the user. This has been a description of illustrative aspects and embodiments the present invention, along with the preferred methods of practicing the present invention as currently known.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/085,017, filed Jul. 31, 2008 (pending), the disclosure of which is also fully incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US09/52112 | 7/29/2009 | WO | 00 | 1/21/2011 |
Number | Date | Country | |
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61085017 | Jul 2008 | US |