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EP-4739230-A1 - CUTTING INSTRUMENT WITH IMPROVED SURFACE TOPOGRAPHY

EP4739230A1EP 4739230 A1EP4739230 A1EP 4739230A1EP-4739230-A1

Abstract

A cutting instrument includes a cutting wedge. The cutting wedge can include a leading edge and one or more cutting fasciae terminating at the leading edge. The one or more cutting fasciae can include an approximately concave recess. Other embodiments are disclosed.

Inventors

  • SPIRO, CLIFFORD
  • TOBIN, TIMOTHY
  • COATS, Eric
  • FENDER, WILLIAM
  • JEFFCOAT, KEITH

Assignees

  • Planatome, LLC

Dates

Publication Date
20260513
Application Date
20240708

Claims (20)

  1. 1. A cutting instrument, comprising: a cutting wedge comprising: a leading edge; and one or more cutting fasciae terminating at the leading edge, wherein the one or more cutting fasciae comprise an approximately concave recess.
  2. 2. The cutting instrument of claim 1, wherein: the one or more cutting fasciae further comprise: a lower surface; and an upper surface; and the approximately concave recess is located between the lower surface and the upper surface.
  3. 3. The cutting instrument of claim 2, wherein: the cutting wedge comprises an upper edge at an opposite end of the cutting wedge from the leading edge of the cutting wedge; the upper surface comprises a length that extends from an upper end of the approximately concave recess to the upper edge of the cutting wedge; the lower surface comprises a length that extends from the leading edge to a lower end of the approximately concave recess, wherein the upper end of the approximately concave recess is located at an opposite end of the approximately concave recess from the lower end of the approximately concave recess; and the length of the upper surface is different from the length of the lower surface.
  4. 4. The cutting instrument of claim 3, wherein: the length of the lower surface is no less than 30 microns.
  5. 5. The cutting instrument of claim 2, wherein: the lower surface is no less than 30 microns in length and extends from the leading edge to an end of the approximately concave recess.
  6. 6. The cutting instrument of claim 2, wherein the lower surface comprises a surface roughness comprising: a measured arithmetic mean height (S a ) of 150 nm or less with a standard deviation of 30 nm or less across a measurement area of 16,641 square microns on at least a portion of the lower surface.
  7. 7. The cutting instrument of claim 1, wherein the one or more cutting fasciae comprise a surface roughness comprising: a measured arithmetic mean height (S a ) of 150 nm or less with a standard deviation of 30 nm or less across a measurement area of 16,641 square microns on at least a portion of the one or more cutting fasciae.
  8. 8. The cutting instrument of claim 1, wherein: the one or more cutting fasciae comprise two cutting fasciae located at opposing faces of the cutting wedge; a first one of the two cutting fasciae comprise: a first lower surface terminating at the leading edge; a first upper surface; and a first approximately concave recess located between the first lower surface and the first upper surface, wherein the approximately concave recess comprises the first approximately concave recess; and a second one of the two cutting fasciae comprise: a second lower surface terminating at the leading edge; a second upper surface; and a second approximately concave recess located between the second lower surface and the second upper surface.
  9. 9. The cutting instrument of claim 8, wherein at least one of: (a) the first lower surface is no less than 30 microns in length and extends from the leading edge to an end of the first approximately concave recess; and the second lower surface is no less than 30 microns in length and extends from the leading edge to an end of the second approximately concave recess; or (b) the first lower surface comprises a first surface roughness comprising: a first measured arithmetic mean height (S a ) of 150 nm or less with a first standard deviation of 30 nm or less across a first measurement area of 16,641 square microns on at least a portion of the first lower surface; and the second lower surface comprises a second surface roughness comprising: a second measured arithmetic mean height (S a ) of 150 nm or less with a second standard deviation of 30 nm or less across a second measurement area of 16,641 square microns on at least a portion of the second lower surface.
  10. 10. The cutting instrument of any one of claims 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein: the cutting instrument comprises a surgical scalpel.
  11. 11. A method of providing a cutting instrument, comprising: providing a cutting wedge comprising: a leading edge; and one or more cutting fasciae terminating at the leading edge, wherein the one or more cutting fasciae comprise an approximately concave recess.
  12. 12. The method of claim 11, wherein: providing the cutting wedge further comprises: using an additive manufacturing process to provide the cutting wedge.
  13. 13. The method of claim 12, wherein: using the additive manufacturing process comprises: using a laser-etching process to provide the cutting wedge.
  14. 14. The method of claim 11, wherein the one or more cutting fasciae comprise a surface roughness comprising: a measured arithmetic mean height (S a ) of 150 nm or less with a standard deviation of 30 nm or less across a measurement area of 16,641 square microns on at least a portion of the one or more cutting fasciae.
  15. 15. The method of claim 11, wherein: the one or more cutting fasciae further comprise: a lower surface; and an upper surface; and the approximately concave recess is located between the lower surface and the upper surface.
  16. 16. The method of claim 15, wherein: the cutting wedge comprises an upper edge at an opposite end of the cutting wedge from the leading edge of the cutting wedge; the upper surface comprises a length that extends from an upper end of the approximately concave recess to the upper edge of the cutting wedge; the lower surface comprises a length that extends from the leading edge to a lower end of the approximately concave recess, wherein the upper end of the approximately concave recess is located at an opposite end of the approximately concave recess from the lower end of the approximately concave recess; and the length of the upper surface is different from the length of the lower surface.
  17. 17. The method of claim 15, wherein: the lower surface is no less than 30 microns in length and extends from the leading edge to an end of the approximately concave recess.
  18. 18. The method of claim 11, wherein: the one or more cutting fasciae comprise two cutting fasciae located at opposing faces of the cutting wedge; a first one of the two cutting fasciae comprise: a first lower surface terminating at the leading edge; a first upper surface; and a first approximately concave recess located between the first lower surface and the first upper surface, wherein the approximately concave recess comprises the first approximately concave recess; and a second one of the two cutting fasciae comprise: a second lower surface terminating at the leading edge; a second upper surface; and a second approximately concave recess located between the second lower surface and the second upper surface.
  19. 19. The method of claim 18, wherein at least one of: the first lower surface is no less than 30 microns in length and extends from the leading edge to an end of the first approximately concave recess; and the second lower surface is no less than 30 microns in length and extends from the leading edge to an end of the second approximately concave recess; or (b) the first lower surface comprises a first surface roughness comprising: a first measured arithmetic mean height (S a ) of 150 nm or less with a first standard deviation of 30 nm or less across a first measurement area of 16,641 square microns on at least a portion of the first lower surface; and the second lower surface comprises a second surface roughness comprising: a second measured arithmetic mean height (S a ) of 150 nm or less with a second standard deviation of 30 nm or less across a second measurement area of 16,641 square microns on at least a portion of the second lower surface.
  20. 20. The method of any one of claims 11, 12, 13, 14, 15, 16, 17, 18, or 19, wherein: the cutting instrument comprises a surgical scalpel.

Description

CUTTING INSTRUMENT WITH IMPROVED SURFACE TOPOGRAPHY CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. Provisional Patent Application No. 63/525,637, filed on July 7, 2023, which is incorporated herein by reference in its entirety. TECHNICAL FIELD [0002] The present disclosure generally relates to cutting instruments, such as scalpel blades, keratomes, scissors, osteotome, endocutters and other medical devices whose purpose is to cut (e.g., make incisions in and resections of living tissue), as well as non-medical cutting instruments. More specifically, this disclosure is related to improving said cutting instruments by creating a nano-precise, highly uniform, ultra-smooth surface topography on cutting surfaces. BACKGROUND [0003] Currently, cutting instruments (e.g., a scalpel) often incorporate a handle and a blade either as a single unit or one with a reusable handle and replaceable blade. Such cutting instruments typically come in various shapes and sizes depending on their purpose, which, in the case of scalpels, are each identified using a numbering system. For example, #15 and #10 scalpel blades have a curved cutting edge and can be used for general tissue incisions. As another example, #11 scalpel blades can have a linear cutting edge and a sharp point that can be used for puncturing type incisions. Many cutting instruments are manufactured from stainless steel or carbon steel, but other materials of suitable hardness can also be used (e.g., diamond, sapphire, ceramics, etc...). [0004] One current method for blade manufacturing is to stamp a near-net shape blade blank from a metal sheet, followed by double-edge bevel grinding using two diamond- embedded disks or grinding wheels, where each disk or wheel is tilted at an angle of approximately 10-20 degrees. The purpose of the diamonds is to act as a grinding medium that rapidly ploughs the metal surfaces into two angularly-oriented faces, referred to collectively as the “fasciae,” or individually as a “fascia,” that then meet to create an edge. This method can cause a number of problems. For example, diamonds embedded in the grinding disk or wheel are discrete, individual crystals of varying sizes and shapes and are non-uniformly spaced on the grinding wheel. This factor alone can result in a non-uniform grind. In addition, the diamonds often fracture during the grinding operation, thereby causing the grind to become even less uniform. Non- uniform diamond ploughing can often leave quasi-parallel tracks of varying depths, profiles, and spacing along the cutting fasciae of the scalpel, thereby resulting in ragged, rough, serrated cutting surfaces on the cutting instrument. When the two fasciae come together to form a leading edge, the uneven grind marks are projected onto the leading edge, thereby resulting in the leading edge being jagged, rough, and quasi-serrated. In surgical cutting instruments, conventionally produced cutting instruments act contrary to Halsted’s principles of surgical technique, which emphasizes, among other things, gentle tissue handling for desirable clinical outcomes. These ragged edges and serrations present along the cutting fasciae and associated leading edge of a standard surgical blade can cause multiple problems, particularly when they contact and incise tissue, including (but not limited to): (i) lack of precision for exact incision placement; (ii) micro-tearing of tissue creating excess and undue trauma and/or bleeding, thereby elongating the healing process; (iii) defect sites for tissue caking and serration fold-over resulting in the need to replace cutting instruments during surgical procedures, often multiple times; (iv) weakened material sites more prone to fracture when contacting bone or other hard structures; and/or (v) high variability of cutting performance from one cutting instrument to the next, even within the same manufacturing lot of cutting instruments. [0005] It is with these observations in mind, among others, that various aspects of the present disclosure were conceived and developed. BRIEF DESCRIPTION OF THE DRAWINGS [0006] FIG. 1 shows an exemplary side view of a cutting instrument having a blade body coupled to a handle; [0007] FIG. 2 shows an exemplary opposite side view of the cutting instrument of FIG. 1 ; [0008] FIGS. 3A-3F show exemplary cross-sectional views of various blade bodies; [0009] FIG. 4 shows an exemplary infographic illustration detailing an areal height parameter used to measure and visualize surface roughness of a cutting instrument. [0010] FIG. 5 is shows an exemplary infographic illustration detailing an areal function parameter used to measure and visualize surface roughness of a cutting instrument; [0011] FIG. 6 is shows an exemplary infographic illustration detailing an areal function parameter used to evaluate and characterize surface roughness of a cutting instrument; [0012] FIG. 7 shows an exemplary an infographic illustration deta