Surgical knife

• US 7,144,403 B2
• Filed: 07/29/2003
• Issued: 12/05/2006
• Est. Priority Date: 07/29/2003
• Status: Active Grant

• Current Assignee: Alcon Incorporated
• Original Assignee: Alcon Incorporated
• Inventors: Booth, David E.
• Primary Examiner(s): BUI, VY Q
• Application Number:
  US10/629,404
• Publication Number:
  US 20050033335A1
• Time in Patent Office: 1,225 Days
• Field of Search: 606/166, 606/167, 606/180, 606/185, 303/465, 303/53, 303/55, 303/57
• US Class Current: 606/166
• CPC Class Codes: A61B 17/3211 Surgical scalpels, knives; Accessories therefor
• CPC Class Codes: A61B 2017/32116 with means for improving the rigidity of the blade, e.g. with a reinforcing rib
• CPC Class Codes: A61F 9/0133 Knives or scalpels specially adapted therefor

Abstract

A knife having a blade tip configuration that reduces incisional force by providing a more efficient distribution of tissue piercing and cutting forces over the cutting edges. The distal tip of the blade has a profile in plan view in the region of approximately 150 microns from the distal most point of the tip that may be described by the equation w=adⁿ, where w is the distance from the blade'"'"'s longitudinal axis to the blade'"'"'s cutting edge, a is a constant of proportionality not greater than 0.5 and d is the distance along the blade'"'"'s longitudinal axis from the extreme distal point of the blade tip. The extreme distal point of the tip has a slightly rounded, rather than pointy, profile, with a tip radius of approximately 40 microns or less.

Claims

1. A surgical knife, comprising:

a) a handle;

b) a blade having opposing cutting edges and a longitudinal axis, the blade being attached to the handle; and

c) a distal tip on the blade, the distal tip having an extreme distal point,

wherein the distal tip has a shape generally described by the equation

w=adⁿ

where

w is the distance from the blade'"'"'s longitudinal axis to the blade'"'"'s cutting edges

a is a constant of proportionality not greater than 0.5

n is an exponent approximately between 0.9 and 1.4

d is the distance along the blade'"'"'s longitudinal axis from the extreme distal point of the blade tip.

2. The surgical knife of claim 1 wherein the distal tip has a thickness of approximately between 0.003 inches and 0.007 inches.

3. The surgical knife of claim 1 wherein an angle between the cutting edges is between approximately 12°

and 20°

.

4. The surgical knife of claim 1 wherein the distal point is slightly rounded, with a radius of less than approximately 40 microns.

5. The surgical knife of claim 4 wherein the radius is between approximately 10 microns and 40 microns.

6. The surgical knife of claim 1 wherein the blade contains a lubricious or friction reducing coating.

7. A surgical knife, comprising:

a) a handle;

b) a blade having opposing cutting edges and a longitudinal axis, the blade being attached to the handle and containing a lubricious or friction reducing coating; and

c) a distal tip on the blade, the distal tip having a slightly rounded end having an extreme distal point,

wherein the distal tip has a shape generally described by the equation

w=adⁿ

where

w is the distance from the blade'"'"'s longitudinal axis to the blade'"'"'s cutting edges

a is a constant of proportionality not greater than 0.5

n is an exponent approximately between 0.9 and 1.4

d is the distance along the blade'"'"'s longitudinal axis from the extreme distal point of the blade tip.

8. The surgical knife of claim 7 wherein the distal tip has a thickness of approximately between 0.003 inches and 0.007 inches.

9. The surgical knife of claim 7 wherein an angle between the cutting edges is between approximately 12°

and 20°

.

10. The surgical knife of claim 7 wherein the rounded end has a radius of less than approximately 40 microns.

11. The surgical knife of claim 10 wherein the radius is between approximately 10 microns and 40 microns.