Surgical knife
View Patent ↗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 that may be described as bounded by the following equations w=5.886(d) 0.663 and w=1.561(d) 0.820 where w is the distance in microns from the blade's longitudinal axis to the blade's cutting edge and d is the distance in microns 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 pointed, profile, with a tip radius of approximately 40 microns or less.
1. A surgical knife, comprising:
a handle;
a blade having opposing cutting edges and a longitudinal axis, the blade being attached to the handle; and
a distal tip on the blade, the distal tip having a distal point, wherein the distal tip has a shape generally described by the equation
w=ad n
where
w is the distance from the blade's longitudinal axis to the blade's cutting edges
a is a constant of proportionality
n is an exponent
d is the distance in microns 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 distal tip has a shape generally described as bounded by the following equations:
w= 5.886( d ) 0.663 ;
and
w= 1.561( d ) 0.820 where the units of w and d are in microns.
7. The surgical knife of claim 1 , wherein w is the distance in microns from the blade's longitudinal axis to the blade's cutting edges.
8. The surgical knife of claim 7 , wherein d is the distance in microns along the blade's longitudinal axis from the extreme distal point of the blade tip.
9. A surgical knife, comprising:
a handle;
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
a distal tip on the blade, the distal tip having a slightly rounded extreme distal point,
wherein the distal tip has a shape generally described by the equation
w=ad n
where
w is the distance in microns from the blade's longitudinal axis to the blade's cutting edges
a is a constant of proportionality
n is an exponent
d is the distance in microns along the blade's longitudinal axis from the extreme distal point of the blade tip.
10. The surgical knife of claim 9 , wherein the distal tip has a thickness of approximately between 0.003 inches and 0.007 inches.
11. The surgical knife of claim 9 , wherein an angle between the cutting edges is between approximately 12° and 20°.
12. The surgical knife of claim 9 , wherein the distal point has a radius of less than approximately 40 microns.
13. The surgical knife of claim 12 , wherein the radius is between approximately 10 microns and 40 microns.
14. The surgical knife of claim 9 , wherein the distal tip has a shape generally described as bounded by the following equations:
w= 5.886( d ) 0.663 ;
and
w= 1.561( d ) 0.820 where the units of w and d are in microns.
15. The surgical knife of claim 9 , wherein w is the distance in microns from the blade's longitudinal axis to the blade's cutting edges.
16. The surgical knife of claim 15 , wherein d is the distance in microns along the blade'longitudinal axis from the extreme distal point of the blade tip.