Endoscopic surgical instrument with electromagnetic sensor

Claim 2

An endoscopic surgical instrument having a distal end, a proximal end for manipulating said distal end from outside the body cavity and an elongated shaft portion connecting said distal and proximal ends, said distal end including a pair of first and second spaced apart jaw members, said jaws members being movable with respect to each other, a plurality of staples disposed in one of said first or second jaw members, and an anvil disposed in said other jaw member, a magnetic target disposed in one of said first and second jaw members to produce an extended magnetic field and an electromagnetic sensor disposed in said other jaw member to measure variations in said magnetic field whereby the position of the jaw members with respect to each other may be determined.

Claim 3

An endoscopic surgical instrument according to claim 1 wherein the electromagnetic sensor is a magneto-resistive sensor.

Claim 4

An endoscopic surgical instrument according to claim 2 wherein the magneto-resistive sensor is magnetically biased.

Claim 5

An endoscopic surgical instrument according to claim 1 wherein variations in the magnetic field measure the distance between the jaw members.

Claim 6

An endoscopic surgical instrument according to claim 2 wherein the magneto-resistive sensor is gamma-radiation sterilizable.

Claim 7

An endoscopic surgical instrument according to claim 1 wherein the target magnet is a permanent magnet.

Claim 8

An endoscopic surgical instrument having a distal end for carrying out a step in a surgical procedure within a body cavity, a proximal end for manipulating said distal end from outside the body cavity and an elongated shaft portion connecting said distal and proximal ends, said distal end including a pair of spaced apart jaw members, one of said jaw members being stationary and the other of said jaw members being movable with respect to said stationary jaw member, a plurality of staples disposed in said stationary jaw member, a magnetic target disposed in said movable jaw to produce an extended magnetic field and a electromagnetic sensor disposed in said stationary jaw to measure variations in said magnetic field whereby the distance between the jaws may be determined.

Claim 9

An endoscopic surgical instrument having a distal end for carrying out a step in a surgical procedure within a body cavity, a proximal end for manipulating said distal end from outside the body cavity and an elongated shaft portion connecting said distal and proximal ends, said distal end including a pair of spaced apart jaw members, one of said jaw members being stationary and the other of said jaw members being movable with respect to said stationary jaw member, a plurality of staples disposed in said stationary jaw member, a magnetic target disposed in said movable jaw to produce an extended magnetic field and a electromagnetic sensor disposed in said stationary jaw to measure variations in said magnetic field whereby the distance between the jaws may be determined.

Claim 10

An endoscopic surgical instrument according to claim 7 wherein the electromagnetic sensor is a magneto-resistive sensor.

Claim 11

An endoscopic surgical instrument according to claim 8 wherein the target magnet is a permanent magnet.

Claim 12

An endoscopic surgical instrument according to claim 8 wherein the magneto-resistive sensor is magnetically bias.

Claim 13

An endoscopic surgical stapler for joining body tissue, said stapler having a distal end, a proximal end, and an elongated shaft portion connecting said distal and proximal ends, said distal end comprising a pair of jaws, one of said jaws being stationary and the other of said jaws being movable with respect to said stationary jaw, a plurality of staples used to join tissue disposed in said stationary jaw, said movable jaw including anvil means for forming staples, means disposed in said elongated shaft portion and extending from the proximal end to the distal end of the stapler to move said movable jaw into forming relationship with said stationary jaw, actuating means disposed in said elongated shaft portion and extending from the proximal end to the distal end of the stapler to urge said staples towards said anvil means and form said staples to join tissue placed between said jaws, a magnetic target disposed adjacent the distal end of said movable jaw and facing said stationary jaw to produce a magnetic field between said jaws and an electromagnetic sensor disposed adjacent the distal end of said stationary jaw and facing said movable jaw to measure variations in said magnetic field whereby the distance between the jaws may be determined.

Claim 14

An endoscopic surgical stapler for joining body tissue, said stapler having a distal end, a proximal end, and an elongated shaft portion connecting said distal and proximal ends, said distal end comprising a pair of jaws, one of said jaws being stationary and the other of said jaws being movable with respect to said stationary jaw, a plurality of staples used to join tissue disposed in said stationary jaw, said movable jaw including anvil means for forming staples, means disposed in said elongated shaft portion and extending from the proximal end to the distal end of the stapler to move said movable jaw into forming relationship with said stationary jaw, actuating means disposed in said elongated shaft portion and extending from the proximal end to the distal end of the stapler to urge said staples towards said anvil means and form said staples to join tissue placed between said jaws, a magnetic target disposed adjacent the distal end of said movable jaw and facing said stationary jaw to produce a magnetic field between said jaws and an electromagnetic sensor disposed adjacent the distal end of said stationary jaw and facing said movable jaw to measure variations in said magnetic field whereby the distance between the jaws may be determined.

Claim 15

An endoscopic surgical staple according to claim 11 wherein the magnetic target is a permanent magnet.

Claim 16

An endoscopic surgical stapler according to claim 11 wherein the electromagnetic sensor is a magneto-resistive sensor.

Claim 17

An endoscopic surgical stapler according to claim 13 wherein the magneto-resistive sensor is magnetically biased.