System and method for controlling electrosurgical snares

• US 20070208339A1
• Filed: 03/03/2006
• Published: 09/06/2007
• Est. Priority Date: 03/03/2006
• Status: Active Grant

• Current Assignee: Covidien AG (Medtronic Plc)
• Original Assignee: Sherwood Services AG
• Inventors: Schmaltz, Dale, Arts, Gene, Craig, Jason
• Granted Patent: US 7,651,493 B2
• Time in Patent Office: Days
• US Class Current: 606/47
• CPC Class Codes: A61B 17/32056 Surgical snare instruments for removing or smashing calculi A61B2017/2212; tonsillotomes A61B17/26
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2018/1407 Loop
• CPC Class Codes: A61B 2018/141 Snare
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension

Abstract

A system and method for controlling electrosurgical snares are disclosed. The system includes an electrosurgical instrument having an elongate tubular sheath having proximal and distal ends, the sheath having a longitudinal axis defined therethrough and a shaft having proximal and distal ends. The shaft extends through and is axially movable relative to the sheath. A snare loop is provided at the distal end of the shaft and is configured for encircling tissue. Movement of the shaft relative to the tubular sheath changes the diameter of the exposed snare loop. A feedback sensor operatively connected to the elongated tubular sheath which determines at least one condition of the snare loop, and an electrosurgical generator provides electrosurgical energy to the electrosurgical snare instrument. The generator is configured to receive feedback measurements from the electrosurgical snare instrument and to adjust electrosurgical energy as a function of the measurements.

Claims

1. An electrosurgical snare instrument comprising:

an elongate flexible tubular sheath having proximal and distal ends, the sheath having a longitudinal axis defined therethrough;

a shaft having proximal and distal ends, the shaft extending through and axially movable relative to the sheath;

a snare loop provided at the distal end of the shaft configured to encircle tissue, wherein the movement of the shaft relative to the tubular sheath changes the diameter of the exposed snare loop; and

a feedback sensor operatively coupled to the elongate tubular sheath that determines at least one condition of the snare loop.

2. An electrosurgical snare instrument as in claim 1, wherein the feedback sensor includes:

a position sensor configured to measure diameter of the snare loop; and

a pressure sensor configured to measure pressure exerted by the snare loop on the encircled tissue.

3. An electrosurgical snare instrument as in claim 2, wherein the position sensor includes a potentiometer.

4. An electrosurgical snare instrument as in claim 1, wherein the potentiometer is disposed on an inner surface of the sheath and a nub in contact therewith disposed on the shaft.

5. An electrosurgical snare instrument as in claim 2, wherein the pressure sensor includes a piezoelectric crystal.

6. An electrosurgical snare instrument as in claim 1, wherein the feedback sensor is selected from a group consisting of a position sensor configured to measure diameter of the snare loop and a pressure sensor configured to measure pressure exerted by the snare loop on the encircled tissue.

7. An electrosurgical snare instrument as in claim 1, wherein the feedback sensor determines when the snare loop is fully retracted and the tissue is severed.

8. A system for performing electrosurgical procedures, comprising:

an electrosurgical instrument including;

an elongate tubular sheath having proximal and distal ends, the sheath having a longitudinal axis defined therethrough;

a shaft having proximal and distal ends, the shaft extending through and axially movable relative to the sheath;

a snare loop provided at the distal end of the shaft configured to encircle tissue, wherein the movement of the shaft relative to the tubular sheath changes the diameter of the exposed snare loop; and

a feedback sensor operatively coupled to the elongated tubular sheath that determines at least one condition of the snare loop; and

an electrosurgical generator to provide electrosurgical energy to the electrosurgical snare instrument, the generator configured to receive feedback measurements from the electrosurgical snare instrument and to adjust electrosurgical energy as a function of the measurements.

9. A system as in claim 8, wherein the feedback sensor comprises:

a position sensor configured to measure diameter of the snare loop; and

a pressure sensor configured to measure pressure exerted by the snare loop on the encircled tissue.

10. A system as in claim 9, wherein the pressure sensor includes a piezoelectric crystal.

11. A system as in claim 8, wherein the feedback sensor is selected from a group consisting of a position sensor configured to measure diameter of the snare loop and a pressure sensor configured to measure pressure exerted by the snare loop on the encircled tissue.

12. A system as in claim 8, wherein the generator automatically controls the movement of the shaft and diameter of the snare loop.

13. A system as in claim 8, wherein the electrosurgical snare instrument includes identifying means readable by the generator, the identifying means comprising instructions to configure the generator.

14. A method for performing electrosurgical snare procedures, the method comprising the steps of:

inserting an electrosurgical snare instrument into a body cavity, the snare instrument comprising;

an elongate tubular sheath having proximal and distal ends, the electrosurgical sheath having a longitudinal axis defined therethrough;

a shaft having proximal and distal ends, the shaft extending through and axially movable relative to the sheath; and

a snare loop provided at the distal end of the shaft configured to encircle tissue, wherein the movement of the shaft relative to the tubular sheath changes the diameter of the exposed snare loop to encircle a portion of the tissue;

positioning the snare loop to encircle a portion of the tissue;

collecting feedback measurements through a feedback sensor operatively coupled to the elongated tubular sheath that determines at least one condition of the snare loop indicative of at least one condition of the snare loop;

transmitting feedback measurements to an electrosurgical generator that provides electrosurgical energy; and

adjusting electrosurgical energy as a function of the feedback measurements.

15. A method as in claim 14, further comprising:

adjusting the diameter of the snare loop as a function of the feedback measurements.

16. A method as in claim 14, wherein the feedback measurements are selected from the group consisting of diameter, pressure measurements and impedance.

17. A method as in claim 14, wherein the at least one condition of the snare loop includes diameter and pressure.

18. A method as in claim 14, wherein the position sensor includes a potentiometer disposed on inner surface of the sheath and a nub in contact therewith disposed on the shaft.

19. A method as in claim 14, further comprising the step of determining when the snare loop is fully retracted and the tissue is severed.

20. A method as in claim 14, further comprising the step of determining when the snare loop is in contact with the tissue.