Jaw closure detection system

• US 8,357,158 B2
• Filed: 04/07/2009
• Issued: 01/22/2013
• Est. Priority Date: 04/22/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: McKenna, Nicole, Wham, Robert H.
• Primary Examiner(s): Mehta, Bhisma
• Assistant Examiner(s): Bosques, Edelmira
• Application Number:
  US12/419,735
• Publication Number:
  US 20090261804A1
• Time in Patent Office: 1,386 Days
• Field of Search: 606/206, 606/207, 606/49, 606 51- 52
• US Class Current: 606/51
• CPC Class Codes: A61B 17/29 Forceps for use in minimally invasive surgery
• CPC Class Codes: A61B 18/1442 Probes having pivoting end effectors, e.g. forceps
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 18/1447 wherein sliding surfaces cause opening/closing of the end effectors
• CPC Class Codes: A61B 2017/2926 Details of heads or jaws
• CPC Class Codes: A61B 2018/0063 Sealing
• CPC Class Codes: A61B 2090/067 for measuring angles

Abstract

A jaw angle detection system for an end effector assembly includes a first electrical contact that connects to a first jaw member and connects to a generator. A sensor connects to a second jaw member (or an actuator) and connects to the generator, and configured to move relative to the first electrical contact upon movement of the second jaw member (or the actuator) when the first and second jaw members are moved to close about tissue disposed therebetween. Information relating to the position of the sensor relative to the first electrical contact is relayed back to the generator to determine an angle between the first and second jaw members.

Claims

1. A jaw angle detection system for performing surgical procedures, comprising:

first and second jaw members;

a capacitive sensing circuit;

a variable capacitor connected to the capacitive sensing circuit, the variable capacitor including first and second conductors, wherein the first conductor is fixed relative to the second conductor, while the second conductor is moveable relative to the first conductor upon movement of the jaw members from a first spaced position relative to one another to a second position closer to one another; and

wherein information relating to the position of the second conductor relative to the first conductor is relayed back to the capacitive sensing circuit to determine an angle between the first and second jaw members.

2. A jaw angle detection system for performing surgical procedures according to claim 1, wherein the first and second conductors are conductive rings.

3. A jaw angle detection system for performing surgical procedures according to claim 1, wherein the second conductor is attached to a drive rod of an endoscopic electrosurgical forceps.

4. A jaw angle detection system for performing surgical procedures according to claim 1, wherein the second conductor is attached to a movable jaw member of a unilateral endoscopic electrosurgical forceps.

5. A jaw angle detection method for performing surgical procedures, comprising:

sensing a position of a first jaw member relative to a second jaw member of an end effector assembly from a variable capacitor, wherein the variable capacitor includes first and second conductors, the first conductor is fixed relative to the second conductor, while the second conductor is moveable relative to the first conductor upon movement of the jaw members from a first spaced position relative to one another to a second position closer to one another;

conducting a signal representative of the sensed position back to one of a controller and a generator; and

determining an angle between the first and second jaw members based on the signal.

6. A jaw angle detection method for performing surgical procedures according to claim 5, further comprising providing information to a user based on the determined angle, the information selected from the group consisting of a tissue thickness, a rate of closure of the jaw members, a seal quality, and a re-grasp condition.

7. A jaw angle detection method for performing surgical procedures according to claim 5, further comprising modifying energy delivery to the jaw members based on the determined angle to enhance the sealing process, wherein the determined angle provides information to the controller or the generator and the information is selected from the group consisting of a tissue thickness, a rate of closure of the jaw members, a seal quality, and a re-grasp condition.

8. A jaw angle detection method for performing surgical procedures according to claim 5, wherein the first and second conductors are separate and different than a first sealing surface on the first jaw member and a second sealing surface on the second jaw member.

9. A jaw angle detection system for performing surgical procedures, comprising:

first and second jaw members;

a variable capacitor including first and second conductors, wherein the first conductor is fixed relative to the second conductor while the second conductor is moveable relative to the first conductor upon movement of the jaw members; and

a capacitive sensing circuit configured to receive a capacitive signal from the variable capacitor and to determine an angle between the first and second jaw members based on a capacitive value determined from the capacitive signal.