Tissue sensing circuit for surgical instrument

A surgical instrument, comprising:

• (a) a body;
• (b) a shaft extending distally from the body;
• (c) an end effector at a distal end of the shaft, wherein the end effector includes:
• (i) a first jaw having a plurality of staple forming pockets configured to form staples,
• (ii) a second jaw configured to cooperate with the first jaw to clamp in vivo material of a patient, and
• (iii) a staple cartridge removably coupled with the second jaw and having a plurality of staples;
• (d) first and second electrodes configured to deliver an electrical signal to the in vivo material positioned between the first and second jaws;
• and
• (e) an electrical circuit electrically coupled with the first and second electrodes and including a microcontroller secured to a portion of one of the first jaw, the second jaw, or the staple cartridge, wherein the electrical circuit is configured to:
• (i) control delivery of the electrical signal to the first electrode such that the electrical signal passes from the first electrode, through the in vivo material, to the second electrode,
• (ii) determine, based on the electrical signal as received by the second electrode, an electrical impedance associated with the in vivo material, and
• (iii) determine, based on the electrical impedance, at least one of:
• (A) a presence of a tissue in the in vivo material,
• (B) an absence of a tissue in the in vivo material, or
• (C) a characteristic of a tissue forming at least a part of the in vivo material.

A method of operating a surgical instrument having first and second electrodes and an end effector that houses a microcontroller, the method comprising:

• (a) controlling, using the microcontroller, delivery of an electrical signal to the first electrode, wherein the first electrode is configured to directly contact and deliver the electrical signal to in vivo material clamped by the end effector;
• (b) receiving the electrical signal with the second electrode after the electrical signal has passed through the in vivo material from the first electrode;
• (c) determining with the microcontroller, based on the electrical signal as received by the second electrode, an electrical impedance associated with the in vivo material;
• and
• (d) determining with the microcontroller, based on the electrical impedance, at least one of:
• (i) a presence of a tissue in the in vivo material,
• (ii) an absence of a tissue in the in vivo material, or
• (iii) a characteristic of a tissue forming at least a part of the in vivo material.