CPC A61B 5/4836 (2013.01) [A61B 5/053 (2013.01); A61B 5/7225 (2013.01); A61B 18/1442 (2013.01); A61B 18/1492 (2013.01); A61B 2018/0063 (2013.01); A61B 2018/00357 (2013.01); A61B 2018/00363 (2013.01); A61B 2018/00577 (2013.01); A61B 2018/00642 (2013.01); A61B 2018/00702 (2013.01); A61B 2018/00875 (2013.01); A61B 2018/126 (2013.01)] | 16 Claims |
1. A biological tissue monitoring system comprising:
control circuitry programmed or configured to monitor an impedance of biological tissue during electrosurgical welding of the biological tissue, wherein the control circuitry is programmed or configured to:
receive or determine an impedance measurement of the biological tissue in response to power delivered to the biological tissue at a plurality of frequencies and a plurality of time points, wherein the impedance measurement comprises real impedance and imaginary impedance;
determine an amount of the biological tissue based on an initial impedance measurement of the biological tissue, an amount of change in the impedance measurement from a first weld stage to a second weld stage, an amount of time required to reach the second weld stage, and a duration of a third weld stage;
wherein in the first weld stage the biological tissue is in an initial tissue state and cell membranes of the biological tissue are substantially intact, in the second weld stage the biological tissue is being heated and the cell membranes begin to rupture, and in the third weld stage the biological tissue is continued to be heated and the rupture of the cell membranes is substantially complete; and
wherein the second weld stage is determined based on a decreasing value of real impedance and an increasing value of imaginary impedance.
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