US-20260123982-A1 - APPARATUS AND METHOD FOR ELECTROSURGERY

US20260123982A1US 20260123982 A1US20260123982 A1US 20260123982A1US-20260123982-A1

Abstract

Methods and systems for treating biological tissue using high frequency electrical energy includes a cycle comprising a desiccating phase, a cutting phase and a coagulating phase. During the dessicating phase of the cycle, a first high frequency electrical energy applied to the tissue for desiccating the tissue is modulated. A first parameter associated with application of the first high frequency electrical energy to the tissue for desiccating the tissue is estimated. During the cutting phase, cutting energy applied to the tissue for cutting the tissue is then modulated based on the first parameter. During the coagulating phase, a second high frequency electrical energy applied to the tissue for coagulating the cut tissue is modulated.

Inventors

Akinori KABAYA

Assignees

OLYMPUS MEDICAL SYSTEMS CORP.

Dates

Publication Date: 20260507
Application Date: 20251230

Claims (20)

1 . A method for treating a tissue, the method comprising: during a first cycle: outputting a first electrical energy from a start of the first cycle to a first discharge timing, outputting a second electrical energy after the first discharge timing to an end of the first cycle, and estimating a parameter associated with application of the second electrical energy to the tissue; and during a second cycle following the first cycle: outputting a third electrical energy from a start of the second cycle to a second discharge timing, wherein the third electrical energy is modulated from the first electrical energy based on the parameter, and wherein a first amount of time for outputting the first electrical energy in the first cycle is different from a second amount of time for outputting the third electrical energy in the second cycle.
2 . The method of claim 1 , wherein the first amount of time is from the start of the first cycle to the first discharge timing, and the second amount of time is from the start of the second cycle to the second discharge timing.
3 . The method of claim 1 , wherein the second amount of time is shorter than the first amount of time.
4 . The method of claim 1 , wherein the parameter includes a rate of increase of voltage across the tissue during outputting the second electrical energy.
5 . The method of claim 1 , wherein modulating the first electrical energy includes estimating a contact area between the tissue and an end effector of a medical device based on the parameter.
6 . The method of claim 1 , wherein the first electrical energy is greater than the second electrical energy, and wherein an amount of time for outputting the first electrical energy is longer than an amount of time for outputting the second electrical energy.
7 . The method of claim 1 , wherein the second electrical energy includes a cutting energy and a coagulating energy.
8 . The method of claim 7 , wherein the parameter is an estimate associated with application of the coagulating energy.
9 . The method of claim 1 , wherein the parameter includes a time for a DC voltage across the tissue during outputting the second electrical energy to reach a first threshold value.
10 . The method of claim 4 , wherein modulating the first electrical energy during the second cycle includes increasing the second amount of time if the contact area exceeds an area threshold.
11 . A controller for a medical device, the controller configured to: during a first cycle: output a first electrical energy from a start of the first cycle to a first discharge timing, output a second electrical energy after the first discharge timing to an end of the first cycle, and estimating a parameter associated with application of the second electrical energy to the tissue; and during a second cycle following the first cycle: output a third electrical energy from a start of the second cycle to a second discharge timing, wherein the third electrical energy is modulated from the first electrical energy based on the parameter, and wherein a first amount of time for the first electrical energy in the first cycle is different from a second amount of time for the first electrical energy in the second cycle.
12 . The controller of claim 11 , wherein the first amount of time is from the start of the first cycle to the first discharge timing, and the second amount of time is from the start of the second cycle to the second discharge timing.
13 . The controller of claim 11 , wherein the second amount of time is shorter than the first amount of time.
14 . The controller of claim 11 , wherein the parameter includes a rate of increase of voltage across the tissue during outputting the second electrical energy.
15 . The controller of claim 11 , wherein modulating the first electrical energy comprises estimating a contact area between the tissue and an end effector of the medical device based on the parameter.
16 . The controller of claim 11 , wherein the first electrical energy is greater than the second electrical energy, and wherein an amount of time for outputting the first electrical energy is longer than an amount of time for outputting the second electrical energy.
17 . The controller of claim 11 , wherein the second electrical energy includes a cutting energy and a coagulating energy.
18 . The controller of claim 17 , wherein the parameter is an estimate associated with application of the coagulating energy.
19 . The controller of claim 11 , wherein the parameter comprises a time for a DC voltage across the tissue during outputting the second electrical energy to reach a first threshold value.
20 . The controller of claim 14 , wherein modulating the first electrical energy during the second cycle includes increasing the second amount of time if the contact area exceeds an area threshold.

Description

RELATED APPLICATION DATA This application is a continuation application of U.S. application Ser. No. 17/536,240, filed on Nov. 29, 2021, and is based on and claims priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 63/155,808 filed on Mar. 3, 2021, the entire contents of each of these applications are incorporated herein by reference. TECHNICAL FIELD The systems, devices and methods disclosed herein are directed to electrosurgery and in particular to cutting of a biological tissue using high frequency electrical energy. BACKGROUND In the discussion that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art against the present invention. Many medical procedures include cutting a biological tissue such as, for example, when making incision or excising mucosa or submucosa. One of the techniques used for cutting biological tissue involves use of high frequency electrical energy to first dry or desiccate tissue by heating the tissue with a high frequency electric current and then cut the dried/desiccated tissue by generating an arc discharge between the tissue and an end-effector of the medical device. The cut tissue is then coagulated or sealed by providing additional high frequency electrical energy to stop bleeding following the cut. When a high frequency electric power is applied impedance of the tissue increases as the tissue is dried/desiccated. The increased impedance causes a rise in the potential across the tissue and when the potential across the tissue reaches a breakdown voltage, a discharge is produced, which cuts the tissue. When the arc discharge is being produced, the high frequency voltage across the tissue is low, but the current is high and flows through a narrow path depending on the contact area between the end-effector and the tissue. Moreover, when the arc discharge occurs, DC voltage is generated across the tissue by rectifying action. The high current density caused by the high current through a small area generates heat that cuts the tissue open. End-effectors with different shapes and sizes have been used in medical devices for cutting biological tissue depending on the type and location of tissue on which the procedure is performed. The difference in shapes and sizes of end-effectors causes undesirable variance in the performance of the medical device. Improved control mechanisms for controlling the power supplied to the end-effectors during an electrosurgical cutting procedure are therefore, desired. SUMMARY To address the above-noted issues in high frequency cutting of biological tissues, improved techniques are needed to reduce the variance in performance of the medical devices for different types of end-effectors. In one aspect, the variance in performance can be reduced by adjusting the parameters associated with the application of high frequency electrical energy to the biological tissue based on the area of contact between the end-effector and the tissue being cut. In another aspect, the contact area between the end-effector and the tissue could be estimated during the process of drying or desiccating the tissue and such a contact area determined in-process can be used as a basis for adjustment of the parameters associated with the application of high frequency electrical energy to the biological tissue. For example, when a high frequency energy is applied to the tissue, the tissue dries or desiccates and the impedance of the tissue increases. This increase in impedance leads to an increase in the potential across the tissue. The rate of increase in the impedance, and thus, the rate of increase in the potential across the tissue, is dependent on the contact area between the end-effector and the tissue. Thus, by measuring the time needed for the potential across the tissue to reach a certain threshold, the contact area between the tissue and the end-effector can be estimated. Parameters for controlling the high frequency electrical energy applied to the tissue can thus be estimated based on the time taken for the potential across the tissue to reach a predetermined threshold. Advantageously, controlling the electrical energy applied to the tissue during a tissue cutting procedure based on a contact area between the end-effector and the tissue can reduce the variance in performance depending on the end-effectors. Accordingly, a method for treating a biological tissue using high frequency electrical energy disclosed herein uses a first parameter estimated during desiccating the tissue to modulate the energy supplied to the tissue during the cutting of the tissue. In one aspect of the present disclosure, a method for treating a biological tissue using high frequency electrical energy includes (a) modulating a