Electrosurgical apparatus with stable coagulation

• US 6,436,096 B1
• Filed: 11/24/1999
• Issued: 08/20/2002
• Est. Priority Date: 11/27/1998
• Status: Expired due to Term

• Current Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Original Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Inventors: Hareyama, Norihiko
• Primary Examiner(s): Dvorak, Linda C. M.
• Assistant Examiner(s): Ruddy, David M.
• Application Number:
  US09/449,129
• Time in Patent Office: 1,000 Days
• Field of Search: 600/32, 600/34, 600/38, 600/40, 600/41, 600/42, 600/46, 600/48, 600/50, 607/98, 607/101, 607/122
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00875 Resistance or impedance

Abstract

An electrosurgical apparatus supplies high-frequency power from a high-frequency power supply unit to an instrument placed in association with an organic tissue to dissect or coagulate the organic tissue. An impedance calculating section calculates the impedance value of the organic tissue. A rate-of-impedance-change calculating section calculates the rate of impedance change of the organic tissue based on the impedance value calculated by the impedance calculating section. A control section controls the high-frequency output of the high-frequency power supply unit based on a predetermined condition provided by combining the impedance value calculated by the impedance calculating section with the rate of impedance change calculated by the rate-of-impedance-change calculating section.

Claims

1. The electrosurgical apparatus for supplying high-frequency power from a high-frequency power supply unit to an instrument placed in association with an organic tissue to dissect or coagulate said organic tissue comprising:

an impedance calculating section for calculating an impedance value of said organic tissue before the instrument starts to coagulate or dissect said organic tissue; and

a load characteristic alternating means which selects a load characteristic of an output in accordance with an initial impedance value of the organic tissue calculated by said impedance calculating section,

wherein said load characteristic altering section selects a first load characteristic in which a load characteristic of an output has a peak at a predetermined impedance in a case where the initial impedance value of the organic tissue calculated by the impedance calculating section is above a designated threshold value, and selects a second load characteristic in which a load characteristic of an output has a peak at an impedance higher than that of the first load characteristic in a case where the initial impedance value of the organic tissue is under the predetermined threshold value.

2. An electrosurgical apparatus for supplying high-frequency power from a high-frequency power supply unit to an instrument placed in association with an organic tissue to dissect or coagulate said organic tissue, comprising:

an impedance calculating section for calculating an initial impedance value of said organic tissue before the instrument is started to coagulate or dissect said organic tissue; and

a load characteristic altering section for changing at least one of a current limiter value and a voltage limiter value in accordance with said initial impedance value of said organic tissue calculated by the impedance calculating section.

3. An electrosurgical apparatus for supplying high-frequency power from a high-frequency power supply unit to an instrument placed in association with an organic tissue to coagulate or dissect said organic tissue, comprising:

a detection section for detecting a coagulation state of said organic tissue in a coagulation operation;

a delay-time setting section for randomly selecting and setting prior to a coagulation operation of the organic tissue, a delay time until a high-frequency output is stopped after the detection section has detected the coagulation state; and

a section for calculating a threshold value for controlling said high-frequency output by detecting a high-frequency current and a high-frequency voltage from said high-frequency power supply unit and said high-frequency output is controlled when a variable delay elapses after the threshold value has been reached.

4. The electrosurgical apparatus according to claim 3, further comprising an informing section for informing a user at a time of controlling said high-frequency output of such control by at least one of an acoustic method and a visual method.