Operation method of electric power source device, electric power source device, and high-frequency treatment system

1. A method of operating a power source device for a high-frequency treatment instrument adapted to perform high-frequency treatment for biological tissue, the method comprising:

causing, by a control circuit, a high-frequency power source circuit to output power;

acquiring, by the control circuit, a value for impedance of the biological tissue during the output, including acquiring an initial impedance value during an initial predetermined time period starting when the biological tissue is first contacted by the instrument with the control circuit activated,

causing, by the control circuit, the high-frequency power source to linearly increase the power from the end of the initial time period until the impedance reaches a change-over impedance value, the change-over impedance value being equal to or greater by a predetermined value than a minimum value of the value for impedance,

setting, by the control circuit, a target impedance value, wherein the target impedance value gradually increases from the change-over impedance value to a stop impedance value within a predetermined period, the stop impedance value representing termination of the output;

repeating, by the control circuit, a first processing and a second processing on a regular basis for a period after the value for impedance reaching the change-over impedance value until the value for impedance reaching the stop impedance value, wherein the value for impedance is adopted as a measured impedance value, and wherein, in the first processing, the measured impedance value is compared to the target impedance value, and in the second processing, the high-frequency power source circuit is caused to change the power being output to decrease from current power in line with a first rule if the measured impedance value is greater than the target impedance value, and the high-frequency power source circuit is caused to change the power being output to increase from current power in line with a second rule if the measured impedance value is smaller than the target impedance value; and

causing, by the control circuit, the high-frequency power source circuit to terminate the output upon the value for impedance reaching the stop impedance value.

2. The method according to claim 1 , wherein

decreasing the power in line with the first rule is decreasing the power from current power by a fixed first ratio, and

increasing the power in line with the second rule is increasing the power from current power by a fixed second ratio.

3. The method according to claim 2 , wherein the first ratio is equal to the second ratio.

4. The method according to claim 2 , wherein the first ratio is unequal to the second ratio.

5. The method according to claim 4 , wherein the first ratio is greater than the second ratio.

6. The method according to claim 1 , wherein the target impedance value varies a speed of increase according to the initial impedance value.

7. The method according to claim 1 , wherein the target impedance value varies a speed of increase according to a set output value.

8. The method according to claim 1 , wherein the target impedance value increases linearly with time.

9. The method according to claim 1 , wherein

decreasing the power in line with the first rule is decreasing the power from current power by a fixed first value, and

increasing the power in line with the second rule is increasing the power from current power by a fixed second value.

10. The method according to claim 9 , wherein the first value is equal to the second value.

11. The method according to claim 9 , wherein the first value is unequal to the second value.

12. The method according to claim 11 , wherein the first value is greater than the second value.

13. A power source device for a high-frequency treatment instrument adapted to perform high-frequency treatment for biological tissue, the power source device comprising:

a high-frequency power source circuit which outputs power;

an output detection circuit which detects the output; and

a control circuit which acquires information about the output from the output detection circuit and controls the high-frequency power source circuit,

wherein the control circuit is configured to

cause the high-frequency power source circuit to output the power,

acquire a value for impedance of the biological tissue during the output, including acquiring an initial impedance value during an initial predetermined time period starting when the biological tissue is first contacted by the instrument with the control circuit activated,

cause the high-frequency power source to linearly increase the power from the end of the initial time period until the impedance reaches a change-over impedance value, the change-over impedance value being equal to or greater by a predetermined value than a minimum value of the value for impedance,

set a target impedance value, wherein the target impedance value gradually increases from the change-over impedance value to a stop impedance value within a predetermined period, the stop impedance value representing termination of the output,

repeat a first processing and a second processing on a regular basis for a period after the value for impedance reaching the change-over impedance value until the value for impedance reaching the stop impedance value, wherein the value for impedance is adopted as a measured impedance value, and wherein, in the first processing, the measured impedance value is compared to the target impedance value, and in the second processing, the high-frequency power source circuit is caused to change the power being output to decrease from current power in line with a first rule if the measured impedance value is greater than the target impedance value, and the high-frequency power source circuit is caused to change the power being output to increase from current power in line with a second rule if the measured impedance value is smaller than the target impedance value, and

cause the high-frequency power source circuit to terminate the output upon the value for impedance reaching the stop impedance value.

14. The power source device according to claim 13 , wherein

decreasing the power in line with the first rule is decreasing the power from current power by a fixed first ratio, and

increasing the power in line with the second rule is increasing the power from current power by a fixed second ratio.

15. The power source device according to claim 14 , wherein the first ratio is equal to the second ratio.

16. The power source device according to claim 14 , wherein the first ratio is unequal to the second ratio.

17. The power source device according to claim 16 , wherein the first ratio is greater than the second ratio.

18. The power source device according to claim 13 , wherein

decreasing the power in line with the first rule is decreasing the power from current power by a fixed first value, and

increasing the power in line with the second rule is increasing the power from current power by a fixed second value.

19. The power source device according to claim 18 , wherein the first value is equal to the second value.

20. The power source device according to claim 18 , wherein the first value is greater than the second value.

21. A method of operating a power source device for a high-frequency treatment instrument adapted to perform high-frequency treatment for biological tissue, the method comprising:

causing, by a control circuit, a high-frequency power source circuit to output predetermined power;

acquiring, by the control circuit, a value for impedance of the biological tissue during performance of the high-frequency treatment, including acquiring an initial value for the impedance during an initial predetermined time period starting when the biological tissue is first contacted by the instrument with the power source circuit outputting the output predetermined power,

setting, by the control circuit, an output pattern of power in which the power linearly increases with time,

causing, by the control circuit, the high-frequency power source to linearly increase the power from the end of the initial time period until the impedance reaches a change-over impedance value based on the set output pattern of the power, the change-over impedance value being equal to or greater by a predetermined value than a minimum value of the value for impedance,

setting, by the control circuit, a target impedance value, wherein the target impedance value gradually increases from the change-over impedance value to a stop impedance value within a predetermined period, the stop impedance value representing termination of the output;

repeating, by the control circuit, a first processing and a second processing on a regular basis for a period after the value for impedance reaching the change-over impedance value until the value for impedance reaching the stop impedance value, wherein the value for impedance is adopted as a measured impedance value, and wherein, in the first processing, the measured impedance value is compared to the target impedance value, and in the second processing, the high-frequency power source circuit is caused to change the power being output to decrease from current power in line with a first rule if the measured impedance value is greater than the target impedance value, and the high-frequency power source circuit is caused to change the power being output to increase from current power in line with a second rule if the measured impedance value is smaller than the target impedance value; and

causing, by the control circuit, the high-frequency power source circuit to terminate the output upon the value for impedance reaching the stop impedance value.