Temperature controlled short duration ablation

• US 10,507,058 B2
• Filed: 05/10/2019
• Issued: 12/17/2019
• Est. Priority Date: 01/25/2016
• Status: Active Grant

• Current Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Original Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Inventors: Govari, Assaf, Ephrath, Yaron, Altmann, Andres Claudio, Zilberman, Israel
• Primary Examiner(s): Cohen, Lee S
• Assistant Examiner(s): Demie, Tigist S
• Application Number:
  US16/409,461
• Publication Number:
  US 20190328453A1
• Time in Patent Office: 221 Days
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/00351 Heart
• CPC Class Codes: A61B 2018/00357 Endocardium
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2018/00642 with feedback, i.e. closed loop control
• CPC Class Codes: A61B 2018/00666 using a threshold value
• CPC Class Codes: A61B 2018/00678 upper
• CPC Class Codes: A61B 2018/00702 Power or energy
• CPC Class Codes: A61B 2018/00708 switching the power on or off
• CPC Class Codes: A61B 2018/00714 Temperature
• CPC Class Codes: A61B 2018/00791 Temperature

Abstract

A method, including selecting a first maximum radiofrequency (RF) power to be delivered by an electrode within a range of 70 W-100 W, and selecting a second maximum RF power to be delivered by the electrode within a range of 20 W-60 W. The method also includes selecting an allowable force on the electrode within a range of 5 g-50 g, selecting a maximum allowable temperature, of tissue to be ablated, within a range of 55° C.-65° C., and selecting an irrigation rate for providing irrigation fluid to the electrode within a range of 8-45 ml/min. The method further includes performing an ablation of tissue using the selected values by initially using the first power, switching to the second power after a predefined time between 3 s and 6 s, and terminating the ablation after a total time for the ablation between 10 s and 20 s.

Claims

1. A method, comprising:

performing an ablation procedure on biological tissue using radiofrequency (RF) power by delivering a first level of RF power to the tissue;

measuring at respective times a temperature of the tissue; and

when the temperature of the tissue exceeds a preset maximum allowable temperature within a range of 55°

C.-65°

C., reducing the RF power by delivering a second level of RF power to the tissue,

wherein the first level of RF power is in a range of 70 W-100 W, and the second level of RFt power is in a range of 20 W-60 W.

2. The method of claim 1, further comprising:

measuring at respective times an impedance to the RF power during the procedure at a frequency of at least 1 Hz; and

when a change in the impedance exceeds a preset value, halting supply of the RF power to the tissue.

3. A method, comprising:

performing an ablation procedure on biological tissue using radiofrequency (RF) power;

measuring at respective times a temperature of the tissue; and

when the temperature of the tissue exceeds a preset maximum allowable temperature within a range of 55°

C.-65°

C., reducing a level of the RF power supplied to the tissue according to the following equations;

Δ

P=min(Δ

P(T),Δ

P(p)),

where Δ

P(T)=(a(T_t-1−

T_t)/T)+(b(T_t-1−

T_t)/T), and

where Δ

P(p)=(P−

P_t)/P.

4. The method of claim 3, wherein the temperature of the tissue is measured at a frequency of at least 30 Hz.

5. The method of claim 3, further comprising:

measuring at respective times an impedance to the RF power during the procedure; and

when a change in the impedance exceeds a preset value, halting supply of the RF power to the tissue.

6. The method of claim 5, wherein the impedance is measured at a frequency of at least 1 Hz.

7. The method of claim 5, wherein the change in the impedance is at least 7Ω

.

8. The method of claim 3, wherein the delivery of the RF power further comprises:

a first time period during which a first level of RF power is operative for 1 s to 6 s and a second time period during which a second level of RF power is operative for up to 14 s.

9. The method of claim 3, wherein the delivery of the RF power is operative for an overall time period of 1 s to 20 s.

10. Apparatus, comprising:

a power control module configured to perform an ablation procedure on biological tissue using radiofrequency (RF) power; and

a processor configured to;

deliver to the tissue a first level of RF power supplied by the power control module;

measure at respective times a temperature of the tissue; and

when the temperature of the tissue exceeds a preset maximum allowable temperature within a range of 55°

C.-65°

C., reduce the RF power supplied to the tissue by the power control module by delivering a second level of RF power to the tissue,

wherein the first level of RF power is in a range of 70 W-100 W, and the second level of RF power is in a range of 20 W-60 W.

11. The apparatus of claim 10, wherein the processor is configured to measure at respective times an impedance to the RF power during the procedure at a frequency of at least 1 Hz;

and

when a change in the impedance exceeds a preset value, halt supply of the RF power to the tissue.

12. The apparatus of claim 10, wherein the processor is configured to reduce the RF power supplied to the tissue by the power control module according to the following equation:

Δ

P=min(Δ

P(T),Δ

P(p)),

where Δ

P(T)=(a(T_t-1−

T_t)/T)+(b(T_t-1−

T_t)/T), and

where Δ

P(p)=(P−

P_t)/P.

13. The apparatus of claim 12, wherein the processor is further configured to:

measure at respective times an impedance to the RF power during the procedure at a frequency of at least 1 Hz; and

when a change in the impedance exceeds a preset value, halt supply of the RF power to the tissue.

14. The apparatus of claim 10, wherein the temperature of the tissue is measured at a frequency of at least 30 Hz.