Temperature controlled short duration ablation

• US 10,441,354 B2
• Filed: 06/10/2016
• Issued: 10/15/2019
• 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:
  US15/179,167
• Publication Number:
  US 20170209210A1
• Time in Patent Office: 1,222 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 2018/00577 Ablation
• 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 2018/00791 Temperature
• CPC Class Codes: A61B 2018/00875 Resistance or impedance
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure

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:

defining a preset impedance value I;

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

measuring an impedance I_T-1 to the RF power during the ablation procedure at time (T−

1);

measuring an impedance I_T to the RF power during the ablation procedure at time (T); and

when a difference between impedance I_T and I_T-1 exceeds the preset impedance value I, halting supply of the RF power to the tissue.

2. The method of claim 1, wherein the preset impedance value I is 7 ohms.

3. The method of claim 1, further comprising measuring temperature of the tissue when the difference between impedance I_T-1 and I_T is not greater than the preset impedance value I.

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

5. The method of claim 4, wherein the reducing supply of the RF power includes reducing supply of the RF power by a range between about 5% 95%.

6. The method of claim 1, further comprising reducing supply of the RF power to the tissue when a measured temperature of the tissue reaches or exceeds a preset maximum temperature value.

7. Apparatus, comprising:

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

a processor configured to;

measure an impedance I_T-1 to the RF power during the procedure at time (T−

1);

measure an impedance I_T to the RF power during the procedure at time (T); and

when difference between impedance I_T-1 and I_T exceeds a preset impedance value, halt supply of the RF power to the tissue.

8. The apparatus of claim 7, wherein the preset impedance value is 7 ohms.

9. The apparatus of claim 7, wherein the processor is configured to measure temperature of the tissue when the difference between impedance I_T-1 and I_T is not greater than the preset impedance value.

10. The method of claim 9, wherein the processor is configured to measure temperature of the tissue at a frequency of at least 30 Hz.

11. The apparatus of claim 7, wherein the processor is configured to reduce supply of the RF power to the tissue when a measured temperature of the tissue reaches or exceeds a preset maximum temperature value.

12. The apparatus of claim 11, wherein the processor is configured to reduce supply of the RF by a range between about 5% 95%.

13. A method, comprising:

defining a preset impedance value I;

performing an ablation procedure on biological tissue using radiofrequency (RF) power at a power up to about 100 W with a duration of no greater than 10 seconds;

measuring an impedance I_T-1 to the RF power during the ablation procedure at time (T−

1);

measuring an impedance I_T to the RF power during the ablation procedure at time (T); and

when a difference between impedance I_T and I_T-1 exceeds the preset impedance value I, halting supply of the RF power to the tissue.

14. The method of claim 13, wherein the impedances I_T-1 and I_T are measured at a rate of about every 500 ms.

15. Apparatus, comprising:

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

a processor configured to;

perform the ablation procedure on the biological tissue using the radiofrequency (RF) power at a power up to about 100 W with a duration of no greater than 10 seconds;

measure an impedance I_T-1 to the RF power during the procedure at time (T−

1);

measure an impedance I_T to the RF power during the procedure at time (T); and

when difference between impedance I_T-1 and I_T exceeds a preset impedance value, halt supply of the RF power to the tissue.

16. The apparatus of claim 15, wherein the processor is configured to measure the impedances I_T-1 and I_T at a rate of about every 500 ms.