IRRIGATED ABLATION CATHETER WITH IMPROVED FLUID FLOW

• US 20110270246A1
• Filed: 04/29/2010
• Published: 11/03/2011
• Est. Priority Date: 04/28/2010
• Status: Active Grant

• Current Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Original Assignee: Biosense Webster Incorporated (Johnson & Johnson)
• Inventors: Brichard, Christopher J., Clark, Jeffrey L.
• Granted Patent: US 9,943,363 B2
• Time in Patent Office: Days
• US Class Current: 606/41
• 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 2017/003 Steerable
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00029 open
• CPC Class Codes: A61B 2018/1472 for use with liquid electrolyte, e.g. virtual electrodes
• CPC Class Codes: A61B 2218/002 Irrigation

Abstract

An irrigated ablation catheter includes a tip electrode with a thin shell and a plug to provide a plenum chamber. The tip electrode has an inlet of a predetermined size and noncircular shape, and outlets in the form of fluid ports formed in the thin shell wall. The plurality of the fluid ports is predetermined, as is their diameter. The tip electrode thus considers a diffusion ratio of total fluid output area to fluid input area, and a fluid port ratio. The tip electrode also considers a fluid inlet aspect ratio where the fluid inlet has a noncircular (for example, oval or elliptical) radial cross-section. The plenum chamber has a narrow proximal portion opening to a wider distal portion so that fluid pressure decreases while fluid velocity increases with the desired effect of increased turbulence which decreases momentum for a more uniform distribution of fluid in the tip electrode. Extending distally from the plug is a baffle member shaped to diffuse fluid entering the tip electrode and to house an electromagnetic position sensor.

Claims

1. An irrigated ablation catheter:

an elongated catheter body;

a deflectable section distal to the catheter body;

a tip electrode distal to the deflectable section;

an outer shell defining a cavity, the shell having a predetermined plurality of fluid ports, each contributing to a total fluid output area of the tip electrode;

an internal member including a fluid inlet into the tip electrode, the fluid inlet having a fluid input area;

wherein the tip electrode has a diffusion ratio less than 2.0.

2. A catheter of claim 1, wherein the diffusion ratio comprises a ratio of total fluid output area to fluid input area.

3. A catheter of claim 1, wherein the tip electrode has a fluid port ratio less than 3.25.

4. A catheter of claim 1, wherein the diffusion ratio is less than about 1.8.

5. A catheter of claim 1, wherein the tip electrodes has a fluid port ratio less than about 1.5.

6. A catheter of claim 1, wherein the cavity exhibits a plenum characteristic.

7. A catheter of claim 1, wherein the shell has a chamber with a variable inner cross section.

8. A catheter of claim 1, wherein the shell has a chamber with a distal portion and a proximal portion, the distal portion having a larger radial cross section and the proximal portion having a smaller radial cross section.

9. A catheter of claim 8, wherein the shell has a tapered section connecting the distal portion and the proximal portion.

10. A catheter of claim 1, wherein the fluid inlet has an inlet aspect ratio greater than 1.0.

11. A catheter of claim 1, wherein the internal member includes a baffle member and a plug member.

12. A catheter of claim 1, wherein the shell has a shell wall thickness between about 0.003 inch and 0.010 inch.

13. A catheter of claim 1, wherein each fluid port has a diameter ranging between about 0.004 inch and 0.003 inch.

14. A catheter of claim 1, wherein, the predetermined plurality of ports ranges between about 96 and 40.

15. An irrigated ablation catheter:

an elongated catheter body;

a deflectable section distal to the catheter body;

a tip electrode distal to the deflectable section, the tip electrode having a predetermined plurality of fluid ports, each contributing to a total fluid output area of the tip electrode, the tip electrode also having a fluid inlet with a fluid input area;

wherein the tip electrode has a diffusion ratio less than about 1.8.

16. An irrigated ablation catheter:

an elongated catheter body;

a deflectable section distal to the catheter body;

a tip electrode distal to the deflectable section;

an outer shell defining a cavity, the shell having a predetermined plurality of fluid ports, each contributing to a total fluid output area of the tip electrode;

an internal member including a fluid inlet into the tip electrode, the fluid inlet having a fluid input area;

wherein the tip electrode has a predetermined diffusion ratio, a predetermined fluid port ration and a predetermined inlet aspect ratio and a chamber with a variable inner cross section, and wherein the cavity has an inner cross-section that varies along a length of the tip electrode.

17. The catheter of claim 16, wherein the inner cross-section increases toward a distal end of the tip electrode.

18. The catheter of claim 16, wherein the predetermined diffusion ratio is less than about 1.8.

19. The catheter of claim 16, wherein the predetermined fluid port ratio less than about 1.5.

20. The catheter of claim 16, wherein the predetermined inlet aspect ration is greater than 1.0.

21. The catheter of claim 16, wherein the fluid inlet has a noncircular cross-section.