Irrigated ablation catheter with improved fluid flow
An irrigated ablation catheter includes a tip electrode with a thin shell and a plug, defining a plenum chamber. The tip electrode has an inlet of a predetermined size and noncircular shape, and a predetermined number of outlet fluid ports having a predetermined diameter shell wall. The tip electrode thus considers a diffusion ratio of total fluid output area to fluid input area, and a fluid port ratio, and considers a fluid inlet aspect ratio where the fluid inlet has a noncircular 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 thereby increasing 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.
1. An irrigated ablation catheter, comprising:
an elongated catheter body;
a deflectable section distal to the catheter body;
a tip electrode distal to the deflectable section and comprising:
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 and an inlet aspect ratio greater than 1.0;
wherein the tip electrode has a diffusion ratio of 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 of 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 electrode has a fluid port ratio of 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 cavity has a variable inner cross section.
8. A catheter of claim 1 , wherein the cavity has 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 outer shell has a tapered section connecting the distal portion and the proximal portion of the cavity.
10. A catheter of claim 1 , wherein the internal member includes a baffle member and a plug member.
11. A catheter of claim 1 , wherein the outer shell has a shell wall thickness of about 0.003 inch to about 0.010 inch.
12. A catheter of claim 1 , wherein each fluid port has a diameter of about 0.004 inch to about 0.003 inch.
13. A catheter of claim 1 , wherein the predetermined plurality of fluid ports is about 96 to about 40.
14. An irrigated ablation catheter, comprising:
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 and an inlet aspect ratio greater than 1.0;
wherein the tip electrode has a diffusion ratio less than about 1.8.
15. An irrigated ablation catheter, comprising:
an elongated catheter body;
a deflectable section distal to the catheter body;
a tip electrode distal to the deflectable section and comprising:
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 of less than about 2.0, a predetermined fluid port ratio and a predetermined inlet aspect ratio greater than 1.0, and
wherein the cavity has an inner cross-section that varies along a length of the tip electrode.
16. The catheter of claim 15 , wherein the inner cross-section of the cavity increases toward a distal end of the tip electrode.
17. The catheter of claim 15 , wherein the predetermined diffusion ratio is less than about 1.8.
18. The catheter of claim 15 , wherein the predetermined fluid port ratio is less than about 1.5.
19. The catheter of claim 15 , wherein the fluid inlet has a noncircular cross-section.