DIAGNOSTIC CATHETER SHAFT CONSTRUCTION AND MANUFACTURING METHOD

1 . A shaft for a diagnostic catheter comprising:

a) a tubular core formed from a polyimide material;

b) a braided layer surrounding the tubular core and formed from stainless steel strands;

c) an inner layer surrounding the braided layer and formed from a polyimide material; and

d) an outer layer surrounding the inner layer and formed from a polyether block amide material.

2 . A shaft as recited in claim 1 , wherein the shaft has an outer diameter that is less than about 4F in size.

3 . A shaft as recited in claim 1 , wherein the shaft has an outer diameter that is about 3.3F in size.

4 . A shaft as recited in claim 1 , wherein the tubular core defines an interior lumen.

5 . A shaft as recited in claim 1 , wherein a handle assembly is operatively associated with a proximal end of the shaft.

6 . A shaft as recited in claim 1 , wherein an electrode assembly is operatively associated with a distal end portion of the shaft.

7 . A shaft for a diagnostic catheter comprising:

a) a tubular core formed from a polyimide material;

b) a braided layer surrounding the tubular core and formed from metal strands;

c) an inner layer surrounding the braided layer and formed from a polyimide material; and

d) an outer layer surrounding the inner layer and formed from a thermoplastic elastomer.

8 . A shaft as recited in claim 7 , wherein the braided layer is formed from stainless steel strands

9 . A shaft as recited in claim 7 , wherein the outer layer is formed from a polyether block amide material.

10 . A shaft as recited in claim 7 , wherein the shaft has an outer diameter that is less than about 4F in size.

11 . A shaft as recited in claim 7 , wherein the shaft has an outer diameter that is about 3.3F in size.

12 . A shaft as recited in claim 7 , wherein the tubular core defines an interior lumen.

13 . A shaft as recited in claim 7 , wherein a handle assembly is operatively associated with a proximal end portion of the shaft.

14 . A shaft as recited in claim 7 , wherein an electrode assembly is operatively associated with a distal end portion of the shaft.

15 . A diagnostic catheter comprising:

a) shaft having a tubular core formed from a polyimide material, a braided layer surrounding the tubular core and formed from stainless steel strands, a radially inner layer surrounding the braided layer and formed from a polyimide material, and a radially outer layer surrounding the radially inner layer and formed from a polyether block amide material.

b) a handle assembly operatively associated with a proximal end portion of the shaft for controlling the catheter; and

c) an electrode assembly joined to a distal end portion of the shaft for conducting a mapping procedure.

16 . A diagnostic catheter as recited in claim 15 , wherein the shaft has an outer diameter that is less than about 4F in size.

17 . A diagnostic catheter as recited in claim 15 , wherein the tubular core defines an interior lumen.

18 . A diagnostic catheter as recited in claim 15 , wherein the electrode assembly includes a tubular shaft portion joined to the shaft of the catheter and a distal loop portion having a plurality of spaced apart electrodes.

19 . A diagnostic catheter as recited in claim 18 , wherein the tubular shaft portion of the electrode assembly is formed from a thermoplastic elastomer.

20 . A method of manufacturing a diagnostic catheter shaft comprising:

a) extruding a polyimide tubular core;

b) braiding a stainless steel layer over the polyimide tubular core;

c) extruding a layer of polyimide material over the stainless steel braided layer; and

d) molding a polyether block amide layer over the polyimide layer.