Design of Ablation Electrode with Tactile Sensor

Abstract

A catheter assembly for assessing contact between the catheter assembly and tissue is disclosed. The assembly includes a catheter shaft and a pressure sensitive conductive composite member whose electrical resistance varies with pressure applied to the catheter assembly. The assembly also includes at least one measurement terminal to permit the measurement of changes in the electrical characteristics of the pressure sensitive conductive composite member. The assembly may optionally include a measurement device to measure resistance, impedance and/or other electrical characteristics. The assembly may utilize a reference electrode secured to the patient's tissue, which permits the measurement device to measure changes between the reference electrode and the at least one measurement terminal. Optionally, the assembly may include a conductive outer layer. Also disclosed are sensor assemblies, contact sensor, methods of contact sensing, and methods of manufacturing relating to the use of pressure sensitive conductive composites.

1 - 27 . (canceled) 
     
     
         28 . A catheter, comprising:
 a catheter shaft comprising a distal portion and a proximal portion, wherein the catheter shaft comprises at least one tactile sensor that extends longitudinally along at least a portion of the catheter shaft, and   at least one electrode,   wherein the at least one tactile sensor comprises an inner non-conductive shaft surrounded by a flexible conductive coil, wherein the flexible conductive coil is operably connected to an electrical conductor.   
     
     
         29 . The catheter of  claim 28 , wherein the electrical conductor comprises a plurality of conductive wires. 
     
     
         30 . The catheter of  claim 28 , wherein the at least one tactile sensor comprises a pressure sensitive conductive composite sensor, a capacitance sensor, or a piezoelectric sensor. 
     
     
         31 . The catheter of  claim 28 , wherein the at least one electrode comprises a second tactile sensor. 
     
     
         32 . The catheter of  claim 31 , wherein the second tactile sensor is a capacitance sensor. 
     
     
         33 . The catheter of  claim 28 , wherein the at least one tactile sensor is contained entirely within a portion of the catheter shaft and proximal of the distal portion, and wherein the electrode is an ablation electrode. 
     
     
         34 . The catheter of  claim 33 , wherein the at least one tactile sensor is located between the distal portion of the catheter shaft and the ablation electrode. 
     
     
         35 . An electrode assembly, comprising:
 a thin elongate catheter shaft having a distal tip and a proximal portion;   at least one tactile sensor contained entirely within a portion of the catheter shaft and proximal of the distal tip; and   an ablation electrode disposed at the distal end of the electrode assembly;   wherein the at least one tactile sensor is located between the distal tip of the catheter shaft and the ablation electrode, such that the at least one tactile sensor detects forces that are applied to the ablation electrode, and wherein the at least one tactile sensor comprises a plurality of tactile sensors positioned substantially in a common plane such that they detect force applied both axially to the electrode assembly and force applied laterally to the electrode assembly.   
     
     
         36 . The electrode assembly of  claim 35  further comprising:
 an analysis device coupled to the at least one tactile sensor to receive respective output signals therefrom, wherein the analysis device provides information regarding an angle defined between the ablation electrode and the longitudinal axis of the catheter shaft. 
 
     
     
         37 . The electrode assembly of  claim 36  wherein:
 the at least one tactile sensor generates an output signal with a magnitude that is proportional to the force applied thereto; and 
 the analysis device provides information regarding a magnitude and direction of the forces that are applied to the electrode. 
 
     
     
         38 . An electrode assembly, comprising:
 a thin elongate catheter shaft having a distal end and a proximal end, wherein the thin elongate catheter shaft comprises at least one tactile sensor, wherein the at least one tactile sensor comprises a flexible conductive coil; and   at least one ablation electrode disposed at the distal end of the thin elongate catheter shaft;   wherein the at least one tactile sensor is located between the distal end of the catheter shaft and the at least one ablation electrode, such that the at least one tactile sensor detects forces that are applied to the at least one ablation electrode, and wherein the flexible conductive coil is connected to at least one electrical conductor.   
     
     
         39 . The electrode assembly of  claim 38 , wherein the at least one electrical conductor comprises a plurality of conductive wires. 
     
     
         40 . The electrode assembly of  claim 38 , wherein the at least one tactile sensor comprises a pressure sensitive conductive composite sensor, a capacitance sensor, or a piezoelectric sensor. 
     
     
         41 . The electrode assembly of  claim 38 , wherein the at least one ablation electrode comprises a second tactile sensor. 
     
     
         42 . The electrode assembly of  claim 41 , wherein the second tactile sensor is a capacitance sensor.