Force sensitive mechanism for contact detection in catheter systems

A catheter adapted to measure a contact force, the catheter comprising:

• an elongate shaft having a proximal end and a distal end;
• a distal end portion extending distally from the distal end of the shaft, the distal end portion defining a longitudinal axis extending therethrough and comprising:
• a proximal segment;
• a distal segment located distally of the proximal segment;
• and
• a force sensing mechanism comprising:
• a proximal housing fixed within the proximal segment, the proximal housing having a lower surface and an upper surface;
• a plurality of piezoelectric sensors mounted to and circumferentially spaced from one another about the proximal housing, each piezoelectric sensor having a first portion fixedly secured to the proximal housing, and a second portion that is not fixedly secured to the proximal housing;
• and
• a distal housing fixed within the distal segment and including a plurality of projections, each of the projections contacting the second portion of a respective one the piezoelectric sensors and being is configured to apply an axial force to the second portion of the respective piezoelectric sensor upon application of an external force to the distal segment,
• wherein each of the plurality of piezoelectric sensors is configured to generate an output indicative of an amount of the axial force applied to the second portion thereof in response to the external force applied to the distal segment.

A force sensing mechanism for an ablation catheter, the force sensing mechanism adapted to measure a contact force and comprising:

• a proximal housing having a lower surface and an upper surface;
• a plurality of piezoelectric sensors mounted to and circumferentially spaced from one another about the proximal housing, each piezoelectric sensor having a first portion fixedly secured to the proximal housing, and a second portion that is not fixedly secured to the proximal housing;
• and
• a distal housing including a plurality of projections, each of the projections contacting the second portion of a respective one the piezoelectric sensors and being configured to apply an axial force to the second portion of the respective piezoelectric sensor upon application of an external force to the distal housing,
• wherein each of the plurality of piezoelectric sensors is configured to generate an output indicative of an amount of the axial force applied to the second portion thereof in response to the external force applied to the distal housing.