Abstract: A catheter for diagnosing or treating the vessels found within a body or body space includes a center strut that is bonded, preferably thermally, along its longitudinal axis with the thermoplastic tubular member within which it is housed. The tubular member preferably has three layers: an inner layer, a braided layer and an outer layer. The composite catheter is made using a process in which two half-cylinder shaped mandrels are placed on each side of the center strut while the strut is heated in order to cause the thermal bonding. The bonded center strut provides in-plane deflection and improved transfer of torque to the tip of the catheter.

Abstract: A force-sensing catheter for diagnosing or treating the vessels found within a body or body space includes a center strut that is bonded, preferably thermally, along its longitudinal axis with the thermoplastic tubular member within which it is housed. The tubular member preferably has three layers: an inner layer, a braided layer and an outer layer. One or more semiconductor or metallic foil strain gages are affixed to the center strut in order to provide a measure of the bending and torsional forces on the distal tip of the catheter. Temperature compensation is achieved by having a temperature sensor near the strain gages and calibrating the catheter over a range of temperatures.