Abstract: Disclosed herein is a catheter apparatus which supports high resolution imaging of the interior of a biological conduit. The apparatus includes an imaging atherectomy catheter of the type having a cutter housing attached to the distal end of a catheter. A tissue cutting member and an ultrasonic imaging transducer are disposed within the housing and are secured to the distal end of a rotatable torque cable. An elongated aperture formed along one side of the housing allows ultrasonic imaging and the intrusion of stenotic material which is removed by axially rotating and translating the cutting member. A miniature rotary encoder is slidably coupled to the end of the torque cable within the housing for precisely determining the rotational orientation of the ultrasonic imaging transducer with respect to the elongated aperture. The rotary encoder is read optically via a fiber optical cable which extends through the catheter.

Abstract: An acoustical lens for focusing ultrasonic energy having a transducer, a curved focussing lens and a voltage generator coupled with the transducer. The transducer is comprised of an array of piezoelectric crystal elements. The focussing lens has a concave upper surface and a planar bottom surface allowing the array of piezoelectric elements to be coupled to the bottom surface of the array. The piezoelectric elements receive voltage from the voltage generator and transmit an energy ray through the focussing lens producing a focussed energy beam.

Abstract: An acoustical lens for focusing ultrasonic energy having a transducer, a curved focussing lens and a voltage generator coupled with the transducer. The transducer is comprised of an array of piezoelectric crystal elements. The focussing lens has a concave upper surface and a planar bottom surface allowing the array of piezoelectric elements to be coupled to the bottomsurface of the array. The piezoelectric elements receive voltage from the voltage generator and transmit an energy ray through the focussing lens producing a focussed energy beam.