Rotary encoder for intravascular ultrasound catheter

• Main Authors: GREENSTEIN; MICHAEL, MELTON, JR.; HEWLETT E, VERDONK; EDWARD, SEYED-BOLORFOROSH; MIR S
• Format: Patent
• Language: English
• Published: 23.01.1996
• Edition: 6
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; DIAGNOSIS; HUMAN NECESSITIES; HYGIENE; IDENTIFICATION; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; MEDICAL OR VETERINARY SCIENCE; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; SURGERY; TESTING

An ultrasound system and method for intravascular ultrasonic imaging includes an array of beacons that are fixed to direct ultrasonic energy toward an imaging transducer, with individual beacons being identifiable in order to determine the angular position of the imaging transducer. Based upon the data related to beacon identification, operation of the imaging device is adaptively adjusted in order to compensate for variations in angular velocity of the transducer. Adaptive compensation may be performed by adjusting the pulse repetition rate of transmitted ultrasonic energy, by adjusting the scan conversion algorithm or mapping reflected ultrasonic energy, or by varying control of the drive structure for rotating the transducer. The beacons are preferably piezoelectrically active, but passive beacons may also be used. Position identification may be performed by techniques including amplitude sensing, phase sensing, pulse length sensing, and frequency sensing. As an alternative to rotation of the transducer, ultrasonic signals may be formed at a proximal end of a probe and then conducting the energy to the distal end via a waveguide.