Transducer position locking system
An ultrasonic endoscopic probe tip device which provides signals to an imaging system for transesophageal diagnosis includes a removable housing adapted to be attached to the distal end of an endoscope. A rotatable, ball-bearing-mounted phased array transducer within the housing is rotatable around its acoustic propagation axis through multiple turns. The transducer is driven by an immersed micro-motorized drive. A torque limiting gearbox couples the drive to the transducer. A position encoder provides the imaging system with transducer position information over a 360° range. An automatic transducer position locking/unlocking system is used to lock the transducer in a selected rotational position.
1. A transducer position locking system for moving ultrasonic imaging devices including a transducer housed within a transducer housing, said position locking system comprising:
a voltage-activated actuating device having a distal end; and
a frictional pad attached to the distal end of the actuating device and adapted to exert pressure against one of (i) the transducer housing and (ii) a circular part associated with the transducer,
said actuating device normally locking said transducer in a normal, transducer locking position by the pressure exerted by said frictional pad, and said actuating device releasing said transducer from said transducer locking position in response to a voltage of a predetermined level being supplied to said actuating device.
2. A probe tip device according to claim 1 wherein said actuating device comprises an elongated, bendable, piezoelectric bimorph device, said frictional pad being attached to the distal end of said bimorph device.
3. A transducer position locking system according to claim 1 wherein said actuator device comprises an extensible actuator member and wherein said frictional pad is attached to the distal end of said actuator member.
4. A transducer position locking system according to claim 3 wherein said actuator device comprises a piezoelectric device.
5. A transducer position locking system according to claim 3 wherein said actuator comprises a multilayer piezoelectric device.
6. A transducer position locking system according to claim 1 wherein said actuator device includes a linear acting, electromagnetically controlled actuator and said frictional pad is attached to the distal end of said actuator.
7. A transducer position locking system according to claim 1 wherein said frictional pad comprises an elastomer material.
8. A transducer position locking system according to claim 7 wherein said elastomer material is selected from the group consisting of silicon rubber, polyurethane and elastomeric rubber.
9. A transducer position locking system according to claim 1 wherein said frictional pad has a contact surface comprising gear teeth.