ROTATIONAL ATHERECTOMY DEVICE WITH BIASING CLUTCH

摘要

A rotational atherectomy system may include a drive shaft, a motor, and a clutch with a threshold torque where the clutch may include a motor plate rotationally connected to the motor, a drive shaft plate rotationally connected to the drive shaft, and a biasing clutch configured to rotationally engage the motor plate and the drive shaft plate, wherein torques less than the threshold torque are transmitted completely between the motor plate and the drive shaft plate, which remain rotationally coupled by static friction, and wherein torques greater than the threshold torque cause the motor plate and the drive shaft plate to rotate relative to one another and cause a residual torque to be transmitted between the motor and the drive shaft, the residual torque being less than the threshold torque and being determined by a kinetic coefficient of friction.

主权项

1. A rotational atherectomy system, comprising:
an elongated, rotatable, flexible drive shaft having a distal end for insertion into a vasculature of a patient and having a proximal end opposite the distal end remaining outside the vasculature of the patient; a motor for rotating the drive shaft; and a clutch having a characteristic threshold torque, comprising:
a motor plate rotationally connected to the motor;a drive shaft plate rotationally connected to the drive shaft, the motor plate and the drive shaft plate being parallel and coaxial, being disposed directly longitudinally adjacent to each other, and being held proximate one another longitudinally with a space therebetween; anda biasing clutch configured to rotationally engage the motor plate and the drive shaft plate, wherein torques between the motor and the drive shaft less than the threshold torque:
are transmitted completely between the motor plate and the drive shaft plate, which remain rotationally coupled by static friction; and wherein torques between the motor and the drive shaft greater than the threshold torque:
cause the motor plate and the drive shaft plate to rotate relative to one another; andcause a residual torque to be transmitted between the motor and the drive shaft, the residual torque being less than the threshold torque and being determined by a kinetic coefficient of friction.