Atherectomy system with excess torque protection
AssigneeBoston Scientific Scimed, Inc.
InventorsCORYDON CARLSON, GARY THOMAS OHRT, WADE ROBERT STRELOW
Life of this patent
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Abstract
An atherectomy system includes a drive mechanism adapted to rotatably actuate an atherectomy burr and a controller that is adapted to regulate operation of the drive mechanism. The controller is adapted to calculate an estimated load torque at the atherectomy burr based upon at least one of an angular velocity of the atherectomy system and an angular acceleration of the atherectomy system. The controller is further adapted to stop or reverse the drive mechanism when the estimated load torque at the atherectomy burr exceeds a torque threshold.
Claims18
An atherectomy system, comprising:
- a drive mechanism adapted to rotatably actuate an atherectomy burr;
- a controller adapted to regulate operation of the drive mechanism;
- the controller adapted to calculate an estimated motor torque Tmotor in accordance with:
- Tmotor=KT*i, where KT is a torque constant for a drive motor and i is a drive motor current;
- the controller adapted to calculate an estimated drag torque Tdrag in accordance with:
- Tdrag=Cp*θ, where Cp is a coefficient of friction value and θ is an angular velocity value;
- wherein the controller is adapted to stop or reverse the drive mechanism when an estimated load torque Tload exceeds a torque threshold, where:
- Tload=Tmotor−Tdrag−I*α, where I is a system inertia value and α is an angular acceleration value.
An atherectomy system, comprising:
- a drive mechanism including a drive motor adapted to rotatably actuate an atherectomy burr;
- a controller adapted to regulate operation of the drive mechanism, the controller comprising:
- a motor state estimation block adapted to:
- receive a motor position signal indicating rotational position of the drive motor;
- receive current and voltage signals from the drive motor;
- and
- output state feedback signals including motor speed;
- a main controller adapted to:
- receive the state feedback signals from the motor state estimation block;
- generate control signals to regulate operation of the drive motor based on the state feedback signals;
- a motor controller adapted to:
- receive the control signals from the main controller;
- control velocity of the drive motor based on the control signals;
- and
- provide current feedback to the motor state estimation block;
- wherein the controller is adapted to stop or reverse the drive mechanism when an estimated load at the atherectomy burr exceeds a threshold value;
- wherein the controller includes memory storing coefficient values in a lookup table, the coefficient values corresponding to different rotational speed ranges of the drive motor.
Dependencies are inferred from the claim text.