Atherectomy system with excess torque protection
AssigneeBoston Scientific Scimed, Inc.
InventorsCORYDON CARLSON, GARY THOMAS OHRT, WADE ROBERT STRELOW
Life of this patent
Estimating the term…
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.
Claims20
An atherectomy system, comprising:
- an atherectomy burr;
- a drive mechanism adapted to rotatably actuate the atherectomy burr;
- a controller adapted to regulate operation of the drive mechanism;
- the controller 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;
- and
- the controller further adapted to stop or reverse the drive mechanism when the estimated load torque at the atherectomy burr exceeds a torque threshold.
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 load torque at the atherectomy burr Tload in accordance with equation (2):
- Tload=Tmotor−Tdrag−I*{umlaut over (θ)} (2),
- where
- Tmotor is an estimated motor torque for the drive motor;
- Tdrag is an estimated drag torque for the drive mechanism;
- I is a system inertia value;
- and
- {umlaut over (θ)} is an angular acceleration value;
- the controller further adapted to stop or reverse the drive mechanism when Tload exceeds a torque threshold.
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 stop or reverse the drive mechanism when an estimated torque value Tload exceeds a torque threshold;
- wherein when the atherectomy system is at steady state, the controller is adapted to calculate Tload in accordance with equation (5):
- Tload=−I*{umlaut over (θ)} (5),
- where
- I is an inertia of the atherectomy system;
- and
- {umlaut over (θ)} is the angular acceleration of the atherectomy system;
- and
- wherein when the atherectomy system is accelerating, the controller is adapted to calculate Tload in accordance with equation (1):
- Tload=KT*i−CD*{dot over (θ)}−I*{umlaut over (θ)} (1),
- where
- KT is a torque constant for the drive motor;
- i is a drive motor current;
- CD is a coefficient of friction value;
- and
- {dot over (θ)} is the angular velocity of the atherectomy system.
Dependencies are inferred from the claim text.