Method and system for reversibly controlled drilling of luminal occlusions

1. A medical device for crossing a stenosis, comprising:

an elongate member having a proximal end, a distal end and a lumen extending therethrough;

a drive shaft extending through the lumen of the elongate member;

a cutting tip attached to a distal end of the drive shaft;

a motor housing including a motor coupled to the drive shaft for rotationally driving the drive shaft and the cutting tip in a first rotational direction relative to the elongate member; and

a control unit powering the motor, the control unit including motor control circuitry configured to signal the motor to automatically reverse a direction of rotation of the drive shaft and the cutting tip to a second rotational direction opposite the first rotational direction upon sensing a load on the motor exceeding a threshold load level, wherein the motor is signaled to reverse direction before the cutting tip reaches a stall condition in which the cutting tip would have a zero rotational speed;

the control unit including circuitry which produces a visual output in response to the sensed load on the motor.

2. The medical device of claim 1 , wherein the visual output includes a first output level when the motor experiences a minimal load, a second output level when the motor experiences a load below a threshold load level, and a third output level when the motor experiences a load at or above a threshold load level and the direction of rotation is reversed.

3. The medical device of claim 1 , wherein the control unit measures a voltage from the motor.

4. The medical device of claim 3 , wherein the visual output is determined based on the measured voltage.

5. The medical device of claim 3 , wherein the voltage is measured across a feedback resistor of the motor.

6. The medical device of claim 1 , wherein the control unit includes a voltage to frequency generator to generate the visual output.

7. The medical device of claim 1 , wherein the sensed load is measured by a change in current drawn by the motor.

8. The medical device of claim 1 , wherein the control unit includes an LED display for providing the visual output.

9. The medical device of claim 1 , wherein the sensed load is compared to a reference voltage.

10. The medical device of claim 9 , wherein the visual output is generated by a visual feedback generator based on a difference between the sensed load and the reference voltage.

11. A medical device for crossing a stenosis, comprising:

an elongate member having a proximal end, a distal end and a lumen extending therethrough;

a drive shaft extending through the lumen of the elongate member;

a cutting tip attached to a distal end of the drive shaft;

a motor housing including a motor coupled to the drive shaft for rotationally driving the drive shaft and the cutting tip in a first rotational direction relative to the elongate member; and

a control unit powering the motor, the control unit including motor control circuitry configured to signal the motor to automatically reverse a direction of rotation of the drive shaft and the cutting tip to a second rotational direction opposite the first rotational direction upon sensing a load on the motor exceeding a threshold load level,

wherein the motor is signaled to reverse direction before the sensed load causes the cutting tip to reach a stall condition in which the cutting tip would have a zero rotational speed;

the control unit including circuitry which produces an audible output in response to the sensed load on the motor.

12. The medical device of claim 11 , wherein the audible output includes a first output level when the motor experiences a minimal load, a second output level when the motor experiences a load below a threshold load level, and a third output level when the motor experiences a load at or above a threshold load level and the direction of rotation is reversed.

13. The medical device of claim 11 , wherein the control unit measures a voltage from the motor.

14. The medical device of claim 13 , wherein the audible output is determined based on the measured voltage.

15. The medical device of claim 13 , wherein the voltage is measured across a feedback resistor of the motor.

16. The medical device of claim 11 , wherein the control unit includes a voltage to frequency generator to generate the audible output.

17. The medical device of claim 16 , wherein the voltage to frequency generator produces a variable sound in response to the sensed load.

18. The medical device of claim 11 , wherein the sensed load is measured by a change in current drawn by the motor.

19. The medical device of claim 11 , wherein the sensed load is compared to a reference voltage.

20. The medical device of claim 19 , wherein a frequency of the audible output is based on a difference between the sensed load and the reference voltage.

21. A medical device for crossing a stenosis, comprising:

an elongate member having a proximal end, a distal end and a lumen extending therethrough;

a drive shaft extending through the lumen of the elongate member;

a cutting tip attached to a distal end of the drive shaft;

a motor housing including a motor coupled to the drive shaft for rotationally driving the drive shaft and the cutting tip in a first rotational direction relative to the elongate member; and

a control unit powering the motor, the control unit including motor control circuitry configured to automatically reverse a direction of rotation of the drive shaft and the cutting tip to a second rotational direction opposite the first rotational direction upon sensing a load on the motor exceeding a threshold load level and before the sensed load causes the motor to stall.