Devices, systems and methods for an oscillating crown drive for rotational atherectomy
The present invention is directed in various methods, devices and systems relating to rotational atherectomy. More specifically, an oscillating driver is connected to a drive shaft, or torque transfer tube, with abrasive element mounted thereon. The result provides a rotational working diameter for the rotating abrasive element that is larger than its resting diameter. Generally, the preferred abrasive element is concentric in profile and/or with center of mass collinear with the drive shaft's rotational axis. However, eccentric abrasive elements, both in terms of offsetting center of mass and/or geometric eccentricity may also be employed.
1. A rotational atherectomy device, comprising:
a prime mover;
a non-oscillating drive shaft having a lumen therethrough, a rotational axis and a distal end;
an oscillating section attached proximate the distal end of the non-oscillating drive shaft, the oscillating section comprising:
a radially offsetting drive shaft attachment fixedly attached to the non-oscillating drive shaft, the drive shaft attachment comprising:
a centered lumen in fluid communication with the lumen of the non-oscillating drive shaft and coincident with the rotational axis of the non-oscillating drive shaft; and
an attachment point radially offset from the centered lumen;
an oscillating drive shaft comprising a proximal end attached to the attachment point; and
an abrading head fixedly attached to the oscillating drive shaft proximate a distal end thereof, the prime mover adapted to rotate the non-oscillating drive shaft, the oscillating section and the abrading head; and
a pulsator configured to introduce pulsations during the rotation of the abrading head for dislodging at least a portion of an atheromatous material from a vasculature.
2. The device of claim 1 , wherein the pulsations comprise one or both of a plurality of intensities and a plurality of frequencies.
3. The device of claim 2 , wherein the prime mover is rotatably coupled to the non-oscillating drive shaft proximate a proximal end thereof, wherein the pulsator operates the prime mover at a plurality of discrete rotational speeds.
4. The device of claim 3 , wherein:
the prime mover comprises an electric motor; and
the pulsator comprises a pulse width modulator for modulating one or both of a peak current supplied to the prime mover and a running current through the prime mover.
5. The device of claim 3 , wherein the prime mover comprises a turbine, and the pulsator modulates one or both of a pressure and a flow rate of a compressed fluid used for operating the prime mover.
6. The device of claim 2 , wherein the pulsator comprises two or more gears configured for rotatably coupling the prime mover and the non-oscillating drive shaft.
7. The device of claim 6 , wherein a rotational speed of the prime mover is different from a rotational speed of the non-oscillating drive shaft.
8. The device of claim 6 , wherein at least one of the two or more gears comprises an irregular circumference.
9. The device of claim 2 , wherein the pulsator comprises an inductor.
10. The device of claim 9 , wherein the inductor is selected from the group consisting of an ultra-sonic generator and a piezo-vibrator.
11. The device of claim 2 , wherein the pulsator generates one or more of energy waves, sound waves, and pressure waves.
12. The device of claim 2 , wherein at least a portion of the pulsator is disposed on one or more of the non-oscillating drive shaft, the oscillating drive shaft, and at least a portion of the abrading head.
13. The device of claim 1 , comprising a guide wire extending through the lumen of the non-oscillating drive shaft, wherein a displacement of the non-oscillating drive shaft over the guide wire induces a displacement of the oscillating section.
14. The device of claim 1 , wherein the radially offsetting drive shaft attachment is circular.
15. The device of claim 1 , wherein an operating diameter of the abrading head is greater than a resting diameter thereof.
16. The device of claim 1 , wherein the abrading head is concentric to a rotational axis of the oscillating drive shaft.
17. The device of claim 16 , wherein a center of mass of the abrading head coincides with a rotational axis of the oscillating drive shaft.
18. The device of claim 1 , wherein the abrading head comprises materials of differing densities.
19. The device of claim 1 , wherein at least a portion of the pulsator is disposed on at least a portion of the abrading head.