JP2017523000A - Vibration crown drive apparatus, system and method for rotational atherectomy - Google Patents

Abstract

The present invention is directed to various methods, devices and systems associated with rotational atherectomy. More specifically, the vibration driver is connected to a drive shaft or a torque transmission tube, and a grinding element is mounted thereon. The result provides a rotating working diameter that is greater than its static diameter of the rotating grinding element. In general, suitable grinding elements are such that the center of mass in the profile is concentric and / or collinear with the axis of rotation of the drive shaft. However, an eccentric grinding element may be used in that it offsets the center of mass and / or geometric eccentricity.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of US filed on March 13, 2014 that claims the benefit of US Provisional Patent Application No. 61 / 782,184, filed March 14, 2013 No. 14 / 208,585, the entire application of which is hereby incorporated by reference.

TECHNICAL FIELD OF THE INVENTION The present disclosure relates generally to devices and systems related to rotational atherectomy. More specifically, the vibration drive unit is connected to a drive shaft on which a grinding head is mounted. The result provides a rotational working diameter of the rotating grinding element that is larger than its static diameter.

2. Description of Related Art Various techniques and devices have been developed for use in removing or repairing tissue in arteries and similar body passages. A frequent purpose of such techniques and devices is the removal of atherosclerotic plaques in patient arteries. Atherosclerosis is characterized by the accumulation of fat deposits (atheromas) in the patient's intima layer (under the endothelium). Initially, a relatively soft and deposited cholesterol-rich atherosclerotic substance hardens into a calcified atherosclerotic plaque over a very long time. Such atheroma restricts blood flow and is therefore often referred to as a stenotic lesion or stenosis, and a blocking substance is referred to as a stenotic substance. If left untreated, such stenosis can cause angina, hypertension, myocardial infarction, stroke, and the like.

  Rotational atherectomy has become a common technique for removing such stenotic material. Such procedures are most often used to initiate the opening of calcified lesions in the coronary arteries. In most cases, the rotational atherectomy procedure is not used alone, but then followed by balloon angioplasty, which very often helps to maintain the open artery patency rate. followed by. For non-calcified lesions, balloon angioplasty is most often used alone to open the arteries, and stents are often positioned to maintain open artery patency. Studies have shown that a significant proportion of patients who have undergone balloon angioplasty and have a stent placed in an artery have developed over a period of time as a result of stent restenosis, most often excessive growth of scar tissue within the stent. Experience undergoing stent occlusion. In such situations, atherectomy is the preferred method to remove excess scar tissue from the stent (balloon angioplasty, which is not very effective within the stent), thereby restoring arterial patency. is there.

  Several types of rotational atherectomy devices have been developed to attempt to remove stenotic material. In one type of device, such as that shown in US Pat. No. 4,990,134 (Auth), a bar coated with abrasive material such as diamond particles is carried to the distal end of a flexible drive shaft. . The bar is rotated at high speed while advancing across the stenosis (eg, typically in the range of about 150,000-190,000 rpm). However, as the bar removes the stenotic tissue, blood flow is blocked. Once the bar is advanced across the stenosis, the artery will be opened to a diameter equal to or slightly larger than the maximum outer diameter of the bar. Frequently, one or more sized bars must be utilized to open the artery to the desired diameter.

  U.S. Pat. No. 5,314,438 (Shturman) discloses another atherectomy device with a drive shaft, the drive shaft portion having an enlarged diameter, at least a portion of the enlarged surface being at least a portion of the drive shaft. Covered with abrasive material that defines the grinding segment. When rotated at high speed, the grinding segment can remove stenotic tissue from the artery. Although this atherectomy device has certain advantages over Auth's device in its flexibility, it also eliminates arteries to a diameter approximately equal to the diameter of the enlarged grinding surface of the drive shaft because the device is essentially not eccentric. It can only be opened.

  U.S. Pat. No. 6,494,890 (Shturman) discloses a known atherectomy device having a drive shaft with an enlarged eccentric portion, at least a segment of this enlarged portion being covered with abrasive material. . When rotating at high speed, the grinding segment can remove stenotic tissue from the artery. The device is capable of opening the artery to a diameter that is larger than the static diameter of the enlarged eccentric portion due in part to the orbital rotational motion during high speed operation. Because the enlarged eccentric portion includes a drive shaft wire that is not coupled together, the enlarged eccentric portion of the drive shaft can bend during placement within a stenosis or during high speed operation. This flexing not only allows for a larger diameter opening during high speed operation, but may provide less control than desired on the diameter of the artery that is actually ground. Also, the Shturman device cannot be placed therethrough, as some stenotic tissue can completely block the passageway. Shturman requires the drive shaft to be located in the stenotic tissue in order to achieve grinding, so the enlarged eccentric part is less effective when movement into the stenosis is prevented Not sure. The disclosure of US Pat. No. 6,494,890 is hereby incorporated by reference in its entirety.

  US Pat. No. 5,681,336 (Clement) provides a known eccentric structure that removes the bar with a coating of abrasive particles secured to a portion of its outer surface with a suitable bonding material. However, this configuration, as Element explains in column 3, lines 53-55, that the asymmetric bar is rotated "slower than used with high speed cautery to compensate for heat or imbalance". Is limited. That is, considering both the size and mass of the solid bar, it is not feasible to rotate the bar used during atherectomy at high speed, i.e., 20,000-200,000 rpm. In essence, the center of mass offset from the rotational axis of the drive shaft will result in significant centrifugal force development, applying excessive pressure to the arterial wall, producing excessive heat and excessively large particles.

  Thus, there is a general need in the art for a rotating atherectomy device, system, and method that allows for increasing the working diameter of a grinding head.

SUMMARY OF THE INVENTION An embodiment of a rotary atherectomy device includes a non-vibrating drive shaft, a vibrator, a vibration drive shaft, a grinding head, and a pulsator. The non-vibrating drive shaft includes a lumen therethrough and a rotation shaft. The vibrating portion includes a radially offset drive shaft attachment fixedly attached to the non-vibrating drive shaft proximate its distal end. The drive shaft attachment includes a central lumen in fluid communication with the lumen of the non-vibrating drive shaft and synchronized with the rotational axis of the non-vibrating drive shaft. The drive shaft attachment further includes an attachment point that is radially offset from the central lumen. The vibration drive shaft is attached to the attachment point at its proximal end, and the grinding head is fixedly attached to the vibration drive shaft proximate its distal end. The pulsator is configured to introduce a pulsation to remove at least a portion of the atherogenic material from the vasculature.

  Another embodiment of a rotary atherectomy device includes a prime mover, a drive shaft, a grinding head, and a pulsator. The drive shaft is rotatably coupled to the prime mover at its proximal end and extends distally therefrom. The grinding head is fixedly attached to the drive shaft proximate its distal end. The pulsator is configured to introduce a pulsation to remove at least a portion of the atherogenic material from the vasculature.

It is a perspective view of one embodiment of the present invention. Figure 2 shows a partial cut and side view of one embodiment of the present invention. Figure 2 shows a partial cut and side view of one embodiment of the present invention. Figure 2 shows a partial cut and side view of one embodiment of the present invention. 1 shows an end view of one embodiment of the present invention. FIG. 1 shows an end view of one embodiment of the present invention. FIG.

DETAILED DESCRIPTION The disclosed embodiments are susceptible to various modifications and alternative forms, the details of which are shown by way of example in the drawings and are described in detail herein. It should be understood that the intent is not to limit the disclosure to the specific embodiments described with reference to the accompanying drawings. On the contrary, the intention is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

  Various embodiments of the present invention may be incorporated into a rotational atherectomy system generally described in US Pat. No. 6,494,890 entitled “ECCENTRIC ROTATIONAL ATHERECTOMY DEVICE”, which is incorporated herein by reference. it can. Additionally, the disclosures of the following jointly owned patents or patent applications are hereby incorporated by reference in their entirety. US Patent No. 6,295,712 entitled "ROTATIONAL ATHERECTOMY DEVICE", US Patent No. 6,132,444 entitled "ECCENTRIC DRIVE SHAFT FOR ATHERECTOMY DEVICE AND METHOD FOR MANUFACTURE", "ECCENTRIC DRIVE SHAFT FOR US Pat. No. 6,638,288 entitled “ATHERECTOMY DEVICE AND METHOD FOR MANUFACTURE”, US Pat. No. 5,314,438 entitled “ABRASIVE DRIVE SHAFT DEVICE FOR ROTATIONAL ATHERECTOMY”, “ROTATIONAL ATHERECTOMY DEVICE” US Pat. No. 6,217,595 entitled, US Pat. No. 5,554,163 entitled “ATHERECTOMY DEVICE”, US Pat. No. 7,507 entitled “ROTATIONAL ANGIOPLASTY DEVICE WITH ABRASIVE CROWN” 245, US Patent No. 6,129,734 entitled “ROTATIONAL ATHERECTOMY DEVICE WITH RADIALLY EXPANDABLE PRIME MOVER COUPLING”, entitled “ECCENTRIC ABRADING HEAD FOR HIGH-SPEED ROTATIONAL ATHERECTOMY DEVICES” US Patent No. 8,597,313, US Patent No. 8,439,937 entitled "SYSTEM, APPARATUS AND METHOD FOR OPENING AN OCCLUDED LESION", "ECCENTRIC ABRADING ELEMENT FOR HIGH-SPEED ROTATIONAL ATHERECTOMY DEVICES" US Patent Application Publication No. 2009/0299392, “MULTI-MATERIAL ABRADING HEAD FOR ATHERECTOMY DEVICES HAVING LATERALLY DISPLACED CENTER OF MASS”, US Patent Application Publication No. 2010/0198239, “ROTATIONAL ATHERECTOMY DEVICE WITH PRE- US Patent Application Publication No. 2010/0036402 entitled “CURVED DRIVE SHAFT”, US Patent Application Publication No. 2009/0299391 entitled “ECCENTRIC ABRADING AND CUTTING HEAD FOR HIGH-SPEED ROTATIONAL ATHERECTOMY DEVICES”, “ECCENTRIC ABRADING AND US Patent Application Publication No. 2010/0100110 entitled “CUTTING HEAD FOR HIGH-SPEED ROTATIONAL ATHERECTOMY DEVICES”, “ROTA US Design Patent No. D610258 entitled “TIONAL ATHERECTOMY ABRASIVE CROWN”, US Design Patent No. D6107102 entitled “ROTATIONAL ATHERECTOMY ABRASIVE CROWN”, US Patent Application Published as “BIDIRECTIONAL EXPANDABLE HEAD FOR ROTATIONAL ATHERECTOMY DEVICE” No. 2009/0306869, US Patent Application Publication No. 2010/0211088 entitled “ROTATIONAL ATHERECTOMY SEGMENTED ABRADING HEAD AND METHOD TO IMPROVE ABRADING EFFICIENCY”, US Patent Application Publication No. 2010 entitled “ROTATIONAL ATHERECTOMY DEVICE WITH ELECTRIC MOTOR” 2013/0018398, and US Pat. No. 7,666,202 entitled “ORBITAL ATHERECTOMY DEVICE GUIDE WIRE DESIGN.”. It is contemplated that one or more features of the present invention can be combined with one or more features of the atherectomy device embodiments described therein.

  FIG. 1 shows an embodiment of a rotary atherectomy device according to the present invention. The apparatus includes a handle portion 10, which has an elongated flexible non-vibrating, thus fixed axis drive shaft 20, and further a drive shaft 20 having a lumen therethrough for passage of a guide wire. A drive shaft attachment 102 having a vibration portion 100 proximate to and attached to the distal end, and a radially offset drive shaft attachment 102, and a grinding head attached to or otherwise disposed on a flexible vibration drive shaft 110 106. The vibration unit 100 and its components and functions will be described in more detail below. The elongate catheter 13 is also illustrated as extending distally from the handle portion 10. The non-oscillating fixed shaft drive shaft 20 is constructed from a helical coiled wire and has an outer surface 24 and an inner surface 22 defining a lumen, as known in the art, so that the non-oscillating drive shaft 20 is a guide. Allows advancement and rotation on the wire. The catheter 13 has a lumen in which most of the length of the drive shaft 20 is disposed, except for the vibration unit 100. A fluid supply line 17 may be provided to introduce a cooling and lubricating solution (typically saline or another biocompatible fluid) into the catheter 13.

  The handle 10 desirably includes a turbine (or similar rotational drive mechanism) for rotating the drive shaft 20 at high speed. The handle 10 may be illustratively connected to a power source such as compressed air carried through the tube 16. A pair of fiber optic cables 25, alternatively a single fiber optic cable, can be used and may be provided to monitor the rotational speed of the turbine and drive shaft 20 (handles and associated instrumentation). Details are known in the industry). The handle 10 also preferably includes a control knob 11 for advancing and retracting the turbine and drive shaft 20 to attach the vibrator 100 to the catheter 13 and the body of the handle.

  Referring now to FIG. 2, the vibrating portion 100 is mounted proximate to the distal end of the non-vibrating drive shaft 20 and includes a radially offset drive shaft attachment 102 and a flexible vibration drive. And a grinding head 106 attached to the shaft 110 or otherwise arranged.

  The radially offset drive shaft attachment 102 comprises a circular structure having a central lumen 103 that is in fluid communication with the lumen and center of the non-vibrating drive shaft 20 as shown. In this configuration, since the center of mass of the circular drive shaft attachment 102 is also synchronized with the rotation axis A of the non-vibration drive shaft 20, the drive shaft attachment is offset in the radial direction when the non-vibration drive shaft 20 rotates. 102 rotates concentrically with the drive shaft 20. FIG. 2 shows that the guidewire may pass through the central lumen 103 as well as the lumen of the non-vibrating drive shaft 20. Those skilled in the art will recognize that the circular shape of the drive shaft attachment 102 in the illustrated embodiment is one of several functionally possible forms. What is required is that the center of mass of the drive shaft attachment 102 is located at the center of the central lumen 103.

  The flexible vibration drive shaft 110 is attached to the drive shaft attachment 102 that is radially offset at an attachment point 104 that is radially offset from the central lumen 103. This radial offset distance, along with the drive shaft 20, and therefore the rotational speed of the vibrator 100 and the mass of the grinding head 106 and its location, determines the working diameter of the grinding head 106 in operation. The increase in the working diameter of the grinding head 106 is directly related to the greater distance between the attachment point 104 and the central lumen 103, and increasing the rotational speed of the drive shaft 20 and the vibrator 100 increases the mass. The increased mass of the grinding head 106 is offset in the radial direction. As described further below, the position of the center of mass C and the attachment point 104, which are radially offset relative to each other in the longitudinal section, is also achieved by the grinding head 106 during bending of the vibration drive shaft 110 and thereby during rotational movement. Has a direct effect on the size of the working diameter.

  The grinding head 106 is concentric, as shown in FIGS. 2 and 3, ie longitudinally and laterally or radially with respect to a vibration drive shaft 110 mounted in a manner as understood in the art. It is a symmetric configuration. As a result, the center of mass C of the grinding head 106 is synchronized with the rotational axis A ′ of the vibration drive shaft 110 in FIGS. 2 and 3.

  Alternatively, as shown in FIG. 4, the grinding head 106 may include a center of mass C that is offset from the rotational axis A ′ of the vibration drive shaft 110. A person skilled in the art can create pure geometric eccentricity having at least radial or lateral geometric asymmetry as shown in FIG. 4 or grinding that is geometrically concentric or geometrically eccentric. By using different density materials in any of the heads 106, it is understood that the radially offset mass center C is moved radially away from the rotational axis A ′ of the vibration drive shaft 110. Will do.

  In both cases, as shown, the working diameter achieved by the grinding head 106 is greater than its static diameter. Using the technique shown in FIG. 4, the damping effect is such that there is an offset of 0 degree between the attachment point 104 and the center of mass C offset in the radial direction in the longitudinal section as shown in FIG. 5. The center of mass C offset in the radial direction of the grinding head 106 can be added to the vibration unit 100 by aligning it with the attachment point 104 of the drive shaft attachment 102 offset in the radial direction.

  Alternatively, as shown in FIG. 6, the bending of the vibration drive shaft 110 causes the center of mass C offset in the radial direction of the grinding head 106 to be compared with the attachment point 104, and the rotation axis A of the vibration drive shaft 110. It may be improved by shifting 180 degrees so that it is located on the opposite side of '.

  In all cases, the working diameter achieved during high speed rotation is greater than the working diameter of the grinding head 106, even if the grinding head 106 is concentric or eccentric.

  In some embodiments, the high speed rotation of the grinding head 106 must be sustained over a long period of time to achieve the desired result. However, sustained high-speed rotation of parts introduced into the bloodstream can cause hemolysis. Also, the high speed rotation of the part can generate heat in the item including the rotating part and the body portion in contact with the rotating part. If the generated heat is not relaxed or restricted, thermal damage can follow. In certain embodiments, saline is used as a heat transfer fluid to minimize heat generation and / or as a lubricant. Additionally, in certain applications, grinding should be used to remove excess calcium deposits in blood vessels, intima, adventitia, etc. and without damaging or removing healthy tissue I can't.

  Alternatively or additionally, to operate the grinding head 106 at a high rotational speed, certain embodiments of the rotary atherectomy device may remove at least a portion of the atherogenic material near the grinding head 106, or Includes a pulsator to destroy. The pulsator, in certain embodiments, is configured to introduce pulsation or vibration to the treatment site at multiple intensities, or multiple frequencies, or both. In some embodiments, the pulsation can be applied discretely or continuously as a variable force between the maximum and minimum values. In certain embodiments, pulsations can be applied as individual bursts or as a continuous force for a specified period of time. In some embodiments, the strength of the applied pulsation, i.e., the applied force, can be fixed or varied. In addition or alternatively, the frequency at which the force is applied can be fixed or varied.

  In some embodiments, in addition to rotating the grinding head 106, the pulsator introduces a pulsation to the treatment site. Thus, by introducing high impact and low duration non-sustained pulsation, i.e. vibration during treatment, the pulsator provides an equivalent trajectory as a device without operating at a sustained high rotational speed. However, the atherectomy device can be adjusted to provide the appropriate cutting surface shear rate. In certain embodiments, introducing further pulsations while rotating the grinding head 106 maintains or provides an effective treatment substantially similar to that provided at sustained high rotational speeds without pulsations. However, the overall rotation speed and the average rotation speed can be reduced. And by reducing the rotational speed, hemolysis and thermal effects are reduced or eliminated.

  The pulsation can be introduced into one or more of the non-vibrating drive shaft 20, the vibration drive shaft 110, and the grinding head 106 in some embodiments while rotating or stationary. In certain embodiments, a prime mover that is rotatably coupled to at least the non-vibrating drive shaft 20 has pulsation (or vibration) introduced into one or both of the vibrating drive shaft 110 and the non-vibrating drive shaft 20. Can work as follows. In a non-limiting exemplary embodiment, the coupling used to removably engage the prime mover and the non-vibrating drive shaft 20 with each other is configured to introduce pulsation within the non-vibrating drive shaft 20. Can then at least partially introduce pulsation into the vibration drive shaft 110. For example, in embodiments where one or more gears are used to rotatably couple the prime mover to the non-vibrating drive shaft 20, the coupling is at least one of the one or more gears having an irregular circumference. One can be included. In some embodiments, pulsations can be introduced by operating the prime mover at individual or variable rotational speeds. For example, the rotation of the electric motor shaft can be interrupted using a pulse width modulated motor controller. In certain embodiments, the rotation of the electric motor shaft can be interrupted by adjusting the peak and / or running current supplied to the motor. In certain embodiments where the turbine is used as a prime mover, the pulsator can be configured to discretely or continuously adjust one or both of the pressure or flow rate of the compressed fluid supplied to the turbine. The described embodiments are illustrative and should not be construed as limiting. As will be apparent to those skilled in the art, additional or alternative embodiments are considered to be within the scope and scope of the present disclosure.

  Additionally or alternatively, the pulsator can be configured to introduce pulsation to one or both of the non-vibrating drive shaft 20 and the vibration drive shaft 110. The pulsator can also be configured to introduce pulsation to the grinding head 106 while it is rotated or fixed at the treatment site. In a non-limiting exemplary embodiment, pulsations such as secondary induced impulses can be introduced into one or more of drive shafts 20, 110 and grinding head 106. For example, the pulsator can be configured as an ultrasonic device, a piezoelectric vibrator, or an electromechanical lithoplasty. These examples should not be construed as limiting. As will be apparent to those skilled in the art, additional or alternative embodiments are considered to be within the scope and scope of the present disclosure.

  Referring again to FIG. 1, an alternative embodiment of a rotary atherectomy device does not include the vibrator 100 and the grinding head 106 is instead proximate its distal end to an elongate flexible drive shaft. Connected. In such an embodiment, the apparatus includes a handle substantially similar to the handle portion 10 and the prime mover is disposed within the handle and is rotatably coupled to the drive shaft proximate its proximal end. The non-limiting exemplary embodiment of the device further includes a pulsator configured to introduce pulsation in a manner substantially similar to and substantially the same as that performed above. Therefore, for the sake of brevity, the details related to the introduction of pulsators and pulsations will not be repeated. However, this should not be interpreted in a limited way. Instead, all alternatives, enhancements, and modifications apparent to those skilled in the art are deemed to be within the scope and scope of the present disclosure.

  The present invention should not be considered limited to the particular embodiments described above, but rather should be understood to cover all aspects of the invention. Various modifications, equivalent processes, and numerous structures that can be applied to the present invention will be readily apparent to those skilled in the art to which the present invention is directed upon reference to the specification.

Claims (42)

A rotational atherectomy device,
A non-vibrating drive shaft having a lumen therethrough, a rotational axis, and a distal end;
A vibration part attached close to the distal end of the non-vibration drive shaft, the vibration part,
A drive shaft attachment that is fixedly attached to the non-vibration drive shaft and offset in the radial direction is provided, and the drive shaft attachment includes:
A central lumen in fluid communication with the lumen of the non-vibrating drive shaft and synchronized with the rotational axis of the non-vibrating drive shaft;
An attachment point radially offset from the central lumen, and the vibration part further comprises
A vibration drive shaft attached to the attachment point at its proximal end;
A grinding head fixedly attached to the vibration drive shaft proximate its distal end, the apparatus further comprising:
A rotating atherectomy device comprising a pulsator for introducing a pulsation to remove at least a portion of atheromatous material from the vasculature.   The apparatus of claim 1, wherein the pulsation comprises one or both of a plurality of intensities and a plurality of frequencies.   The apparatus of claim 2, comprising a prime mover rotatably coupled to the non-vibrating drive shaft proximate its proximal end, wherein the pulsator operates the prime mover at a plurality of discrete rotational speeds. The prime mover comprises an electric motor;
The apparatus of claim 3, wherein the pulsator comprises a pulse width modulator for adjusting one or both of a peak current supplied to the prime mover and a running current through the prime mover.   The apparatus of claim 3, wherein the prime mover comprises a turbine and the pulsator regulates one or both of pressure and flow rate of a compressed fluid for operating the prime mover.   The apparatus of claim 2, comprising a prime mover, wherein the pulsator comprises two or more gears configured to rotatably couple the prime mover and the non-vibrating drive shaft proximate a proximal end thereof. .   The apparatus according to claim 6, wherein a rotational speed of the prime mover is different from a rotational speed of the non-vibrating drive shaft.   The apparatus of claim 6, wherein at least one of the two or more gears comprises an irregular circumference.   The apparatus of claim 2, wherein the pulsator comprises an inductor.   The apparatus of claim 9, wherein the inductor is selected from the group consisting of an ultrasonic generator and a piezoelectric vibrator.   The apparatus of claim 2, wherein the pulsator generates one or more of energy waves, sound waves, and pressure waves.   The apparatus of claim 2, wherein at least a portion of the pulsator is disposed on one or more of the non-vibration drive shaft, the vibration drive shaft, and at least a portion of the grinding head.   The apparatus of claim 1, comprising a guide wire extending through the lumen of the non-vibrating drive shaft, wherein displacement of the non-vibrating drive shaft on the guide wire induces displacement of the vibrating portion. .   The apparatus of claim 1, wherein the radially offset drive shaft attachment is circular.   The apparatus of claim 1, wherein the working diameter of the grinding head is greater than its static diameter.   The apparatus of claim 1, wherein the grinding head is concentric.   The apparatus of claim 16, wherein a center of mass of the grinding head is synchronized with a rotation axis of the vibration drive shaft.   The apparatus of claim 16, wherein a center of mass of the grinding head is offset radially from a rotation axis of the vibration drive shaft.   The apparatus of claim 1, wherein the grinding head is eccentric.   The apparatus of claim 19, wherein a center of mass of the grinding head is offset radially from a rotational axis of the vibration drive shaft.   The apparatus of claim 1, wherein the grinding head comprises different densities of material.   The apparatus of claim 1, wherein at least a portion of the pulsator is disposed over at least a portion of the grinding head. A device,
Prime mover,
A drive shaft having a proximal end rotatably coupled to the prime mover and extending distally therefrom;
A grinding head fixedly attached to the drive shaft proximate its distal end;
A pulsator for introducing a pulsation for removing at least a portion of the atherogenic substance from the vasculature.   24. The apparatus of claim 23, wherein the pulsation comprises one or both of a plurality of intensities and a plurality of frequencies.   25. The apparatus of claim 24, wherein the pulsator operates the prime mover at a plurality of discrete rotational speeds. The prime mover comprises an electric motor;
26. The apparatus of claim 25, wherein the pulsator comprises a pulse width modulator for adjusting one or both of a peak current supplied to the prime mover and a running current through the prime mover.   26. The apparatus of claim 25, wherein the prime mover comprises a turbine and the pulsator regulates one or both of the pressure and flow rate of the compressed fluid used to operate the prime mover.   25. The apparatus of claim 24, wherein the pulsator comprises two or more gears configured to rotatably couple the prime mover and the drive shaft.   29. The apparatus according to claim 28, wherein a rotational speed of the prime mover is different from a rotational speed of the drive shaft.   30. The apparatus of claim 28, wherein at least one of the two or more gears comprises an irregular circumference.   The apparatus of claim 24, wherein the pulsator comprises an inductor.   32. The apparatus of claim 31, wherein the inductor is selected from the group consisting of an ultrasonic generator and a piezoelectric vibrator.   25. The apparatus of claim 24, wherein the pulsator generates one or more of energy waves, sound waves, and pressure waves.   25. The apparatus of claim 24, wherein at least a portion of the pulsator is disposed on one or both of the drive shaft and at least a portion of the grinding head.   24. The apparatus of claim 23, comprising a guide wire extending through a lumen of the drive shaft, wherein displacement of the drive shaft on the guide wire induces displacement of the grinding head.   24. The apparatus of claim 23, wherein the working diameter of the grinding head is greater than its static diameter.   24. The apparatus of claim 23, wherein the grinding head is concentric.   38. The apparatus of claim 37, wherein a center of mass of the grinding head is synchronized with a rotational axis of the drive shaft.   38. The apparatus of claim 37, wherein a center of mass of the grinding head is offset radially from a rotational axis of the drive shaft.   24. The apparatus of claim 23, wherein the grinding head is eccentric.   41. The apparatus of claim 40, wherein a center of mass of the grinding head is offset radially from a rotational axis of the drive shaft.   24. The apparatus of claim 23, wherein the grinding head comprises different densities of material.

Images