JP2021041197A - Rotational atherectomy device with a system of eccentric abrading heads - Google Patents

Abstract

To provide a rotational atherectomy device having a flexible, elongated, and rotatable drive shaft.SOLUTION: At least part of eccentric enlarged abrading heads 28, 29 have a tissue removing surface-typically an abrasive surface. In certain embodiments, the abrading heads may be at least partially hollow. Preferably the eccentric enlarged abrading heads have centers of mass spaced radially from the rotational axis of the drive shaft 20, facilitating ability of a system of the eccentric abrading heads to work together to open a stenotic lesion to a diameter substantially larger than the outer resting diameter of the enlarged abrading heads when operated at high speeds. Therefore, certain embodiments comprise a system having unbalanced centers of mass to not only stimulate greater rotational diameters but also be arranged in a manner whereby a debris-removing augering effect occurs. Alternatively, other embodiments may comprise systems having abrading heads with balanced centers of mass.SELECTED DRAWING: Figure 2

Description

Cross-reference to related applications This is a partial continuation application of 333ion serial number 13 / 621,398 filed on September 17, 2012, the contents of which are incorporated herein by reference.

Background of the Invention The present invention relates to a device and a method for removing tissue from a body passage (for example, removing atherosclerotic plaque from an artery) using a high-speed rotating atherosctomy device.

Description of Related Techniques Various techniques and instruments have been developed for use in the removal or repair of tissues in arteries and similar body passages. The general purpose of such techniques and instruments is to remove atherosclerotic plaques in the patient's arteries. Atherosclerosis is characterized by the accumulation of fatty deposits (atheroma) in the intima layer (under the endothelium) of the patient's blood vessels. Very often, what was initially deposited as a relatively soft, cholesterol-rich atherosclerotic substance hardens over time to become calcified atherosclerotic plaques. Such atheroma restricts blood flow and is often referred to as a stenotic lesion or stenosis, and the occlusive substance is called a stenotic substance. Such strictures, if left untreated, can cause angina, hypertension, myocardial infarction, and stroke.

Rotational atherectomy has become a common technique for the removal of such stenotic material. Such procedures are most often used to initiate the opening of calcified lesions in the coronary arteries. In many cases, rotary atherectomy treatment is not used alone, but is followed by balloon angioplasty treatment. Further then, stents are often placed to help maintain openness of the dilated arteries. In the case of non-calcified lesions, balloon angioplasty is often used alone to dilate the artery and often place a stent to maintain patency of the dilated artery. However, a very large proportion of patients who have undergone balloon angioplasty and placed a stent in an artery have stent restenosis (ie, stent occlusion that often occurs over the years due to overgrowth of scar tissue within the stent). Experience has been shown by studies. In such situations, atherectomy treatment is the preferred procedure for regaining arterial patency by removing excess scar tissue from the stent (balloon angioplasty is less effective within the stent).

Several types of rotary atherectomy devices have been developed to attempt to remove stenotic material. In one device, as shown in US Pat. No. 4,990,134 (Ath), a bar covered with an abrasive, such as diamond particles, is held at the distal end of the flexible drive shaft. To. The bar rotates at high speed (typically, for example, about 150,000 rpm to 190,000 rpm), advancing from end to end of the stenosis. However, the bar blocks blood flow when removing constricted tissue. When the bar advances from end to end of the stenosis, the artery extends to a diameter that is equal to or slightly larger than the maximum outer diameter of the bar. In many cases, bars of two or more sizes must be used to widen the artery to the desired diameter.

U.S. Pat. No. 5,314,438 (Shturman) discloses another atherectomy device with a drive shaft that includes a section with an expanded diameter. At least a portion of this expanded surface is covered with abrasive to form the grinding segment of the drive shaft. The ground segment is capable of removing stenotic tissue from the artery as it rotates at high speed. The disclosure of US Pat. No. 5,314,438 is incorporated herein by reference in its entirety.

U.S. Pat. No. 5,681,336 provides an eccentric tissue removal bar in which a portion of the outer surface is coated with ground particles with a suitable bonding agent. However, there are restrictions on this configuration. Because, as explained in column 3, lines 53-55 of Clement, the asymmetric bar rotates "slower than it is used in fast excision devices to compensate for heat or imbalance". Because. That is, considering both the size and mass of this solid bar, it is not possible to rotate the bar at the high speeds (ie, 20,000 rpm to 200,000 rpm) used during atherectomy treatment. In essence, in this prior art device, the center of mass is offset from the axis of rotation of the drive shaft, creating significant centrifugal force, resulting in excessive pressure on the arterial wall, excessive heat and Excessive particles are produced.

U.S. Pat. No. 5,584,843 (Wulfman) discloses one or more elliptical bars or elliptical cuffs attached to a flexible drive shaft. The drive shaft is located on a preformed molded guide wire. Therefore, the drive shaft and bar follow the shape and contour of the guide wire (ie, a loose "S" or "corkscrew" shape). However, Wolfman requires pre-formed guide wires to achieve the molding of non-linear drive shafts, the deformed molding conditions that are exhibited when the device is not rotating. Therefore, the locus diameter of the Wolfman bar is limited by the shape of the guide wire and by the shape of the guide wire. Further, each bar of Wolfman is elliptical and symmetrical with respect to the rotation axis of the drive shaft, and the center of mass of each bar is on the rotation axis of the drive shaft. Therefore, since the locus diameter of Wolfman does not depend on the rotation speed, it cannot be controlled by other than the shape of the guide wire. There is also the difficulty of placing a molded, non-deformable guidewire without damaging the patient's vascular system.

The present invention overcomes these drawbacks.

Description of the Invention The present invention provides a rotary atherectomy device to which a system of eccentric grinding heads is attached and which in various embodiments has a flexible elongated rotatable drive shaft. At least a portion of the eccentric extended grinding head in the system has a texture removal surface, which is typically the grinding surface. In certain embodiments, the grinding head may be at least partially hollow. Preferably, the center of mass of the eccentric expansion grinding head is radially separated from the axis of rotation of the drive shaft. This facilitates the cooperation of the eccentric grinding head system when operating at high speeds to spread the stenotic lesion to a diameter substantially larger than the outer static diameter of the extended grinding head. Thus, one embodiment is configured such that the disproportionate system of mass centers not only promotes a larger diameter of rotation, but also produces an auger effect of debris removal. Alternatively, other embodiments may include a system with a mass center balanced grinding head.

The drawings and detailed description below exemplify the above and other embodiments of the present invention more specifically.

Brief Description of Drawings The present invention can be more fully understood by considering the detailed description of various embodiments of the invention below in connection with the accompanying drawings below.

It is a perspective view of one Embodiment of this invention. It is a partial cut-out side view of one Embodiment of this invention. It is an end view of one Embodiment of this invention. It is an end view of one Embodiment of this invention. It is a schematic chart which shows the possible rotational direction angular separation of this invention. It is a side fracture view of one Embodiment of this invention. It is a perspective fracture view of one Embodiment of this invention. It is a side fracture view of one Embodiment of this invention. It is a side fracture view of one Embodiment of this invention. It is a perspective view of one Embodiment of this invention. It is a bottom view of one Embodiment of this invention. It is a side fracture view of one Embodiment of this invention. It is a breaking view of one Embodiment of this invention. It is a schematic diagram which shows one Embodiment of this invention. FIG. 5 is a cross-sectional view of an eccentric grinding element, an eccentric proximal counterweight, and an eccentric distal counterweight. FIG. 5 is a cross-sectional view of an eccentric grinding element, an eccentric proximal counterweight, and a concentric distal counterweight. FIG. 5 is a cross-sectional view of an eccentric grinding element, a concentric proximal counterweight, and an eccentric distal counterweight. FIG. 5 is a cross-sectional view of an eccentric grinding element, a concentric proximal counterweight, and a concentric distal counterweight. FIG. 5 is a cross-sectional view of a concentric grinding element, an eccentric proximal counterweight, and an eccentric distal counterweight. FIG. 5 is a cross-sectional view of a concentric grinding element, an eccentric proximal counterweight, and a concentric distal counterweight. FIG. 5 is a cross-sectional view of a concentric grinding element, a concentric proximal counterweight, and an eccentric distal counterweight. FIG. 5 is a cross-sectional view of a concentric grinding element, a concentric proximal counterweight, and a concentric distal counterweight. It is a schematic diagram of a grinding element and a counterweight, the distance between the mass centers of a proximal counterweight and a grinding element is D1, and the distance between the mass centers of a distal counterweight and a grinding element is D2.

Detailed Description of the Invention, Including Best Modes The present invention is applicable to a variety of modified and alternative forms, the particular examples of which are illustrated in the drawings and will be described in detail herein. However, it should be understood that it is not intended to limit the invention to the particular embodiments described. Instead, it is intended to cover all modifications, equivalents, and alternatives within the spirit and scope of the invention.

FIG. 1 shows an embodiment of a rotary atherectomy device according to the present invention. The device includes a handle portion 10 and a system of eccentric grinding heads 27, including, but not limited to, a proximal eccentric expansion grinding head 28 and a distal eccentric expansion grinding head or grinding element 29 in the illustrated embodiment. ), And an elongated catheter 13 extending distally from the handle portion 10. The drive shaft 20 is from an exemplary system 27 comprising a spirally wound wire, as is known in the art, and a proximal grinding head 28 and a distal grinding head 29 fixedly attached thereto. It is composed. The catheter 13 has a lumen. Most of the length of the drive shaft 20 fits into this hole, except for the extended proximal and distal grinding heads 28, 29, and the short distal section of the distal extended grinding head 29. The drive shaft 20 also includes an inner hole that allows the drive shaft 20 to advance and rotate on the guide wire 15. A liquid supply line 17 may be provided in the catheter 13 for introducing a cooling and lubricating liquid (typically saline or another biocompatible liquid).

The handle 10 preferably includes a turbine (or similar rotary drive mechanism) for rotating the drive shaft 20 at high speed. The handle 10 may typically be connected to a power source such as compressed air delivered from the tube 16. A set of fiber optic cables 25 (alternatively one fiber optic cable may be used) may be provided to monitor the rotational speeds of the turbine and drive shaft 20. Details about such handles and related appliances are well known in the industry. The handle 10 also preferably includes an operating knob 11 for advancing and retracting the turbine and drive shaft 20 with respect to the catheter 13 and the handle body.

The proximal eccentric grinding head 28 and the distal eccentric grinding head 29 of the exemplary system 27 are mounted on the drive shaft or otherwise placed on the drive shaft, or integrated with the drive shaft, or drive. It is formed from a shaft. The proximal grinding head 28 is located proximal to the distal grinding head 29. That is, the distal grinding head 29 is closest to the distal end of the drive shaft 20. Proximal and distal grinding heads 28, 29 are distanced or spaced from each other along the drive shaft 20. In addition, the proximal and distal grinding heads 28, 29 have quiescent diameters D and D', respectively. In the present invention, it is necessary that the static diameter D of the proximal grinding head 28 is larger than the static diameter D'of the distal grinding head 29. Further, the present invention is not limited to the system 27 including two grinding heads, and may include two or more grinding heads. However, in all cases, the most distal grinding head (eg 29) has the smallest static diameter, and the proximal grinding head (eg 28) is more than the adjacent distal head (eg 29). However, the static diameter gradually increases. In other words, the static diameter of the grinding head increases from the distal end of the drive shaft 20 toward the proximal position on the drive shaft, and the stationary of the most distal grinding head of all grinding heads. The smallest diameter.

As shown, a preferred embodiment comprises two grinding heads (ie, 28, 29). The exemplary static diameter D of the proximal grinding head may be 2 mm to 3 mm, and the static diameter D'of the distal grinding head may be 1.25 mm to 5 mm. However, as described above, in each embodiment, the static diameter of the most distal grinding head in the system 27 is the smallest, and the static diameter of the grinding head gradually increases toward the proximal side.

Therefore, one of the main objects of the invention is to provide a system of grinding heads 27 comprising at least one proximal eccentric grinding head 28 having a larger quiescent diameter as well as a distal eccentric grinding head 29 having a smaller quiescent diameter. is there. This allows the small diameter distal eccentric grinding head 29 to be placed in a small hole in the obstructive material in the vascular system before it spins at high speed in the patient's vascular system. As detailed herein, when the drive shaft 20 begins to rotate, the system including the drive shaft 20 to which the grinding heads 28, 29 are mounted begins to generate centrifugal force. As a result, in particular, the orbital motion of the grinding heads 28 and 29 occurs. In this orbital motion, the grinding heads 28, 29 begin to depict a path having a working diameter of, for example, two to three times the rest diameters D, D', respectively.

2, FIG. 3A, and FIG. 3B show the arrangement of the system 27 of an embodiment. As an example, FIGS. 2 and 3A show a system of unbalanced grinding heads 27 with a proximal grinding head 28 and a distal grinding head 29 attached to a drive shaft 20. The proximal grinding head 28 and the distal grinding head 29 are arranged at a distance from each other, and as shown by the dotted line in FIG. 3A, the mass centers of the grinding heads 28 and 29 are both rotated in the same direction and in the same plane as the drive shaft 20. It deviates from the axis A in the radial direction. In other words, the deviation of the center of mass of the entire system of the grinding head 27 is maximized in one radial deviation direction (for example, along the dotted line in FIG. 3A). In a balanced embodiment, for example, the centers of mass of the proximal grinding head 28 and the distal grinding head 29 are 180 degrees apart in the rotational direction, and the centers of mass of the grinding heads 28 and 29 are both shown in FIG. 3A. Although they are on the dotted line, they may be located on opposite sides of the rotation axis of the drive shaft 20. Alternatively, an even number (eg, 4) of eccentric grinding heads may be provided, with equal rotational spacing of rotational angles between each of the four exemplary eccentric grinding heads (eg, four). , 45 degrees or 90 degrees, etc.). This results in a balanced system. In such a balanced embodiment, in a preferred arrangement, the static diameter gradually decreases from the most proximal eccentric grinding head to the most distal eccentric grinding head, but the center of mass of the eccentric grinding head is It is almost even as a whole.

FIG. 3B shows an alternative embodiment of the imbalanced grinding head 27 system. Similar to the embodiments of FIGS. 2 and 3A, in this exemplary embodiment, the proximal and distal grinding heads 28, 29 are fixed or mounted on or mounted on the drive shaft 20 or formed from the drive shaft 20. They are located at a distance from each other. However, in the embodiment of FIG. 3B, the centers of mass of the proximal and distal grinding heads 28, 29 are radially offset from the axis of rotation of the drive shaft in different directions and different planes. For example, as shown in the figure, the center of mass of the distal grinding head 29 is substantially perpendicular to the rotation axis of the drive shaft 20, as shown by the dotted line in the vertical direction. However, the center of mass of the proximal grinding head 28 is not on the dotted line in the longitudinal direction, but is actually a position rotated by about 100 degrees from the dotted line in the longitudinal direction representing the plane including the mass center of the distal grinding head 29. It is in. Therefore, the weight of the system of the grinding head 27 is unbalanced, and as a result, like the system 27 of FIG. 3A, centrifugal force is likely to be generated at the time of high speed rotation of the drive shaft 20 and the orbital movement of the grinding heads 28 and 29. ..

The main difference between the embodiment of FIG. 3A and the embodiment of FIG. 3B is the distal along the drive shaft 20 in the system of the grinding head 27 during high speed rotation and orbital motion of the heads 28, 29. The effect of liquid flow in the direction. FIG. 3A creates a regular, unpatterned turbulence of the surrounding liquid (not only blood, but also debris scraped from the blockage during high speed rotation).

In contrast, FIG. 3B shows a substantially spiral cross-sectional shape that travels distally along the drive shaft 20 from a point proximal to the proximal grinding head 28 to a point distal to the distal grinding head 29. .. This spiral cross-sectional shape is due to the rotational distance between the centers of mass of the grinding heads 28 and 29 (approximately 100 degrees in the illustrated example). In the illustrated example, the radial deviation of the center of mass is achieved by the eccentricity of the grinding heads 28, 29 caused by the geometric eccentricity. In other words, the geometric longitudinal sections of the grinding heads 28, 29 are eccentric. As a result, the cross-sectional shape of the system 27 is a spiral channel as described above, along which a liquid flow occurs. The spiral cross-sectional shape at high speed makes it easier for liquids, including blood and debris, to move distally along the spiral. That is, it becomes easy to move in the distal direction from the proximal grinding head 28 having a large diameter toward the distal grinding head 29 having a small diameter and beyond the distal grinding head 29. In this way, the debris produced by the atherectomy procedure by the system 27 is flowed away from the obstruction along the spiral channel of the system 27 in a controlled manner.

The spiral channel of system 27 is further shown in FIG. 4A. FIG. 4A shows a longitudinal sectional view of the drive shaft 20 having the rotation axis A in a state of being overlapped with the rotation direction angle grid. The rotational angle grid is exemplifiedly divided into 45 degree sections centered on the drive shaft 20. The formation of the spiral channel and its cross-sectional shape can be achieved by separating the geometric and mass centers of the eccentric grinding head of the system 27 in the rotational direction. As an example, the geometric and mass centers of the eccentric proximal grinding head 28 may be located within a rotating section of 0 to 45 degrees in the direction of rotation shown. In that case, the distal eccentric grinding head 29 may be arranged such that its geometric center and center of mass are located within a rotating section of 45 to 90 degrees in the direction of rotation. In certain embodiments, if the system 27 includes three or more grinding heads, as shown, the third eccentric grinding head has a rotating section whose geometric and mass centers are 90 to 135 degrees in the direction of rotation. It may be arranged so as to be located inside. If yet other eccentric grinding heads (eg, a fourth eccentric grinding head) are included in the system 27, their geometric and mass centers will rotate greater than 135 degrees using the same logical progression. It is preferably located within the section.

The rotating section shown is only an example. Those skilled in the art will recognize that it may be a larger and / or smaller section. Further, those skilled in the art will recognize that, for example, the proximal eccentric grinding head 28 may be separated from the distal eccentric grinding head 29 by more than 45 degrees.

As the ultimate effect of longitudinal rotational travel along the drive shaft 20 in the system 27, a spiral channel as shown in FIG. 4B is provided. In FIG. 4B, a liquid containing blood, coolant, and debris flows along the liquid streamline between the peaks of the grinding heads of the system 27, which are continuously provided apart from each other in the direction of rotation. The peak of the grinding head enters the closure, which enhances and assists the spiral flow of liquid.

The grinding head of the system of the grinding head 27 may include one or more types of grinding heads.

For example, FIGS. 5 and 6 show grinding heads that can be used in one or more of the grinding heads of the present invention (eg, proximal and distal grinding heads 28, 29). This embodiment includes an eccentric extended diameter grinding section 28A of the drive shaft 20A. In this embodiment, the name 28A is only given for the sake of explanation, and the name does not limit the illustrated embodiment to the position of the proximal grinding head on the drive shaft. The drive shaft 20A includes one or more spirally wound wires 18 defining a guide wire hole 19A and a cavity 25A in the extended grinding section 28A. The cavity 25A is substantially empty, except that the guide wire 15 crosses the cavity 25A. The eccentric extended diameter grinding section 28A includes a proximal portion 30A, an intermediate portion 35A, and a distal portion 40A with respect to the location of the constriction. The diameter of the wire winding 31 of the proximal portion 30A of the eccentric dilated diameter section 28A preferably gradually increases in the distal direction at a substantially constant rate, thereby forming a substantially conical shape. The diameter of the wire winding 41 of the distal portion 40A preferably gradually decreases towards the distal direction at a substantially constant rate, thereby forming a substantially conical shape. The wire winding 36 of the intermediate portion 35A provides a substantially convex outer surface by having a gradually changing diameter. This outer surface is shaped to provide a smooth transition between the proximal and distal cones of the extended eccentric diameter section 28A of the drive shaft 20A. In the embodiment of this grinding head, the center of mass is located radially deviated from the drive shaft rotation axis A.

In addition, at least a portion (preferably intermediate 35A) of the eccentric extended diameter grinding section of the drive shaft 28A has an outer surface capable of removing tissue. The tissue removal surface 37 containing the coating of the abrasive 24A defining the tissue removal segment of the drive shaft 20A is illustrated in a state of being directly adhered to the wire winding of the drive shaft 20A with a suitable bonding agent 26A.

Thus, FIGS. 5 and 6 show an embodiment of an extended diameter grinding section disclosed in US Pat. No. 6,494,890 (Shturman) by the same applicant. This extended section is at least partially covered with abrasive and can be used in the system 27 of the present invention. The ground segment is capable of removing stenotic tissue from the artery during high speed rotation. The device is capable of dilating arteries to a diameter larger than the resting diameter of the dilated eccentric section, in part by orbital rotational motion during high speed operation. Since the extended eccentric sections have drive shaft wires that are not bundled together, the drive shafts of the extended eccentric sections can bend when placed in a constriction or during high speed operation. This bending allows for greater diameter expansion during high speed operation. The disclosure of US Pat. No. 6,494,890 is incorporated herein by reference in its entirety.

With reference to FIGS. 7 and 8A-8C, another embodiment of a feasible grinding head comprising the system of the eccentric grinding head 27 of the present invention will be described. Similar to the embodiments of FIGS. 4 and 5, this embodiment can be used for one or more of the grinding heads of the system of eccentric grinding head 27. In a non-limiting example, the present embodiment may include one or both of the proximal and / or distal grinding heads 28, 29. Alternatively, the present embodiment may be combined with another type of grinding head (eg, the embodiments shown in FIGS. 5 and 6) to form the system 27. For example, the present embodiment may have a proximal grinding head 28 and the embodiments of FIGS. 5 and 6 may have a distal grinding head 29 to configure the system 27. Many other equivalent variants and combinations that can be easily conceived by those skilled in the art are also within the scope of the present invention.

As described above, the drive shaft 20 has a rotation shaft A coaxial with the guide wire 15 arranged in the hole 19 of the drive shaft 20. In particular, with reference to FIGS. 7 and 8A-8C, the proximal portion 30S of the eccentric expansion grinding head 28S is a cone (a cone having an axis 32 that intersects the rotation axis 21 of the drive shaft 20 at a relatively shallow angle β). Has an outer surface substantially defined by the outer surface of the truncated cone. Similarly, the distal portion 40S of the extended grinding head 28S is substantially defined by the outer surface of the truncated cone of a cone (a cone having an axis 42 intersecting the axis 21 of the drive shaft 20 at a relatively shallow angle β). Has an outer surface. The conical shaft 32 of the proximal portion 30S and the conical shaft 42 of the distal portion 40S intersect each other and are coplanar with the longitudinal rotation axis A of the drive shaft.

The opposing sides of the cone should be at an angle α of approximately 10 ° to about 30 ° with respect to each other. The angle α is preferably from about 20 ° to about 24 °, most preferably from about 22 °. Further, the conical shaft 32 of the proximal portion 30S and the conical shaft 42 of the distal portion 40S usually intersect the rotating shaft 21 of the drive shaft 20 at an angle β of about 20 ° to about 8 °. Preferably, the angle β is from about 3 ° to about 6 °. In the preferred embodiment shown, the distal angle α and the proximal angle α of the extended grinding head 28S are substantially equal, but they do not have to be equal. The same is true for angle β.

In an alternative embodiment, the diameter of the intermediate portion 35S may gradually increase from the intersection with the distal portion 40 to the intersection with the proximal portion 30. In this embodiment, the angle α shown in FIG. 7 may be larger in the proximal 30S than in the distal 40S, or vice versa. In another alternative embodiment, the surface of the intermediate 35S is convex, the intermediate outer surface providing a smooth transition between the proximal and distal proximal and distal outer surfaces. It may be shaped as follows.

The grinding head 28S may have at least one tissue removing surface 37 on the outer surface of the intermediate portion 35S, the distal portion 40S, and / or the proximal portion 30S. This facilitates grinding of the narrowed portion during high-speed rotation. The tissue removal surface 37 may include a coating of abrasive 24 bonded to the outer surface of the intermediate 35S, distal 40S, and / or proximal 30S of the grinding head 28S. The abrasive may be any suitable material, such as diamond powder, fused quartz, titanium nitride, tungsten carbide, aluminum oxide, boron carbide, or other ceramic materials. Preferably, the abrasive consists of diamond chips (or diamond dust particles) that are directly adhered to the tissue removal surface with a suitable bonding agent. Such adhesion may be achieved using well-known techniques such as, for example, conventional electroplating techniques or melting techniques (see, eg, US Pat. No. 4,018,576). Alternatively, in order to provide a suitable ground tissue removal surface 37, the outer tissue removal surface mechanically or chemically covers the outer surfaces of the intermediate 35S, distal 40S, and / or proximal 30S. It may be roughened. In yet another variant, the outer surface may be etched or cut (eg, by laser) to provide a small but effective ground surface. Other similar techniques may be used to provide a suitable tissue removal surface 37.

As best shown in FIGS. 8A-8C, at least a partially enclosed hole or slot 23 runs longitudinally through the extended grinding head 28S along the axis 21 of the drive shaft 20. It may be provided. The holes or slots 23 are for attaching the grinding head 28 to the drive shaft 20 in a manner well known to those skilled in the art. In the illustrated embodiment, the grinding head 28S is reduced in weight by providing the hollow section 26. This facilitates grinding without damaging the structure and improves the predictability of controlling the trajectory of the grinding head 28S during high speed operation (ie, 20,000 rpm to 200,000 rpm). In this embodiment, the drive shaft 20 to which the grinding head 28S is fixedly attached may consist of a single unit. Alternatively, the drive shaft 20 may consist of two separate pieces, and the extended eccentric grinding head 28S may be fixedly attached to both pieces of the drive shaft 20 having a gap between them. By combining this two-piece drive shaft construction method with the hollow section 26, it may be possible to further manipulate the position of the center of mass of the grinding head 28S. In all embodiments, the size and shape of the hollow section 26 may be modified to optimize the trajectory rotation path of the grinding head 28S to obtain particularly desired rotational speeds. It is understood that the illustrated hollow section 26 is symmetrical in all planes. However, of course, this is not a limited example. The hollow section 26 may be asymmetric in the longitudinal and / or radial directions in order to move the center of mass of the grinding head 28S to the desired position. Those skilled in the art will readily recognize the various feasible configurations. All of these configurations are within the scope of the present invention.

Also, embodiments of FIGS. 7 and 8A-8C show proximal 30S and distal 40S that are symmetrical in shape and length. In an alternative embodiment, an asymmetric cross-sectional shape may be formed by increasing the length of the proximal 30S or the distal 40S.

Since the conical shafts 32 and 42 intersect the rotating shaft 21 of the drive shaft 20 at an angle β, the center of mass of the eccentric expansion grinding head 28S is radially separated from the longitudinal rotating shaft 21 of the drive shaft 20. As described in detail below, the expansion grinding head 28S becomes eccentric by shifting the center of mass from the rotation shaft 21 of the drive shaft. This eccentricity allows the extended grinding head 28S to dilate the artery to a diameter substantially larger than the nominal diameter of the extended eccentric grinding head 28S. The expanded diameter is preferably at least twice the nominal static diameter of the extended eccentric grinding head 28S.

As used herein, the word "eccentricity" is an exemplary location difference between the geometric center of the extended grinding head 28S and the axis 21 of the drive shaft 20 or a component of the system 27. It is understood that it is defined and used to mean a difference in position between the center of mass of the extended grinding head 28S and / or the eccentric grinding head 28A and the rotating shaft 21 of the drive shaft 20. In any of these differences, the eccentric extended grinding heads 28S, 28A, which are parts of the system 27, are substantially larger than the nominal diameter of the eccentric extended grinding heads 28S, 28A at an appropriate rotational speed. It is possible to widen the stenosis to the diameter. Further, with respect to the eccentric expansion grinding heads 28S and 28A having a shape other than the regular geometric shape, the concept of "geometric center" is drawn through the rotating shaft 21 of the drive shaft 28 and the eccentric expansion grinding head 28S. , 28A can be approximated by identifying the midpoint of the longest string connecting the two points on the outer circumference of the cross section cut at the position where the circumference is maximum.

The grinding heads 28S and / or 28A of the rotary atherectomy device of the present invention may be made of stainless steel, tungsten, or a similar material. To achieve the object of the present invention, the grinding head 28 may be an integral structure of a single piece, or alternative, assembling two or more grinding head parts fitted and fixed to each other. It may be a product.

The extent to which an arterial stenosis can be widened to a diameter larger than the nominal diameter of the eccentric expansion grinding head of the present invention depends on several parameters. The parameters include the shape of the eccentric expansion grinding head, the mass of the eccentric expansion grinding head, the distribution of the mass, that is, the position of the center of mass of the grinding head with respect to the rotation axis of the drive shaft, and the rotation speed.

Rotational speed is an important factor in determining the centrifugal force that presses the tissue removal surface of the extended grinding head against the constricted tissue, thereby controlling the rate of tissue removal by the operator. In addition, the control of the rotation speed makes it possible to control the maximum diameter of the constriction widened by the device to some extent. In addition, the applicant can not only more accurately control the rate of tissue removal, but also more accurately the size of the particles to be removed, if the force that presses the tissue removal surface against the constricted tissue can be reliably controlled. I also found that it can be controlled.

FIG. 9 shows a substantially spiral trajectory path taken in various embodiments of an eccentric grinding head (including 28S and / or 28A) of an exemplary system 27 of the present invention. The grinding head 28 is shown in relation to the guide wire 15 (the grinding head 28A and / or 28S is advancing on the guide wire 15). The pitch of the spiral path in FIG. 9 is enlarged for illustration purposes. However, in practice, in each spiral path of the system 27 with the eccentric expansion grinding head 28A and / or 28S, the tissue removal surface 37 only removes a very thin layer of tissue. A large number of such spiral paths are formed by the system 27 as the device repeatedly moves back and forth from end to end of the stenosis to fully widen the stenosis. FIG. 10 schematically shows three different rotational positions of the eccentric extended grinding head 28S and / or 28A of the rotary atherectomy device of the present invention. At each position, the grinding surface of the eccentric expansion grinding head 28S and / or 28A contacts the plaque "P" to be removed. That is, the three positions are identified by three different points of contact with the plaque "P". In the figure, those points are represented as points B1, B2, and B3. It should be noted that what comes into contact with the structure at each point is substantially the same portion of the grinding surface of the eccentric expansion grinding head 28S and / or 28A. That is, it is the portion of the tissue removing surface 37 that is farthest in the radial direction from the rotation axis of the drive shaft.

Although we do not want to limit it to any particular principle of operation, shifting the center of mass from the axis of rotation causes the "trajectory" motion of the extended grinding head, and the "trajectory" diameter changes the rotational speed of the drive shaft in particular. The applicant believes that it can be controlled by making it. Applicants have experimentally demonstrated that the centrifugal force that presses the tissue removal surface of the eccentric extended grinding head 28S and / or 28A against the surface of the constriction can be controlled by varying the rotational speed of the drive shaft. This centrifugal force can be determined according to the following formula.

F _c = mΔx (πn / 30) ²
Here, Fc is the centrifugal force, m is the mass of the eccentric expansion grinding head, Δx is the distance between the center of mass of the eccentric expansion grinding head and the rotation axis of the drive shaft, and n is the distance per minute. It is a rotation speed expressed in rotation speed (rpm). By controlling this force Fc, it is possible to control the rate of tissue removal, control of the maximum diameter of the stenosis widened by the device, and control of the particle size of the tissue to be removed.

The grinding heads 28S and / or 28A of the present invention have a larger mass than the conventional high-speed atherectomy grinding device. As a result, a larger trajectory can be achieved at high speeds, which in turn may allow the use of smaller grinding heads than prior art devices. The use of smaller grinding heads not only allows pilot holes to be drilled in completely or substantially occluded arteries, but also facilitates access during insertion and reduces tissue damage.

As an operation, when using the rotary atherectomy device of the present invention, the eccentric expansion grinding head 28S and / or 28A repeatedly moves distally and proximally within the constriction. By varying the rotation speed of the device, the operator can control the force with which the tissue removal surface is pressed against the constricted tissue, thereby more accurately determining the rate of plaque removal and the particle size of the tissue to be removed. Can be controlled. In addition, the quiescent diameter of the two or more eccentric grinding heads of the system 27 gradually increases (from the distal side to the proximal side), thereby increasing the static diameter of the extended eccentric grinding head (eg, 28S and / or 28A). It is possible to widen the stenosis to a diameter larger than the resting diameter. Further, in the above-mentioned imbalanced embodiment in which a spiral channel is formed around the eccentric grinding head of the system 27, the cooling solution and blood can flow continuously around the extended grinding head. As the grinding head passes through the lesion, the removed tissue particles are constantly flushed downstream of the spiral channel by such a continuous flow of blood and cooling solution, resulting in uniform release of the removed particles.

The maximum cross-sectional diameter of the eccentric extended grinding head 28S and / or 28A may be from about 1.0 mm to about 3.0 mm. Therefore, the cross-sectional diameter of the eccentric expansion grinding head may include 1.0 mm, 1.25 mm, 1.50 mm, 1.75 mm, 2.0 mm, 2.25 mm, 2.50 mm, 2.75 mm, and 3.0 mm. , Not limited to these. The amount of increase of 0.25 mm in the above-listed cross-sectional diameters is merely an example, and the present invention is not limited to the above-listed examples, and therefore other increases in cross-sectional diameter are also possible and within the scope of the present invention. Those skilled in the art will easily recognize this.

Since the eccentricity of the extended grinding head 28S and / or 28A is determined by a number of parameters as described above, the geometry of the rotary shaft 21 of the drive shaft 20 and the cross section cut at the position of the maximum cross-sectional diameter of the eccentric extended grinding head. The applicant has found that the following design parameters can be considered with respect to the distance to the target center. For devices with eccentric extended grinding heads with a maximum cross-sectional diameter of about 1.0 mm to about 1.5 mm, the geometric center is at least about 0.02 mm, preferably at least about 0.035 mm, from the axis of rotation of the drive shaft. It is desirable to separate them by a distance. For devices with eccentric extended grinding heads with a maximum cross-sectional diameter of about 1.5 mm to about 1.75 mm, the geometric center is at least about 0.05 mm, preferably at least about 0.07 mm, from the axis of rotation of the drive shaft. Most preferably, they are separated by a distance of at least about 0.09 mm. For devices with eccentric extended grinding heads with a maximum cross-sectional diameter of about 1.75 mm to about 2.0 mm, the geometric center is at least about 0.1 mm, preferably at least about 0.15 mm, from the axis of rotation of the drive shaft. Most preferably, they are separated by a distance of at least about 0.2 mm. For devices with eccentric extended grinding heads with a maximum cross-sectional diameter greater than 2.0 mm, the geometric center is at least about 0.15 mm, preferably at least about 0.25 mm, most preferably at least about about the axis of rotation of the drive shaft. It is desirable to separate them by a distance of 0.3 mm.

The design parameters may also be based on the position of the center of mass. For devices with eccentric extended grinding heads 28S and / or 28A with a maximum cross-sectional diameter of about 1.0 mm to about 1.5 mm, the center of mass is at least about 0.013 mm, preferably at least about 0, from the axis of rotation of the drive shaft. It is desirable to separate them by a distance of .02 mm. For devices with eccentric extended grinding heads 28S and / or 28A with a maximum cross-sectional diameter of about 1.5 mm to about 1.75 mm, the center of mass is at least about 0.03 mm, preferably at least about 0, from the axis of rotation of the drive shaft. It is desirable to separate them by a distance of 0.05 mm. For devices with eccentric extended grinding heads with a maximum cross-sectional diameter of about 1.75 mm to about 2.0 mm, the center of mass is at least about 0.06 mm, preferably at least about 0.1 mm from the axis of rotation of the drive shaft. It is desirable to separate them. For devices with eccentric extended grinding heads with a maximum cross-sectional diameter greater than 2.0 mm, the center of mass should be separated from the axis of rotation of the drive shaft by a distance of at least about 0.1 mm, preferably at least about 0.16 mm. ..

In addition, this application comprises at least one counterweight positioned and fixedly mounted on the drive shaft to facilitate orbital motion of the grinding elements (which may be concentric or eccentric). You may. One of the at least one counterweight may be located proximal to the grinding section and another counterweight of the at least one counterweight may be located distal to the grinding section. The at least one counterweight may further include a grinding portion on it. As a result, at least one grinding counterweight is formed.

As used herein, a counterweight is defined as an element located proximal or distal to the grinding element on the drive shaft. The grinding elements may be concentric (ie, the center of mass is located on the axis of rotation of the drive shaft) or, instead, eccentric (ie, the center of mass is radially offset from the axis of rotation of the drive shaft). ) May be. The counterweights may also be eccentric or concentric. Thus, the counterweight is further defined as having the center of mass deviated radially from the position of the center of mass of the grinding element. Those skilled in the art will easily come up with a wide variety of possibilities. In each case, an unbalanced system is conceivable in which the position of the mass center of at least one counterweight of at least one counterweight is radially offset from the mass center of the grinding element. Counterweights are further defined in a system of grinding elements having two or more counterweights where the distance between each counterweight and the grinding element is not equal. Thus, even if the center of mass of the grinding element and at least one counterweight is located on the axis of rotation of the drive shaft, the proximal counterweight is located at a distance D1 from the grinding element and the distal counterweight. The counterweight effect is exhibited by arranging the counterweight at a distance D2 from the grinding element (D1 is larger than D2).

For example, FIGS. 11 to 17 show an outline of a cross section of a drive shaft 120 including grinding elements 121C and 121E provided with a grinding portion 122, proximal counterweights 123C and 123E, and distal counterweights 124C and 124E. It is a figure. The rotating shaft 125 extends through the center of the drive shaft 120. For clarity, the individual coils of the drive shaft 120 are not shown. Elements 121C, 121E, 123C, 123E, 124C and 124E are simply represented in circles in these figures, but any or all of these elements are grinding bars (masses of any shape). It will be understood that it is also good. Further, it is also understood that they include, but are not limited to, variations in the size and / or shape of the drive shaft coils, or others that are distinguishable from the drive shaft 120, which is largely featureless. Will. The center of mass of each element of FIGS. 10 to 18 is marked with an “x”, and further, in order to indicate the deviation of the drive shaft 120 from the rotation shaft 125 in the radial direction, the drive shaft is shown. The rotation shaft 125 of 120 is represented.

FIG. 11 shows an eccentric grinding element 121E, an eccentric proximal counterweight 123E, and an eccentric distal counterweight 124E mounted on a rotary drive shaft 120. FIG. 12 shows an eccentric grinding element 121E, an eccentric proximal counterweight 123E, and a concentric distal counterweight 124C. FIG. 13 shows an eccentric grinding element 121E, a concentric proximal counterweight 123C, and an eccentric distal counterweight 124E. FIG. 14 shows the eccentric grinding element 121E, the concentric proximal counterweight 123C, and the concentric distal counterweight 124C. FIG. 15 shows the concentric grinding element 121C, the eccentric proximal counterweight 123E, and the eccentric distal counterweight 124E. FIG. 16 shows a concentric grinding element 121C, an eccentric proximal counterweight 123E, and a concentric distal counterweight 124C. FIG. 17 shows a concentric grinding element 121C, a concentric proximal counterweight 123C, and an eccentric distal counterweight 124E. FIG. 18 shows a concentric grinding element 121C, a concentric proximal counterweight 123C, and a concentric distal counterweight 124C.

Although FIGS. 11 to 17 all show the proximal counterweight and the distal counterweight, the center of gravity of one counterweight is displaced radially from the position of the center of gravity of the related grinding element. If so, it is understood that the case of one counterweight is also within the scope of the present invention described in the present specification.

FIG. 19 is a schematic view of the grinding element 121 and the counterweights 123 and 124. The distance between the center of mass of the proximal counterweight 123 and the grinding element 121 is the distance D1, and the distance between the center of mass of the distal counterweight 124 and the grinding element 121 is the distance D2. D1 and D2 may be equal or different. Note that in FIG. 18, D1 and D2 are shown as distances between the centers of mass of different elements, but instead, D1 and D2 may represent longitudinal distances along the axis of rotation of the drive shaft. ..

For example, one or both of the proximal and distal counterweights 100, 102 may include an extended diameter section of the drive shaft formed in a manner similar to the extended eccentric diameter grinding section 28A. In this application, the counterweights 100, 102 are essentially hollow expansion wire windings of the drive shaft 20 formed using a mandrel during the wire winding process. If there is only one counterweight (either the proximal counterweight 102 or the distal counterweight 100), which is the extended eccentric diameter grinding section of the drive shaft 20, the remaining counterweights are concentric (ie, center of mass). It may be on the same line as the axis of rotation of the drive shaft) and may be an extended diameter section of the drive shaft, a solid crown, or at least a partially hollow crown. Alternatively, the remaining counterweight may be an eccentric and solid bar, or at least a partially hollow crown or grinding head.

Alternatively, one or both of the proximal and distal counterweights 100, 102 may be solid and may be attached to the wire winding of the drive shaft 20 by means well known to those of skill in the art. FIG. 6). Alternatively, the proximal and distal counterweights may be at least partially hollow.

Alternatively, one or both of the at least one counterweight comprises a combination of different materials, and at least one of the counterweights 100, 102 is heavier or heavier than the other. It may be made of high density material. This results in the eccentricity defined herein. As one of ordinary skill in the art will recognize, creating eccentricity by using different materials in at least one counterweight, i.e. shifting the center of mass from the axis of rotation of the drive shaft, is any counterweight. It can also be applied to the configuration. That is, it can be applied to either concentric or eccentric solid bars, partially hollow crowns or grinding heads, or extended sections of drive shafts, or their equivalents.

Further, in one application, the proximal and distal counterweights are substantially equal in total mass, and each counterweight is approximately half the total mass of the grinding element. Proximal and distal counterweights are equidistant from the grinding section, the center of gravity of the proximal and distal counterweights is equidistant from the axis of rotation of the drive shaft, and the center of gravity of the proximal and distal counterweights is ground. Equidistant from the center of mass of the element. Those skilled in the art will easily come up with alternative and equal examples of the mass distribution between the grinding element and the counterweight used to manipulate the orbital rotation diameter of the grinding element at high speeds.

Alternatively, at least one of the counterweights may be eccentric. That is, in one configuration, the center of mass of the counterweight (proximal and / or distal) is radially separated from the axis of rotation of the drive shaft and is the same longitudinal plane as the center of mass of the eccentric grinding element. You may line up inside. Separating the center of mass of the counterweights in the radial direction can be achieved by separating the geometric center of each counterweight from the axis of rotation of the drive shaft. The center of mass of each of the proximal and distal counterweights may be offset by a rotational angle of 180 degrees from the center of gravity of the grinding element. The mass centers of the proximal and / or distal counterweights described herein may promote (ie, increase the diameter of rotation) or suppress (ie, decrease) the orbital motion of the grinding element. May be done.

Importantly, in this application, while using small diameter grinding elements in combination with proximal and / or distal counterweights, the large diameter of known literature that does not include the counterweights described herein. It is possible to make a hole with a trajectory diameter equivalent to that of the grinding element.

One of ordinary skill in the art will recognize any number of combinations and changes of these parameters for a given rotational speed of the drive shaft. Those skilled in the art will recognize that changes in any of these parameters may increase or decrease (suppress) the diameter of the trajectory path taken by the grinding section. Will do. Thus, the diameter of the orbital path can be customized for individual holes.

In one application where the grinding sections 28 are concentric, the proximal and distal counterweights 1
The total masses of 00 and 102 are substantially equal, and the counterweights 100 and 102 are approximately half of the total mass of the concentric grinding section 28. The proximal counterweight 102 and the distal counterweight 100 are equidistant from the concentric grinding section 100, the proximal and distal mass centers are equidistant from the axis of rotation of the drive shaft 20, and the proximal and distal masses. The center is equidistant from the center of mass of the concentric grinding section 28.

Proximal and / or distal counterweights may be concentric (ie, spherical or elliptical in cross section or other concentric), with the center of mass of the counterweight substantially on the axis of rotation of the drive shaft. May be.

In applications with concentric grinding elements, the proximal and / or distal counterweights are preferably eccentric. That is, for example, as shown in FIG. 15, the center of mass of the proximal and / or distal counterweights may be radially separated from the axis of rotation of the drive shaft. The center of mass of each counterweight is offset in the same longitudinal plane and is offset in the same longitudinal plane as the center of mass of the concentric grinding section on the same line as the axis of rotation. Also, the centers of mass of the proximal and / or distal counterweights may both be above or below the axis of rotation of the drive shaft, but both of these centers of mass are in the same longitudinal plane. Lined up inside. Therefore, a "deviation" is formed between the center of mass of the grinding element and the center of mass of the proximal and / or distal counterweights. As can be seen by reference to FIG. 4A, the centers of mass of the proximal and / or distal counterweights are 180 degrees or other offset angles about the axis of rotation of the drive shaft, as will be readily recognized by those skilled in the art. It may deviate from.

As with the eccentric grinding section, for the concentric grinding section, the radial separation of the center of mass for proximal and / or eccentric distal counterweights drives the geometric center of each counterweight. It can be realized by separating it from the axis of rotation of. The center of mass of each of the proximal and distal counterweights is distant from the center of mass of the concentric grinding section and in the same longitudinal plane. In such a counterweight configuration, the orbital motion of the grinding element is promoted so that the grinding element moves in an arc, expanding the stenotic lesion to a diameter substantially larger than the outer diameter of the stationary concentric grinding element. It becomes easy. As described above, in this application, a hole with a locus diameter equivalent to that of a large diameter concentric grinding element in the known literature is drilled while using a small diameter grinding element in combination with proximal and / or distal counterweights. It is possible.

As used herein, the term "eccentricity" refers to an eccentric extended diameter section of a drive shaft, or an eccentric solid bar, or at least a partially hollow eccentric crown or eccentric grinding head, or a grinding element with an eccentric counterweight. Means the difference in position between the geometric center of the drive shaft and the axis of rotation of the drive shaft, or an eccentric extended diameter section, an eccentric solid bar, at least a partially hollow eccentric crown or eccentric grinding head 28C, Or it should be understood that it is defined as meaning a difference in position between the center of mass of an eccentric grinding element with proximal and / or distal eccentric counterweights and the axis of rotation of the drive shaft. .. In any of these differences, the grinding element is capable of widening the constriction to a diameter substantially larger than the nominal diameter of the grinding element at an appropriate rotational speed. Also, for eccentric grinding elements with non-regular geometric shapes, the concept of "geometric center" is drawn through the axis of rotation of the drive shaft and maximizes the circumference of the eccentric extended diameter section. It can be approximated by identifying the midpoint of the longest string connecting the two points on the outer circumference of the cross section cut at position. In addition, the defined eccentricity was designed so that, for example, one portion of the grinding element is hollowed out to make one portion of the cross-sectional shape heavier than the rest, although the grinding element has a substantially concentric cross-sectional shape. Those skilled in the art will recognize that it may be one.

Further, as used herein, the term concentric means that the grinding elements and / or proximal and / or distal counterweights are on the axis of rotation of the drive shaft (ie, of the drive shaft, as shown in FIG. It should also be understood that it is defined as having a center of mass (on the same line as the axis of rotation) and having a substantially symmetrical cross-sectional shape.

As used herein, the term "element" refers to any feature along the drive shaft, such as a grinding bar, mass, weight, counterweight, variable size and / or shape of the drive shaft coil, or Can be used to indicate any other drive shaft that is distinct from the almost featureless drive shaft.

In general, the drive shaft may include at least one spirally wound coil. The coil surrounds the guide wire so that it translates longitudinally with respect to the drive shaft. In other words, the guide wire can advance and retract longitudinally with respect to the drive shaft and / or the drive shaft can advance and retract longitudinally with respect to the guide wire. This advance and / or retreat may be performed at any suitable timing before, during, and / or after removal of the stenosis.

If the atherectomy device contains only one element (for example, if it has only one grinding bar or only one part of the drive shaft with an expansion coil), it causes instability during operation. there is a possibility. For example, if only one element is rotated at high speed around the axis of rotation of the drive shaft, this one element is so prone to deflection that the orbital motion of this element becomes irregular and inside the blood vessel being removed. May cause damage.

To increase stability, you may simply want to increase the mass of just one element. Such an increase in mass can increase drag against deflection, but if the element is eccentric (the center of mass is laterally offset from the axis of rotation of the drive shaft), the mass will be. If it increases, the stability of the orbital motion itself may decrease simply by having an excessively large mass far away from the axis. By increasing the mass of the eccentricity in this way, the drive shaft and / or the guide wire may be damaged at high speed rotation.

A better remedy than simply increasing the mass of a single element is to provide one or more counterweights along the drive shaft longitudinally away from the element. Overall, increasing mass does improve operational stability, but by increasing mass at positions proximal and / or distal to that single element, the trajectory of that single element. Stability can be improved without impairing exercise.

In some cases, the mass increase may be proximal and distal counterweights located on either side of the grinding element longitudinally along the drive shaft. The following paragraphs describe the various configurations of these counterweights.

In some cases, the grinding element may be located between the proximal and distal counterweights. In other applications, the grinding element may be located closer to one counterweight than to the other counterweight.

In some cases, the masses of the proximal and distal counterweights may be equal. In some cases, the masses of the proximal and distal counterweights may both be equal to half the mass of the grinding element. In some cases, the masses of the proximal and distal counterweights may both be equal to half the mass of the grinding elements, and the grinding elements may be located at the longitudinal midpoint of those counterweights. ..

In some cases, the grinding element may be eccentric. In some cases, the grinding element is eccentric and both counterweights may be eccentric. In other applications, the grinding elements may be eccentric, one counterweight may be eccentric, and the other counterweight may be concentric. In some of these applications, the counterweight and grinding element may have a synthetic center of mass that coincides with the axis of rotation of the drive shaft. In other examples of these applications, the counterweight and grinding element may have a synthetic center of mass laterally offset from the axis of rotation of the drive shaft.

In some cases, the grinding elements may be concentric. In some cases, the grinding elements may be concentric and both counterweights may be concentric. In another application, the grinding elements are concentric and both counterweights are concentric, but their combined mass centers are on opposite sides of the drive shaft so that they are approximately aligned with the axis of rotation of the drive shaft. May be good. In yet another application, the grinding elements are concentric and both counterweights are concentric, but both are on the same side of the drive shaft so that their combined mass center is offset approximately laterally from the axis of rotation of the drive shaft. May be.

In some cases, there may be two or more proximal counterweights and / or two or more distal counterweights. In some cases, the lateral offsets may be opposite to each other so that the adjacent counterweights are eccentric and their combined mass center is approximately aligned with the drive shaft rotation axis. ..

In some cases, at least one counterweight may be substantially round with a substantially smooth outer surface. This can help control unwanted damage to the inside of blood vessels during use.

In some cases, the guide wire may remain extended throughout the interior of the drive shaft during use, and may further extend to or beyond the distal end of the drive shaft. .. This can improve the stability of the entire atherectomy device. This is because the local stiffness of the guide wire may be greater than the local stiffness of the drive shaft, but it may reduce the width of the orbital motion of any eccentric element on the drive shaft. However, the guide wire may be subject to undesired bending stress under these conditions.

In other applications, the guidewire may be partially or completely retracted from the distal end of the drive shaft prior to (or during) use. The drive shaft can flex more freely when it rotates under the influence of centrifugal force when the locally rigid guide wire is not inside than when the guide wire stays inside. As a result, an eccentric element through which the guide wire does not pass can extend farther from the axis of rotation at high speeds for a given speed and element size, thus preferably having a larger cutting diameter. Can be created. Depending on the stiffness, flexibility, and / or flexibility of the material involved, the increase in cutting diameter can be up to 4 times or more.

Retracting the guide wire in this way can be advantageous in several respects. For example, if one of the design objectives is to achieve a particular cutting diameter for a given rotational speed, compare with the case where the guide wire remains extended throughout the drive shaft during use. Therefore, when the guide wire is retracted, the static diameter of the eccentric grinding element can be reduced. In other words, if all other conditions are the same, the desired cutting diameter can be achieved with a miniaturized grinding element if the guide wire is retracted before (or during) use. The miniaturized elements are easy to put into the patient's vascular system, and such elements are hard to clog, easy to operate, and less likely to cause incidental internal vascular damage before and after use. In that respect, it may be advantageous to include a miniaturized grinding element.

Further, the guide wire is less likely to be damaged by retracting because it is less likely to receive bending stress. This further reduces the risk of internal damage to the vessel during the removal process.

In some cases, the guidewire extends during use to or beyond the distal end of the drive shaft. In some cases, the guide wire may retract to the distal counterweight before or during use. In some cases, the guide wire may retract to the grinding element before or during use. In some cases, the guide wire may retract to the proximal counterweight before or during use. In some cases, the guide wire may retract beyond the proximal counterweight before or during use.

The present invention should not be considered in the context of the particular examples described above, but should be understood as covering all aspects of the invention. Examination of the present specification will readily reveal to those skilled in the art to which the invention is directed, the various modifications, equivalent methods, and numerous structures to which the invention applies.

Claims (35)

A high-speed rotating atherectomy device
With a guide wire
It comprises a flexible elongated rotatable drive shaft capable of advancing on the guide wire, the drive shaft having a rotating shaft, and the device further.
The eccentric grinding element is provided on the drive shaft, the eccentric grinding element has a mass, and the center of mass of the eccentric grinding element is radially from the rotation axis of the drive shaft in a direction along a longitudinal plane. The device is further isolated
The eccentric proximal grinding counterweight is provided on the drive shaft, the eccentric proximal grinding counterweight has a mass, and the center of mass of the eccentric proximal grinding counterweight is along the longitudinal plane. Further, the center of gravity of the eccentric grinding element separated radially from the rotation axis along the longitudinal plane is separated from the rotation axis in the radial direction in the direction opposite to the separation of the center of mass of the eccentric grinding element. The center of mass of the counterweight is separated from the center of mass of the eccentric grinding element, and the device further
The eccentric distal grinding counterweight is provided on the drive shaft, the eccentric distal grinding counterweight has a mass, and the center of mass of the eccentric distal grinding counterweight is the drive along the longitudinal plane. A high-speed rotary atelectomy device that is radially separated from the axis of rotation of the shaft and the center of mass of the eccentric distal grinding counterweight is separated from the center of mass of the eccentric grinding element. The mass center of the eccentric distal grinding counterweight is further radially separated from the rotation axis in the same direction as the radial separation of the mass center of the eccentric grinding element and the mass center of the eccentric proximal grinding counterweight. The device according to claim 1. The device of claim 1, wherein the center of mass of the eccentric distal grinding counterweight is further radially separated from the axis of rotation of the drive shaft in the opposite direction of the eccentric proximal grinding element. The device of claim 1, wherein the grinding element further comprises an extended eccentric grinding head. The device according to claim 1, wherein the mass of the eccentric proximal grinding counterweight is equal to the mass of the eccentric distal grinding counterweight, and each mass is 1/2 the mass of the eccentric grinding element. The device according to claim 1, wherein the mass of the eccentric proximal grinding counterweight and the mass of the eccentric distal grinding counterweight are not equal to each other. The device of claim 6, wherein the sum of the mass of the eccentric proximal grinding counterweight and the mass of the eccentric distal grinding counterweight is equal to the mass of the eccentric grinding element. The device according to claim 6, wherein the total mass of the eccentric proximal grinding counterweight and the mass of the eccentric distal grinding counterweight is different from the mass of the eccentric grinding element. The radial separation distance of the mass center of the eccentric proximal grinding counter weight is equal to the radial separation distance of the mass center of the eccentric distal grinding counter weight, and the radial distance of each grinding counter weight is the same. The device according to claim 1, which is 1/2 of the radial separation distance of the eccentric grinding head. The device according to claim 1, wherein the radial separation distance of the mass center of the eccentric proximal grinding counterweight and the radial separation distance of the mass center of the eccentric distal grinding counterweight are not equal to each other. The sum of the radial separation distance of the mass center of the eccentric proximal grinding counterweight and the radial separation distance of the mass center of the eccentric distal grinding counterweight is the sum of the radial separation distances of the mass center of the eccentric grinding element. The device according to claim 1, which is equal to the radial separation distance. The sum of the radial separation distance of the mass center of the eccentric proximal grinding counterweight and the radial separation distance of the mass center of the eccentric distal grinding counterweight is the sum of the radial separation distances of the mass center of the eccentric grinding element. The device according to claim 1, which is equal to the radial separation distance. The separation of the mass center of the eccentric proximal grinding counterweight from the mass center of the eccentric grinding element is equal to the separation of the mass center of the eccentric distal counterweight from the mass center of the eccentric grinding element, claim 1. Described device. The distance of the mass center of the eccentric proximal grinding counterweight from the mass center of the eccentric grinding element is not equal to the distance of the mass center of the eccentric distal grinding counterweight from the mass center of the eccentric grinding element. The device according to 1. The device of claim 1, wherein at least one of the proximal grinding counterweight and the distal grinding counterweight is at least partially hollow. A high-speed rotating atherectomy device
With a guide wire
It comprises a flexible elongated rotatable drive shaft capable of advancing on the guide wire, the drive shaft having a rotating shaft, and the device further.
The device comprises an eccentric grinding element disposed on the drive shaft, the eccentric grinding element having a mass, the center of mass of the eccentric grinding element being radially separated from the rotation axis of the drive shaft. further,
The concentric proximal grinding counterweight is provided on the drive shaft, the concentric proximal grinding counterweight has a mass, and the center of mass of the concentric proximal grinding counterweight is on the axis of rotation of the drive shaft. Positioned and separated from the center of mass of the eccentric grinding element, the device further
The concentric distal grinding counterweight is provided on the drive shaft, the concentric distal grinding counterweight has a mass, and the center of mass of the concentric distal grinding counterweight is on the axis of rotation of the drive shaft. A high-speed rotary atelectomy device that is located and separated from the center of mass of the eccentric grinding element. A high-speed rotating atherectomy device
With a guide wire
It comprises a flexible elongated rotatable drive shaft capable of advancing on the guide wire, the drive shaft having a rotating shaft, and the device further.
The eccentric grinding element is provided on the drive shaft, the eccentric grinding element has a mass, and the center of mass of the eccentric grinding element is radially from the rotation axis of the drive shaft in a direction along a longitudinal plane. The device is further isolated
The eccentric proximal grinding counterweight is provided on the drive shaft, the eccentric proximal grinding counterweight has a mass, and the center of mass of the eccentric proximal grinding counterweight is along the longitudinal plane. In addition, in the direction opposite to the separation of the center of mass of the eccentric grinding element, which is radially separated from the rotation axis, along a longitudinal plane different from the radial separation of the center of mass of the eccentric grinding element. Radially separated from the axis of rotation, the device further
The drive shaft comprises an eccentric distal grinding counterweight disposed on the drive shaft, the eccentric distal grinding counterweight has a mass, and the center of mass of the eccentric distal grinding counterweight is along a longitudinal plane. A high-speed rotating counterweight device that is radially separated from the axis of rotation of the. The mass center of the eccentric distal grinding counterweight is further radially separated from the rotation axis in the same direction as the radial separation of the mass center of the eccentric grinding element and the mass center of the eccentric proximal grinding counterweight. 17. The device of claim 17, which is in the same longitudinal plane. 17: The center of mass of the eccentric distal grinding counterweight is further radially separated from the axis of rotation of the drive shaft in the opposite direction of the eccentric proximal grinding element and in the same longitudinal plane. Described device. 17. The device of claim 17, wherein the center of mass of the eccentric distal grinding counterweight is further radially separated from the axis of rotation in a longitudinal plane different from the center of mass of the eccentric grinding head. 20. The device of claim 20, wherein the center of mass of the eccentric distal grinding counterweight is further radially separated from the axis of rotation in a longitudinal plane different from the center of mass of the eccentric proximal grinding counterweight. 17. The device of claim 17, wherein the grinding element further comprises an extended eccentric grinding head. 17. The device of claim 17, wherein the mass of the eccentric proximal grinding counterweight is equal to the mass of the eccentric distal grinding counterweight, each mass being 1/2 the mass of the eccentric grinding element. 17. The device of claim 17, wherein the mass of the eccentric proximal grinding counterweight and the mass of the eccentric distal grinding counterweight are not equal to each other. 23. The device of claim 23, wherein the sum of the mass of the eccentric proximal grinding counterweight and the mass of the eccentric distal grinding counterweight is equal to the mass of the eccentric grinding element. 23. The device of claim 23, wherein the sum of the mass of the eccentric proximal grinding counterweight and the mass of the eccentric distal grinding counterweight is different from the mass of the eccentric grinding element. The radial separation distance of the mass center of the eccentric proximal grinding counter weight is equal to the radial separation distance of the mass center of the eccentric distal grinding counter weight, and the radial distance of each grinding counter weight is the same. The device according to claim 17, which is 1/2 of the radial separation distance of the eccentric grinding head. The device according to claim 17, wherein the radial separation distance of the mass center of the eccentric proximal grinding counterweight and the radial separation distance of the mass center of the eccentric distal grinding counterweight are not equal to each other. The sum of the radial separation distance of the mass center of the eccentric proximal grinding counterweight and the radial separation distance of the mass center of the eccentric distal grinding counterweight is the sum of the radial separation distances of the mass center of the eccentric grinding element. 17. The device of claim 17, which is equal to the radial separation distance. The sum of the radial separation distance of the mass center of the eccentric proximal grinding counterweight and the radial separation distance of the mass center of the eccentric distal grinding counterweight is the sum of the radial separation distances of the mass center of the eccentric grinding element. 17. The device of claim 17, which is equal to the radial separation distance. 17. The distance of the center of mass of the proximal eccentric grinding counterweight from the center of mass of the eccentric grinding element is equal to the distance of the center of mass of the distal eccentric grinding counterweight from the center of gravity of the eccentric grinding element. The device described in. The distance of the mass center of the eccentric proximal grinding counterweight from the mass center of the eccentric grinding element is not equal to the distance of the mass center of the eccentric distal grinding counterweight from the mass center of the eccentric grinding element. 17. The device according to 17. The rotational separation between adjacent longitudinal planes, including the center of gravity of the eccentric grinding element, the center of gravity of the proximal eccentric counterweight, and the center of gravity of the distal eccentric counterweight, is zero. 21. The device of claim 21, which is from degree to 90 degrees. The rotational separation between adjacent longitudinal planes, including the center of gravity of the eccentric grinding element, the center of gravity of the proximal eccentric counterweight, and the center of gravity of the distal eccentric counterweight, is approximately. The device of claim 33, which is 45 degrees. 17. The device of claim 17, wherein at least one of the proximal grinding counterweight and the distal grinding counterweight is at least partially hollow.

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