Patent Description:
This document relates to rotational atherectomy devices and systems with an electric motor that removes or reduces stenotic lesions in blood vessels by rotating an abrasive element within the vessel to partially or completely remove the stenotic lesion material.

Atherosclerosis, the clogging of arteries with plaque, is often a result of coronary heart disease or vascular problems in other regions of the body. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, the plaque hardens and narrows the arteries. This limits the flow of oxygen-rich blood to organs and other parts of the body.

Blood flow through the peripheral arteries (e.g., carotid, iliac, femoral, renal etc.), can be similarly affected by the development of atherosclerotic blockages. Peripheral artery disease (PAD) can be serious because without adequate blood flow, the kidneys, legs, arms, and feet may suffer irreversible damage. Left untreated, the tissue can die or harbor infection.

One method of removing or reducing such blockages in blood vessels is known as rotational atherectomy. In some implementations, a drive shaft carrying an abrasive burr or other abrasive surface (e.g., formed from diamond grit or diamond particles) rotates at a high speed within the vessel, and the clinician operator slowly advances the atherectomy device distally so that the abrasive burr scrapes against the occluding lesion and disintegrates it, reducing the occlusion and improving the blood flow through the vessel.

<CIT> describes a device for modifying a body lumen of a mammal in need thereof is provided, comprising a helically-cut tube comprising cutting teeth, said helically-cut tube substantially coaxial with the longitudinal axis of said device, a ramp wire that is displaced from the longitudinal axis of said device over at least a portion of said ramp wire and is enclosed by said helically-cut tube over at least a part of the length of said ramp wire, a drive rod wherein the broach may be moved proximally, distally, and/or radially via proximal, distal, and radial motions, respectively, of the drive rod. Also provided are methods for using the device.

<CIT> describes a rotational atherectomy system that includes an elongated, flexible spin-to-open drive shaft having a distal end for insertion into a vasculature of a patient and having a proximal end opposite the distal end remaining outside the vasculature of the patient, a concentric or eccentric abrasive element attached to the drive shaft proximate the distal end of the drive shaft, an electric motor rotatably coupled to the proximal end of the drive shaft, the electric motor being capable of rotating the drive shaft in a spin-to-open direction, and control electronics for monitoring and controlling the rotation of the electric motor.

<CIT> describes a thrombus removal device that includes a catheter having a proximal end and a distal end, an aspiration lumen therebetween, and a guidewire lumen, a vacuum source fluidly connected to the proximal end of the aspiration lumen, a wire having a straight proximal portion and a macerating portion distal the proximal portion and disposed in the aspiration lumen, and a motor mechanically connected to the wire proximal portion to effect movement of the wire and may further include a wire having a wave-propagating portion.

<CIT> describes a luminal drilling system that includes a drilling device and a control unit. The drilling device includes an elongate member having a drive shaft with a drill tip. The control unit includes a motor connectable to the drive shaft and control circuitry which rotationally oscillates the drive shaft with the direction of rotation automatically reversing whenever the load on the motor and/or drive shaft exceeds a threshold value.

<CIT> describes a rotational atherectomy system that includes a drive shaft, a motor, and a clutch with a threshold torque where the clutch may include a motor plate rotationally connected to the motor, a drive shaft plate rotationally connected to the drive shaft, and a biasing clutch configured to rotationally engage the motor plate and the drive shaft plate, wherein torques less than the threshold torque are transmitted completely between the motor plate and the drive shaft plate, which remain rotationally coupled by static friction, and wherein torques greater than the threshold torque cause the motor plate and the drive shaft plate to rotate relative to one another and cause a residual torque to be transmitted between the motor and the drive shaft, the residual torque being less than the threshold torque and being determined by a kinetic coefficient of friction.

<CIT> describes a method for treating a patient having thrombus.

Some embodiments of a rotational atherectomy device for removing stenotic lesion material from a blood vessel of a patient, includes: an elongate flexible drive shaft; an abrasive element coupled to a distal portion of the elongate flexible drive shaft; and a handle comprising an outer housing. The handle further includes an electric motor coupled to a proximal portion of the elongate flexible drive shaft, where the electric motor can be configured to cause rotation of the elongate flexible drive shaft in a first rotational direction. The device also includes a pump configured to provide fluid to a distal portion of the elongate flexible drive shaft, wherein the outer housing contains the electric motor and the pump.

In some embodiments, the rotational atherectomy device further comprises a control system configured to control rotation of the electric motor by monitoring an amount of current supplied to the electric motor and limiting the amount of current supplied such that the amount of current does not exceed a threshold current value. In some embodiments, the control system is configured to control rotation of the electric motor by initiating a stopping protocol when the amount of the current supplied reaches a threshold current value. In some embodiments, the stopping protocol comprises reducing the amount of current supplied to the electric motor to approximately zero. In some embodiments, the stopping protocol comprises reversing rotation of the elongate drive shaft by reversing the rotation caused by the electrical motor from the first rotational direction to a second rotational direction. In some embodiments, the stopping protocol occurs after a predetermined amount of time. In some embodiments, the predetermined amount of time is about <NUM> second to about <NUM> seconds. In some embodiments, the predetermined amount of time begins after the threshold current value is reached. In some embodiments, the elongate flexible drive shaft defines a longitudinal axis and comprising a torque-transmitting coil of one or more filars that are helically wound around the longitudinal axis in a second rotational direction, such that rotation of the elongate flexible drive shaft in the first rotational direction causes unwinding of the one or more filars of the elongate flexible drive shaft.

In some embodiments, the device further comprises a power source configured to couple to the handle. In some embodiments, the device further comprises a rechargeable battery removably coupled to the handle. In some embodiments, the handle further comprises a battery. In some embodiments, the handle further comprises a pump motor coupled to the pump and configured to run the pump. In some embodiments, the pump comprises at least one of a micropump, a piezoelectric pump, an electromechanical integrated pump, a peristaltic pump, or a quasiperistaltic pump. In some embodiments, the electric motor comprises at least one of a DC motor, or a DC motor controller. In some embodiments, the elongate flexible drive shaft is directly coupled to the electric motor. In some embodiments, the elongate flexible drive shaft is directly coupled to the electric motor via a cannulation in the electric motor. In some embodiments, the electric motor is coupled to the elongate flexible drive shaft in a gearless configuration. In some embodiments, the elongate flexible drive shaft is coupled to the electric motor via one or more gears. In some embodiments, the gear ratio is <NUM>:<NUM>.

Some of the embodiments described herein may provide one or more of the following advantages. First, some embodiments of the rotational atherectomy system are configured to advance the drive shaft and the handle assembly over a guidewire, and to use an electric motor to drive the rotation of the drive shaft while the guidewire remains within the drive shaft. Accordingly, in some embodiments the handle assemblies provided herein include features that allow the drive shaft to be positioned over a guidewire. Thereafter, the guidewire can be detained in relation to the handle so that the guidewire will not rotate while the drive shaft is being rotated.

Second, some embodiments of the rotational atherectomy system include a drive shaft constructed of one or more helically wound filars that are wound in the same direction that the drive shaft is rotated during use. Accordingly, the turns of the helically wound filars can tend to radially expand and separate from each other (or "open up") during rotational use. Such a scenario advantageously reduces frictional losses between adjacent filar turns. Additionally, when a guidewire is disposed within the lumen defined by the helically wound filars during rotational use, the drive shaft will tend to loosen on the guidewire rather than to tighten on it. Consequently, in some cases no use of lubricant between the guidewire and the drive shaft is necessary. Moreover, since the drive shaft will tend to loosen on the guidewire, less stress will be induced on the guidewire during rotation of the drive shaft. Thus, the potential for causing breaks of the guidewire is advantageously reduced. Further, since the drive shaft will tend to loosen on the guidewire during use, a larger guidewire can be advantageously used in some cases.

Third, some embodiments of the rotational atherectomy devices and systems provided herein include multiple abrasive elements that are offset from each other around the drive shaft such that the centers of mass of the abrasive elements define a path that spirals around a central longitudinal axis of the drive shaft. In particular embodiments, the rotational atherectomy systems are used by rotating the drive shaft around the longitudinal axis in a direction opposite of the spiral path defined by the centers of mass of the abrasive elements. Such an arrangement can advantageously provide a smoother running and more controllable atherectomy procedure as compared to systems that rotate the drive shaft in the same direction as the spiral path defined by the centers of mass of the abrasive elements.

Fourth, some embodiments of the rotational atherectomy devices and systems provided herein include a handle assembly with an electric motor that is used to drive rotations of the drive shaft. Such an electric motor can be entirely or substantially entirely housed within the handle assembly of the rotational atherectomy devices. The electric motor can provide the benefits of providing increased control and reliability over the rotational movement of the shaft. Such benefits can improve the rotational responsiveness of rotational actuation of the shaft and can reduce or eliminate unintentional or excessive rotational actuation during an atherectomy procedure. Furthermore, the electric motor does not rely on pneumatic equipment, and therefore eliminates the burden of providing pneumatic power, such as a compressed gas (e.g., air, nitrogen, or the like) supply, during a medical procedure. Additionally, the handle assembly can incorporate or externally couple a control system for monitoring and controlling the rotation of the electric motor.

Fifth, certain embodiments of the handle assembly may integrate a pump or micropump, such as a saline pump (with a pump motor), within the housing. The pump can provide the benefit of delivering saline, or other fluids, to a distal end of the rotational atherectomy device, providing lubrication, and/or preventing blood from back flowing through a sheath of the rotational atherectomy device outside of the body. The integrated pump can increase the versatility of the handle assembly by eliminating the need to obtain and connect an external pump to the handle assembly during a medical procedure.

Also, by integrating the electric motor and pump into the handle assembly, additional advantages can be realized. For example, the handle assembly and/or the entire rotational atherectomy system provided herein can be sterilizable as well as disposable, thus reducing the risk of contamination and infection.

Sixth, the handle assembly can also house a battery, or couple to a battery. Such a device would not need external power to operate, making the rotational atherectomy device more readily available in remote areas with limited power supplies, or provide the user with increased convenience of use. As such, a clinician can have increased mobility with the handle assembly, as the handle assembly only needs to attach to an external fluid reservoir. Accordingly, a clinician would be less restricted and obstructed by connection cables during use.

Seventh, in some embodiments rotational atherectomy systems described herein include user controls that are convenient and easy to operate. In one such example, the user controls can include selectable elements on the handle assembly, reducing the need for a clinician to operate a secondary control device while operating the handle assembly. For example, the user controls can include selectable elements that correspond to the speed of drive shaft rotations. In some such examples, the user can conveniently select "low" or "high" speeds. Hence, in such a case the clinician-user conveniently does not need to explicitly select or control the rpm of the drive shaft.

Referring to <FIG>, in some embodiments a rotational atherectomy system <NUM> for removing or reducing stenotic lesions in blood vessels can include a guidewire <NUM>, a handle assembly <NUM>, and an elongate flexible drive shaft assembly <NUM>. The drive shaft assembly <NUM> extends distally from the handle assembly <NUM>. The handle assembly <NUM> can be operated by a clinician to perform and control the rotational atherectomy procedure.

In the depicted embodiment, the elongate flexible drive shaft assembly <NUM> includes a sheath <NUM> and a flexible drive shaft <NUM>. A proximal end of the sheath <NUM> is fixed to a distal end of the handle assembly <NUM>. The flexible drive shaft <NUM> is slidably and rotatably disposed within a lumen of the sheath <NUM>. The flexible drive shaft <NUM> defines a longitudinal lumen in which the guidewire <NUM> is slidably disposed. In this embodiment, the flexible drive shaft <NUM> includes a torque-transmitting coil that defines the longitudinal lumen along a central longitudinal axis, and the drive <NUM> shaft is configured to rotate about the longitudinal axis while the sheath <NUM> remains generally stationary. Hence, as described further below, during a rotational atherectomy procedure the flexible drive shaft <NUM> is in motion (e.g., rotating and longitudinally translating) while the sheath <NUM> and the guidewire <NUM> are generally stationary.

In some optional embodiments, an inflatable member (not shown) can surround a distal end portion of the sheath <NUM>. Such an inflatable member can be selectively expandable between a deflated low-profile configuration and an inflated deployed configuration. The sheath <NUM> may define an inflation lumen through which the inflation fluid can pass (to and from the optional inflatable member). The inflatable member can be in the deflated low-profile configuration during the navigation of the drive shaft assembly <NUM> through the patient's vasculature to a target location in a vessel. Then, at the target location, the inflatable member can be inflated so that the outer diameter of the inflatable member contacts the wall of the vessel. In that arrangement, the inflatable member advantageously stabilizes the drive shaft assembly <NUM> in the vessel during the rotational atherectomy procedure.

Still referring to <FIG>, the flexible driveshaft <NUM> is slidably and rotatably disposed within a lumen of the sheath <NUM>. A distal end portion of the driveshaft <NUM> extends distally of the distal end of the sheath <NUM> such that the distal end portion of the driveshaft <NUM> is exposed (e.g., not within the sheath <NUM>, at least not during the performance of the actual rotational atherectomy).

In the depicted embodiment, the exposed distal end portion of the driveshaft <NUM> includes one or more abrasive elements <NUM>, a (optional) distal stability element <NUM>, and a distal drive shaft extension portion <NUM>. In the depicted embodiment, the one or more abrasive elements <NUM> are eccentrically-fixed to the driveshaft <NUM> proximal of the distal stability element <NUM>. In this embodiment, the distal stability element <NUM> is concentrically-fixed to the driveshaft <NUM> between the one or more abrasive elements <NUM> and the distal drive shaft extension portion <NUM>. As such, the center of mass of the distal stability element <NUM> is aligned with the central axis of the drive shaft <NUM> while the center of mass of each abrasive element <NUM> is offset from the central axis of the drive shaft <NUM>. The distal drive shaft extension portion <NUM>, which includes the torque-transmitting coil, is configured to rotate about the longitudinal axis extends distally from the distal stability element <NUM> and terminates at a free end of the drive shaft <NUM>.

In some optional embodiments, a proximal stability element (not shown) is included. The proximal stability element can be constructed and configured similarly to the depicted embodiment of the distal stability element <NUM> (e.g., a metallic cylinder directly coupled to the torque-transmitting coil of the drive shaft <NUM> and concentric with the longitudinal axis of the drive shaft <NUM>) while being located proximal to the one or more abrasive elements <NUM>.

In the depicted embodiment, the distal stability element <NUM> has a center of mass that is axially aligned with a central longitudinal axis of the drive shaft <NUM>, while the one or more abrasive elements <NUM> (collectively and/or individually) have a center of mass that is axially offset from central longitudinal axis of the drive shaft <NUM>. Accordingly, as the drive shaft <NUM> is rotated about its longitudinal axis, the principle of centrifugal force will cause the one or more abrasive elements <NUM> (and the portion of the drive shaft <NUM> to which the one or more abrasive elements <NUM> are affixed) to follow a transverse generally circular orbit (e.g., somewhat similar to a "jump rope" orbital movement) relative to the central axis of the drive shaft <NUM>. In general, faster speeds (rpm) of rotation of the drive shaft <NUM> will result in larger diameters of the orbit (within the limits of the vessel diameter). The orbiting one or more abrasive elements <NUM> will contact the stenotic lesion to ablate or abrade the lesion to a reduced size (i.e., small particles of the lesion will be abraded from the lesion).

The rotating distal stability element <NUM> will remain generally at the longitudinal axis of the drive shaft <NUM> as the drive shaft <NUM> is rotated. In some optional embodiments, two or more distal stability elements <NUM> are included. As described further below, contemporaneous with the rotation of the drive shaft <NUM>, the drive shaft <NUM> can be translated back and forth along the longitudinal axis of the drive shaft <NUM>. Hence, lesions can be abraded radially and longitudinally by virtue of the orbital rotation and translation of the one or more abrasive elements <NUM>, respectively.

The flexible drive shaft <NUM> of rotational atherectomy system <NUM> is laterally flexible so that the drive shaft <NUM> can readily conform to the non-linear vasculature of the patient, and so that a portion of the drive shaft <NUM> at and adjacent to the one or more abrasive elements <NUM> will laterally deflect when acted on by the centrifugal forces resulting from the rotation of the one or more eccentric abrasive elements <NUM>. In this embodiment, the drive shaft <NUM> comprises one or more helically wound wires (or filars) that provide one or more torque-transmitting coils of the drive shaft <NUM> (as described below, for example, in connection with <FIG>). In some embodiments, the one or more helically wound wires are made of a metallic material such as, but not limited to, stainless steel (e.g., <NUM>, <NUM>, or 316LVM), nitinol, titanium, titanium alloys (e.g., titanium beta <NUM>), carbon steel, or another suitable metal or metal alloy. In some alternative embodiments, the filars are or include graphite, Kevlar, or a polymeric material. In some embodiments, the filars can be woven, rather than wound. In some embodiments, individual filars can comprise multiple strands of material that are twisted, woven, or otherwise coupled together to form a filar. In some embodiments, the filars have different cross-sectional geometries (size or shape) at different portions along the axial length of the drive shaft <NUM>. In some embodiments, the filars have a cross-sectional geometry other than a circle, e.g., an ovular, square, triangular, or another suitable shape.

In this embodiment, the drive shaft <NUM> has a hollow core. That is, the drive shaft <NUM> defines a central longitudinal lumen running therethrough. The lumen can be used to slidably receive the guidewire <NUM> therein, as will be described further below. In some embodiments, the lumen can be used to aspirate particulate or to convey fluids that are beneficial for the atherectomy procedure.

In some embodiments, the drive shaft <NUM> includes an optional coating on one or more portions of the outer diameter of the drive shaft <NUM>. The coating may also be described as a jacket, a sleeve, a covering, a casing, and the like. In some embodiments, the coating adds column strength to the drive shaft <NUM> to facilitate a greater ability to push the drive shaft <NUM> through stenotic lesions. In addition, the coating can enhance the rotational stability of the drive shaft <NUM> during use. In some embodiments, the coating is a flexible polymer coating that surrounds an outer diameter of the coil (but not the abrasive elements <NUM> or the distal stability element <NUM>) along at least a portion of drive shaft <NUM> (e.g., the distal portion of the drive shaft <NUM> exposed outwardly from the sheath <NUM>). In some embodiments, a portion of the drive shaft <NUM> or all of the drive shaft <NUM> is uncoated. In particular embodiments, the coating is a fluid impermeable material such that the lumen of the drive shaft <NUM> provides a fluid impermeable flow path along at least the coated portions of the drive shaft <NUM>.

The coating may be made of materials including, but not limited to, PEBEX, PICOFLEX, PTFE, ePTFE, FEP, PEEK, silicone, PVC, urethane, polyethylene, polypropylene, and the like, and combinations thereof. In some embodiments, the coating covers the distal stability element <NUM> and the distal extension portion <NUM>, thereby leaving only the one or more abrasive elements <NUM> exposed (non-coated) along the distal portion of the drive shaft <NUM>. In alternative embodiments, the distal stability element <NUM> is not covered with the coating, and thus would be exposed like the abrasive element <NUM>. In some embodiments, two or more layers of the coating can be included on portions of the drive shaft <NUM>. Further, in some embodiments different coating materials (e.g., with different durometers and/or stiffnesses) can be used at different locations on the drive shaft <NUM>.

In the depicted embodiment, the distal stability element <NUM> is a metallic cylindrical member having an inner diameter that surrounds a portion of the outer diameter of the drive shaft <NUM>. In some embodiments, the distal stability element <NUM> has a longitudinal length that is greater than a maximum exterior diameter of the distal stability element <NUM>. In the depicted embodiment, the distal stability element <NUM> is coaxial with the longitudinal axis of the drive shaft <NUM>. Therefore, the center of mass of the distal stability element <NUM> is axially aligned (non-eccentric) with the longitudinal axis of the drive shaft <NUM>. In alternative rotational atherectomy device embodiments, stability element(s) that have centers of mass that are eccentric in relation to the longitudinal axis may be included in addition to, or as an alternative to, the coaxial stability elements <NUM>. For example, in some alternative embodiments, the stability element(s) can have centers of mass that are eccentric in relation to the longitudinal axis and that are offset <NUM> degrees (or otherwise oriented) in relation to the center of mass of the one or more abrasive elements <NUM>.

The distal stability element <NUM> may be made of a suitable biocompatible material, such as a higher-density biocompatible material. For example, in some embodiments the distal stability element <NUM> may be made of metallic materials such as stainless steel, tungsten, molybdenum, iridium, cobalt, cadmium, and the like, and alloys thereof. The distal stability element <NUM> has a fixed outer diameter. That is, the distal stability element <NUM> is not an expandable member in the depicted embodiment. The distal stability element <NUM> may be mounted to the filars of the drive shaft <NUM> using a biocompatible adhesive, by welding, by press fitting, and the like, and by combinations thereof. The coating may also be used in some embodiments to attach or to supplement the attachment of the distal stability element <NUM> to the filars of the drive shaft <NUM>. Alternatively, the distal stability element <NUM> can be integrally formed as a unitary structure with the filars of the drive shaft <NUM> (e.g., using filars of a different size or density, using filars that are double-wound to provide multiple filar layers, or the like). The maximum outer diameter of the distal stability element <NUM> may be smaller than the maximum outer diameters of the one or more abrasive elements <NUM>.

In some embodiments, the distal stability element <NUM> has an abrasive coating on its exterior surface. For example, in some embodiments a diamond coating (or other suitable type of abrasive coating) is disposed on the outer surface of the distal stability element <NUM>. In some cases, such an abrasive surface on the distal stability element <NUM> can help facilitate the passage of the distal stability element <NUM> through vessel restrictions (such as calcified areas of a blood vessel).

In some embodiments, the distal stability element <NUM> has an exterior cylindrical surface that is smoother and different from an abrasive exterior surface of the one or more abrasive elements <NUM>. That may be the case whether or not the distal stability element <NUM> have an abrasive coating on its exterior surface. In some embodiments, the abrasive coating on the exterior surface of the distal stability element <NUM> is rougher than the abrasive surfaces on the one or more abrasive elements <NUM>.

Still referring to <FIG>, the one or more abrasive elements <NUM> (which may also be referred to as a burr, multiple burrs, or (optionally) a helical array of burrs) can comprise a biocompatible material that is coated with an abrasive media such as diamond grit, diamond particles, silicon carbide, and the like. In the depicted embodiment, the abrasive elements <NUM> includes a total of five discrete abrasive elements that are spaced apart from each other. In some embodiments, one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, or more than fifteen discrete abrasive elements are included as the one or more abrasive elements <NUM>. Each of the five discrete abrasive elements can include the abrasive media coating, such as a diamond grit coating.

In the depicted embodiment, the two outermost abrasive elements are smaller in maximum diameter than the three inner abrasive elements. In some embodiments, all of the abrasive elements are the same size. In particular embodiments, three or more different sizes of abrasive elements are included. Any and all such possible arrangements of sizes of abrasive elements are envisioned and within the scope of this disclosure.

Also, in the depicted embodiment, the center of mass of each abrasive element <NUM> is offset from the longitudinal axis of the drive shaft <NUM>. Therefore, as the eccentric one or more abrasive elements <NUM> are rotated (along an orbital path), at least a portion of the abrasive surface of the one or more abrasive elements <NUM> can make contact with surrounding stenotic lesion material. As with the distal stability element <NUM>, the eccentric one or more abrasive elements <NUM> may be mounted to the filars of the torque-transmitting coil of the drive shaft <NUM> using a biocompatible adhesive, high temperature solder, welding, press fitting, and the like. In some embodiments, a hypotube is crimped onto the driveshaft and an abrasive element is laser welded to the hypotube. Alternatively, the one or more abrasive elements <NUM> can be integrally formed as a unitary structure with the filars of the drive shaft <NUM> (e.g., using filars that are wound in a different pattern to create an axially offset structure, or the like).

In some embodiments, the spacing of the distal stability element <NUM> relative to the one or more abrasive elements <NUM> and the length of the distal extension portion <NUM> can be selected to advantageously provide a stable and predictable rotary motion profile during high-speed rotation of the drive shaft <NUM>. For example, in embodiments that include the distal driveshaft extension portion <NUM>, the ratio of the length of the distal driveshaft extension <NUM> to the distance between the centers of the one or more abrasive elements <NUM> and the distal stability element <NUM> is about <NUM>:<NUM>, about <NUM>:<NUM>, about <NUM>:<NUM>, about <NUM>:<NUM>, about <NUM>:<NUM>, about <NUM>:<NUM>, about <NUM>:<NUM>, about <NUM>:<NUM>, about <NUM>:<NUM>, or higher than <NUM>:<NUM>.

Still referring to <FIG>, and further referring to <FIG> and <FIG>, the rotational atherectomy system <NUM> also includes the handle assembly <NUM>. The handle assembly <NUM> includes a housing <NUM> and a carriage assembly <NUM>. The carriage assembly <NUM> is slidably translatable along the longitudinal axis of the handle assembly <NUM> along an aperture <NUM> defining a path, such that carriage assembly <NUM> along the longitudinal axis as indicated by the arrow <NUM>. For example, in some embodiments the carriage assembly <NUM> can be translated, without limitation, about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>. As the carriage assembly <NUM> is translated in relation to the housing <NUM>, the drive shaft <NUM> translates in relation to the sheath <NUM> in a corresponding manner.

In the depicted embodiment, the carriage assembly <NUM> includes an electrical motor switch <NUM>. While the electrical motor switch <NUM> is depressed, power is supplied to the electric motor (as shown in <FIG>, and <FIG>) which is fixedly coupled to the drive shaft <NUM>. Hence, an activation of the electrical motor switch <NUM> will result in a rotation of the turbine member and, in turn, the drive shaft <NUM> (as depicted by arrow <NUM>). It should be understood that the rotational atherectomy system <NUM> is configured to rotate the drive shaft <NUM> at a high speed of rotation (e.g., <NUM>,<NUM>-<NUM>,<NUM> rpm) such that the eccentric one or more abrasive elements <NUM> revolve in an orbital path to thereby contact and remove portions of a target lesion (even those portions of the lesion that are spaced farther from the axis of the drive shaft <NUM> than the maximum radius of the one or more abrasive elements <NUM>).

To operate the handle assembly <NUM> during a rotational atherectomy procedure, a clinician can grasp the carriage assembly <NUM> and depress the electrical motor switch <NUM> with the same hand. The clinician can move (translate) the carriage assembly <NUM> distally and proximally by hand (e.g., back and forth in relation to the housing <NUM>), while maintaining the electrical motor switch <NUM> in the depressed state. In that manner, a target lesion(s) can be ablated radially and longitudinally by virtue of the resulting orbital rotation and translation of the one or more abrasive elements <NUM>, respectively.

To further operate the handle assembly <NUM> during a rotational atherectomy procedure, a clinician can select a rotational speed using electrical switches 210a and 210b. In some cases, the rotational speed can be selected through a range of speeds with electrical switch 210a causing an increase in speed and electrical switch 210b causing a decrease in speed. In some embodiments, rotational speed is changed incrementally between a plurality of preset speeds. For example, a single depression of electrical switch 210a or 210b will cause an incremental change in speed. In some embodiments, depression of the electrical switch 210a or 210b will cause a change in speed corresponding to a length of time that the electrical switch 210a or 210b is depressed. In another embodiment, the electrical switch 210a will cause a selection of a "high" rotational speed and the electrical switch 210b will cause a selection of a "low" rotational speed, in comparison to the high rotational speed.

Optionally, the electrical switches 210a and 210b can also include a light indicator. For example, when the electrical switches 210a and 210b allow for selection for a "high" and "low" speed, respectively, the electrical switches 210a and 210b can each have a single light, such that when a speed is selected, the light corresponding to the selected electrical switch 210a or 210b is illuminated to inform a clinician of the selected speed. In some embodiments, the light can shine through electrical switches 210a and 210b. Alternatively, a light can be positioned proximal electrical switch 210a and 210b. As another example, when the electrical switches 210a and 210b allow modification of a speed between a range of speeds, the light indicator can be a light bar, such that a number of lights illuminated on the light bar correspond to a selected speed.

Optionally, handle assembly <NUM> can include an electrical pump switch <NUM>. Electrical pump switch <NUM> can turn a saline pump on and off. In some cases, a first depression of the electrical pump switch <NUM> will turn the saline pump on, while a second depression will turn the saline pump on. In some embodiments, the electrical pump switch <NUM> includes a light indicator, such that when the pump is on, a light is illuminated to inform the clinician that the pump is on.

During an atherectomy treatment, in some cases the guidewire <NUM> is left in position in relation to the drive shaft <NUM> generally as shown. For example, in some cases the portion of the guidewire <NUM> that is extending beyond the distal end of the drive shaft <NUM> (or extension portion <NUM>) is about <NUM> inches to about <NUM> inches (about <NUM> to about <NUM>), about <NUM> inches to about <NUM> inches (about <NUM> to about <NUM>), or about <NUM> inches to about <NUM> inches (about <NUM> to about <NUM>). In some cases, the guidewire <NUM> is pulled back to be within (while not extending distally from) the drive shaft <NUM> during an atherectomy treatment. The distal end of the guidewire <NUM> may be positioned anywhere within the drive shaft <NUM> during an atherectomy treatment. In some cases, the guidewire <NUM> may be completely removed from within the drive shaft during an atherectomy treatment. The extent to which the guidewire <NUM> is engaged with the drive shaft <NUM> during an atherectomy treatment may affect the size of the orbital path of the one or more abrasive elements <NUM>. Accordingly, the extent to which the guidewire <NUM> is engaged with the drive shaft <NUM> may be situationally selected to be well-suited for a particular patient anatomy, physician's preference, type of treatment being delivered, and other such factors.

In the depicted embodiment, the handle assembly <NUM> also includes a guidewire detention mechanism <NUM>. The guidewire detention mechanism <NUM> can be selectively actuated (e.g., rotated) to releasably clamp and maintain the guidewire <NUM> in a stationary position relative to the handle assembly <NUM> (and, in turn, stationary in relation to rotations of the drive shaft <NUM> during an atherectomy treatment). While the drive shaft <NUM> and handle assembly <NUM> are being advanced over the guidewire <NUM> to put the one or more abrasive elements <NUM> into a targeted position within a patient's vessel, the guidewire detention mechanism <NUM> will be unactuated so that the handle assembly <NUM> is free to slide in relation to the guidewire <NUM>. Then, when the clinician is ready to begin the atherectomy treatment, the guidewire detention mechanism <NUM> can be actuated to releasably detain/lock the guidewire <NUM> in relation to the handle assembly <NUM>. That way the guidewire <NUM> will not rotate while the drive shaft <NUM> is rotating, and the guidewire <NUM> will not translate while the carriage assembly <NUM> is being manually translated.

In some embodiments, when the guidewire detention mechanism <NUM> is actuated to detain/lock the guidewire <NUM>, a light indicator <NUM> can illuminate, such that a clinician can confirm the guidewire detention mechanism <NUM> is actuated.

Optionally, the handle assembly <NUM> can include a safety mechanism regarding operation of the handle assembly. For example, rotation of the drive shaft assembly <NUM> may be prohibited until the guidewire detention mechanism <NUM> is actuated, the pump has been turned on via electrical pump switch <NUM>, and a rotation speed has been selected via electrical switch 210a or 210b. As another example, the indicator lights associated with the electrical switch 210a or 210b, the electrical pump switch <NUM>, and the guidewire detention mechanism <NUM> light indicator <NUM> will alert a clinician that the rotational atherectomy system <NUM> should not be operated until all three systems (the motor, the pump, the guidewire lock) are lit. For example, each system may have a green light, such that three green lights indicates the clinician can proceed with the atherectomy procedure. Optionally, only the guidewire detection mechanism <NUM> needs to be actuated to allow rotation of the rotational atherectomy system <NUM>.

Referring to <FIG>, and <FIG>, an interior cavity <NUM> of the handle assembly <NUM> is shown. The housing <NUM> can include an upper housing 202a and a lower housing 202b that encapsulate a motor assembly <NUM>, a pump assembly <NUM>, and a controller assembly <NUM>. The interior cavity <NUM> can also house the electrical switches 210a and 210b, the electrical pump switch <NUM>, and the light indicator <NUM>, collectively, user controls <NUM>. In some cases, the user controls <NUM> can protrude through apertures of upper housing 202a. In some embodiments, the user controls <NUM> can abut a flexible portion of upper housing 202a, such that the user controls <NUM> can be actuated without direct contact. In some embodiments, the handle assembly <NUM> is disposable. In some embodiments, the handle assembly <NUM> is a sterilized handle assembly, or is partially or fully sterilizable handle assembly. For example, in some embodiments, the handle can be sterilized using ethylene oxide (EtO) sterilization, or hydrogen peroxide sterilization.

The motor assembly <NUM> can include a motor <NUM> and, optionally, a gear assembly <NUM> (as shown in <FIG>). The motor <NUM> can be electric motor, such as a DC motor. Exemplary motors can include a brush DC motor, or a brushless DC motor. Other suitable motors may, however, include a servo motor, a stepper motor, and/or an AC motor. Motor <NUM> can be mechanically coupled to carriage assembly <NUM>, such that motor <NUM> can translate along housing <NUM>, and more specifically, inside sheath <NUM> to cause translation of drive shaft <NUM>. Further, motor <NUM> can be electrically coupled to electrical motor switch <NUM>, such that depression of electrical motor switch <NUM> causes motor <NUM> to run. In some embodiments, motor <NUM> can be directly coupled to drive shaft <NUM> to cause rotation of drive shaft <NUM>, and accordingly, abrasive elements <NUM>. For example, the motor <NUM> can include a cannulation through a longitudinal axis of the motor <NUM> that is configured to receive and secure the drive shaft <NUM>, direct drive of the drive shaft <NUM>.

As mentioned above, motor assembly <NUM> can include a gear assembly <NUM>. In some embodiments, the gear assembly <NUM> can have a <NUM>:<NUM> gear ratio to increase an rpm output from motor <NUM>. In some cases, using a motor with lower rpm capabilities, but supplementing the motor <NUM> with the gear assembly <NUM> can be more cost effective, especially for a disposable handle assembly <NUM>. For example, motor <NUM> can have an output of <NUM> rpm, and can cause rotation of the drive shaft <NUM> at <NUM> rpm. Motor <NUM> can be controlled by controller assembly <NUM>, as will be described below.

In another embodiment, as shown in <FIG>, motor assembly <NUM> can include a cannulated motor <NUM>. Cannulated motor <NUM> can include a cannulation to receive a hypotube of the rotational atherectomy device. In some embodiments, the cannulated motor <NUM> can provide a simpler design, which can reduce breakage by reducing the number of components involved in rotation of the elongate flexible drive shaft. Further, direct translation of the rotational components can increase simplicity of the design and operation of the rotational atherectomy device. Cannulated motor <NUM> can provide the improved torque transmission during the rotation of the elongate flexible drive shaft.

The pump assembly <NUM> can include a pump <NUM> (or micropump), tubes <NUM>, an external fitting <NUM>, and a pump motor <NUM>. Pump <NUM> can pump saline, or other fluids, to a distal portion of rotational atherectomy device <NUM>. Pump <NUM> can be a peristaltic pump, a piezoelectric pump, an electromechanical integrated pump, a microdosing pump, a positive displacement pump, a quasi-peristaltic pump, or other micropump. Pump <NUM> can include one or more tubes <NUM> extend from, or extending through, pump <NUM> to pump saline from an exterior of housing <NUM> to a distal end of the rotational atherectomy device <NUM>. In some embodiments, due to sterilization needs, it can be beneficial to use a pump with separation between the fluid and pump <NUM>, such that the fluid only contacts tubes <NUM>. External fitting <NUM> can couple to tube <NUM> and further couple to a tube external to housing <NUM>. For example, external fitting <NUM> can be a luer fitting to couple a fluid bag (e.g., a saline bag). Pump <NUM> can be powered by pump motor <NUM>, which can be controlled by controller assembly <NUM>. Optionally, pump motor <NUM> can be a brushless DC motor. Pump motor <NUM> can allow pump <NUM> to operate at about <NUM> kPa (<NUM> psi) to about <NUM> kPa (<NUM> psi), such that the fluid pumped by pump <NUM> prevents backflow of blood during the atherectomy procedure. Pump assembly <NUM> can include seals to prevent leakage into housing <NUM>.

The controller assembly <NUM> can include a housing <NUM>, and a controller <NUM>. Housing <NUM> can provide a seal and barrier between controller <NUM> and the other components of handle assembly <NUM> to protect the controller <NUM> from liquid (e.g., blood from a patient, fluid from the pump <NUM>). In some embodiments, the housing <NUM> can also provide a structural support for the pump assembly <NUM>, as shown in <FIG>. The controller <NUM> can be electrically coupled to the components of the user controls <NUM> and control function of the components.

For example, the controller <NUM> can cause motor <NUM> to run or stop based on electrical motor switch <NUM>, such that when electrical motor switch <NUM> is depressed, controller <NUM> causes motor <NUM> to run. In addition, controller <NUM> can determine and control a speed for rotating the drive shaft <NUM>, and supply the appropriate power to the motor <NUM> based on user input via electrical switches 210a and/or 210b. For example, the rotational speed can be selected through a range of speeds with electrical switch 210a causing an increase in speed and electrical switch 210b causing a decrease in speed. In some embodiments, rotational speed is changed incrementally between a plurality of preset speeds. As such, a single depression of electrical switch 210a or 210b can cause controller <NUM> to increase current supplied to the motor <NUM> to cause an incremental change in speed. In some embodiments, depression of the electrical switch 210a or 210b will cause controller <NUM> to supply a current to cause a change in speed corresponding to a length of time that the electrical switch 210a or 210b is depressed. In another embodiment, the electrical switch 210a will cause controller <NUM> to determine a selection of a "high" rotational speed was made and provide the appropriate current, and the electrical switch 210b will cause controller <NUM> to determine a selection of a "low" rotational speed, in comparison to the high rotational speed, was made and provide the appropriate current. Additionally, controller <NUM> can control the light indicators associated with electrical switches 210a and 210b, as described above.

In some embodiments, the controller <NUM> can monitor and control a parameter, such as an amount of current supplied to the motor <NUM>. Such monitoring and controlling features can provide a safety (shut-off) feature to the rotational atherectomy system <NUM> that prevents damage from occurring to the system <NUM> and/or a patient during use. For example, in various embodiments, the controller <NUM> is configured such that the current supplied does not exceed a threshold current value (e.g., prevents a large amount of current from being supplied to motor <NUM>). Thus, the controller <NUM> can be programmed to provide current to the motor <NUM>, but at a current level that is no greater than the threshold current value. The controller <NUM> can optionally limit the system <NUM> based exclusively on the current threshold value, in some embodiments, to provide an effective, yet simplified algorithm to the controller <NUM> as a safety feature.

The threshold current value can be a predetermined value that prevents irreversible damage or undesirable performance of the system <NUM> from occurring during use. For example, in some embodiments, the threshold current value is configured to limit the torque and/or speed of rotation of the system <NUM> such that the rotation of the elongate flexible drive shaft in a particular rotational direction (e.g., a first rotational direction) does not cause unwinding of the one or more filars of the elongate flexible drive shaft to occur. In some embodiments, the threshold current value is configured to limit the torque and/or speed of rotation of the system <NUM> such that the rotation of the elongate flexible drive shaft in a particular rotational direction (e.g., a first rotational direction) does not cause a change in a maximum diameter of the elongate flexible drive shaft to occur.

In some embodiments, if the current supplied reaches a threshold current value, the controller <NUM> can initiate a stopping protocol. For example, the stopping protocol can cause the controller <NUM> to reduce the amount of current supplied to the electrical motor to approximately zero. In some embodiments, such a reduction of current supplied can occur in a short period of time, substantially instantaneously, or over a longer period of time. In some embodiments, the stopping protocol can cause the controller <NUM> to reverse the direction of rotation of the motor <NUM>, and therefore the rotation of the drive shaft <NUM>. Such a reversal in direction of rotation of the drive shaft <NUM> can cause rotation of a distal end of the drive shaft to <NUM> to slow down or stop. The stopping protocol can aid in preventing motor <NUM> from burning out. In some cases, the stopping protocol is caused to a distal portion of drive shaft <NUM> being stuck in a vessel. Optionally, once rotation has begun, the stopping protocol can be executed after a predetermined amount of time (e.g., about <NUM> seconds to about <NUM> seconds). In some cases, the predetermined amount of time for executing the stopping protocol can be selected such that the predetermined amount of time begins when the current threshold is reached. For example, the drive shaft coil may begin to unwind once the current threshold is reached, and the controller may continue to provide current to the motor until the predetermined amount of time has passed. In some cases, the drive shaft coil may begin to unwind before the current threshold is reached, and the controller will continue to motor the current supplied and initiate the stopping protocol after the current threshold is reached.

Optionally, controller <NUM> can cause pump motor <NUM> to run or stop pump <NUM> based on depression of electrical pump switch <NUM>. In some cases, a first depression of the electrical pump switch <NUM> will turn the saline pump on, while a second depression will turn the saline pump on. In some embodiments, the controller <NUM> control the light indicator associated with electrical pump switch <NUM>, such that when the pump is on, a light is illuminated to inform the clinician that the pump is on.

In some embodiments, controller <NUM> can monitor guidewire detention mechanism <NUM> (e.g., via a sensor), such that controller <NUM> can determine when guidewire detention mechanism <NUM> is actuated (e.g., rotated) to releasably clamp and maintain the guidewire <NUM> in a stationary position relative to the handle assembly <NUM> (and, in turn, stationary in relation to rotations of the drive shaft <NUM> during an atherectomy treatment). In some embodiments, when the clinician is ready to begin the atherectomy treatment, the guidewire detention mechanism <NUM> can be actuated to releasably detain/lock the guidewire <NUM> in relation to the handle assembly <NUM>. That way the guidewire <NUM> will not rotate while the drive shaft <NUM> is rotating, and the guidewire <NUM> will not translate while the carriage assembly <NUM> is being manually translated. Accordingly, controller <NUM> can prevent motor <NUM> from rotating the drive shaft <NUM> unless controller <NUM> detects that the guidewire detention mechanism <NUM> is actuated. Further, controller <NUM> can control illumination of the light indicator <NUM>.

Optionally, the controller <NUM> can include a safety mechanism regarding operation of the handle assembly <NUM>. For example, rotation of the drive shaft assembly <NUM> may be prohibited until the controller <NUM> detects that guidewire detention mechanism <NUM> is actuated, the pump has been turned on via electrical pump switch <NUM>, and a rotation speed has been selected via electrical switch 210a or 210b. As another example, the controller <NUM> can selectively illuminate indicator lights associated with the electrical switch 210a or 210b, the electrical pump switch <NUM>, and the guidewire detention mechanism <NUM> light indicator <NUM> to inform a clinician which systems are powered on. In some embodiments, a lack of three lights indicts to the clinician that the rotational atherectomy system <NUM> should not be operated, at least until all three systems (the motor, the pump, the guidewire lock) are lit. For example, each system may have a green light, such that three green lights indicates the clinician can proceed with the atherectomy procedure. Optionally, only the guidewire detection mechanism <NUM> needs to be actuated for the controller <NUM> to allow rotation of the rotational atherectomy system <NUM>.

In some embodiments, the handle assembly <NUM> can also include a battery or other power source (not shown). The battery or power source may be integrated into the housing <NUM>. For example, the battery could be disposable with handle assembly <NUM>. In some embodiments, the power source could have an external component configured to make an electrical connection (e.g., plug into a wall socket) to provide power. Optionally, the battery could be reusable. For example, housing <NUM> can be configured to receive a rechargeable battery, either on an exterior portion of housing <NUM>, or within interior cavity <NUM>.

Referring to <FIG>, a schematic diagram 150a depicting an end view of the drive shaft <NUM> (looking distally) with the abrasive elements <NUM> can be used to illustrate the filar spiral wind direction 131a (of the drive shaft <NUM>) in comparison to the spiral path defined by the abrasive element centers of mass 133a (of the abrasive elements <NUM> of <FIG>, and the abrasive elements 144a-e of <FIG>), and also in comparison to the rotation direction 145a of the drive shaft <NUM> during use. In the depicted embodiment, the filar spiral wind direction 131a is clockwise around the central longitudinal axis <NUM> of the drive shaft <NUM>. Also, the rotation direction 145a of the drive shaft <NUM> during use is clockwise around the central longitudinal axis <NUM> of the drive shaft <NUM>. In contrast, the spiral path defined by the abrasive element centers of mass 133a is counterclockwise around the central longitudinal axis <NUM> of the drive shaft <NUM>. In other words, the filar spiral wind direction 131a and the rotation direction 145a of the drive shaft <NUM> during use are the same direction, whereas the spiral path defined by the abrasive element centers of mass 133a is the opposite direction of: (i) the filar spiral wind direction 131a and (ii) the opposite direction of the rotation direction 145a of the drive shaft <NUM> during use.

Referring also to <FIG>, another schematic diagram 150b depicting an end view of the drive shaft <NUM> (looking distally) with the abrasive elements 144a-e (as shown in <FIG>) can be used to illustrate another arrangement of the filar spiral wind direction 131b (of the drive shaft <NUM>) in comparison to the spiral path defined by the abrasive element centers of mass 133b (of the abrasive elements 144a-e), and also in comparison to the rotation direction 145b of the drive shaft <NUM> during use. In the depicted embodiment, the filar spiral wind direction 131b is counterclockwise around the central longitudinal axis <NUM> of the drive shaft <NUM>. Also, the rotation direction 145b of the drive shaft <NUM> during use is counterclockwise around the central longitudinal axis <NUM> of the drive shaft <NUM>. In contrast, the spiral path defined by the abrasive element centers of mass 133b is clockwise around the central longitudinal axis <NUM> of the drive shaft <NUM>. In other words, here again in this example, the filar spiral wind direction 131b and the rotation direction 145b of the drive shaft <NUM> during use are the same direction, whereas the spiral path defined by the abrasive element centers of mass 133b is the opposite direction of: (i) the filar spiral wind direction 131b and (ii) the opposite direction of the rotation direction 145b of the drive shaft <NUM> during use.

The relative arrangements between: (i) the filar spiral wind direction 131a or 131b, (ii) the spiral path defined by the abrasive element centers of mass 133a or 133b, and (iii) the rotation direction 145a or 145b of the drive shaft <NUM> during use, as described above in reference to <FIG> and <FIG>, provide particular operational advantages in some usage scenarios. For example, when the direction of rotation and the direction the filars are wound are the same direction, the winds of the filars will tend to radially expand (the drive shaft <NUM> will tend to "open up," as shown in <FIG>), resulting in less friction, little to no need for lubrication, less stress induced on the guidewire, and so on. Additionally, when the direction of rotation of the drive shaft <NUM> and the direction of the spiral path defined by the centers of mass of the abrasive elements <NUM> are opposite, such an arrangement can advantageously provide a smoother running and more controllable atherectomy procedure as compared to systems that rotate the drive shaft in the same direction as the spiral path defined by the centers of mass of the abrasive elements. For example, rather than causing the abrasive elements <NUM> to corkscrew into the stenotic lesion material (as can occur when the drive shaft rotational direction is the same as the direction of the spiral path defined by the centers of mass of the abrasive elements), the abrasive elements <NUM> can instead abrade the stenotic lesion material in more of a gradual, smooth, and controllable manner.

Referring to <FIG>, a distal end portion of the drive shaft <NUM> is shown in a longitudinal cross-sectional view. The distal end portion of the drive shaft <NUM> includes the one or more abrasive elements <NUM> that are eccentrically-fixed to the driveshaft <NUM>, the optional distal stability element <NUM> with an abrasive outer surface, and the distal drive shaft extension portion <NUM>.

In the depicted embodiment, the one or more abrasive elements <NUM> includes a total of five discrete abrasive elements that are spaced apart from each other. In some embodiments, one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, or more than fifteen discrete abrasive elements are included as the one or more abrasive elements <NUM>. Each of the five discrete abrasive elements can include the abrasive media coating.

In the depicted embodiment, the two outermost abrasive elements of the abrasive elements <NUM> are smaller in maximum diameter than the three inner abrasive elements of the abrasive elements <NUM>. In some embodiments, all of the abrasive elements are the same size. In particular embodiments, three or more different sizes of abrasive elements are included. Any and all such possible arrangements of sizes of abrasive elements are envisioned and within the scope of this disclosure.

The one or more abrasive elements <NUM> can be made to any suitable size. For clarity, the size of the one or more abrasive elements <NUM> will refer herein to the maximum outer diameter of individual abrasive elements of the one or more abrasive elements <NUM>. In some embodiments, the one or more abrasive elements <NUM> are about <NUM> in size (maximum outer diameter). In some embodiments, the size of the one or more abrasive elements <NUM> is in a range of about <NUM> to about <NUM>, or about <NUM> to about <NUM>, or about <NUM> to about <NUM>, without limitation. Again, in a single embodiment, one or more of the abrasive elements <NUM> can have a different size in comparison to the other abrasive elements <NUM>. In some embodiments, the two outermost abrasive elements are about <NUM> in diameter and the inner abrasive elements are about <NUM> in diameter.

In the depicted embodiment, the one or more abrasive elements <NUM>, individually, are oblong in shape. A variety of different shapes can be used for the one or more abrasive elements <NUM>. For example, in some embodiments the one or more abrasive elements <NUM> are individually shaped as spheres, discs, rods, cylinders, polyhedrons, cubes, prisms, and the like. In some embodiments, such as the depicted embodiment, all of the one or more abrasive elements <NUM> are the same shape. In particular embodiments, one or more of the abrasive elements <NUM> has a different shape than one or more of the other abrasive elements <NUM>. That is, two, three, or more differing shapes of individual abrasive elements <NUM> can be combined on the same drive shaft <NUM>.

In the depicted embodiment, adjacent abrasive elements of the one or more abrasive elements <NUM> are spaced apart from each other. For example, in the depicted embodiment the two distal-most individual abrasive elements are spaced apart from each other by a distance 'X'. In some embodiments, the spacing between adjacent abrasive elements is consistent between all of the one or more abrasive elements <NUM>. Alternatively, in some embodiments the spacing between some adjacent pairs of abrasive elements differs from the spacing between other adjacent pairs of abrasive elements.

In some embodiments, the spacing distance X in ratio to the maximum diameter of the abrasive elements <NUM> is about <NUM>:<NUM>. That is, the spacing distance X is about equal to the maximum diameter. The spacing distance X can be selected to provide a desired degree of flexibility of the portion of the drive shaft <NUM> to which the one or more abrasive elements <NUM> are attached. In some embodiments, the ratio is about <NUM>:<NUM> (i.e., X is about <NUM> times longer than the maximum diameter). In some embodiments, the ratio is in a range of about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>. <NUM> :<NUM>, or about <NUM>:<NUM> to about <NUM>. <NUM> :<NUM>, or about <NUM>:<NUM> to about <NUM> :<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, or about <NUM>:<NUM> to about <NUM>:<NUM>, and anywhere between or beyond those ranges.

In the depicted embodiment, the center of mass of each one of the one or more abrasive elements <NUM> is offset from the longitudinal axis of the drive shaft <NUM> along a same radial angle. Said another way, the centers of mass of all of the one or more abrasive elements <NUM> are coplanar with the longitudinal axis of the drive shaft <NUM>. If the size of each of the one or more abrasive elements <NUM> is equal, the centers of mass of the one or more abrasive elements <NUM> would be collinear on a line that is parallel to the longitudinal axis of the drive shaft <NUM>.

Referring to <FIG>, according to some embodiments of the rotational atherectomy devices provided herein, one or more abrasive elements <NUM> are arranged at differing radial angles in relation to the drive shaft <NUM> as depicted here. Further, the draft shaft <NUM> is shown as in an unwinding state, as unwinding may optionally occur during rotation of the drive shaft <NUM> in some embodiments. In such a case, a path defined by the centers of mass of the one or more abrasive elements <NUM> spirals along the drive shaft <NUM> around the central longitudinal axis of the drive shaft <NUM>. In some cases (e.g., when the diameters of the one or more abrasive elements <NUM> are equal and the adjacent abrasive elements are all equally spaced), the centers of mass of the one or more abrasive elements <NUM> define a helical path along/around the drive shaft <NUM>. It has been found that such arrangements can provide a desirably-shaped orbital rotation of the one or more abrasive elements <NUM>. It should be noted that, in some embodiments, a controller assembly (e.g., controller assembly <NUM>) is configured to control rotation and current input such that the drive shaft <NUM> is prevented from unwinding during rotation of the drive shaft <NUM>.

It should be understood that any of the structural features described in the context of one embodiment of the rotational atherectomy devices provided herein can be combined with any of the structural features described in the context of one or more other embodiments of the rotational atherectomy devices provided herein. For example, the size, spacing, and/or shape features (and any other characteristics) of the one or more abrasive elements <NUM> described in the context of <FIG> can be incorporated in any desired combination with the spiral arrangement of the one or more abrasive elements <NUM>.

In some embodiments, the drive shaft assembly <NUM> includes at least four abrasive elements <NUM> attached to a distal end portion of the drive shaft <NUM> and each has a center of mass offset from the longitudinal axis of the drive shaft <NUM>. A spiral path defined by connecting the centers of mass of the at least four abrasive elements <NUM> spirals around the longitudinal axis of the drive shaft <NUM>. An overall radial angle of the spiral path is defined by a radial angle between a distal-most abrasive element of the at least four abrasive elements <NUM> and a proximal-most abrasive element of the at least four abrasive elements <NUM>. In some embodiments, the overall radial angle of the spiral path of the at least four abrasive elements <NUM> is always less than <NUM> degrees along any <NUM> length of the distal end portion of the drive shaft <NUM>. In some embodiments, the overall radial angle of the spiral path of the at least four abrasive elements <NUM> is always less than <NUM> degrees, or less than <NUM> degrees, or less than <NUM> degrees, or less than <NUM> degrees, or less than <NUM> degrees, or less than <NUM> degrees, or less than <NUM> degrees, or less than <NUM> degrees, or less than <NUM> degrees along any <NUM> length of the distal end portion of the drive shaft <NUM>.

In some embodiments, such as the depicted embodiment, the drive shaft assembly <NUM> includes a concentric abrasive tip member <NUM>. The concentric abrasive tip member <NUM> can be affixed to, and extending distally from, a distal-most end of the drive shaft <NUM>. In some embodiments that include the concentric abrasive tip member <NUM>, no distal stability element is included <NUM>. In particular embodiments (such as the depicted embodiment), the concentric abrasive tip member <NUM> and the distal stability element are both included <NUM>.

In some embodiments the concentric abrasive tip member <NUM> may be made of metallic materials such as stainless steel, tungsten, molybdenum, iridium, cobalt, cadmium, and the like, and alloys thereof. The concentric abrasive tip member <NUM> has a fixed outer diameter. That is, the concentric abrasive tip member <NUM> is not an expandable member in the depicted embodiment. The concentric abrasive tip member <NUM> may be mounted to the filars of the drive shaft <NUM> using a biocompatible adhesive, by welding, by press fitting, and the like, and by combinations thereof. Alternatively, the concentric abrasive tip member <NUM> can be integrally formed as a unitary structure with the filars of the drive shaft <NUM> (e.g., using filars of a different size or density, using filars that are double-wound to provide multiple filar layers, or the like).

In some embodiments, the concentric abrasive tip member <NUM> has an abrasive coating on its exterior surface. In particular embodiments, the concentric abrasive tip member <NUM> includes an abrasive material along an exterior circumferential surface, or on a distal end face/surface, or both. For example, in some embodiments a diamond coating (or other suitable type of abrasive coating) is disposed on the outer surface of the concentric abrasive tip member <NUM>. In some cases, such an abrasive surface on the concentric abrasive tip member <NUM> can help facilitate the passage of the concentric abrasive tip member <NUM> through vessel restrictions (such as calcified areas of a blood vessel).

In some embodiments, the concentric abrasive tip member <NUM> has an exterior surface that is smoother and different from an abrasive exterior surface of the one or more abrasive elements <NUM>. That may be the case whether or not the concentric abrasive tip member <NUM> have an abrasive coating on its exterior surface. In some embodiments, the abrasive coating on the exterior surface of the concentric abrasive tip member <NUM> is rougher than the abrasive surfaces on the one or more abrasive elements <NUM>.

The maximum outer diameter of the concentric abrasive tip member <NUM> may be smaller than, equal to, or larger than the outer diameter of the adjacent portion of the drive shaft <NUM>. The maximum outer diameter of the concentric abrasive tip member <NUM> may be smaller than, equal to, or larger than the maximum outer diameter of each of the one or more abrasive elements 144a-e. The lateral width of the concentric abrasive tip member <NUM> (e.g., measured parallel to the longitudinal axis of the drive shaft <NUM>) may be smaller than, equal to, or larger than the maximum lateral width of each of the one or more abrasive elements 144a-e.

The concentric abrasive tip member <NUM> defines a central opening that is coaxial with the lumen defined by the drive shaft <NUM>. Accordingly, a guidewire (e.g., the guidewire <NUM> of <FIG>) can extend through the concentric abrasive tip member <NUM>. In some embodiments, the concentric abrasive tip member <NUM> is shaped as a toroid. In particular embodiments, the concentric abrasive tip member <NUM> is shaped as a hollow cylinder. In certain embodiments, the outer surface of the concentric abrasive tip member <NUM> defines one or more grooves, teeth, edges, and the like, and combinations thereof.

Next, as depicted by <FIG>, the rotation and translational motions of the drive shaft <NUM> (and the one or more abrasive elements <NUM>) can be commenced to perform ablation of the lesion <NUM>.

In some implementations, prior to the ablation of the lesion <NUM> by the one or more abrasive elements <NUM>, an inflatable member can be used as an angioplasty balloon to treat the lesion <NUM>. That is, an inflatable member (on the sheath <NUM>, for example) can be positioned within the lesion <NUM> and then inflated to compress the lesion <NUM> against the inner wall <NUM> of the vessel <NUM>. Thereafter, the rotational atherectomy procedure can be performed. In some implementations, such an inflatable member can be used as an angioplasty balloon after the rotational atherectomy procedure is performed. In some implementations, additionally or alternatively, a stent can be placed at lesion <NUM> using an inflatable member on the sheath <NUM> (or another balloon member associated with the drive shaft assembly <NUM>) after the rotational atherectomy procedure is performed.

The guidewire <NUM> may remain extending from the distal end of the drive shaft <NUM> during the atherectomy procedure as shown. For example, as depicted by <FIG>, the guidewire <NUM> extends through the lumen of the drive shaft <NUM> and further extends distally of the distal end of the distal extension portion <NUM> during the rotation and translational motions of the drive shaft <NUM> (refer, for example, to <FIG>). In some alternative implementations, the guidewire <NUM> is withdrawn completely out of the lumen of the drive shaft <NUM> prior to during the rotation and translational motions of the drive shaft <NUM> for abrading the lesion <NUM>. In other implementations, the guidewire is withdrawn only partially. That is, in some implementations a portion of the guidewire remains within the lumen of the drive shaft <NUM> during rotation of the drive shaft <NUM>, but remains only in a proximal portion that is not subject to the significant orbital path in the area of the one or more abrasive elements <NUM> (e.g., remains within the portion of the drive shaft <NUM> that remains in the sheath <NUM>).

To perform the atherectomy procedure, the drive shaft <NUM> is rotated at a high rate of rotation (e.g., <NUM>,<NUM>-<NUM>,<NUM> rpm) such that the eccentric one or more abrasive elements <NUM> revolve in an orbital path about an axis of rotation and thereby contacts and removes portions of the lesion <NUM>.

Still referring to <FIG>, the rotational atherectomy system <NUM> is depicted during the high-speed rotation of the drive shaft <NUM>. The centrifugal force acting on the eccentrically weighted one or more abrasive elements <NUM> causes the one or more abrasive elements <NUM> to orbit in an orbital path 131a around the axis of rotation <NUM>. In some implementations, the orbital path can be somewhat similar to the orbital motion of a "jump rope. " As shown, some portions of the drive shaft <NUM> (e.g., a portion that is just distal of the sheath <NUM> and another portion that is distal of the distal stability element <NUM>) can remain in general alignment with the axis of rotation <NUM>, but the particular portion of the drive shaft <NUM> adjacent to the one or more abrasive elements <NUM> is not aligned with the axis of rotation <NUM> (and instead orbits around the axis <NUM>). As such, in some implementations, the axis of rotation <NUM> may be aligned with the longitudinal axis of a proximal part of the drive shaft <NUM> (e.g., a part within the distal end of the sheath <NUM>) and with the longitudinal axis of the distal extension portion <NUM> of the drive shaft <NUM>.

In some implementations, as the one or more abrasive elements <NUM> rotates, the clinician operator slowly advances the carriage assembly <NUM> distally (and, optionally, reciprocates both distally and proximally) in a longitudinal translation direction so that the abrasive surface of the one or more abrasive elements <NUM> scrapes against additional portions of the occluding lesion <NUM> to reduce the size of the occlusion, and to thereby improve the blood flow through the vessel <NUM>. This combination of rotational and translational motion of the one or more abrasive elements <NUM> is depicted by the sequence of <FIG>.

In some embodiments, the sheath <NUM> may define one or more lumens (e.g., the same lumen as, or another lumen than, the lumen in which the drive shaft <NUM> is located) that can be used for aspiration (e.g., of abraded particles of the lesion <NUM>). In some cases, such lumens can be additionally or alternatively used to deliver perfusion and/or therapeutic substances to the location of the lesion <NUM>, or to prevent backflow of blood from vessel <NUM> into sheath <NUM>.

Claim 1:
A rotational atherectomy device for removing stenotic lesion material from a blood vessel of a patient by rotating an abrasive element within the vessel so that the abrasive element scrapes against the stenotic lesion material in the blood vessel and disintegrates the stenotic lesion material in the blood vessel, the rotational atherectomy device comprising:
an elongate flexible drive shaft (<NUM>);
the abrasive element (<NUM>) coupled to a distal portion of the elongate flexible drive shaft; and
a handle (<NUM>) comprising an outer housing (<NUM>), the handle further comprising:
an electric motor (<NUM>) coupled to a proximal portion of the elongate flexible drive shaft (<NUM>), the electric motor configured to cause rotation of the elongate flexible drive shaft in a first rotational direction so that the abrasive element scrapes against the stenotic lesion material and disintegrates the stenotic lesion material in the blood vessel; and
a pump (<NUM>) configured to provide fluid to a distal portion of the elongate flexible drive shaft,
wherein the outer housing contains the electric motor and the pump.