Atherectomy system with guidewire detection

Abstract

An atherectomy system includes a drive mechanism adapted to rotatably actuate an atherectomy head; and a controller adapted to regulate operation of the drive mechanism. A guidewire motion detector adapted to detect movement of the guidewire. The controller is further adapted to take action when the guidewire motion detector detects movement of the guidewire relative to the drive mechanism while the drive mechanism is in operation.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority under 35 U.S.C. §119 to U.S. Provisional Application Serial No. 16 / 444,761, filed on June 18, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to medical devices and methods for making and using medical devices. More particularly, the present invention relates to devices and methods for removing occlusive material from a body lumen. In addition, the present invention relates to an atherectomy device for forming a passage through an occlusion of a body lumen, such as a blood vessel. Background Art

[0004] Many patients suffer from occluded arteries and other blood vessels that restrict blood flow. The occlusion may be a partial occlusion, which reduces blood flow through the occluded portion of the blood vessel, or a complete occlusion (e.g., chronic total occlusion), which substantially blocks blood flow through the occluded blood vessel. In some cases, a stent may be placed in the area of ​​the treated occlusion. However, restenosis may occur in the stent, which further occludes the vessel and restricts blood flow. Revascularization techniques include using various devices to create or expand an opening through the occlusion through the occlusion. Atherectomy is a technique in which a catheter with a cutting element thereon is advanced through the occlusion to form or expand a path through the occlusion. There is still a need for alternative atherectomy devices to pass through the occlusion. Summary of the invention

[0005] The present invention provides designs, materials, manufacturing methods and use alternatives for medical devices. For example, an atherectomy system includes an atherectomy head and a drive mechanism adapted to rotatably actuate the atherectomy head and accommodate a guide wire extending therethrough. The guide wire extends through the drive mechanism. A guide wire motion detector is adapted to detect movement of the guide wire. A controller is operably coupled to the guide wire motion detector and adapted to regulate operation of the drive mechanism. The controller is further adapted to take action when the guide wire motion detector detects movement of the guide wire relative to the drive mechanism while the drive mechanism is operating.

[0006] Alternatively or additionally, the controller may also be adapted to stop operation of the drive mechanism when the guidewire movement detector detects movement of the guidewire.

[0007] Alternatively or additionally, the controller may also be adapted to provide an alarm when the guidewire motion detector detects movement of the guidewire.

[0008] Alternatively or additionally, the guidewire movement detector may also be adapted to determine whether a guidewire is present within the drive mechanism.

[0009] Alternatively or additionally, the guidewire movement detector may include an optical detector adapted to allow the guidewire to pass through the optical detector, wherein the presence of the guidewire is detected by the guidewire blocking at least some of the light from passing through the optical detector.

[0010] Alternatively or additionally, the guidewire motion detector may include an axial encoder wheel positioned in contact with the guidewire such that translation of the guidewire causes the axial encoder wheel to rotate.

[0011] Alternatively or additionally, the guidewire movement detector may further include a position sensing encoder positioned to detect rotation of the axial encoder wheel and send an axial movement signal to the controller.

[0012] Alternatively or additionally, the axial encoder wheel may include a plurality of slots extending through the axial encoder wheel, and the guidewire motion detector further includes an optical sensor sensitive to changes in light passing through the plurality of slots extending through the axial encoder wheel.

[0013] Alternatively or additionally, the guidewire motion detector may include a radial encoder wheel positioned in contact with the guidewire such that rotation of the guidewire causes the radial encoder wheel to rotate.

[0014] Alternatively or additionally, the guidewire movement detector may further include a position sensing encoder positioned to detect rotation of the radial encoder wheel and send a radial movement signal to the controller.

[0015] Alternatively or additionally, the radial encoder wheel may include a plurality of slots extending through the radial encoder wheel, and the guidewire motion detector further includes an optical sensor sensitive to changes in light passing through the plurality of slots extending through the radial encoder wheel.

[0016] Alternatively or additionally, the guidewire movement detector may further include a trackball positioned to contact the guidewire such that translation or rotation of the guidewire causes the trackball to move; a light source positioned such that light from the light source shines on the trackball; and a light detector positioned such that light reflected from the trackball contacts the light detector, wherein changes in light detected by the light detector indicate movement of the trackball and thereby movement of the guidewire.

[0017] Alternatively or additionally, the guidewire movement detector may include a light source positioned so that light from the light source shines on the guidewire; and a light detector positioned so that light reflected from the guidewire contacts the light detector, wherein changes in light detected by the light detector indicate movement of the guidewire.

[0018] Alternatively or additionally, the atherectomy system may further include a wire brake that facilitates insertion of the guide wire into the drive mechanism, the guide wire motion detector being fixed relative to the wire brake.

[0019] Alternatively or additionally, the drive mechanism may include a drive cable coupled to the atherectomy head and a drive motor adapted to rotate the drive cable.

[0020] As another example, a plaque removal system includes a plaque removal atherectomy head and a drive mechanism suitable for rotatably actuating the plaque removal atherectomy head and accommodating a guide wire extending therethrough. The guide wire extends through the drive mechanism. The first encoder wheel is positioned to contact the guide wire so that the translation of the guide wire relative to the drive mechanism causes the first encoder wheel to rotate. The first position sensor is suitable for detecting the rotation of the first encoder wheel and outputting a translation movement signal. The second encoder wheel is positioned to contact the guide wire so that the rotation of the guide wire relative to the drive mechanism causes the second encoder wheel to rotate. The second position sensor is suitable for detecting the rotation of the second encoder wheel and outputting a rotation movement signal. The controller is operably connected to the guide wire motion detector and is suitable for regulating the operation of the drive mechanism, and is also suitable for receiving the translation movement signal and / or the rotation movement signal and taking action when the translation movement signal or the rotation movement signal indicates the movement of the guide wire relative to the drive mechanism.

[0021] Alternatively or additionally, taking action may include at least one of stopping operation of the drive mechanism and providing an alarm.

[0022] Alternatively or additionally, the drive mechanism may include a drive cable coupled to the atherectomy head and a drive cable adapted to rotate the drive cable.

[0023] In another example, an atherectomy system includes an atherectomy head and a drive mechanism adapted to rotatably actuate the atherectomy head and accommodate a guide wire extending therethrough. The guide wire extends through the drive mechanism. A trackball is positioned to contact the guide wire such that translation or rotation of the guide wire causes the trackball to move. A light source is positioned such that light from the light source impinges on the trackball; and a light detector is positioned such that light reflected from the trackball contacts the light detector, and changes in light detected by the light detector cause the light detector to output a signal. A controller is operably coupled to the guidewire motion detector and adapted to regulate the operation of the drive mechanism, and further adapted to receive a signal from the light detector, and to take action when the signal from the light detector indicates movement of the guidewire relative to the drive mechanism while the drive mechanism is operating.

[0024] Alternatively or additionally, the drive mechanism may include a drive cable coupled to the atherectomy head and a drive cable adapted to rotate the drive cable.

[0025] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present invention. The following figures and detailed description more particularly exemplify these embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention may be more fully understood by considering the following detailed description of various embodiments of the invention taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 is a schematic block diagram of an example atherectomy system;

[0028] Figure 2 is a schematic block diagram of an example atherectomy system;

[0029] Figure 3 is a schematic block diagram of an example atherectomy system;

[0030] Figure 4 is a schematic block diagram of an example atherectomy system;

[0031] Figure 5 is a schematic block diagram of an example atherectomy system;

[0032] Figure 6 is a schematic block diagram of an example atherectomy system;

[0033] Figure 7 It is available for Figure 6 Schematic diagram of a guidewire motion detector in an example atherectomy system;

[0034] Figure 8 It is available for Figure 6 Schematic diagram of a guidewire motion detector in an example atherectomy system;

[0035] Fig. 9 It is available for Figure 6 Schematic diagram of a guidewire motion detector in an example atherectomy system;

[0036] Fig.10 It is available for Figure 6 Schematic diagram of a guidewire motion detector in an example atherectomy system;

[0037] Fig.11 It is available for Figure 6 A schematic diagram of a guidewire motion detector in an example atherectomy system; and

[0038] Fig.12 It is available for Figure 6 An example of a stereoscopic image of guidewire motion detection in an atherectomy system.

[0039] Although the present invention is suitable for various modifications and alternative forms, its specific details have been shown in the drawings by way of example and will be described in more detail. However, it should be understood that it is not intended to limit the present invention to the specific embodiments described. On the contrary, it is intended to cover all modifications, equivalents and substitutes that fall within the spirit and scope of the present invention. DETAILED DESCRIPTION

[0040] For the following defined terms, these definitions shall apply unless a different definition is given in the claims or elsewhere in this specification.

[0041] All numerical values ​​are assumed herein to be modified by the term "about", whether or not expressly indicated. The term "about" generally refers to a range of numbers that one skilled in the art considers to be equivalent to the referenced value (i.e., having the same function or result). In many cases, the term "about" may include numbers that are rounded to the nearest significant value.

[0042] The recitation of numerical ranges by endpoints includes all numbers within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0043] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in its sense including "and / or" unless the content clearly dictates otherwise.

[0044] The following detailed description should be read with reference to the drawings, in which similar elements in different drawings have the same reference numerals. The drawings, which are not necessarily drawn to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.

[0045] Many patients suffer from occluded arteries, other blood vessels, and / or occluded ducts or other body cavities that may restrict the flow of body fluids (e.g., blood, bile, etc.). The occlusion may be a partial occlusion or a complete occlusion (e.g., a chronic complete occlusion), wherein a partial occlusion reduces blood flow through the occluded portion of the blood vessel, while a complete occlusion substantially blocks blood flow through the occluded blood vessel. Revascularization techniques include using various devices to create or expand an opening through the occlusion through the occlusion. Atherectomy is a technique in which a catheter with a cutting element thereon is advanced through the occlusion to form or expand a path through the occlusion. Ideally, the cutting element excises the occlusion without damaging the surrounding vessel wall and / or a previously implanted stent that has restenosis. However, in some cases, the cutting element may be manipulated and / or advanced so that it contacts the vessel wall and / or the stent. Therefore, it may be desirable to utilize materials and / or design an atherectomy device that can excise the occlusion without damaging the surrounding vessel and / or a previously implanted stent that has restenosis. Additionally, it may be desirable to use cutting elements for removing hard occlusive materials, such as calcified materials, as well as softer occlusive materials. The methods and systems disclosed herein can be designed to overcome at least some of the limitations of previous atherectomy devices while effectively removing occlusive materials. For example, some of the devices and methods disclosed herein can include cutting elements having unique cutting surface geometries and / or designs.

[0046] Figure 1 is a schematic block diagram of an example atherectomy system 10 that includes a drive mechanism 12 adapted to rotatably actuate an atherectomy head 14. The atherectomy system 10 includes a controller 16 adapted to regulate the operation of the drive mechanism 12. In some cases, the atherectomy system 10 may include a user interface 18 that may be operably connected to the controller 16 so that the controller 16 can display information about the performance of the drive mechanism 12. For example, the information may include one or more of the instantaneous speed of the drive mechanism 12, the instantaneous torque experienced by the atherectomy head 14, etc. In some cases, the atherectomy system 10 may not include the user interface 18. In some cases, the atherectomy head 14 may also be referred to as or include a cutting head or a cutting member, and these terms may be used interchangeably.

[0047] Figure 2 is a schematic block diagram of an example atherectomy system 20, wherein the drive mechanism 12 may include a drive motor 22 and a drive cable 24, which is operably coupled to the drive motor 22 and the atherectomy head 14. In some cases, features of the atherectomy system 20 may be combined with features of the atherectomy system 10. In some cases, the atherectomy system 20 may also include a handle (not shown).

[0048] Figure 3is a schematic block diagram of an example atherectomy system 40 that includes a control system 42 adapted to regulate the operation of a drive mechanism 12 so as to rotatably actuate an atherectomy head 14. In some cases, features of the atherectomy system 40 may be combined with one or more of the atherectomy system 10 and the atherectomy system 20. The control system 42 may include a reference frame 32 and a proportional-derivative-integral (PID) controller 44 operably coupled to the reference frame 32. In some cases, the reference frame 32 may determine a speed reference value 46 that may be selected between a nominal value, a negative value, and zero. Although in some cases, the reference frame 32 may add an offset value, in some cases, the PID controller 44 may also be adapted to add the offset value to the speed reference value 46 received from the reference frame 32. The PID controller 44 may also be adapted to provide a reduction in the motor speed of the drive mechanism 12 that is greater than a reduction that would normally occur in response to an increased torque experienced at the atherectomy head 14 in other cases.

[0049] Figure 4 is a schematic block diagram of an example atherectomy system 50 that includes a control system 52 adapted to regulate the operation of the drive motor 22 so as to rotatably actuate the atherectomy head 14. In some cases, features of the atherectomy system 50 may be combined with one or more of the atherectomy system 10, the atherectomy system 20, or the atherectomy system 40. The control system 52 is operably coupled to the drive motor 22 and includes a feedback loop 54 adapted to monitor the performance of the drive motor 22 and output a control force signal 56. The drive circuit 58 is adapted to receive the control force signal 56 and regulate the operation of the drive motor 22 based on the control force signal 56.

[0050] In some cases, the feedback loop 54 may include a reference frame for determining a speed reference value and a proportional-integral-derivative (PID) controller operably coupled to the reference frame for receiving the speed reference value, the PID controller being adapted to determine the control force signal using the speed reference value, a proportional (P) gain value, an integral (I) gain value, and a derivative (D) gain value. In some cases, the feedback loop 54 may be adapted to add an offset value to the reference signal provided to the reference loop 54 so as to accurately maintain the speed of the drive motor 22 during no-load conditions. In some cases, for example, if the atherectomy head 14 is stuck, the control system 52 may also be adapted to increase the torque provided by the drive motor 22 until a torque threshold is reached within a short period of time, and then direct the drive motor 22 to reverse at a slow speed so as to release energy in the drive mechanism.

[0051] Figure 5is a schematic block diagram of an example atherectomy system 300. In some cases, atherectomy system 300 can be considered an example of atherectomy system 10, 20, 40, or 50. In some cases, features of atherectomy system 300 can be combined with, for example, features of any of atherectomy systems 10, 20, 40, or 50. Atherectomy system 300 includes a motor 302 that drives a drive cable 304 that itself engages a load 306. For example, load 306 represents an atherectomy head. Motor 302 is controlled by a drive circuit 308, which can be considered, for example, to drive motor 22 ( Figure 2 ) and / or controller 16( Figure 1 to Figure 2 ) or otherwise incorporated into the drive motor 22 and / or controller 16. In some cases, the motor 302 can be sized relative to the weight and other dimensions of the atherectomy system 300 to accelerate the atherectomy head to full speed in less than 3 seconds, or in some cases less than 2 seconds. As an example, the motor 302 can be rated at at least 60 watts. In a particular example, the motor 302 can be rated at approximately 80 watts. These are merely examples.

[0052] The drive circuit 308 receives input from a feedback portion 310. In some cases, the feedback portion 310 begins with a reference input 312 from a reference schedule block 314, which provides the reference input 312 to a PID controller 316. In some cases, the reference schedule block 314 can be configured to receive additional inputs, such as from a user and / or from additional sensors not shown. As an example, if the device has been running for too long a period of time, the reference schedule block 314 can reduce the speed reference value to prevent overheating. A PID controller is a controller that includes a (P) proportional part, an (I) integral part, and a (D) derivative part. The PID controller 316 outputs a control force value or reference current 318 to the drive circuit 308. The motor state estimation block 320 receives a current / voltage signal 322 and a motor position signal 323 from the drive circuit 308, and receives a state feedback 324 from the PID controller 316. The motor state estimation block 320 provides a state feedback signal 325 back to the PID controller 316.

[0053] The motor state estimation block 320 outputs a speed value 326 back to the reference dispatch block 314. Although the feedback from the motor state estimation block 320 to the reference dispatch block 314 is shown as a speed value, in some cases, the feedback may additionally or alternatively include one or more of position, torque, voltage, or current, and in some cases may include a differential or integral of any of these values. In some cases, the motor state estimation block 320 may alternatively receive a signal 323 representing speed rather than position (as shown). The motor position signal 323 may be an indication of the relative rotational position of the output shaft of the motor 302, and therefore the relative rotational position of the load 306, which, if tracked over time, may provide an indication of speed.

[0054] In some cases, the drive circuit 308 and the feedback loop 310 can be considered in combination to form a controller 350 that is suitable for determining an estimated torque at the atherectomy head (eg, Figure 5 306 shown). Controller 350 can be considered as controller 16 ( Figure 1 ). In some cases, controller 350 may be considered to include only drive circuit 308 and some elements of feedback loop 310. In some cases, some of the features and functions of controller 350 may occur in motor state estimation block 320. It should be understood that although Figure 5 Various components are shown as separate components, but in some cases, the functionality of one or more of the components may actually be spread among separate components. In some cases, the functionality of one or more of the components may be combined into one or more components.

[0055] If the estimated torque at the load 306 becomes too high, this may be an indication that the atherectomy head is stuck. To prevent possible damage to the drive cable 304, and to prevent possible injury to the patient, the atherectomy system 300 may be adapted to stop or even reverse operation of the atherectomy system 300 if the estimated torque reaches or exceeds a predetermined torque threshold. It will be appreciated that the actual value of the predetermined torque threshold may vary depending on the mechanics of the atherectomy system 300, but may be set at a level low enough to prevent damage and injury, but not so low as to cause too many false alarms due to minor and / or temporary torque increases that are not caused by the load 306 being stuck. For example, as the atherectomy system 300 is advanced through the patient's vasculature, the instantaneous torque may vary by small amounts.

[0056] Figure 6is a schematic block diagram of an example atherectomy system 400. In some cases, the atherectomy system 400 can be considered an example of the atherectomy system 10, 20, 40, or 50. In some cases, features of the atherectomy system 400 can be combined with, for example, features of any of the atherectomy systems 10, 20, 40, or 50. The atherectomy system 400 includes a drive mechanism 402 adapted to rotatably actuate the atherectomy head 306. In some cases, as shown, the drive mechanism 402 can be considered to include a drive motor 302 and a drive cable 304. Although shown schematically, it should be understood that the drive mechanism 402 can be adapted to accommodate a guide wire 404 extending through the drive mechanism 402 and through the atherectomy head 306.

[0057] The guidewire movement detector 406 can be adapted to detect movement of the guidewire 404 relative to the drive mechanism 402. The controller 410, which can be considered an example of the controller 16 or the controller 350, is operably coupled to the guidewire movement detector 406 and is adapted to regulate the operation of the drive mechanism 402. The controller 410 is adapted to take action when the guidewire movement detector 406 detects movement of the guidewire 404 relative to the drive mechanism 402. In some cases, taking action includes stopping the operation of the drive mechanism 402. Taking action can additionally or alternatively include the controller 410 providing an alarm, such as an audible alarm, a visual alarm, or a vibration alarm, so that the user is aware that there may be a problem related to the safety of the guidewire 404.

[0058] In some cases, the guidewire motion controller 406 may also be adapted to determine whether the guidewire 404 is present within the drive mechanism 402. For example, the plaque removal system 400 may include (as part of the guidewire motion detector 406 or as a separate component) a guidewire presence detector 412. The guidewire presence detector 412 may take any form. The guidewire presence detector 412 may be, for example, an optical device, such as may be otherwise used to detect bubbles in a fluid. It should be understood that in the absence of the guidewire 404, a certain amount of light will pass through a cavity adapted to accommodate the guidewire 404. In the presence of the guidewire 404, less light will pass through the above-mentioned cavity. Therefore, a light sensor may be used to detect relative light levels and thereby determine whether the guidewire 404 is present. This information may be transmitted to the controller 410. When the guidewire 404 is not present, the controller 410 may warn the user, and / or may not allow operation of the drive mechanism 402.

[0059] Figure 7 can be used as a guidewire motion detector 406 ( Figure 6) is a schematic diagram of a portion of a guidewire motion detector 420 of FIG. The guidewire motion detector 420 includes an axial encoding wheel 422, which is positioned to contact the guidewire 404 and is positioned relative to the guidewire 404, so that the translation or axial movement of the guidewire 404 will cause the axial encoding wheel to rotate around the axis L1. Similarly, the guidewire motion detector 420 includes a radial encoding wheel 424, which is positioned to contact the guidewire 404 and is positioned relative to the guidewire 404, so that the rotation of the guidewire 404 will cause the radial encoding wheel 424 to rotate around the axis L2. It should be understood that the axial encoding wheel 422 and the radial encoding wheel 424 are arranged so that the axis L1 is orthogonal to the axis L2. For example, the axial encoding wheel 422 can be positioned above or below the guidewire 404. The radial encoding wheel 424 can be positioned above, below, in front of or behind the guidewire 404.

[0060] It should be appreciated that the movement of the axial encoder wheel 422 or the radial encoder wheel 424 or both needs to be communicated to the controller 410 . Figure 8 4 is a schematic diagram of a guidewire motion detector 430. The guidewire motion detector 430 includes an encoder wheel 432, which can, for example, represent an axial encoder wheel 422 or a radial encoder wheel 424. A position sensing encoder 434 is operably coupled to the encoder wheel 432 so that the position sensing encoder 434 can detect when the encoder wheel 432 moves. In response to detecting movement of the encoder wheel 432, the position sensing encoder sends a communication notifying the controller 410. The position sensing encoder 434 can take any form. The position sensing encoder 434 can be, for example, a mechanical encoder.

[0061] In some cases, light may be used to detect movement of encoder wheel 432 . Fig. 9 4 is a schematic diagram of a guide wire motion detector 440 including an encoder wheel 432. As shown, the encoder wheel 432 includes a plurality of slots or holes 442. Light can be emitted from a light source 444 and can be irradiated on the encoder wheel 432. For example, the light source 444 can be an LED, a laser, or a small incandescent bulb. If the encoder wheel 432 is stationary, any light passing through the plurality of slots or holes 442 will remain constant. However, if the encoder wheel 432 is rotating, the light passing through the plurality of slots or holes 442 will change because the light either passes through the slots 442 or is blocked by the encoder wheel 432. A light detector 446 can be positioned to receive light passing through the encoder wheel 432. The light detector 446 can be, for example, a photodiode, a phototransistor, or a photocell. In response to detecting movement of the encoder wheel 432, the light detector 446 sends a communication notifying the controller 410.

[0062] Fig.104 is a schematic diagram of a guide wire motion detector 450, which includes a tracking ball 452, which is positioned to contact the guide wire 404 so that any translation of the guide wire 404 or any rotation of the guide wire 404 causes the tracking ball to rotate. It should be understood that the tracking ball 452 can rotate freely in any direction. The light source 470 provides a light beam that is irradiated on the tracking ball 452. In some cases, as shown in the figure, the light beam can pass through an optical element 454 positioned between the light source 470 and the tracking ball 452. In some cases, the light source 470 can be a laser or a light emitting diode (LED). For example, the optical element 454 can be a fiber optic element, which enables flexibility in the position where the light source 470 can be located. As another example, the optical element 454 can be a focusing lens. In some cases, the tracking ball 452 can be a rubber ball and can have sufficient surface roughness so that the movement of the tracking ball 452 causes the light to be reflected by the tracking ball 452 to change. The light reflected by the tracking ball 452 can pass through the lens 456 before being irradiated on the light detector 472. In some cases, light detector 472 can be positioned to receive light from light source 470 that is reflected by the surface of trackball 452 and passes through lens 456. Light detector 472 can be an image processing chip that receives an image formed by the reflected light. In response to detecting movement of trackball 452, light detector 472 sends a communication notifying controller 410.

[0063] Fig.11 4 is a schematic diagram of a guide wire motion detector 460 configured to detect the movement of a guide wire 404. A light source 454 provides a light beam that shines on the guide wire 404. Although not shown, in some cases, the guide wire 404 may include a polymer coating that provides a roughness suitable for the guide wire motion detector 460 to function, because in some cases, it is conceivable that the guide wire 404 may have a surface that is too smooth to function well with respect to detecting movement via changes in reflected light. The movement of the guide wire 404 may cause the way in which light is reflected by the guide wire 404 to change. A light detector 472 may be positioned to receive light from the light source 470 that passes through the optical element 454 and then through the lens 456 before being reflected by the surface of the guide wire 404. As previously described, the optical element 454 may be an optical cable, or the optical element 454 may be a focusing lens. In some cases, the light source 470 may be a laser or a light emitting diode (LED). In some cases, the light detector 472 may be a photodetector. The light detector 472 may be an optical detector. In some cases, optical fiber may be used to allow light source 454 and / or light detector 456 to be placed away from guidewire 404 at a location that may be more desirable from a packaging perspective. In response to detecting movement of guidewire 404, light detector 472 sends a communication notifying controller 410.

[0064] Fig.12 4 is a perspective view of a guide wire movement detection assembly 480. As can be seen, the guide wire movement detection assembly 480 includes several components fixed relative to a circuit board 482. The guide wire movement detection assembly 480 includes a wire brake 490 that can be actuated between a first position (shown) and a second position, in which the guide wire 404 is locked in place and in which the guide wire 404 is free to move relative to the guide wire movement detection assembly 480. The wire brake 490 includes a clamping rod 492 that is adapted to pivot relative to the circuit board 482 to lock or unlock the guide wire 404. The wire brake 490 includes a clamping chuck 494 that selectively engages the guide wire 404.

[0065] and Fig.10 and Fig.11 The lens 456, which is the same as the lens 456 referenced in FIG. 4, is fixed relative to the circuit board 482. As shown, the lens 456 is shown as transparent to make it easier to see the light detector 472 fixed to the circuit board 482. As shown, the light detector 472 is an image processing chip that is operably connected to the controller 410 ( Figure 6 ) so that any detected movement of the guidewire 404 can be transmitted to the controller 410. The guidewire presence detector 496 is fixed relative to the circuit board 482 and can be considered as the guidewire presence detector 412 ( Figure 6 ) example.

[0066] In some cases, the guidewire movement detection assembly 480 may include a guidewire cover 484 extending between the wire brake 490 and the guidewire presence detector 496. The guidewire cover 484 can be considered to provide a cavity for the guidewire 404 to easily extend through without entering any other components. In some cases, the guidewire cover 484 may include a slot that exposes the guidewire 404 to light. Figure 7 ) and guidewire motion detector 430 ( Figure 8 ), can be omitted in Fig.12 The lens 456 and the light detector 472 shown in FIG. Fig.10 ), it will be appreciated that the trackball 452 can be positioned to contact the guidewire 404 so that light emitted from the light source 470 is reflected from the trackball 452 and ultimately reflected to the light detector 472. In some cases, although not shown, the trackball 452 can be slightly spring loaded so as to keep the trackball 452 in sufficient contact with the guidewire 404 so that movement of the guidewire 404 causes movement of the trackball 452. Fig.11 , it will be appreciated that the light source 470 may be an LED or other light source (not shown) mounted to a circuit board 482.

[0067] It should be understood that the present invention is in many respects merely illustrative. Changes may be made in details, particularly matters of shape, size, and arrangement of steps, without exceeding the scope of the present invention. To the extent appropriate, this may include using any of the features of an example embodiment used in other embodiments. Of course, the scope of the present invention is defined by the language of the appended claims.

Claims

1. A plaque removal system, comprising: Atherectomy atherectomy head; a drive mechanism adapted to rotatably actuate the atherectomy head, the drive mechanism adapted to receive a guide wire extending therethrough; a guide wire extending through the drive mechanism; a guidewire presence detector configured to detect the presence of the guidewire extending through the drive mechanism; a guidewire movement detector separate from the guidewire presence detector and adapted to detect translational and rotational movement of the guidewire in the presence of the guidewire extending through the drive mechanism; as well as a controller operably coupled to the guidewire presence detector and the guidewire movement detector, the controller adapted to regulate operation of the drive mechanism; wherein the controller is further adapted to take action when the guidewire motion detector detects that the guidewire translates or rotates relative to the drive mechanism while the drive mechanism is in operation; and Wherein the controller is further adapted to prevent operation of the drive mechanism when the guidewire presence detector indicates an absence of the guidewire extending through the drive mechanism.

2. The plaque removal system of claim 1, wherein the guidewire motion detector comprises an axial encoder wheel positioned in contact with the guidewire such that translation of the guidewire causes the axial encoder wheel to rotate.

3. The plaque removal system of claim 2, wherein the guidewire motion detector further comprises a position sensing encoder positioned to detect rotation of the axial encoder wheel and send an axial motion signal to the controller.

4. The plaque removal system according to any one of claims 1 to 3, wherein the guidewire motion detector includes a radial encoding wheel, which is positioned to contact the guidewire so that rotation of the guidewire causes the radial encoding wheel to rotate.

5. The plaque removal system of claim 4, wherein the guidewire motion detector further comprises a position sensing encoder positioned to detect rotation of the radial encoder wheel and send a radial motion signal to the controller.

6. The atherectomy system of claim 1, wherein the guidewire motion detector comprises: a trackball positioned in contact with the guidewire such that translation or rotation of the guidewire causes movement of the trackball; a light source positioned so that light from the light source shines on the trackball; as well as a light detector positioned so that light reflected from the trackball contacts the light detector; Wherein changes in the light detected by the light detector are indicative of movement of the trackball and thereby movement of the guidewire.

7. The atherectomy system of claim 1, wherein the guidewire motion detector comprises: a light source positioned so that light from the light source shines on the guidewire; as well as a light detector positioned so that light reflected from the guidewire contacts the light detector; Wherein changes in the light detected by the light detector indicate movement of the guidewire.

8. The plaque removal system according to any one of claims 1-3, 6, and 7, further comprising a wire brake, which facilitates the insertion of the guide wire into the drive mechanism, and the guide wire motion detector is fixed relative to the wire brake.

9. The plaque removal system according to any one of claims 1-3, 6, and 7, wherein the driving mechanism comprises: a drive cable connected to the atherectomy head; as well as A drive motor is adapted to rotate the drive cable.

10. A plaque removal system, comprising: Atherectomy atherectomy head; a drive mechanism adapted to rotatably actuate the atherectomy head, the drive mechanism adapted to receive a guide wire extending therethrough; a guide wire extending through the drive mechanism; a guidewire presence detector configured to detect the presence of the guidewire extending through the drive mechanism; A guidewire movement detector, the guidewire movement detector is separate from the guidewire presence detector, the guidewire movement detector comprising: a first encoder wheel positioned in contact with the guidewire such that translation of the guidewire relative to the drive mechanism causes rotation of the first encoder wheel; a first position sensor adapted to detect rotation of the first encoder wheel and output a translational movement signal; a second encoder wheel positioned in contact with the guidewire such that rotation of the guidewire relative to the drive mechanism causes the second encoder wheel to rotate; a second position sensor adapted to detect rotation of the second encoder wheel and output a rotational movement signal; a controller operably coupled to the guidewire presence detector and the guidewire movement detector and adapted to regulate operation of the drive mechanism; wherein the controller is further adapted to receive information indicating the presence of the guidewire extending through the drive mechanism, the translational movement signal and / or the rotational movement signal, and to take action when the information indicates the absence of the guidewire extending through the drive mechanism, the translational movement signal indicates movement of the guidewire relative to the drive mechanism, or the rotational movement signal indicates movement of the guidewire relative to the drive mechanism; Wherein the controller is further adapted to prevent operation of the drive mechanism when the guidewire presence detector indicates an absence of the guidewire extending through the drive mechanism.

11. The plaque removal system of claim 10, wherein taking action includes at least one of stopping operation of the drive mechanism and providing an alarm.

12. The plaque removal system according to claim 10 or 11, wherein the driving mechanism comprises: a drive cable connected to the atherectomy head; as well as A drive motor is adapted to rotate the drive cable.

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