Battery powered rotary atherectomy device

Abstract

A rotary atherectomy device includes an elongate flexible shaft and an abrasive element connected to a distal end of the elongate flexible shaft. The handle includes a housing including an electric motor operably connected to the elongate flexible shaft to rotate the elongate flexible shaft. A power source is electrically connected to the electric motor to power the electric motor. The controller is configured to monitor a motor supply current of the electric motor and to monitor a speed of the electric motor using a signal from the sensor. If the motor supply current is above a first predetermined threshold, the controller reduces the speed of the electric motor while attempting to maintain the motor supply current of the electric motor. Then, if the motor supply current is higher than a second predetermined threshold higher than the first predetermined threshold, the controller stops the electric motor.

Description

Technical Field

[0001] The present invention relates to an atherectomy system and, more particularly, to an orbital atherectomy system having an abrasive element. Background Art

[0002] Coronary heart disease may be caused, for example, by atherosclerosis. Atherosclerosis occurs when fat, cholesterol, and / or other substances build up on the walls of blood vessels, forming hard structures called occlusives, such as plaques and / or atherosclerotic (stenotic) lesions. Over time, these occlusives may increase in size, causing the blood vessel to become substantially blocked and / or completely blocked, forming a chronic total occlusion (CTO).

[0003] Rotational atherectomy is a technique used to abrade, for example, calcified arterial lesions. Rotational atherectomy devices and rotational atherectomy procedures may also be referred to as rotational angioplasty devices and / or rotational angioplasty procedures. One type of rotational atherectomy device is known as an orbital atherectomy device, such as the Diamondback 1000 available from Cardiovascular Systems Inc. ("CSI"). Peripheral orbital atherectomy device.

[0004] A rotary atherectomy device may include an abrasive element attached to a rotatable elongated flexible drive shaft. The abrasive element may be referred to as a burr, a crown and / or a bead. The rotatable elongated flexible drive shaft may be delivered to a desired position via a guide wire and / or a sheath. The drive shaft may rotate at high speed (e.g., between 20,000-160,000 rpm). As the abrasive element rotates, it may advance over a stenotic lesion so that the abrasive element contacts an obstructing plaque. In this way, the abrasive element engages with the surface of the diseased lesion and abrades the plaque into very small particles. These small particles may be absorbed by the body or captured by using an embolic protection device.

[0005] What is needed is an atherectomy device including a controller with improved motor control logic that stops or slows the motor during high torque events based on torque magnitude detected by the controller in order to reduce high torque events and motor stalling conditions. Summary of the invention

[0006] In an embodiment, a rotary atherectomy device includes an elongated flexible shaft and an abrasive element connected to the distal end of the elongated flexible shaft. The handle includes a housing including an electric motor operably connected to the elongated flexible shaft to rotate the elongated flexible shaft. A power source is electrically connected to the electric motor to supply power to the electric motor. A controller controls the operation of the electric motor using the power source. The sensor provides a signal indicating the operating state of the electric motor. The controller is configured to monitor the motor supply current of the electric motor and monitor the speed of the electric motor using the signal from the sensor. If the motor supply current is above a first predetermined threshold, the controller reduces the speed of the electric motor while attempting to maintain the motor supply current of the electric motor. Then, if the motor supply current is above a second predetermined threshold that is higher than the first predetermined threshold, the controller stops the electric motor.

[0007] In another embodiment, a rotary atherectomy device includes an elongated flexible shaft and an abrasive element connected to the distal end of the elongated flexible shaft. The handle includes a housing. The electric motor is operably connected to the elongated flexible shaft to rotate the elongated flexible shaft. A power source is electrically connected to the electric motor to supply power to the electric motor. A controller uses the power source to control the operation of the electric motor. The sensor provides a signal indicating the operating condition of the electric motor. The controller is configured to monitor the motor supply current of the electric motor and monitor the speed of the electric motor using the signal from the sensor. If the motor supply current is above a predetermined threshold, the speed of the electric motor and the motor supply current are reduced. Within a preselected time period after reducing the speed of the electric motor and the motor supply current, the controller increases the speed of the electric motor and the motor supply current. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The above and other features and advantages described herein and the manner in which they are achieved will become more apparent, and the present disclosure will be better understood, by referring to the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0009] Figure 1 is a schematic perspective view of an embodiment of a rotational atherectomy device having a handle assembly coupled to a rotational device having an elongated flexible drive shaft and an abrasive element according to one or more aspects shown and described herein;

[0010] Figure 2 According to one or more embodiments shown and described herein Figure 1 A schematic side view of an abrasive element;

[0011] Figure 3 A method of manufacturing a device including a handle assembly, a flexible drive shaft, and an abrasive element according to one or more embodiments shown and described herein is shown. Figure 1 Block diagram of the atherectomy device in;

[0012] Figure 4 A method for communicating with a computer according to one or more embodiments shown and described herein is shown. Figure 1 a control system for use with an atherectomy device; and

[0013] Figure 5 A torque-based Figure 4 The control curve of the control system.

[0014] Corresponding reference characters indicate corresponding parts throughout the several views.The exemplifications set out herein illustrate embodiments of the present disclosure, and these exemplifications should not be construed as limiting the scope of the embodiments in any way. DETAILED DESCRIPTION

[0015] Embodiments described herein generally relate to a rotary atherectomy device comprising an elongated flexible shaft, an abrasive element connected to a distal end of the elongated flexible shaft, and a handle assembly comprising a housing. The handle comprises an electric motor operably connected to the elongated flexible shaft to rotate the elongated flexible shaft. A power source is electrically connected to the electric motor to supply power to the electric motor. A controller controls the operation of the electric motor using the power source. A sensor provides a signal indicating an operating condition of the electric motor. The controller is configured to monitor a motor supply current of the electric motor and to monitor a speed of the electric motor using a signal from the sensor. If the motor supply current is above a first predetermined threshold, the speed of the electric motor is reduced while attempting to maintain the motor supply current of the electric motor. If the motor supply current is above a second predetermined threshold that is higher than the first predetermined threshold, the controller stops the electric motor.

[0016] Referring now to the drawings, and in particular to Figure 1 and Figure 2, a rotary atherectomy system 10 is shown, which includes an atherectomy device 14, which includes a handle assembly 12 having a housing 13, and the handle assembly 12 is configured to rotate an elongated flexible drive shaft 16 at a high speed (e.g., 1000-50000 rpm). The atherectomy device 14 includes an elongated flexible drive shaft 16 and an abrasive element 18. The elongated flexible drive shaft 16 is flexible so that it can adapt to the curvature of the vascular system and extend through a flexible outer conduit 17 (e.g., a catheter). The abrasive element 18 is disposed on the elongated flexible drive shaft 16 and is fixedly (i.e., non-detachable or non-removable) attached to the elongated flexible drive shaft 16. In this embodiment, the atherectomy device 14 can axially pass through a guidewire 20 and rotate around it. In some embodiments, a lubricant or saline can be supplied through the elongated flexible drive shaft 16 to cool / lubricate the coil shaft / guidewire interface. The abrasive element 18 abrades (e.g., grinds) the occlusion (e.g., calcified plaque and / or atherosclerotic (stenotic) lesions in a blood vessel) by rotating the atherectomy device 14 at high speed and contacting the abrasive element 18 with the occlusion, thereby reducing at least a portion of the occlusion to small particles. When the abrasive element 18 spins at high speed, the abrasive element 18 undergoes a concentric motion path. In some embodiments, the motion of the rotating abrasive element 18 can be orbital, depending on the shape of the abrasive element 18. As an example, an abrasive element that is symmetrical about an axis of rotation can be considered to be rotational, and an abrasive element that is asymmetrical about an axis of rotation can be considered to be orbital.

[0017] The handle assembly 12 may include a motor 22 (such as a direct current (DC) brushed or brushless motor), a controller 24, and a user interface 26. An onboard battery power supply 28 is electrically connected to the motor 22, the controller 24, and the user interface 26. The motor 22 may operate in a speed range of about 1000rpm to 50000rpm, with a power supply voltage in a range of 5V to 24V. The supply current of the motor 22 may be in a range of 200mA to 8A. Electricity may be supplied to the motor 22, the controller 24, and the user interface 26 via the onboard battery power supply 28. In the present embodiment, the onboard battery power supply 28 includes a rechargeable or replaceable battery. If the drive motor supply voltage is in a range of 8V to 15V, and the motor supply current is in a range of 1A to 6A, the number of batteries required may be reduced. Alternatively, an off-board power supply (such as an alternating current (AC) wall outlet) may power the handle assembly 12.

[0018] User interface 26 may include, for example, one or more switches for providing input commands to controller 24. These user input commands may include, for example, selectable speed commands, motor acceleration and / or torque curve commands, and / or rotational direction commands.

[0019] The atherectomy device 14 including the elongated flexible drive shaft 16 and the abrasive element 18 is configured to be extended into a blood vessel (e.g., an artery) of a patient. In the present embodiment, the elongated flexible drive shaft 16 can be, for example, an elongated tightly wound metal coil. Alternatively, the elongated flexible drive shaft 16 can be a flexible metal or polymer tube. The elongated flexible drive shaft 16 includes a proximal portion 30, a distal portion 32, a distal end 34, and an elongated lumen 36 ( Figure 2 ), for example, an elongated guidewire lumen. The distal end 34 is the distal terminus of the distal end portion 32 of the elongated flexible drive shaft 16.

[0020] The proximal end portion 30 of the elongated flexible drive shaft 16 is drivably coupled, i.e., connected, for example, directly or indirectly, via a gear train, to a rotatable motor shaft of the motor 22. In the present embodiment, the distal end portion 32 may constitute, for example, 0.5 to 10% of the total length of the elongated flexible drive shaft 16. The distal end portion 40 of the elongated flexible drive shaft 16 defines an axis of rotation 42 about which the abrasive element 18 rotates together with the elongated flexible drive shaft 16.

[0021] The size and shape of the elongated lumen 36 are configured, for example, to accommodate a guidewire 20. The elongated lumen 36 is configured to slidably receive the guidewire 20 so that the elongated flexible drive shaft 16 carrying the abrasive element 18 can be axially advanced over and rotated about the guidewire 20 and the axis of rotation 42. In this embodiment, the distal portion 40 of the elongated flexible drive shaft 16 and the abrasive element 18 can be longitudinally advanced using the conduit 17, over the guidewire 20 and into a patient's blood vessel so as to extend longitudinally outward from the conduit 17 and engage an occlusion in the blood vessel.

[0022] The atherectomy device 14 also includes an irrigation pump represented by element 50 located in the handle assembly 12. Positioning the irrigation pump 50 in the handle assembly 12 can make the atherectomy device 14 a stand-alone disposable device. A user interface 26 can be provided for turning the irrigation pump 50 on and off. The irrigation pump 50 can pump a fluid (such as saline) through the flexible tubing 17 and to the distal end 34 of the flexible drive shaft 16 for cooling and lubrication purposes. In some embodiments, the atherectomy device 14 can be a single-use device that includes a fluid source 54 located inside the handle assembly 12. Although the fluid source 54 is shown as being external to the pump 50, it can be part of the pump 50. The flow rate of the fluid can be 5 ml / min to 100 ml / min. The irrigation pump 50 can include an encoder for monitoring whether the irrigation pump 50 is running at a desired speed and direction during operation. The irrigation pump 50 can be any suitable type of electric pump, such as an electromechanical pump, a volumetric pump, a diaphragm pump, etc.

[0023] The controller 24 may provide power from the power source 28 to the motor 56 of the electric pump 50, thereby driving the electric pump 50. The controller 24 may operate the electric pump 50 based on input from the user interface 26. The controller 24 may also control the operation of the motor 56 of the electric pump 50 and the motor 22 of the flexible drive shaft 16 based on current operating conditions, which will be described in more detail below.

[0024] Figure 3 A block diagram of an atherectomy device 14 is shown that includes a handle assembly 12, a flexible drive shaft 16, and an abrasive element 18. Located in the handle assembly 12 is a motor 22 for the flexible drive shaft 16, a gear train 60 that provides mechanical advantage and varies the speed and torque of the flexible drive shaft 16 relative to the motor 22, an electric pump 50 with a motor 56, and a controller 24 that is electrically connected to one or both of the motors 22 and 56. The controller 24 is electrically connected to a power source 28 for providing power to the motors 22 and 56 and controlling their operation.

[0025] The controller 24 may be implemented as a single printed circuit board (PCB) configured to monitor the power supply 28 and both motors 22 and 56. The output voltage of the power supply 28 may change as the power supply 28 is used or the current of the power supply 28 increases. The controller 24 monitors the supply voltage to determine if the supply voltage drops below a predetermined threshold for the motor 22. The controller 24 also monitors the sensors 62 and 64 (encoders) of the motors 22 and 56 and shuts down the system 10 if the motors 22 and 56 are not operating at a desired speed or within a speed range.

[0026] refer to Figure 4 , the controller 24 includes a communication path 66, a processor 68, and a memory module 70, which are electrically connected to the power source 28 and the motors 22 and 56 for powering the motors 22 and 56 and controlling their operation. The memory module 70 includes logic that, when processed by the processor, causes the controller 24 to use the signal from the sensor 64 to monitor the motor supply current of the motor 22 and monitor the speed of the motor 22. If the motor supply current is above a first predetermined threshold, the controller 24 attempts to maintain the motor supply current of the motor 22 by reducing the supply voltage to reduce the speed of the motor 22. Then, if the supply current exceeds a second predetermined threshold that is higher than the first predetermined threshold, the controller 24 stops the motor 22.

[0027] In some embodiments, during the stall control mode, if the motor supply current is above a predetermined threshold, the controller 24 may also reduce the speed and motor supply current of the motor 22. The stall control mode may be activated under certain preselected potential stall conditions, for example, by a user or by the controller 24 using logic. After reducing the speed and motor supply current of the motor 22 during the stall prevention control operation, the speed and motor supply current of the motor 22 are increased to avoid a motor stall condition within a preselected time period.

[0028] The controller 24 may also use a signal from a sensor 72 (e.g., a contact sensor, a proximity sensor, etc.) to detect the presence of the guidewire 20, which may be used to detect a guidewire breakage condition. The user interface 26 may be used to allow motor 22 and 56 speed selection and on / off commands from a switch (e.g., a membrane switch), and control an LED light 74 that provides an indication of the operating condition.

[0029] refer to Figure 5 , illustrates a control curve 80 of the torque-based controller 24. At region A, the flexible drive shaft 16 rotates freely within the blood vessel at low torque until the abrasive element 18 contacts the occlusion at B. When the abrasive element contacts the occlusion, the rotation speed of the flexible drive shaft 16 slows down, and the motor torque increases in region C. If the torque increases to or above P1 of the first torque threshold T1, the speed of the motor 22 is reduced, and the controller 24 attempts to maintain the torque by maintaining the supply current to the motor 22 in region D. However, if the torque continues to rise to point P2 above threshold T2 in region E, the controller 24 cuts off the power to the motor 22, and the torque (and speed) becomes zero in region F. The controller 24 maintains the off state of the motor 22 in region G.

[0030] The above-described atherectomy systems provide relatively low-cost atherectomy devices that can be single-use (i.e., disposable) and self-contained in that they do not require connection to any external device (such as a power source or fluid lines) to operate. Thus, little to no setup of the atherectomy device is required and the atherectomy device can operate as intended. In addition, the atherectomy device described herein includes a controller with improved motor control logic that the controller uses to monitor torque at multiple thresholds and first attempts to maintain the torque at a first threshold while reducing the motor speed, and if this does not work and the torque continues to rise to a second predetermined threshold that is greater than the first predetermined threshold, then stops the motor. Thus, the controller stops or slows the motor speed at a high torque event depending on the torque magnitude detected by the controller. The atherectomy device can also be provided with stall control logic that is used to reduce the speed at a predetermined torque and then increase the speed and current to break a potential stall condition.

[0031] Embodiments may be described with reference to the following numbered clauses, with certain features listed in dependent clauses:

[0032] Item 1: A rotational atherectomy device comprising: an elongated flexible shaft; an abrasive element connected to the distal end of the elongated flexible shaft; a handle including a housing, the handle comprising: an electric motor operably connected to the elongated flexible shaft to rotate the elongated flexible shaft; a power source electrically connected to the electric motor to power the electric motor; a controller controlling the operation of the electric motor using the power source; and a sensor providing a signal indicating an operating condition of the electric motor; wherein the controller is configured to: monitor a motor supply current of the electric motor; monitor a speed of the electric motor using a signal from the sensor; if the motor supply current is above a first predetermined threshold, reduce the speed of the electric motor while attempting to maintain the motor supply current of the electric motor; and then, if the motor supply current is above a second predetermined threshold that is higher than the first predetermined threshold, stop the electric motor.

[0033] Clause 2: The rotary atherectomy device of clause 1 further comprising an irrigation pump electrically connected to the power source.

[0034] Clause 3: The rotary atherectomy device of clause 2, wherein the controller controls operation of the irrigation pump.

[0035] Clause 4: The rotary atherectomy apparatus of Clause 3, wherein the controller monitors the speed of the irrigation pump and shuts off the irrigation pump if the irrigation pump operates below a predetermined speed.

[0036] Clause 5: The rotational atherectomy apparatus of any of Clauses 2-4, wherein the controller comprises a single printed circuit board that controls operation of both the irrigation pump and the electric motor.

[0037] Clause 6: The rotary atherectomy device of any of clauses 1-5, wherein the power source is between 5V and 24V.

[0038] Clause 7: The rotary atherectomy device of clause 6, wherein the power source comprises one or more batteries located in the handle.

[0039] Clause 8: The rotary atherectomy device of any of Clauses 1-7, wherein the controller is configured to monitor the motor supply voltage.

[0040] Clause 9: The rotational atherectomy device of any of clauses 1-8, wherein the controller is configured to detect the presence of the guidewire using input from the sensor.

[0041] Clause 10: The rotational atherectomy device of any of Clauses 1-9, wherein the handle includes a user input device, and the controller receives input from the user input device to control operation of the electric motor.

[0042] Item 11: A rotational atherectomy device comprising: an elongated flexible shaft; an abrasive element connected to the distal end of the elongated flexible shaft; a handle including a housing, the handle comprising: an electric motor operably connected to the elongated flexible shaft to rotate the elongated flexible shaft; a power source electrically connected to the electric motor to power the electric motor; a controller controlling the operation of the electric motor using the power source; and a sensor providing a signal indicating the operating condition of the electric motor; wherein the controller is configured to: monitor the motor supply current of the electric motor; monitor the speed of the electric motor using a signal from the sensor; reduce the speed of the electric motor and the motor supply current if the motor supply current is above a predetermined threshold; and increase the speed of the electric motor and the motor supply current within a preselected time period after reducing the speed of the electric motor and the motor supply current.

[0043] Clause 12: The rotary atherectomy device of clause 11 further comprising an irrigation pump electrically connected to the power source.

[0044] Clause 13: The rotary atherectomy device of clause 12, wherein the controller controls operation of the irrigation pump.

[0045] Clause 14: The rotary atherectomy apparatus of Clause 13, wherein the controller monitors the speed of the irrigation pump and shuts off the irrigation pump if the irrigation pump operates below a predetermined speed.

[0046] Clause 15: The rotational atherectomy apparatus of any of Clauses 12-14, wherein the controller comprises a single printed circuit board that controls operation of both the irrigation pump and the electric motor.

[0047] Clause 16: The rotary atherectomy device of any of clauses 11-15, wherein the power source is between 5V and 24V.

[0048] Clause 17: The rotational atherectomy device of any of Clauses 11-16, wherein the power source comprises one or more batteries located in the handle.

[0049] Clause 18: The rotary atherectomy device of any of clauses 11-17, wherein the controller is configured to monitor the motor supply voltage.

[0050] Clause 19: The rotational atherectomy device of any of clauses 11-18, wherein the controller is configured to detect the presence of the guidewire using input from the sensor.

[0051] Clause 20: The rotational atherectomy device of any of Clauses 11-19, wherein the handle includes a user input device, and the controller receives input from the user input device to control operation of the electric motor.

[0052] As used herein, unless otherwise indicated or supplemented by the context of their use, the terms "substantially," "approximately," and other words of degree are relative modifiers intended to indicate variations permitted from the modified property, more of the physical or functional property than its opposite, and near or approximate such physical or functional property.

[0053] Although the present disclosure has been described with respect to at least one embodiment, the present disclosure may be further modified within the spirit and scope of the present disclosure. Therefore, the present application is intended to cover any variation, use or adaptation of the embodiments described herein using its general principles. In addition, the present application is intended to cover content that is different from the present disclosure, as long as such content belongs to known or customary practice in the field to which the present invention belongs and falls within the scope of the appended claims.

Claims

1. A rotary atherectomy device comprising: Slender flexible shaft; an abrasive element coupled to the distal end of the elongated flexible shaft; A handle comprising a housing, the handle comprising: an electric motor operably connected to the elongated flexible shaft to rotate the elongated flexible shaft; a power source electrically connected to the electric motor to supply power to the electric motor; a controller that controls operation of the electric motor using the power supply; and a sensor that provides a signal indicative of an operating condition of the electric motor; The controller is configured as: monitoring motor supply current to the electric motor; monitoring the speed of the electric motor using a signal from a sensor; If the motor supply current is above a first predetermined threshold, reducing the speed of the electric motor while attempting to maintain the motor supply current of the electric motor; and then If the motor supply current is above a second predetermined threshold value which is higher than the first predetermined threshold value, the electric motor is stopped.

2. The rotational atherectomy device of claim 1 further comprising an irrigation pump electrically connected to the power source located in the handle.

3. The rotational atherectomy apparatus of claim 2, wherein the controller controls operation of the irrigation pump.

4. The rotary atherectomy apparatus of claim 3, wherein the controller monitors the speed of the irrigation pump and shuts off the irrigation pump if the irrigation pump operates below a predetermined speed.

5. The rotational atherectomy apparatus of claim 4, wherein the controller comprises a single printed circuit board that controls operation of both the irrigation pump and the electric motor.

6. The rotary atherectomy device of claim 1, wherein the power supply is between 5V and 24V.

7. The rotational atherectomy device of claim 6, wherein the power source comprises one or more batteries located in the handle.

8. The rotary atherectomy device of claim 1, wherein the controller is configured to monitor the motor supply voltage.

9. The rotational atherectomy device of claim 1, wherein the controller is configured to detect the presence of the guidewire using input from another sensor.

10. The rotational atherectomy device of claim 1, wherein the handle includes a user input device, and the controller receives input from the user input device to control operation of the electric motor.

11. A rotary atherectomy device comprising: Slender flexible shaft; an abrasive element coupled to the distal end of the elongated flexible shaft; A handle comprising a housing, the handle comprising: an electric motor operably connected to the elongated flexible shaft to rotate the elongated flexible shaft; a power source electrically connected to the electric motor to supply power to the electric motor; a controller that controls operation of the electric motor using the power supply; and a sensor that provides a signal indicative of an operating condition of the electric motor; The controller is configured as: monitoring motor supply current to the electric motor; monitoring the speed of the electric motor using a signal from a sensor; reducing the speed of the electric motor and the motor supply current if the motor supply current is above a predetermined threshold; The speed of the electric motor and the motor supply current are increased within a preselected time period after the speed of the electric motor and the motor supply current are decreased.

12. The rotary atherectomy device of claim 11, further comprising an irrigation pump electrically connected to the power source.

13. The rotational atherectomy apparatus of claim 12, wherein the controller controls operation of the irrigation pump.

14. The rotary atherectomy apparatus of claim 13, wherein the controller monitors the speed of the irrigation pump and shuts off the irrigation pump if the irrigation pump operates below a predetermined speed.

15. The rotational atherectomy apparatus of claim 14, wherein the controller comprises a single printed circuit board that controls operation of both the irrigation pump and the electric motor.

16. The rotary atherectomy device of claim 11, wherein the power supply is between 5V and 24V.

17. The rotational atherectomy device of claim 16, wherein the power source comprises one or more batteries located in the handle.

18. The rotational atherectomy device of claim 11, wherein the controller is configured to monitor the motor supply voltage.

19. The rotational atherectomy device of claim 11, wherein the controller is configured to detect the presence of the guidewire using input from another sensor.

20. The rotational atherectomy device of claim 11, wherein the handle includes a user input device, and the controller receives input from the user input device to control operation of the electric motor.

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