Blood clot detection method and device

Abstract

Described herein are methods and devices for characterizing material at the distal end of an aspiration catheter using one or more sensors. The methods and devices described herein may include multiple sensing electrodes at the distal end region of the device and a controller configured to sense contact and / or proximity to the sensing electrodes. These methods and devices can determine or detect the size of a blood vessel. These methods and devices may include a distal contrast port for adding contrast material distal to the aspiration catheter. In some examples, these devices include one or more reference electrodes near the sensing electrodes that can improve detection of material (e.g., blood clots, blood vessel walls). These methods and devices may include a steerable distal end region. In some cases, the devices and methods may include a retriever probe to assist in capturing clot material.

Description

[Technical Field]

[0001]

[0001] (Priority claim) This patent application claims priority to U.S. Provisional Patent Application No. 63 / 477,556, entitled "CLOT SENSING METHODS AND APPARATUSES," filed December 28, 2022, which is incorporated herein by reference in its entirety.

[0002]

[0002] (Incorporated by reference) All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. [Background technology]

[0003] Aspiration thrombectomy systems can be used to treat blockages within blood vessels, including both veins and arteries, which can cause serious medical problems. For example, thromboembolism manifests itself in a variety of life-threatening conditions. Fatal diseases resulting from thrombotic blockages are pulmonary embolism, deep vein thrombosis, and acute limb ischemia. Acute pulmonary embolism is a significant cause of death in the United States. This condition can develop as a complication from deep vein thrombosis and has an annual incidence of 1% among patients aged 60 years or older. All of the aforementioned conditions are illustrative scenarios in which treatment may involve the aspiration or removal of blood clots and / or blood.

[0004] However, aspiration thrombectomy systems are limited by the potential risk of excessive blood loss from the patient, especially when large aspiration catheters are employed. Distinguishing whether the opening of the aspiration catheter is in contact with clot material, non-clot material (e.g., the vessel wall), or unintentionally aspirating healthy, clot-free blood can pose significant challenges. Even when the aspiration device is occluded, determining the intrusion of a clot into the device lumen can also be difficult. Furthermore, accurately and quantitatively measuring the amount of clot removed remains a challenge. Summary of the Invention [Problem to be solved by the invention]

[0005]

[0005] It would therefore be desirable to provide methods and apparatus (systems, devices, etc.) that can assist or regulate the aspiration of thrombus and clot material through an aspiration catheter by accurately sensing clot material at or near the opening of the aspiration catheter. The methods and apparatus described herein can address these aforementioned problems. [Means for solving the problem]

[0006]

[0006] Described herein are methods and apparatus (e.g., devices and / or systems, including aspiration / thrombectomy devices, aspiration / thrombectomy catheters, and systems for controlling the same) for removing occlusive material in a body lumen, such as blood clot material. While the following description primarily refers to blood clot material, such as blood clot (e.g., thrombus) material, the present technology is adapted to remove other types of occlusive material, such as plaque, pathological growths (e.g., bacterial material surrounded by a platelet / fibrin layer), and the like.

[0007] The methods and apparatus described herein may be configured to control the operation of an aspiration catheter. In some embodiments, the present technology includes one or more sensors coupled to and / or integrated with one or more components of a treatment system, such as a suction catheter, sometimes referred to herein as an aspiration catheter. The one or more sensors may provide sensor data, and a system including a controller including one or more processors can analyze this data to verify the presence of clot material, and the controller can coordinate the operation of the aspiration catheter, actuators (e.g., for bending and / or advancing / retracting the catheter, etc.), and / or optional macerators within the catheter. These apparatus (e.g., devices, systems, etc.) described herein can provide accurate and rapid confirmation that clot material is near, adjacent to (including contacting), and / or within the lumen of the aspiration apparatus. In some examples, these apparatus can provide a rapid and accurate estimation of the amount of clot removed. These devices may provide an indication that the clot has been removed from all or a portion of the aspiration lumen and / or an estimate of the rate of clot removal (e.g., movement of clot material within the lumen of the aspiration device). These methods and devices may also, or optionally, provide an indication of the relative (or in some cases, approximate actual) diameter of the blood vessel in which the catheter is positioned.

[0008] One or more sensors described herein may be positioned at specific locations on and / or within the aspiration catheter and / or (in some optional examples) the macerator assembly. The location of the sensor may be important in providing control information for controlling and / or regulating the activity of the aspiration catheter and / or the macerator assembly. As described herein, any suitable type of sensor may be used, including combinations of different types of sensors. Sensor types may include sensors for detecting electrical properties such as impedance (e.g., bioimpedance, including bioimpedance spectroscopy), sensors for detecting pressure, and / or sensors for detecting optical properties (e.g., optical spectroscopy). Sensor types may include ultrasound sensors. Sensor types may include optical sensors (including sensors for detecting color). Any combination of these sensors may be used.

[0009] Sensors may be present on the exterior distal and / or lateral regions of the catheter and / or within the catheter lumen (e.g., at the distal end region, the proximal end region, and one or more interior end regions). For example, pairs of sensing electrodes may be used on the exterior and / or interior of the aspiration catheter.

[0010] The methods and devices described herein may typically use these sensors to provide an output (visual, audio, data, etc.) to a user and / or an output that is stored for subsequent analysis. For example, these methods and devices may be used to provide an output to a user (e.g., a doctor, nurse, surgeon, technician, etc.) that clot material is near, adjacent to, and / or within the aspiration catheter. In some examples, these devices may provide an indication that clot material has entered and passed through (or is lodged within) the lumen of the aspiration catheter. These methods and devices may optionally be used to automatically and / or semi-automatically control the operation of one or more aspects of the device, such as the application of suction, maceration, etc. For example, the device may automatically or semi-automatically control turning suction on / off and / or adjusting (increasing, decreasing, etc.) the level of suction.

[0011] For example, methods are described herein, including methods for controlling a suction catheter, that may include detecting clot material at the distal end of the suction catheter using a first sensor or set of sensors at the distal end of the suction catheter, initiating or increasing suction by the suction catheter after the clot material is detected, detecting clot material in the distal end of the suction catheter using a second sensor or set of sensors in the distal end of the suction catheter to confirm that the clot material has been aspirated into the suction catheter, and ceasing or reducing the application of suction by the suction catheter after the clot material is no longer detected by the first sensor or set of sensors and the second sensor or set of sensors.

[0012]

[0012] The method may include inserting an aspiration catheter into the lumen of a blood vessel; detecting clot material at the distal end of the aspiration catheter using a first sensor and / or set of sensors at the distal end of the aspiration catheter, where detecting the clot material includes processing a signal from the first sensor or set of sensors to confirm the presence of clot material; initiating or increasing suction by the aspiration catheter after the clot material is detected; monitoring that the clot material has been sucked into the aspiration catheter using a second sensor or set of sensors in the distal end of the aspiration catheter; and ceasing or reducing the application of suction by the aspiration catheter after the clot material is no longer detected by the first sensor or set of sensors and the second sensor or set of sensors.

[0013] Generally, the methods described herein may be used to confirm the presence and / or proximity of clot material relative to a sensor. As previously mentioned, detecting clot material using a first sensor or set of sensors may include detecting clot material by one or more of detecting an electrical property (e.g., impedance), ultrasound, and / or light. In particular, detecting clot material by a first sensor or set of sensors may include detecting clot material by impedance.

[0014] Any of these methods and devices may be configured to initiate or increase suction when the controller determines that clot material is near or distal to the catheter and / or within the catheter, and particularly within the distal end of the catheter. The controller may process signals from a sensor or set of sensors to confirm the identity of the clot material as opposed to blood, a vessel wall, or other non-clot material. In some examples, multiple sensor types or modalities may be used to confirm the identity of the clot material, such as bioimpedance (or bioimpedance spectroscopy) and / or ultrasound and / or one or more optical properties (e.g., color). The controller may initiate suction when the controller determines that a clot is near one or more of the sensors. In some cases, the suction catheter may include a low level of suction (e.g., 0.5-50 mmHg), and the controller may then increase the suction to a higher (or high) level of suction (e.g., greater than about 300 mmHg, greater than about 350 mmHg, greater than about 400 mmHg, etc.) when a blood clot is identified or confirmed.

[0015] Similarly, the second sensor and / or set of sensors may be configured to sense the same modality as the first sensor or set of sensors or a different modality. Any of the sensors in the first or second set of sensors may be configured to sense a different modality (e.g., impedance, ultrasound, optical, etc.). Thus, any of these methods (using the controller) may confirm that clot material has been aspirated into the aspiration catheter by detecting clot material within the lumen of the aspiration catheter by one or more of impedance, ultrasound, and / or optical detection using the second sensor or set of sensors.

[0016] Generally, the methods and devices described herein may process signals from a first sensor or set of sensors to confirm the presence of clot material and / or process signals from a second sensor or set of sensors to confirm the presence of clot material. Sensor signal processing may include averaging (time averaging), windowing, etc. Because signals from sensors may be continuous and / or analog, or sampled using a sample frequency and digitized, signal processing of the sensed signals may be analog or digital signal processing. Signals may be transmitted in real time to a controller for processing. The controller may process signals in real time or with a slight delay to allow processing. During a medical procedure, signals may be processed and / or stored, and / or transmitted for display and / or storage.

[0017] For example, signals from one or more sensors, including adjacent sensors of the same or different types, may be processed using one or more analog signal processing techniques, such as by convolving the signals. Analog signals may be converted from the time domain to the frequency domain (e.g., by Fourier transform, Laplace transform, etc.) or through a representation such as a Bode plot, including using frequency spectrum impedance measurements. Digital signal processing may be performed, including functional analysis and / or numerical analysis techniques, such as decomposition into intrinsic mode functions and / or wavelets. Any of these methods and devices may determine noise in the sensors to help distinguish and verify contact or proximity to clot material.

[0018] The controller may identify clot material based on characteristics of the sensed values. For example, the signals from the first and / or second sensor or set of sensors may be processed to reduce noise and / or amplify the signals, and the signals may then be compared to known or expected values ​​corresponding to clot material within a predetermined or calculated confidence range to enable the controller to distinguish between clot material, blood, and the vessel wall. For example, in any of these examples, processing may include processing to distinguish from contacting the luminal wall of the vessel in which the aspiration catheter is positioned.

[0019] The methods and devices described herein can provide numerous advantages over systems that measure pressure or flow to control the operation of aspiration, but cannot ascertain the identity and / or characteristics of the clot material. In some cases, the methods and devices described herein may include sensors for detecting pressure and / or flow within the lumen of the aspiration catheter.

[0020] Generally, these methods and devices may be configured to initiate or increase suction after an initiation delay. In some examples, the initiation delay may allow for further sensing and processing to determine and / or confirm the presence of clot material and / or allow a user or device to configure for aspiration and / or maceration of the clot material. The initiation delay may be, for example, a predefined delay (e.g., 0.1 seconds to 10 seconds, 0.1 seconds to 8 seconds, 0.1 seconds to 7.5 seconds, 0.1 seconds to 6 seconds, 0.1 seconds to 5 seconds, 0.1 seconds to 4 seconds, 0.1 seconds to 3 seconds, 0.1 seconds to 2 seconds, 0.1 seconds to 1 second, etc.), or in some examples, the initiation delay may be defined based on user input. For example, in some (semi-automatic) configurations, the device may alert the user that suction can or should begin after clot material is confirmed at or near the distal end of the device, and may then allow the user to manually begin suction. Doing so can be useful for a number of reasons, including allowing the user to position the macerator within the lumen of the aspiration catheter.

[0021] As previously discussed, these methods and devices may be configured to allow for automatic stopping or reduction of suction (and / or in some instances, a macerator, if included), including automatically stopping after clot material is no longer detected within the suction catheter and distal to the end of the suction catheter. Generally, these methods and devices may be configured to stop or reduce the application of suction after clot material is no longer detected by the first sensor or set of sensors and the second sensor or set of sensors by stopping or reducing the application of suction through the suction catheter after a predetermined delay period. The stop delay may be, for example, 0.1 seconds to 10 seconds, 0.1 seconds to 8 seconds, 0.1 seconds to 7.5 seconds, 0.1 seconds to 6 seconds, 0.1 seconds to 5 seconds, 0.1 seconds to 4 seconds, 0.1 seconds to 3 seconds, 0.1 seconds to 2 seconds, 0.1 seconds to 1 second, etc. In some examples, the system may issue a stop warning that may indicate a stop of the suction catheter (and / or macerator) or may alert the user to manually stop suction and / or macerator operation. As used herein, a warning may be an audible alert (tone, chime, etc.) and / or a visible alert (light, indicator, etc.), a tactile alert (e.g., buzzer, vibration, etc.).

[0022] Any of the methods described herein may be used to remove clot material from a lumen of the human body, such as a blood vessel (e.g., an artery, a vein, etc.). In some instances, these methods may include methods of performing thrombectomy using suction. A medical method may be performed using suction alone or in combination with another device or subsystem, such as a mechanical device (e.g., a stent retriever device). The methods and apparatus described herein may be used in any suitable region of the human body, including, but not limited to, the lungs (e.g., in the pulmonary artery), the peripheral vasculature, the neurovasculature, etc.

[0023] Also described herein are devices for performing any of these methods, including devices for controlling suction within a suction catheter. For example, the device may include a suction catheter, a first sensor or set of sensors at a distal end face of the suction catheter, a second sensor or set of sensors within a lumen of the suction catheter, and a controller having one or more processors, the controller configured to enable or increase suction through the suction catheter when signals from the first sensor and / or set of sensors indicate that clot material is in front of the distal end of the suction catheter and / or in line with a particular portion of the suction catheter (such as an opening in the catheter wall).

[0024] Any of these devices may include a macerator within the lumen of the aspiration catheter (and / or may be configured to fit within the lumen). Additional examples of macerators are described below. The macerator may be a separate element slidably disposed within the lumen of the aspiration catheter, e.g., that can be inserted or removed within the lumen, or the macerator may be integrated into the aspiration catheter. As described in further detail below, the macerator may be controlled by the same controller (or a separate controller) as the aspiration through the aspiration catheter. The sensors (e.g., a first sensor or set of sensors and a second sensor or set of sensors) may process and provide input to the controller (or multiple controllers) to identify the presence and / or proximity of clot material within the lumen of the aspiration catheter, in addition to clot material at or near the distal end of the aspiration catheter.

[0025] A sensor or set of sensors within the catheter lumen may be positioned along all or part of the length of the catheter lumen. In some examples, the device may include one or more sensors within the distal end region of the aspiration catheter lumen. The distal end region may include the length of the aspiration catheter lumen extending proximally from the distal end of the aspiration catheter toward the macerator, which may be located more proximally within the catheter lumen. While any of the examples described herein may include a macerator, these methods and devices may be used without or adapted for use without a macerator, as described herein. In some examples, this distal end region may be referred to as the monitored distal end region. In some examples, the distal end region may have an inner diameter larger than the inner diameter of the more proximal region of the aspiration catheter, and sensors may be included within this larger region. Alternatively, the distal end region may have the same outer diameter (or optionally, a smaller outer diameter) as the more proximal region of the catheter, including the immediately proximal region. One or more sensors (e.g., in some examples, a second sensor or set of sensors) may be included within the larger diameter distal end region, or one or more sensors may extend proximally beyond this larger diameter region. As described with respect to some examples, the larger diameter region may be expandable (e.g., biased to expand). In any of these devices, one or more sensors within the lumen may be coupled (via wires or wirelessly) to a controller. Similarly, one or more sensors (first sensor or set of sensors) at the distal end of the aspiration catheter may be wired or wirelessly connected to the controller. For example, in any of these devices, one or more electrical connections (wires, lines, traces, etc.) may be made between the sensor and the controller, either directly or indirectly. In some examples, each sensor is coupled via one or more wires that extend proximally down the aspiration catheter (along the outside or within the sidewall) and ultimately connect to the controller.Separate power and data lines may be used, or the same lines (power and data) may be used in the same device.

[0026]

[0026] In some examples, the device may include a pump coupled to a controller. Any suitable pump that provides suction may be used. For example, the pump may be a positive displacement pump (e.g., a diaphragm pump, a gear pump, a peristaltic pump, a piston pump, etc.) or a dynamic pump (e.g., a centrifugal pump). The pump may be controlled by a controller. For example, the controller may output a control signal to turn the pump on, turn the pump off, or adjust the speed or suction applied by the pump. Thus, the device may include a pump coupled to a controller. Optionally, suction may be provided by a manually operated pump (vacuum source).

[0027] In some examples, the pump is not included directly in the device, and instead (or in addition) the device may include one or more valves and / or manifolds for regulating the source of suction, whether received from "wall" suction or by a separate pump. Thus, the system may include a suction interface that can control suction into the suction catheter to allow suction (turn on), not allow suction (turn off), or adjust the level of suction (higher / lower, including within a predetermined range of negative pressure). The suction interface may be part of or coupled to the controller. For example, the controller may include one or more valves for adjusting suction through the suction catheter. In some examples, the device may include a pump, and the controller may adjust the applied suction by controlling the suction interface rather than directly controlling the pump.

[0028] As previously mentioned, the first sensor or set of sensors and / or the second sensor or set of sensors may include one or more of acoustic sensors, electrical sensors (e.g., bioimpedance sensors), and optical sensors. The sensors within the first set of sensors may be the same or different. Similarly, the sensors within the second set of sensors may be the same or different. The first sensor may be the same as the second sensor. The first set of sensors may be the same as the second set of sensors. In some examples, groups of sensors (pairs or single sensors, three or more sensors, etc.) may be combined in similar locations to provide multiple sensing modalities in approximately the same (or same) location. In general, the sensors may be one or more of acoustic sensors, electrical (e.g., bioimpedance) sensors, and optical sensors.

[0029] In any of these devices, a first sensor or set of sensors may be disposed on a deformable cover that extends at least partially beyond the distal end of the aspiration catheter. The deformable cover may deform to open or close to allow clot material to enter the lumen of the aspiration catheter while restricting blood flow into the aspiration catheter. The deformable cover may be a sheet of expandable / contractible material, e.g., a polymeric material such as, but not limited to, silicone. The deformable cover may include one or more openings and / or slits, cuts, etc., to allow the cover to flex and allow clot material to enter the cover. In some examples, the first sensor or set of sensors may be disposed around an opening on the distal face of the aspiration catheter. The first sensor or set of sensors may be normally forward-facing, e.g., facing distally into the lumen.

[0030] As used herein, the terms "distally" or "proximally" can refer to directions away from or toward the body of a user manipulating the device. For example, the distal end of a suction catheter is typically the end that is inserted into a subject (e.g., a patient) by a user and moved away from the user into the subject.

[0031] As previously mentioned, these devices generally may include a set of sensors (e.g., optionally, a second sensor or set of sensors) sometimes referred to as internal sensors located within the lumen of the aspiration catheter. The internal sensor or set of sensors may be located on the sidewall of the lumen of the aspiration catheter. In some examples, the internal sensor or set of sensors may be located in a macerator component located within the lumen of the aspiration catheter. In some examples, the internal sensor set may be located both on the wall (sidewall) of the lumen and on the outside of the macerator ("macerator component"). Thus, in some examples, the position of the internal sensor or set of sensors may be adjustable within the lumen of the aspiration catheter. The internal sensor may optionally be referred to as a second sensor or set of sensors when used in conjunction with an external sensor or set of sensors. The internal sensor or set of sensors may be used without the external sensor or set of sensors ("first sensor" or set of sensors).

[0032]

[0032] One or more processors in the controller may control the application of suction through the suction catheter by directly and / or indirectly controlling the pump (e.g., using one or more valves, etc.).

[0033] In some examples, the processor may be configured to disable or reduce suction through the aspiration catheter after a predetermined delay (stop delay) after a signal from a first sensor or set of sensors indicates that clot material is not in front of the distal end of the aspiration catheter and a second sensor or set of sensors indicates that clot material is not within the lumen of the aspiration catheter. The stop delay may be based on a predetermined period of time (e.g., 0.1 seconds to 10 seconds, 0.1 seconds to 8 seconds, 0.1 seconds to 7.5 seconds, 0.1 seconds to 6 seconds, 0.1 seconds to 5 seconds, 0.1 seconds to 4 seconds, 0.1 seconds to 3 seconds, 0.1 seconds to 2 seconds, 0.1 seconds to 1 second, etc.). In any of these methods and devices, the stop delay may be based on one or more of the length of the aspiration catheter, the flow rate of material through the aspiration catheter, and the intensity of the suction applied.

[0034]

[0034] For example, the present specification describes an apparatus that includes a suction catheter, a first sensor or set of sensors at the distal end face of the suction catheter, a second sensor or set of sensors within the lumen of the suction catheter, and a controller that receives input from the first sensor or set of sensors and the second sensor or set of sensors and has one or more processors, wherein the one or more processors are configured to analyze signals from the first sensor or set of sensors to determine that clot material is in contact with or adjacent to the first sensor or set of sensors and to determine that clot material is within the lumen of the suction catheter based on data from the second sensor or set of sensors, and further wherein the controller is configured to enable or increase suction through the suction catheter when the one or more processors indicate that clot material is in front of the distal end of the suction catheter, and the controller is configured to disable or reduce suction through the suction catheter after a predetermined period of time from when the processor indicates that clot material is not in front of the distal end of the suction catheter and the processor has determined that clot material is not within the lumen of the suction catheter.

[0035] Also described herein are methods and apparatus for controlling a macerator within a suction catheter. In any of these apparatus, the macerator may be controlled separately from (or without) controlling the suction through the suction catheter as described above. For example, the methods and apparatus (systems and devices) described herein may include only methods and apparatus for controlling a macerator within a suction catheter.

[0036]

[0036] For example, the present specification describes a method that includes applying suction to suck a blood clot into an aspiration catheter, detecting blood clot material in the aspiration catheter using a sensor or set of sensors in the distal end of the aspiration catheter, activating a macerator in the aspiration catheter after the blood clot material is detected in the aspiration catheter, and ceasing activation of the macerator after the blood clot material is no longer detected by the sensor or set of sensors in the aspiration catheter.

[0037]

[0037] The method may include, for example, applying suction to suck the clot into the aspiration catheter, detecting clot material in the aspiration catheter using a sensor or set of sensors positioned on a macerator in the distal end of the aspiration catheter, activating the macerator after the clot material is detected, and stopping activation of the macerator after the clot material is no longer detected by the sensor or set of sensors.

[0038] The sensor or set of sensors may be present in the macerator. For example, the sensor or set of sensors may be present on the outside of the macerator. In some examples, one or more sensors may be present in a distal end region of the macerator near the cutting member (or cutting element) of the macerator. In some examples, one or more sensors may be present in a distal end region of the elongate body of the macerator. In general, the macerator may be used to unclog a suction catheter.

[0039]

[0039] Macerators are typically configured to disrupt occlusive material. Macerators may include wires, blades, etc., or multiple wires, blades, plates, threads, etc. The cutting members (e.g., wires, blades, threads, etc.) may move, and in some instances, rotate, to cut clot material. For example, in some instances, macerators may include multiple maceration wires having a linear configuration. Alternatively, or in combination, the maceration wires may be partially or completely straight, circular, curved, spiraled about an axis, or randomly shaped, or any combination thereof. The macerator may include a distal hub at its distal end coupled to the macerator inner shaft (e.g., the rotating shaft) and a proximal hub at its proximal end. The multiple maceration wires may be attached to the macerator drive shaft, the distal hub, the proximal hub, or any combination thereof. The inner shaft may be concentrically surrounded by the outer shaft. The inner and outer shafts of the macerator may be flexible. The inner (rotatable) shaft may be a drive shaft.

[0040]

[0040] In some examples, the macerator includes a threaded distal blade within a distal housing of the macerator that includes one or more openings for receiving and breaking up the clot material so that it can be more easily removed down the aspiration catheter.

[0041]

[0041] Accordingly, any of the methods described herein may include driving the macerator by driving rotation of the macerator (e.g., a drive shaft) to rotate or otherwise actuate a cutting member of the macerator. In some examples, the macerator may be driven or actuated by extending the cutting member out of a protective housing (e.g., a distal housing). The macerator may be positioned within the lumen of the aspiration catheter, for example, by advancing it distally within the lumen of the aspiration catheter. Any of these methods may include extending the macerator within the lumen of the aspiration catheter prior to applying suction to draw the clot into the aspiration catheter.

[0042] Any of these methods may include applying suction by applying intermittent suction. The suction may be applied in a pattern (e.g., a repeating pattern of high / low negative pressure) or in an oscillatory pattern. The suction may be applied at a constant level.

[0043] In any of the methods and devices described herein, the clot material may be detected by the sensor or set of sensors by sensing one or more of impedance (including impedance spectroscopy), ultrasound, and / or light sensing. For example, among other things, detecting the clot by the sensor or set of sensors may include detecting the clot material by impedance.

[0044]

[0044] Detecting clot material in the aspiration catheter using a sensor or set of sensors in the distal end of the aspiration catheter may include detecting clot material at or adjacent to a window exposing the cutter of the macerator.

[0045] Also described herein are devices configured to control operation of a macerator based on the presence and / or proximity of clot material. For example, described herein are devices that include an aspiration catheter including an aspiration lumen, a macerator having an elongate body, the macerator configured to extend distally through the aspiration catheter to a distal end region of the aspiration catheter, a sensor or set of sensors within the lumen of the aspiration catheter, and a controller including one or more processors, the controller configured to enable the macerator when a signal from the sensor or set of sensors indicates that clot material is within the lumen of the aspiration catheter.

[0046] As previously mentioned, a sensor or set of sensors (in some examples, a second sensor or set of sensors) may be positioned in the macerator. This sensor or set of sensors may be present in the lumen of the aspiration catheter. As previously mentioned, the sensor or set of sensors may include one or more of an acoustic sensor, an electrical (e.g., bioimpedance) sensor, and an optical sensor. In any of these examples, a sensor within the lumen of the aspiration catheter may be positioned on the sidewall of the lumen and / or on the macerator.

[0047] In any of these methods and devices, the controller may be configured to disable the macerator when a signal from the sensor or set of sensors indicates that clot material is no longer present in the lumen of the aspiration catheter. For example, the controller may be connected to a motor that drives rotation of the macerator drive shaft. The controller may be directly or indirectly wired to the macerator motor (macerator driver). The controller may send a digital and / or analog signal to the macerator to turn on (enable) when clot material is within the lumen of the aspiration catheter, including when clot material is near (proximate to) the macerator's cutting member (and in some cases, only when clot material is near the cutting member). The controller may send a digital and / or analog signal to the macerator to turn off (disable) when clot material is not within the lumen of the aspiration catheter and / or when clot material is not near the macerator's cutting member. The controller may be configured to enable the macerator by driving rotation of a drive shaft that typically extends through the elongate body.

[0048]

[0048] In some examples, the macerator includes one or more side-facing windows configured to expose the cutting member (eg, the rotary cutting member).

[0049] For example, described herein is an apparatus that includes an aspiration catheter including an aspiration lumen; a macerator having an elongated body surrounding a drive shaft, the macerator configured to extend distally through the aspiration catheter to a distal end region of the aspiration catheter; a sensor or set of sensors at the distal end region of the macerator; and a controller having one or more processors, the controller configured to enable the macerator when a signal from the sensor or set of sensors detects clot material and to disable the macerator when a signal from the sensor or set of sensors does not detect clot material.

[0049]

[0050] Any of the methods described herein may include controlling both the suction and the macerator of the aspiration catheter device by sensing a clot, and may include any of the component steps of any of the aforementioned methods. For example, a method is described herein that includes detecting clot material at the distal end of the aspiration catheter using a first sensor or set of sensors at the distal end of the aspiration catheter, initiating or increasing suction by the aspiration catheter after the clot material is detected, detecting clot material in the distal end of the aspiration catheter using a second sensor or set of sensors in the distal end of the aspiration catheter to confirm that the clot material has been aspirated into the aspiration catheter, activating the macerator in the aspiration catheter after the clot material is detected in the aspiration catheter, ceasing activation of the macerator after clot material is no longer detected by the second sensor or set of sensors in the aspiration catheter, and ceasing or reducing application of suction by the aspiration catheter after clot material is no longer detected by the first sensor or set of sensors and the second sensor or set of sensors.

[0050]

[0051] For example, the method may include inserting an aspiration catheter into a lumen of a blood vessel; detecting clot material at the distal end of the aspiration catheter using a first sensor or set of sensors at the distal end of the aspiration catheter, where detecting clot material includes processing a signal from the first sensor or set of sensors to confirm the presence of clot material; initiating or increasing suction by the aspiration catheter after the clot material is detected; monitoring that the clot material has been aspirated into the aspiration catheter using a second sensor or set of sensors in the distal end of the aspiration catheter; actuating a macerator in the aspiration catheter after clot material in the aspiration catheter is detected from the second sensor or set of sensors; stopping actuation of the macerator after clot material is no longer detected by the second sensor or set of sensors; and stopping or reducing application of suction by the aspiration catheter after clot material is no longer detected by the first sensor or set of sensors and the second sensor or set of sensors.

[0051]

[0052] Any of the devices described herein may be devices for controlling both aspiration and maceration of clot material, e.g., for controlling both aspiration through the aspiration catheter and operation of a macerator within the aspiration catheter, or may be additional devices. For example, the device may include an aspiration catheter including an aspiration lumen, a macerator having an elongate body, the macerator configured to extend distally through the aspiration catheter to a distal end region of the aspiration catheter, a first sensor or set of sensors at a face of the distal end of the aspiration catheter, a second sensor or set of sensors within the lumen of the aspiration catheter, and a controller including one or more processors, the controller configured to enable or increase aspiration through the aspiration catheter when a signal from the first sensor or set of sensors indicates that clot material is in front of the distal end of the aspiration catheter, and the controller configured to enable the macerator when a signal from the second sensor or set of sensors indicates that clot material is within the lumen of the aspiration catheter.

[0052]

[0053] In some examples, the device includes an aspiration catheter including an aspiration lumen; a macerator comprising an elongate body surrounding a drive shaft, the macerator configured to extend distally through the lumen of the aspiration catheter to a distal end region of the aspiration catheter; a first sensor or set of sensors at the distal end surface of the aspiration catheter; a second sensor or set of sensors within the lumen of the aspiration catheter; and a controller receiving inputs from the first sensor or set of sensors and the second sensor or set of sensors and comprising one or more processors, wherein the one or more processors analyze signals from the first sensor or set of sensors to verify that clot material is in contact with or adjacent to the first sensor or set of sensors and determine whether the clot material is being aspirated based on data from the second sensor or set of sensors. The controller is further configured to verify that clot material is in front of the distal end of the aspiration catheter, and the controller is further configured to enable or increase suction through the aspiration catheter when the one or more processors indicate that clot material is in front of the distal end of the aspiration catheter, and to enable the macerator when the signal from the second sensor or set of sensors detects clot material and to disable the macerator when the signal from the second sensor or set of sensors does not detect clot material, and the controller is configured to disable or reduce suction through the aspiration catheter after a predetermined period of time from when the processor indicates that clot material is not in front of the distal end of the aspiration catheter and the processor has confirmed that clot material is not within the lumen of the aspiration catheter.

[0053]

[0054] Generally, described herein are methods for detecting obstructions (e.g., blood clots) and controlling suction to remove and / or sense obstructions using a thrombectomy device (including, but not limited to, a suction catheter) and / or to control a macerator within the thrombectomy device.

[0054]

[0055] For example, any of the methods described herein may include a method including moving a thrombectomy device within a blood vessel; detecting an obstruction in an extraction zone distal to an extraction inlet of the thrombectomy device using a sensor configured to sense the obstruction in the extraction zone of the thrombectomy device; determining whether the obstruction is a vessel wall or clot material; and if the obstruction is clot material, triggering a clot extraction response including one or more of notifying a user that the thrombectomy device is in contact with clot material, activating an extractor to remove the clot material from the extraction inlet, and / or activating a macerator in an extraction chamber region of the thrombectomy device; and stopping the extractor when clot material is no longer present in the extraction chamber region based at least in part on one or more of the sensor configured to sense clot material in the extraction chamber region and a change in the macerator response.

[0055]

[0056] Any suitable thrombectomy device may be used in the methods described herein, including, but not limited to, a suction-applying thrombectomy device. The thrombectomy device may be a mechanical thrombectomy device that removes the clot by grasping and / or otherwise pulling on the clot. For example, the thrombectomy device may include a stent-based thrombectomy device, with or without suction, or a thrombectomy device that pulls a mesh or other material to engage and capture the clot.

[0056]

[0057] Generally, these methods and devices may be configured to determine the distance between clot material and a wall of a blood vessel. The clot material may be a thrombus, atheroma, an embolus, plaque, etc. In some instances, the clot material may be present within a blood vessel and / or a pulmonary vein. For example, the clot material may be a pulmonary embolism.

[0057]

[0058] Generally, the devices described herein may include an extraction zone distal to the extraction inlet of the thrombectomy device. For example, the extraction zone may be a region within a few millimeters (e.g., within 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 1 mm, etc.) of the entrance to the portion of the thrombectomy device that removes clot material. The extraction inlet may be an entrance to a chamber of the device, such as an entrance to a suction catheter in a variation that removes clots by applying suction. In some cases, the extraction inlet may be at least partially covered; for example, the extraction inlet may be covered by a material such as a membrane with an opening ("extraction opening" or simply "opening") formed therein. The extraction inlet may be covered by a fluid-impermeable material, and the covering material may be an elastomeric membrane.

[0058]

[0059] Detecting an obstruction in the extraction zone may include sensing the obstruction by one or more techniques, such as bioimpedance. For example, detecting an obstruction in the extraction zone may include detecting a change in pressure. Detecting an obstruction in the extraction zone may include optically detecting clot material. Detecting an obstruction in the extraction zone may include detecting contact with the obstruction using a contact sensor.

[0059]

[0060] In some examples, the sensor may include a contact sensor, and detecting an obstacle in the extraction zone includes detecting contact with the contact sensor.

[0061] Determining whether the obstruction is a vessel wall or clot material may include applying suction and determining whether the obstruction is sucked through the extraction inlet into the extraction chamber region of the thrombectomy device. In some examples, determining whether the obstruction is a vessel wall or clot material may include applying suction and determining whether the obstruction is sucked a predetermined distance beyond the extraction inlet into the extraction chamber region of the thrombectomy device. For example, determining whether the obstruction is a vessel wall or clot material may include applying suction, waiting 100 to 1000 milliseconds, and determining a change in macerator response for a macerator in the extraction chamber. Determining whether the obstruction is a vessel wall or clot material may include applying suction and monitoring pressure in the extraction chamber.

[0060]

[0062] In any of these methods, triggering the clot extraction response may include emitting a signal that the thrombectomy device is in contact with clot material. The signal may be audible (e.g., a tone, buzzer, beep, recorded message, etc.) and / or visual (e.g., a light / LED, display, etc.), tactile (e.g., vibration, resistance, etc.), etc. In any of these methods, triggering the clot extraction response may include automatically activating an extractor to remove clot material from the extraction inlet by applying or increasing suction through the thrombectomy device, the extractor comprising a source of suction. For example, triggering the clot extraction response may include automatically activating an extractor to remove clot material from the extraction inlet, the extractor comprising a mechanical extractor. In some examples, triggering the clot extraction response includes automatically activating or increasing a macerator in the extraction chamber region of the thrombectomy device. Alternatively or additionally, these methods and devices may include signaling that clot material is (or was) present in the aspiration catheter, including providing an alert that the aspiration catheter is clogged and / or a location within the lumen of the catheter where the clog exists (e.g., the distal end region, the proximal end region, or one or more intermediate regions).

[0061]

[0063] In any of these methods and devices, detecting an obstruction in the extraction zone may include detecting the obstruction on the outside of a cover covering the extraction inlet of the thrombectomy device, the cover comprising an expandable opening through which the clot material may be sucked.

[0062]

[0064] Also described herein are thrombectomy devices capable of performing any of these methods. For example, the apparatus may include an elongate body having an aspiration lumen extending therethrough, an extraction chamber region at a distal end region of the elongate body in fluid communication with the aspiration lumen, an extraction inlet into the extraction chamber region at the distal end of the extraction chamber region, an obstruction sensor configured to sense an obstruction in an extraction zone distal to the extraction inlet, and a controller configured to detect an obstruction in the extraction zone using the obstruction sensor, determine whether the obstruction is a vessel wall or clot material, and trigger an alert indicating the nature of the obstruction, the controller further configured for manual or automatic activation of suction in the extraction chamber region when the controller determines that the obstruction is clot material.

[0063]

[0065] Any of the devices described herein may include a macerator within the extraction chamber region configured to macerate clot material within the extraction chamber region.

[0066] As previously mentioned, any of these devices may include a cover over the extraction inlet. The cover may have an expandable opening. The opening may be a slit, a cut, a lid, etc. The extraction chamber area may be expandable.

[0064]

[0067] In any of these devices, the obstacle sensor may include a contact sensor, a pressure sensor, an optical sensor, or a bioimpedance sensor including two or more electrodes.

[0065]

[0068] Any of these devices may include a suction regulator coupled to a controller, which may be configured to apply suction using the suction regulator and determine whether the obstruction is a vessel wall or clot material.

[0066]

[0069] Generally, any of these devices may include an extraction chamber. The extraction chamber may refer to the distal end region of the lumen of the aspiration catheter, or may be similar to or identical to the proximal or more intermediate region of the catheter lumen; alternatively, in some cases, the extraction chamber may be a structurally distinct region of the catheter. As previously mentioned, the extraction chamber may be partially or completely covered by a cover. The extraction chamber may be an expandable region. The extraction chamber may be partially or completely closed to prevent blood loss into the device (when drawing suction) or minimize blood loss through the device, as described herein. Thus, generally, the extraction chamber may refer to the distal end region of a catheter (such as a suction catheter), as described herein.

[0067]

[0070] Any of these devices may include an extraction chamber sensor configured to detect an obstruction in the extraction chamber, and in some examples, the controller is configured to determine whether the obstruction is a blood vessel wall or clot material based on an output of the extraction chamber sensor when suction is applied. The extraction chamber sensor may be one or more of a contact sensor, a pressure sensor, an optical sensor, or an electrical (e.g., bioimpedance) sensor. In some examples, the controller is configured to determine whether the obstruction is a blood vessel wall or clot material based on a change in macerator response.

[0068]

[0071] Generally, any of these devices may include a macerator and a macerator driver for driving the operation of the macerator. The macerator may be driven by the macerator driver and operated to reciprocate one or more members and / or rotate one or more members. The controller may be configured to detect changes in energy applied to drive the macerator and determine whether the obstruction is a vessel wall or clot material. In some examples, the controller may be configured to detect changes in the vibration of the macerator and determine whether the obstruction is a vessel wall or clot material. In any of these devices, the controller may be configured to determine a load on or a change in the load of the macerator based on sounds emitted by the macerator and / or driver (e.g., a drive shaft, etc.). Accordingly, any of these devices may include a microphone input for detecting sounds from the device (e.g., from the macerator).

[0069]

[0072] For example, the device may include an elongate body having an aspiration lumen extending therethrough, an extraction chamber region at a distal end region of the elongate body in fluid communication with the aspiration lumen, a macerator in the extraction chamber region configured to macerate clot material in the extraction chamber region, an extraction inlet into the extraction chamber region at the distal end of the extraction chamber region, an obstacle sensor configured to sense an obstacle in the extraction zone distal to the extraction inlet, and a controller configured to sense an obstacle in the extraction zone using the obstacle sensor, determine whether the obstacle is a vessel wall or clot material, and trigger an alert indicating the nature of the obstacle, as described herein, wherein the controller is further configured for manual or automatic activation of suction in the extraction chamber region when the controller determines that the obstacle is clot material, and the controller is further configured to stop suction through the extraction chamber region when the controller determines that no further clot material is present in the extraction chamber region.

[0070]

[0073] Also described herein are methods for optically detecting blood clots and distinguishing walls from blood clots by spectroscopic analysis. For example, the method may include moving a thrombectomy device within a blood vessel, detecting an obstruction in an extraction zone distal to an extraction inlet of the thrombectomy device using an optical sensor in the thrombectomy device, determining whether the obstruction is a blood vessel wall or clot material based on a reflectance spectral value of the obstruction, and triggering a clot extraction response if the obstruction is clot material, the clot extraction response including one or more of notifying a user that the thrombectomy device is adjacent to clot material, applying suction from the extraction inlet, and / or activating a macerator in an extraction chamber region of the thrombectomy device, and clot extraction response stopping suction when clot material is no longer detected in the extraction chamber region.

[0071]

[0074] Any of these methods may include sensing clot material in the extraction chamber region based at least in part on one or more of a sensor configured to detect clot material in the extraction chamber region and a change in macerator response. As previously described, the method may include detecting an obstruction in the extraction zone by detecting the obstruction outside a cover covering an extraction inlet of the thrombectomy device, the cover including an expandable opening through which the clot material may be drawn. Detecting an obstruction in the extraction zone using an optical sensor may include detecting contact between the optical sensor and the obstruction. In some examples, detecting an obstruction in the extraction zone using an optical sensor may include detecting an oxygenation level of the obstruction.

[0072]

[0075] Generally, triggering the clot extraction response may include signaling that the thrombectomy device is in contact with clot material. In some examples, triggering the clot extraction response includes automatically activating or increasing suction to remove clot material from the extraction inlet by applying or increasing suction through the thrombectomy device. Triggering the clot extraction response may also include automatically activating or increasing activity of a macerator within the extraction chamber region of the thrombectomy device.

[0073]

[0076] In any of these methods and devices, stopping the suction may include stopping the suction after a predetermined period of time after no clot material is detected within the extraction chamber area.

[0074]

[0077] Also described herein are methods for mechanically removing a blood clot (without or in addition to suction). For example, the method may include using an optical sensor in a thrombectomy device to detect an obstruction in an extraction zone adjacent an extraction inlet of the thrombectomy device in a blood vessel, determining whether the obstruction is a blood vessel wall or clot material based on a reflectance spectral value of the obstruction, and if the obstruction is clot material, triggering a clot extraction response including one or more of notifying a user that the thrombectomy device is in contact with clot material, activating an extractor to capture the clot material, and / or activating a macerator in an extraction chamber region of the thrombectomy device, and stopping the extractor when clot material is no longer detected in the extraction chamber region.

[0075]

[0078] In some examples, activating the extractor to capture the clot material includes applying suction from the extraction inlet.

[0079] Also described herein are thrombectomy devices including one or more optical sensors. For example, the device may include an elongate body having an aspiration lumen extending therethrough, an extraction chamber region at a distal end region of the elongate body in fluid communication with the aspiration lumen, an extraction inlet into the extraction chamber region at the distal end of the extraction chamber region, an optical sensor configured to sense an obstruction in an extraction zone distal to the extraction inlet, a light source coupled to the optical sensor, a photodetector coupled to the optical sensor, and a controller coupled to the photodetector and configured to detect the obstruction in the extraction zone and determine whether the obstruction is a vessel wall or clot material based on a reflectance spectral value of the obstruction, the controller further configured to trigger an alarm indicating the nature of the obstruction and enable manual or automatic activation of suction in the extraction chamber region when the controller determines that the obstruction is clot material.

[0076]

[0080] The optical sensor may include a sensing fiber and an emitting fiber. In some examples, the distal ends of the sensing fiber and the emitting fiber may be embedded within a spherical material having a first refractive index, and the sphere may be at least partially coated or covered with a material having a second refractive index. For example, any of these devices may include a macerator within the extraction chamber region configured to macerate clot material within the extraction chamber region. The device may include a cover over the extraction inlet, the cover including an expandable opening. The extraction chamber region may be expandable.

[0077]

[0081] Any of these devices may include a suction regulator coupled to a controller configured to apply suction using the suction regulator and determine whether the obstruction is a vessel wall or clot material.

[0078]

[0082] As previously mentioned, the controller may be further configured to determine whether the obstruction is a vessel wall or clot material based on a change in macerator response. Any of these devices may include a macerator driver, and the controller is configured to detect a change in energy applied to drive the macerator and determine whether the obstruction is a vessel wall or clot material. The controller may also be configured to detect a change in the vibration of the macerator and determine whether the obstruction is a vessel wall or clot material.

[0079]

[0083] For example, the device may include an elongate body having an aspiration lumen extending therethrough; an extraction chamber region at a distal end region of the elongate body in fluid communication with the aspiration lumen; a macerator within the extraction chamber region configured to macerate clot material within the extraction chamber region; an extraction inlet into the extraction chamber region at a distal end of the extraction chamber region; an optical sensor configured to sense an obstruction within an extraction zone distal to the extraction inlet; a light source coupled to the optical sensor; a photodetector coupled to the optical sensor; and a controller coupled to the photodetector and configured to sense an obstruction within the extraction zone and determine whether the obstruction is a vessel wall or clot material based on a reflectance spectral value of the obstruction; the controller is further configured to trigger an alert indicating the nature of the obstruction and to enable manual or automatic activation of suction within the extraction chamber region when the controller determines that the obstruction is clot material; and the controller is further configured to cease suction when clot material is no longer detected within the extraction chamber region based at least in part on one or more of the sensor configured to sense clot material within the extraction chamber region and a change in macerator response.

[0080]

[0084] Also described herein are methods of detecting a blood clot (and / or distinguishing between clot material and a vessel wall or other material) based on contact pressure. For example, the method may include moving a thrombectomy device within a blood vessel, detecting contact with an obstruction in an extraction zone adjacent an extraction inlet of the thrombectomy device using a sensor at a distal end of the thrombectomy device within or adjacent to the extraction zone, determining whether the obstruction is a vessel wall or clot material by applying suction from the extraction inlet and detecting the obstruction within an extraction chamber region of the thrombectomy device, and triggering a clot extraction response if the obstruction is clot material, the clot extraction response including one or more of notifying a user that the thrombectomy device is in contact with clot material, applying or increasing suction, and / or enabling a macerator within the extraction chamber region of the thrombectomy device, and clot extraction response stopping suction when clot material is no longer detected within the extraction chamber region.

[0081]

[0085] Detecting an obstruction within the extraction chamber region may be based at least in part on one or more of a sensor configured to sense clot material within the extraction chamber region and a change in macerator response. For example, detecting contact may include optically detecting contact. Detecting contact may include detecting contact using a pressure sensor. In some examples, detecting contact includes detecting contact using a contact-sensing balloon.

[0082]

[0086] In any of these methods, determining whether the obstruction is a vessel wall or clot material by applying suction may include applying a pulse of suction (e.g., a pulse of 5 seconds to 1 msec, e.g., 2 seconds to 1 msec, 1 second to 1 msec, less than 5 seconds, less than 4 seconds, less than 3 seconds, less than 2 seconds, less than 1 second, 900 msec or less, 800 msec or less, 700 msec or less, 600 msec or less, 500 msec or less, 400 msec or less, 300 msec or less, 200 msec or less, 100 msec or less, 75 msec or less, 50 msec or less, etc.). In any of these methods and devices, the method or device may apply a low level of constant or variable suction, and the pulse may be a pulse of higher suction (e.g., a 2-fold higher, 3-fold higher, 4-fold higher, 5-fold higher, 10-fold higher, 15-fold higher, 20-fold higher, 50-fold higher, 100-fold higher, etc. pulse).

[0083]

[0087] Any of these methods may include determining whether the obstruction is a blood vessel wall or clot material by detecting the clot material using a sensor configured to detect the obstruction within the extraction chamber. For example, the sensor may include one of a bioimpedance sensor, an optical sensor, a pressure sensor, and a contact sensor. Determining whether the obstruction is a blood vessel wall or clot material may include determining the clot material based on a change in the response of the macerator, as described above. For example, the change in the response of the macerator may include a change in the electrical load of the macerator. The change in the response of the macerator may include a change in the vibration of the macerator. The change in the response of the macerator may include a change in the acoustics of the macerator.

[0084]

[0088] In any of these methods and apparatus, triggering the clot extraction response may include signaling that the thrombectomy device is in contact with clot material. Triggering the clot extraction response may include automatically activating an extractor to remove clot material from the extraction inlet by applying or increasing suction through the thrombectomy device, the extractor comprising a source of suction. Triggering the clot extraction response may include automatically activating an extractor to remove clot material from the extraction inlet, the extractor comprising a mechanical extractor. In some examples, triggering the clot extraction response includes automatically activating or increasing a macerator in the extraction chamber region of the thrombectomy device.

[0085]

[0089] Detecting an obstruction in the extraction zone may include detecting the obstruction on the outside of a cover covering an extraction inlet of the thrombectomy device, the cover comprising an expandable opening through which clot material may be sucked.

[0086]

[0090] Also described herein are methods for mechanically removing blood clots (without or in addition to suction). In some of these examples, suction may be used to distinguish a wall from a blood clot. For example, the method may include moving a thrombectomy device within a blood vessel; detecting contact with an obstacle within an extraction zone distal to an extraction inlet of the thrombectomy device using a sensor at a distal end of the thrombectomy device within or adjacent to the extraction zone; determining whether the obstacle is a blood vessel wall or clot material by applying suction from the extraction inlet and detecting the obstacle within an extraction chamber region of the thrombectomy device; and triggering a clot extraction response if the obstacle is clot material, the clot extraction response including one or more of notifying a user that the thrombectomy device is in contact with clot material, activating an extractor to capture the clot material, and / or activating a macerator within the extraction chamber region of the thrombectomy device; and stopping extraction when clot material is no longer detected within the extraction chamber region. In any of these methods, activating the extractor to capture the clot material may include applying suction from the extraction inlet.

[0087]

[0091] Also described herein is a thrombectomy device including one or more pressure sensors configured to detect a blood clot near or within the extraction chamber. For example, the device may include an elongate body having an aspiration lumen extending therethrough, an extraction chamber region at a distal end region of the elongate body fluidly communicating with the aspiration lumen, an extraction inlet into the distal end of the extraction chamber region, a contact sensor in an extraction zone adjacent to the extraction inlet, the contact sensor configured to detect contact pressure, a sensing subsystem configured to detect blood clot material within the extraction chamber region, and a controller coupled to the contact detector and the sensing subsystem and configured to detect contact with an obstacle within the extraction zone based on the contact sensor and determine whether the obstacle is a blood vessel wall or blood clot material based on the sensing subsystem, the controller further configured to trigger an alarm indicating the nature of the obstacle and enable manual or automatic activation of suction within the extraction chamber region when the controller determines that the obstacle is blood clot material, and the controller further configured to stop suction when blood clot material is no longer detected within the extraction chamber region.

[0088]

[0092] The sensing subsystem may include one or more of a bioimpedance sensor, a pressure sensor, and an optical sensor. The device may include a macerator within the extraction chamber region configured to macerate clot material within the extraction chamber region. In any of these devices, the sensing subsystem may be configured to detect changes in macerator response. As previously mentioned, any of these devices may include a cover over the extraction inlet, the cover comprising an expandable opening. The extraction chamber region may be expandable.

[0089]

[0093] Also described herein are methods of detecting a blood clot, for example, by applying pulses of suction (e.g., on demand or periodically) and determining whether the blood clot has been partially or completely drawn into the extraction chamber and / or into the cover, as well as devices configured to carry out the methods. The presence of clot material may be confirmed by detecting a change in the activity of the macerator and / or by sensing an internal sensor within the chamber. For example, the method may include detecting clot material in an extraction zone distal to an extraction inlet of a thrombectomy device in a blood vessel by applying a pulse of suction through the extraction inlet; confirming that clot material is within the extraction zone by detecting clot material in an extraction chamber region of the thrombectomy device during or immediately after the pulse of suction; triggering a clot extraction response if clot material is confirmed within the extraction zone, the clot extraction response including one or more of notifying a user that the thrombectomy device is in contact with clot material, activating an extractor to capture the clot material, and / or activating a macerator in the extraction chamber region of the thrombectomy device; and stopping extraction when clot material is no longer detected in the extraction chamber region.

[0090]

[0094] Detecting clot material within the extraction chamber region may be based at least in part on one or more of a sensor configured to sense clot material within the extraction chamber region and a change in macerator response. Applying the pulse of suction may include applying a pulse of suction having a predetermined duration of about 0.1 seconds to 10 seconds. Detecting clot material within the extraction chamber region of the thrombectomy device during or immediately after the pulse of suction may include detecting clot material using a sensor configured to detect an obstruction within the extraction chamber.

[0091]

[0095] The sensor may include one or more of a bioimpedance sensor, an optical sensor, a pressure sensor, and a contact sensor. Alternatively or additionally, detecting clot material in the extraction chamber region of the thrombectomy device during or immediately after the pulse of suction may include detecting clot material based on a change in the response of the macerator. The change in the response of the macerator may include a change in the electrical load of the macerator, and / or a change in the vibration of the macerator, and / or a change in the sound of the macerator, e.g., a change in the acoustics of the macerator.

[0092]

[0096] In any of these examples, triggering the clot extraction response includes signaling that the thrombectomy device is in contact with clot material. Triggering the clot extraction response may include automatically activating an extractor to remove clot material from the extraction inlet by applying or increasing suction through the thrombectomy device, the extractor comprising a source of suction. Triggering the clot extraction response may include automatically activating an extractor to remove clot material from the extraction inlet, the extractor comprising a mechanical extractor. Triggering the clot extraction response may include automatically activating or increasing a macerator in the extraction chamber region of the thrombectomy device.

[0093]

[0097] Detecting clot material within the extraction zone may include applying a pulse of suction through an expandable opening in a cover over the extraction inlet of the thrombectomy device.

[0098] For example, the method may include moving the thrombectomy device within the blood vessel; detecting clot material in an extraction zone adjacent to the extraction inlet of the thrombectomy device by applying pulses of suction through the extraction inlet while operating a macerator within the extraction chamber region of the thrombectomy device during or immediately after the pulses of suction and identifying clot material in the extraction zone based on a change in macerator response; triggering a clot extraction response if clot material is identified in the extraction zone, the clot extraction response including one or more of notifying a user that the thrombectomy device is in contact with clot material, activating a mechanical extractor to capture the clot material, and / or activating a macerator within the extraction chamber region of the thrombectomy device; and stopping extraction after clot material is no longer detected in the extraction chamber region based on the change in macerator response.

[0094]

[0099] Also described herein is a device comprising an elongate body having a suction lumen extending therethrough, an extraction chamber region at a distal end region of the elongate body in fluid communication with the suction lumen, an extraction inlet into the distal end of the extraction chamber region, a macerator within the extraction chamber region, and a controller configured to couple to a suction regulator and control the application of pulses of suction from the suction regulator through the extraction inlet when the macerator is operating, and to confirm the presence of clot material within the extraction chamber region by detecting a change in macerator response during the pulse of suction, wherein the controller is further configured to do one or more of: signaling the presence of clot material, enabling suction to capture the clot material, enabling the macerator, and / or stopping suction after clot material is no longer detected within the extraction chamber region based on the macerator response during capture of the clot material.

[0095]

[0100] Also described herein are methods for detecting clots using a sensor that detects the opening of an opening into an extraction chamber (e.g., separation of sides of a partially or completely closed opening). For example, the method may include moving a thrombectomy device within a blood vessel, detecting clot material in an extraction zone adjacent to the extraction inlet of the thrombectomy device by applying a pulse of suction through the extraction inlet while manipulating a macerator within the extraction chamber region of the thrombectomy device during or immediately after the pulse of suction and detecting separation between two or more sides of the opening through a cover over the extraction inlet of the thrombectomy device, and triggering a clot extraction response if the separation between the two or more sides exceeds a threshold, the clot extraction response including one or more of notifying a user that the thrombectomy device is in contact with clot material, activating suction to capture the clot material, and / or activating a macerator within the extraction chamber region.

[0096]

[0101] Any of these methods may include stopping the clot extraction response when a clot is no longer detected outside the extraction region and / or within the extraction chamber, either immediately or after a delay (to allow clot material already present within the device to be removed.) For example, any of these methods and devices may be configured to stop the clot extraction process after the separation between two or more sides no longer exceeds a threshold value when applying suction.

[0097]

[0102] Detecting separation between two or more lobules may include detecting separation between two or more electrodes at the lobules based on impedance measurements. Detecting separation between two or more lobules may include optically detecting separation between two or more lobules.

[0098]

[0103] Also described herein is a device comprising: an extraction chamber region at a distal end region of the elongate body in fluid communication with the suction lumen; an extraction inlet into the extraction chamber region; a cover over the extraction inlet; an opening through the cover, the opening having two or more sides; a sensor configured to detect separation between the two or more sides of the opening; and a controller coupled to the suction regulator and configured to control application of pulses of suction from the suction regulator through the extraction inlet and to trigger a clot extraction response when the separation between the two or more sides exceeds a threshold, the clot extraction response including one or more of: signaling contact with clot material, activating suction to capture the clot material, and / or activating a macerator within the extraction chamber region. The device may include a macerator within the extraction chamber region. The controller may be further configured to stop suction after the separation between the two or more sides falls below a threshold.

[0099]

[0104] Generally, described herein are devices for detecting clot material within an aspiration catheter (including an aspiration lumen) using a sensor within the aspiration lumen (or at least partially within the aspiration lumen). In some examples, the sensor is a deflection sensor including a deflectable member. The device (e.g., a controller and / or sensing circuitry) may detect deflection of the deflectable member to confirm the presence of clot material within the aspiration lumen and / or to distinguish between clot material and the vessel wall at the distal end or distal end region of the device.

[0100]

[0105] For example, described herein is a device that includes an elongate body having an aspiration lumen extending therethrough; a deflection sensor extending at least partially within the aspiration lumen, the deflection sensor comprising a deflectable member including a first region coupled to a location of a wall within the aspiration lumen and a second region separated from the first region by a length of the deflectable member, the deflectable member having an undeflected configuration and a deflected configuration, wherein in the deflected configuration the second region has an axial offset relative to the location of the wall that differs from the axial offset between the second region and the location of the wall in the undeflected configuration; and a controller configured to detect an obstruction within the aspiration lumen based on a signal from the deflection sensor indicative of deflection of the deflectable member.

[0101]

[0106] The deflectable member may be configured as an elongate member that protrudes into and / or across the aspiration lumen (e.g., across the distal end region, also referred to herein as the clot extraction chamber region of the aspiration lumen). In the first configuration, the deflectable member may be disposed across the longitudinal axis of the aspiration lumen. In some examples, the deflectable member may be disposed along and / or helically wound around the longitudinal axis (e.g., as a spring). In some examples, the deflectable member may be referred to as a barb, e.g., the deflectable member may include a barb.

[0102]

[0107] The deflectable sensor may include a first electrode in the first region and a second electrode on a wall of the aspiration lumen opposite the deflectable member, wherein when the deflectable member is in an undeflected configuration, the deflectable member extends across the aspiration lumen such that the first electrode is proximate to the second electrode, and when the deflectable member is in a deflected configuration, the first and second electrodes are axially spaced further apart compared to the undeflected configuration. In some examples, the device may include a third electrode axially spaced within the aspiration lumen relative to the location of the wall such that in the deflected configuration, the first electrode is closer to the third electrode compared to the undeflected configuration.

[0103]

[0108] In some examples, the deflectable member includes a shape-sensing optical fiber. Alternatively or additionally, in some examples, the deflectable member includes a piezoelectric material. For example, the controller may be configured to detect a transition of the deflectable member between an undeflected configuration and a deflected configuration based on a piezoelectric signal. In some examples, the deflectable member includes a variable resistance material that changes resistivity when bent, and the controller may be configured to detect a change in resistance when the deflectable member bends.

[0104]

[0109] In any of these examples, the controller may be configured to determine whether the obstruction is a vessel wall or clot material. For example, the controller may be configured to use signals from a deflection sensor representative of deflection of the deflectable member and / or one or more of pressure through and / or flow within the aspiration lumen to determine whether clot material is stuck within the aspiration lumen, particularly including the distal end of the aspiration lumen (this is often referred to as "lollypopping," where a large portion of the clot is stuck in the distal end region of the aspiration lumen).

[0105]

[0110] In some examples, the deflectable member is located in a distal end region of the aspiration lumen configured as an extraction chamber region. In a first configuration, the deflectable member may extend beyond the wall of the aspiration lumen and may be configured to deflect such that a second region of the deflectable member is moved axially and radially relative to the undeflected configuration. In some examples, the extraction chamber region is expandable; alternatively, in some examples, the extraction chamber region is not distinct from other portions of the aspiration lumen but refers to a region distal to the aspiration lumen at the distal end of the device. In any of these devices, the location of the wall within the aspiration lumen is within about 5 mm of the distal end of the aspiration lumen of the elongate body.

[0106]

[0111] The deflectable member typically couples to the wall of the aspiration lumen at a first region (first end) and may be configured to deflect or deform such that a second region (e.g., a second end region) of the deflectable member moves relative to the first region when a force is applied by material in the aspiration lumen, such as blood or clot material. Generally, the deflectable member is configured to resiliently deflect so as to return to the first (undeflected) configuration when the force from interacting with material in the aspiration lumen is removed. In some cases, the deflectable member is formed of a superelastic material, such as a nickel-titanium material (e.g., nitinol) and / or a polymeric material. The deflectable member may include a polymeric inner liner, a reinforcing layer, and a polymeric exterior. In some examples, in the first configuration, the first electrode is separated from the second electrode by about 0.01 mm to about 2 mm.

[0107]

[0112] In any of these devices, the suction lumen may be covered or partially covered. For example, the device may include a cover over the distal end of the suction lumen, the cover having an expandable opening. In any of these devices, the suction lumen may be surrounded by a deformable lip.

[0108]

[0113] Any of these devices may include a macerator within the suction lumen configured to macerate clot material within the suction lumen. Any of these devices may include a macerator drive. A controller may control the application of energy to drive the macerator (e.g., to rotate a macerator drive shaft / drive wire), either manually or automatically. In some examples, the controller is configured to apply pulsed suction.

[0109]

[0114] As previously mentioned, the device may include a pressure sensor configured to determine the pressure within the aspiration lumen. Any of these devices may include a flow sensor configured to determine the flow rate through the aspiration lumen.

[0110]

[0115] The controller may be configured to trigger an alarm indicating the nature of the obstruction. The controller may be configured for manual or automatic activation of suction if the controller determines that the obstruction is clot material.

[0111]

[0116] Any of these devices may include one or more stops within the aspiration lumen to prevent advancement of the macerator distally beyond the deflectable member.

[0117] The devices described herein may include multiple deflection sensors within the aspiration lumen. For example, the device may include a second deflectable member extending from the wall of the aspiration lumen, the second deflectable member being located in a more proximal region of the aspiration lumen.

[0112]

[0118] For example, described herein are devices (e.g., thrombectomy devices) configured to remove material from within a blood vessel using one or more deflectable barbs to confirm and / or detect the presence of clot material and / or to distinguish clot material from the vessel wall. Any of these devices may include an elongate body having an aspiration lumen extending therethrough, deflectable bristles extending from a wall of the aspiration lumen, a first electrode at a distal end region of the deflectable bristles, and a second electrode at a wall of the aspiration lumen opposite the deflectable bristles, the second electrode having a first configuration in which the deflectable bristles extend across the aspiration lumen such that the first electrode is proximal to the second electrode, and a second configuration in which the deflectable bristles deflect such that the first electrode is spaced farther from the second electrode compared to the first configuration, and a controller configured to detect an obstruction within the aspiration lumen based on an electrical signal between the first electrode and the second electrode indicative of deflection of the deflectable bristles.

[0113]

[0119] In some examples, the device may include an elongate body having an aspiration lumen extending therethrough, the distal end region of the aspiration lumen configured as an extraction chamber region; deflectable bristles extending from a wall of the extraction chamber region; a first electrode at the distal end region of the deflectable bristles; a second electrode at a wall of the aspiration lumen opposite the deflectable bristles, the second electrode having a first configuration in which the deflectable bristles extend protruding across the extraction chamber region such that the first electrode is proximal to the second electrode, and a second configuration in which the deflectable bristles deflect such that the first electrode is spaced farther from the second electrode compared to the first configuration; and a controller configured to detect an obstruction in the extraction chamber region based on an electrical signal between the first electrode and the second electrode and determine whether the obstruction is a blood vessel wall or a blood clot material.

[0114]

[0120] In any of these devices, the controller may be configured to determine whether the obstruction is a vessel wall or clot material. For example, the controller may include one or more processors that can analyze the electrical signal (e.g., impedance, conductance, etc.) between the first and second electrodes and determine whether the barbs are deflecting due to clot material within the aspiration lumen, e.g., in the extraction chamber region, based on electrical characteristics over time (e.g., a comparison between impedance before, during, and / or after application of suction, such as a pulse of suction).

[0115]

[0121] In any of these devices and methods, the deflectable bristles may be located at a distal end region of the aspiration lumen configured as an extraction chamber region. The deflectable bristles may extend beyond the wall of the aspiration lumen in a first configuration and may be deflected such that the distal end region of the deflectable bristles is moved axially and radially relative to the second electrode in a second configuration. As previously mentioned, the extraction chamber region may be expandable.

[0116]

[0122] In some examples, the deflectable bristles may be within about 5 mm of the distal end of the aspiration lumen of the elongate body. The deflectable bristles may comprise a superelastic material. In some examples, the deflectable bristles comprise a polymer inner liner, a reinforcing layer, and a polymer outer casing.

[0117]

[0123] In any of these examples, the device may include a cover over the distal end of the aspiration lumen, which may have an expandable opening.

[0124] Any of these devices may include a macerator within the aspiration lumen configured to macerate clot material within the aspiration lumen, as described above. The macerator may be prevented from damaging the deflectable barbs by including one or more features on the macerator, such as a distally extending sleeve or cuff that restricts movement of the macerator within the aspiration lumen (e.g., preventing the macerator from moving past the barbs) and / or deflects the deflectable barbs distally, away from the opening of the macerator.

[0118]

[0125] Any of these devices may include a pressure sensor configured to determine the pressure within the aspiration lumen, and / or a flow sensor (e.g., a thermal anemometer such as a hot wire anemometer) for determining the flow rate within the aspiration lumen.

[0119]

[0126] Any of these devices may include a macerator driver. The controller may control the drive (e.g., drive wires) of the rotary cutting elements within the macerator.

[0127] In any of these devices, the controller may be configured to apply pulsed suction. The use of pulsed suction may allow the device to determine that clot material is present.

[0120]

[0128] In any of these devices, the controller may be configured to trigger an alarm indicating the nature of the obstruction. The controller may be further configured for manual or automatic activation of suction if the controller determines that the obstruction is clot material.

[0121]

[0129] The devices described herein may include multiple deflectable bristles. For example, the device may include a second deflectable bristle extending from the wall of the aspiration lumen, the second deflectable bristle being located in a more proximal region of the aspiration lumen.

[0122]

[0130] In some cases, the first electrode may be kept separated (e.g., uncontracted) from the second electrode, which can improve the sensitivity of the device. For example, the first electrode may be separated from the second electrode by about 0.01 mm to about 2 mm.

[0123]

[0131] Also described herein are methods of controlling the devices described herein, and / or removing clot material, and / or distinguishing clot material from the vessel wall, which may be particularly well suited to removing clot material without removing too much blood.

[0124]

[0132] For example, the method may include applying suction through an aspiration lumen of a device within a blood vessel; detecting deflection of a flexible member at a distal end region of the aspiration lumen that extends at least partially into an extraction chamber region; determining whether the deflection is caused by clot material trapped in the extraction chamber region; and, if clot material is trapped in the extraction chamber region, triggering a clot extraction response including one or more of notifying a user that the device is adjacent clot material, applying continuous suction through the aspiration lumen, and / or activating a macerator in the extraction chamber region of the device.

[0125]

[0133] Applying suction can include applying a pulse of suction. Applying a pulse of suction can enable the device to detect clot material and / or remove clot material without removing excessive amounts of blood from the subject. The pulse of suction can be, for example, 2 seconds or less (e.g., 1.5 seconds or less, 1 second or less, 0.9 seconds or less, 0.7 seconds or less, 0.6 seconds or less, 0.5 seconds or less, 0.4 seconds or less, 0.3 seconds or less, 0.2 seconds or less, 0.1 seconds or less, 50 milliseconds or less, 10 milliseconds or less, 5 milliseconds or less, 1 millisecond or less, etc.).

[0126]

[0134] Any of these methods may include stopping suction when the deflectable member indicates that clot material is no longer present in the extraction chamber area (e.g., using one or more deflectable members) and / or within the aspiration lumen. Stopping suction may include stopping suction a predetermined period of time (e.g., 1 second, 2 seconds, 3 seconds, 4 seconds, 5 seconds, 6 seconds, 7 seconds, 8 seconds, 9 seconds, 10 seconds, 12 seconds, 15 seconds, etc.) after clot material is no longer detected within the aspiration lumen. Suction may be stopped manually or automatically.

[0127]

[0135] Any of these methods may include sensing one or more of the pressure within the aspiration lumen and / or the flow rate through the aspiration lumen. The method may further include determining that clot material is within (e.g., trapped within) the aspiration lumen using one or more of the pressure within the aspiration lumen and / or the flow rate through the aspiration lumen. Any of these methods may include distinguishing between the vessel wall and the clot material using one or more of the pressure within the aspiration lumen and / or the flow rate through the aspiration lumen.

[0128]

[0136] Triggering the clot extraction response may include signaling that the device is in contact with clot material. In some examples, triggering the clot extraction response includes automatically activating or increasing suction to remove clot material from the extraction chamber region by applying or increasing suction through the suction lumen. Alternatively or additionally, triggering the clot extraction response may include automatically activating or increasing activity of a macerator within the extraction chamber region.

[0129]

[0137] The deflectable member may be part of a deflection sensor that identifies deflection of the deflectable member by sensing one or more parameters, such as electrical or mechanical parameters. The deflectable member may be part of a sensing circuit configured to detect changes in the shape or deflection of the deflectable member within the aspiration lumen (or a region of the aspiration lumen, such as the extraction chamber region). Note that in any of the devices described herein, a different extraction chamber region may be included as part of the aspiration lumen or in fluid communication with the aspiration lumen. Alternatively, in some examples, the extraction chamber region may be an undivided (undivided) section of the aspiration lumen (e.g., at or near the distal end).

[0130]

[0138] For example, detecting deflection of the flexible member includes detecting a change in the resistance, conductance, or inductance of the flexible member. In some examples, detecting deflection of the flexible member includes detecting a change in the shape of the flexible member using a fiber optic bend sensor. In some examples, detecting deflection of the flexible member includes detecting a change in voltage or current in a sensing circuit to which the flexible member is electrically coupled.

[0131]

[0139] For example, the method may include moving a device within a blood vessel, applying suction through an aspiration lumen of the device, detecting an obstruction within the extraction chamber region at a distal end region of the aspiration lumen through the device using deflectable barbs extending at least partially across the extraction chamber region, determining whether the obstruction is a vessel wall or clot material based on an electrical signal between a first electrode at the distal end of the deflectable barbs and a second electrode in communication with a wall of the extraction chamber region, and if the obstruction is clot material, triggering a clot extraction response including one or more of notifying a user that the device is adjacent clot material, applying continuous suction through the aspiration lumen, and / or enabling a macerator within the extraction chamber region of the device.

[0132]

[0140] In any of these methods, applying suction may include applying a pulse (or multiple pulses) of suction.

[0141] Any of these methods may include stopping suction when clot material is no longer detected within the extraction chamber region. For example, stopping suction may include stopping suction a predetermined period of time after clot material is no longer detected within the aspiration lumen.

[0133]

[0142] These methods may include sensing one or more of the pressure within the aspiration lumen and / or the flow rate through the aspiration lumen.

[0143] As previously described, triggering the clot extraction response may include signaling that the device is in contact with clot material. For example, triggering the clot extraction response may include automatically activating or increasing suction to remove clot material from the extraction chamber region by applying or increasing suction through the suction lumen. In some examples, triggering the clot extraction response includes automatically activating or increasing activity of a macerator within the extraction chamber region.

[0134]

[0144] Also described herein are methods for performing a pulmonary embolectomy. For example, a method for performing a pulmonary embolectomy may include advancing a suction catheter into a pulmonary artery (e.g., in some examples, the left pulmonary artery), applying suction through the suction catheter, determining the identity of the obstruction as clot material or as vascular anatomy when flow through the suction catheter is obstructed, and outputting an indicator of the identity of the clot material. Advancing the suction catheter may include advancing the suction catheter through the pulmonary valve, around a bend, and into the pulmonary artery.

[0135]

[0145] Generally, determining the identity of the occlusion as clot material or vascular anatomy may include detecting clot material using an intraluminal sensor. For example, determining the identity of the occlusion as clot material or vascular anatomy may include deflecting a deflectable member within the lumen of the aspiration catheter. Determining the identity of the occlusion as clot material or vascular anatomy may include optically confirming that the occlusion is clot material.

[0136]

[0146] In any of these examples, outputting the indicator may include triggering a warning to a user. Outputting the indicator may include ceasing application of suction if the obstruction is inherent in the vascular anatomy.

[0137]

[0147] Also described herein are methods and devices for determining characteristics of clot material within an aspiration lumen. For example, described herein is a device including an elongate body having an aspiration lumen extending therethrough, a first internal impedance sensor at a distal end region of the aspiration lumen, a second internal impedance sensor at a proximal region of the aspiration lumen, and a controller configured to track clot material within the aspiration lumen based on signals from the first and second internal impedance sensors.

[0138]

[0148] For example, the device may include an elongate body having an aspiration lumen extending therethrough; a first internal impedance sensor at a distal end region of the aspiration lumen comprising a first pair of annular electrodes extending at least partially adjacent to the periphery of the aspiration lumen; a second internal impedance sensor at a proximal region of the aspiration lumen comprising a second pair of annular electrodes extending at least partially adjacent to the periphery of the aspiration lumen; and a controller configured to track clot material within the aspiration lumen and determine a size estimate of the clot material based on impedance signals over time from the first internal impedance sensor and impedance signals over time from the second internal impedance sensor.

[0139]

[0149] The first internal impedance sensor may comprise a pair of annular electrodes extending radially around the aspiration lumen. In some examples, the annular electrodes comprise ring electrodes extending radially around the aspiration lumen (completely or partially). In some examples, the annular electrodes comprise helical electrodes. The pair of annular electrodes may be separated from each other by 1 to 20 mm (e.g., 5 to 20 mm, 5 to 10 mm, etc.). Each pair of annular electrodes may extend radially around the aspiration lumen by more than 40 degrees. Either or both of the first impedance sensor or the second impedance sensor may include an AC power source configured to establish and control a variable voltage between the annular electrodes of the first internal impedance sensor. The controller may be further configured to determine the size of the clot material based on signals from the first internal impedance sensor and the second internal impedance sensor. In some examples, the controller is configured to determine a flow rate of the clot material within the aspiration lumen. The controller may be configured to distinguish between the clot material and the vessel wall based on signals from the first internal impedance sensor and the second internal impedance sensor. In some examples, the controller is further configured to adjust suction through the suction catheter based at least on a signal from the first internal impedance sensor.

[0140]

[0150] Also described herein is a method for tracking clot material within an aspiration catheter by detecting impedance signals over time from a first impedance sensor (e.g., a first pair of annular electrodes) at a distal end region of the aspiration lumen and a second impedance sensor at a proximal region of the aspiration lumen. The method may include identifying matching patterns representing clot material from both the first and second impedance sensors and determining a time delay between the matching patterns to estimate the movement rate of the clot material within the aspiration lumen. The method may include estimating the time it takes for the clot material to pass through the second impedance sensor at the proximal end of the aspiration lumen to estimate the length of the clot material, and / or using the known cross-sectional area of ​​the aspiration lumen to estimate the amount (e.g., volume, size, etc.) of clot material removed.

[0141]

[0151] Any of these methods may include applying alternating current power (e.g., AC voltage) to establish and control a variable voltage between sensing electrodes forming the first impedance sensor and / or the second impedance sensor. Separate AC voltages may be applied from different AC voltage sources or the same AC voltage source. Any of these methods may include distinguishing between blood vessel wall and clot material using signals from the first impedance sensor and the second impedance sensor.

[0142]

[0152] Any of these methods may include outputting tracking data, for example, outputting the rate of removal of clot material, and / or outputting the size (e.g., length, volume, etc.) of the clot material removed through the aspiration lumen, and / or outputting the presence and / or location of a clot within the aspiration lumen.

[0143]

[0153] For example, generally, described herein are methods for detecting and / or tracking clot material within the lumen of an aspiration catheter using impedance sensing. These methods and devices can be particularly useful for determining whether clot material is still present in the lumen of the catheter. Generally, knowing whether clot material is present within the lumen can be very beneficial because, if the clot material is stuck in the lumen, suction / pressure alone may not be sufficient to detect the material. If the clot material is stuck in the lumen, a physician may need to know this, including when it is desirable to apply contrast through the lumen. If the clot material is still present in the catheter, it may be dislodged and return to the patient, causing further problems for the patient. For example, described herein are devices including a flexible, elongated catheter having an aspiration lumen extending therethrough; an internal electrical impedance sensor having two or more electrodes within the aspiration lumen; and a controller coupled to the internal electrical impedance sensor and configured to apply an alternating current between the two or more electrodes to detect occlusive material within the aspiration lumen based on the electrical impedance signal from the internal electrical impedance sensor.

[0144]

[0154] In any of these devices, the internal electrical impedance sensor may be configured to operate at 50 kHz or greater (e.g., 100 kHz or greater, etc.). The internal electrical impedance sensor may be located within about 20 mm of an aspiration opening into the aspiration lumen at the distal end region of the flexible, elongate catheter. The controller may be further configured to output a signal indicating the presence of occlusive material in the aspiration lumen.

[0145]

[0155] The controller may be configured to apply the alternating current after initiating suction through the aspiration lumen.

[0156] Any of these devices may include a second internal electrical impedance sensor comprising two or more electrodes in a region proximal to the aspiration lumen.

[0146]

[0157] The apparatus may include a current generator configured to apply an alternating current.

[0158] Generally, the two or more electrodes may be any suitable electrodes. In some examples, the two or more electrodes comprise ring electrodes that extend at least partially radially around the aspiration lumen. For example, the ring electrodes may include helical electrodes. The ring electrodes may be separated from one another by 0.1 to 20 mm. Each of the ring electrodes may extend radially around the aspiration lumen by 30 degrees or more.

[0147]

[0159] For example, described herein is a device comprising: a flexible, elongate catheter having an aspiration lumen extending therethrough; an internal electrical impedance sensor comprising two or more electrodes within the aspiration lumen between the proximal and distal ends of the flexible, elongate catheter; and a controller coupled to the internal electrical impedance sensor and configured to apply an alternating current between the two or more electrodes to detect occlusive material within the aspiration lumen based on the electrical impedance signal from the internal electrical impedance sensor and output a signal indicative of the presence of occlusive material within the aspiration lumen.

[0148]

[0160] Generally, these devices may include only a catheter (for use with a controller and other system components) or only a controller and other system components for use with a catheter, as described herein. For example, a device may include a flexible, elongate catheter having an aspiration lumen extending therethrough, an aspiration opening at a distal end region of the flexible, elongate catheter, a first internal electrical impedance sensor at the distal end region of the aspiration lumen comprising two or more electrodes extending at least partially around the aspiration lumen, a second internal electrical impedance sensor at a region proximal to the aspiration lumen comprising two or more electrodes extending at least partially around the aspiration lumen, and one or more connectors at the proximal end region of the flexible, elongate catheter, the one or more connectors in electrical communication with the first and second internal electrical impedance sensors, and further, the one or more connectors coupled to a controller and configured to provide an electrical impedance input for detecting occlusive material in the aspiration lumen based on the electrical impedance signals from the first and second internal electrical impedance sensors.

[0149]

[0161] The first internal electrical impedance sensor may be located within approximately 20 mm of the aspiration opening into the aspiration lumen. Any of these devices may include a proximal aspiration port in communication with the aspiration lumen. The aspiration opening may be located on a tapered side of the distal end region of the flexible, elongate catheter. The two or more electrodes of the first internal electrical impedance sensor may include annular electrodes. The annular electrodes of the first internal electrical impedance sensor may include helical electrodes. The annular electrodes of the first internal electrical impedance sensor may be separated from one another by 0.1 to 20 mm. The annular electrodes of the first internal electrical impedance sensor may each span 30 degrees or more radially around the aspiration lumen.

[0150]

[0162] Also described herein are methods for detecting occlusive material within a lumen of an aspiration catheter, the methods including applying suction through the lumen of the aspiration catheter, applying a variable current between two or more electrodes of a first internal electrical impedance sensor within the lumen of the aspiration catheter between the proximal and distal ends of the aspiration catheter to generate an impedance signal, and detecting occlusive material within the lumen of the aspiration catheter based on the impedance signal. Detecting occlusive material may include distinguishing the occlusive material from blood within the lumen of the aspiration catheter based on the impedance signal. Any of these methods may include outputting a signal indicating the presence of occlusive material within the lumen of the aspiration catheter.

[0151]

[0163] Any of these methods may include analyzing the impedance signal to detect a change in impedance indicating the presence of occlusive material within proximity of the first internal electrical impedance sensor. Applying a variable current may include applying a variable current having a frequency of 50 kHz or greater. Any of these methods may include determining whether occlusive material has lodged in the lumen based on the impedance signal.

[0152]

[0164] In any of these methods, applying a variable current between two or more electrodes may include applying multiple frequencies to obtain an impedance spectrum, and detecting occlusive material in the lumen may include detecting the occlusive material using the impedance spectrum. Any of these methods may include determining a rate of movement of the occlusive material in the lumen. The method may include applying the same or different variable currents between two or more electrodes of a second internal electrical impedance sensor in the lumen of the aspiration catheter and detecting occlusive material in the lumen of the aspiration catheter near the second internal electrical impedance sensor.

[0153]

[0165] Also described herein are devices configured to determine the identity of material at the suction opening using electrical impedance. For example, the methods and devices described herein may include one or more sensors (suction opening sensors) at the suction opening to distinguish between a blood clot and a vessel wall. In these devices and methods, a force (e.g., suction) may be applied between the material and the suction opening at the distal (tip) region. Generally, distinguishing between a blood clot and a vessel wall can be difficult, especially when initially applying suction; during this time, material may block the suction opening into the suction lumen, making it unclear whether the suction opening is blocked because the device is in contact with the vessel wall or because the device is in contact with a large blood clot. Typically, this can lead to a long delay while the physician waits to see if the material is removed by suction (or by increasing suction). Therefore, it would be beneficial to more accurately and quickly distinguish between clot material and wall material. Additionally, it may be particularly beneficial to provide an analytical technique that separates material (clot or wall) from blood and / or from situations where both the wall and blood vessel are in contact with the suction opening, which may give ambiguous results. As described herein, the use of an impedance sensing electrode at the distal suction opening (or simply recessed relative to the distal suction opening) can allow for rapid identification of either wall or clot material.

[0154]

[0166] For example, described herein is a device comprising a flexible elongate body having an aspiration lumen extending therethrough, a suction opening into the aspiration lumen at a distal end region of the flexible elongate body, a suction opening sensor comprising two or more electrodes positioned at a lip of the suction opening, and a controller coupled to the suction opening sensor and configured to distinguish between a blood clot and a vessel wall based on an impedance signal between the two or more electrodes when a force is applied to the flexible elongate body or through the suction lumen. The controller may be configured to distinguish between a blood clot and a vessel wall when a negative pressure in the suction lumen exceeds a threshold. The controller may be configured to distinguish between a blood clot and a vessel wall when a mechanical force exceeding a threshold is applied to the suction opening.

[0155]

[0167] In some examples, the suction opening is present on a tapered side of the distal end region of the flexible elongate body. The two or more electrodes of the suction opening sensor may be recessed from the edge. The two or more electrodes of the suction opening sensor may be recessed into the suction lumen at the edge. The two or more electrodes of the suction opening sensor may be spaced evenly apart from each other at the edge of the suction opening. The two or more electrodes of the suction opening sensor may be positioned opposite each other across the suction opening. In some examples, the two or more electrodes of the suction opening sensor are positioned opposite each other across the suction opening at the region of smallest diameter.

[0156]

[0168] Any of these devices may include a plurality of smaller flow-modifying openings into the aspiration lumen positioned adjacent to the aspiration opening, and a second impedance sensor comprising two or more electrodes positioned adjacent to the plurality of smaller flow-modifying openings.

[0157]

[0169] The device may include a flexible elongate body having an aspiration lumen extending therethrough, a suction opening into the aspiration lumen at a distal end region of the flexible elongate body, a suction opening sensor having two or more electrodes positioned on an edge of the suction opening, and a controller coupled to the suction opening sensor and configured to distinguish between a blood clot and a vessel wall based on an impedance signal between the two or more electrodes when negative pressure applied through the suction lumen exceeds a threshold value.

[0158]

[0170] Also described herein is a device comprising a flexible elongate body having a suction lumen extending therethrough, a suction opening at a distal end region of the flexible elongate body into the suction lumen, a suction opening sensor comprising two or more electrodes positioned at the edge of the suction opening, a proximal suction port in communication with the suction lumen, and one or more connectors at the proximal end region of the flexible elongate body, the one or more connectors in electrical communication with the two or more electrodes of the suction opening sensor, and further, the one or more connectors coupled to a controller and configured to provide an electrical impedance input for distinguishing between a blood clot and a vessel wall when a force is applied to the flexible elongate body or through the suction lumen.

[0159]

[0171] The device may include a second set of two or more electrodes in the suction lumen proximal to the suction opening sensor, and further, the one or more connectors may be in electrical communication with the second set of two or more electrodes and provide a differential electrical impedance input from the two or more electrodes of the suction opening sensor to distinguish between a blood clot and a vessel wall when a force is applied to the flexible elongate body or through the suction lumen.

[0160]

[0172] The suction opening is angled. The two or more electrodes of the suction opening sensor may be recessed from the edge. The two or more electrodes of the suction opening sensor may be recessed into the suction lumen at the edge. The two or more electrodes of the suction opening sensor may be spaced evenly apart from each other at the edge of the suction opening. The two or more electrodes of the suction opening sensor may be positioned opposite each other across the suction opening. The two or more electrodes of the suction opening sensor may be positioned opposite each other across the suction opening at the region of smallest diameter.

[0161]

[0173] Any of these devices may include multiple smaller flow rate variation openings into the aspiration lumen positioned adjacent the aspiration opening, and / or a second impedance sensor comprising two or more electrodes positioned adjacent the multiple smaller flow rate variation openings.

[0162]

[0174] Also described herein is a method of distinguishing a blood clot from a blood vessel wall, the method including applying suction through a lumen of a flexible, elongate catheter, the flexible, elongate catheter comprising a suction opening at a distal end region and two or more electrodes at or adjacent to the suction opening, and determining whether the suction opening is engaged with a blood clot or a blood vessel wall based on impedance measured from the two or more electrodes at or adjacent to the suction opening when the force at the suction opening exceeds a threshold value.

[0163]

[0175] The force at the suction opening may include negative pressure within the lumen. Any of these methods may include emitting a warning indicating whether the suction opening is engaged with one or both of the clot and the vessel wall.

[0164]

[0176] The methods described herein may include applying an alternating current having a frequency of about 1 kHz to 1 MHz. For example, the alternating current may have a frequency of about 10 kHz to 100 kHz.

[0165]

[0177] The methods described herein may include delaying the step of determining whether the suction opening is engaged with the clot or the vessel wall for a delay period after the force exceeds a threshold. In any of these methods, determining whether the suction opening is engaged with the clot or the vessel wall may be based on a difference in impedance measurements from two or more electrodes at or adjacent to the suction opening and a second set of two or more electrodes positioned proximally from the two or more electrodes at or adjacent to the suction opening. Any of these methods may include adjusting suction through the lumen based on the impedance measured from the two or more electrodes at or adjacent to the suction opening.

[0166]

[0178] Also described herein is a method of removing occlusive material from a blood vessel, the method including applying negative pressure to an aspiration lumen of a flexible, elongate catheter including an aspiration opening and two or more electrodes at or adjacent to the aspiration opening, receiving impedance measurements from the two or more electrodes at or adjacent to the aspiration opening while applying the negative pressure, and adjusting the negative pressure based on the received impedance measurements.

[0167]

[0179] Generally, the methods and devices described herein may use impedance sensing to track clot material within a lumen of a catheter. Tracking the material may include confirming that clot material is present in (or has left) the aspiration lumen, determining the flow rate of the material through the aspiration lumen, estimating the volume or amount of clot material removed through the aspiration lumen, etc.

[0168]

[0180] For example, the device may include a flexible elongate body having an aspiration lumen extending therethrough, a first pair of electrodes within the aspiration lumen, a second pair of electrodes proximal to the first pair of electrodes, and a controller coupled to the first pair of electrodes and the second pair of electrodes and configured to track clot material within the aspiration lumen based on electrical impedance signals from the first pair of electrodes and the second pair of electrodes.

[0169]

[0181] The first pair of electrodes may include a pair of annular electrodes extending at least partially radially around the aspiration lumen. The pair of annular electrodes may include ring electrodes extending radially around the aspiration lumen. The pair of annular electrodes may include helical electrodes. The pair of annular electrodes may be separated from each other by 0.1 to 20 mm. Each pair of annular electrodes may extend radially around the aspiration lumen by 30 degrees or more. The first pair of electrodes and the second pair of electrodes may comprise quad detectors. For example, the first pair of electrodes may be spaced from the second pair of electrodes by 0.1 to 20 mm along the length between the distal and proximal ends of the aspiration lumen.

[0170]

[0182] Any of these devices may include an AC power source coupled to the first pair of electrodes and configured to apply a variable voltage. The controller may be further configured to determine a size of the clot material based on the electrical impedance signals from the first pair of electrodes and the second pair of electrodes. The controller may be configured to determine a flow rate of the clot material within the aspiration lumen based on the electrical impedance signals from the first pair of electrodes and the second pair of electrodes.

[0171]

[0183] The controller may be configured to distinguish between clot material and a vessel wall based on the electrical impedance signals from the first pair of electrodes and the second pair of electrodes. For example, the controller may be further configured to adjust suction through the aspiration lumen based at least in part on the electrical impedance signals from the first pair of electrodes.

[0172]

[0184] The device may include a flexible elongate body having an aspiration lumen extending therethrough, a suction opening at a distal end region of the flexible elongate body to the aspiration lumen, a first pair of electrodes within the aspiration lumen extending at least partially around the aspiration lumen, a second pair of electrodes proximal to the first pair of electrodes in the aspiration lumen and extending at least partially around the aspiration lumen, a proximal suction port in communication with the aspiration lumen, and one or more connectors at the proximal end region of the flexible elongate body in electrical communication with the first pair of electrodes and the second pair of electrodes, the one or more connectors further configured to couple to a controller and provide an electrical impedance input for tracking clot material within the aspiration lumen based on electrical impedance signals from the first pair of electrodes and the second pair of electrodes. The first pair of electrodes and the second pair of electrodes may comprise a quad detector comprising two pairs of electrodes. The first pair of electrodes and the second pair of electrodes may be spaced 0.1 to 20 mm apart from one another along the length between the distal and proximal ends of the aspiration lumen.

[0173]

[0185] A method for tracking clot material within an aspiration lumen of a catheter may include receiving a first impedance signal from a first pair of electrodes within the aspiration lumen, receiving a second impedance signal from a second pair of electrodes within the aspiration lumen, and estimating one or more of a clot material flow rate and a clot material volume from the first impedance signal and the second impedance signal. Any of these methods may include outputting one or more of the clot material flow rate and the clot material volume. The method may include detecting an occlusion of the catheter based on the first impedance signal and the second impedance signal. Any of these methods may include adjusting suction through the aspiration lumen based on the first impedance signal and the second impedance signal.

[0174]

[0186] Estimating one or more of a flow rate of the clot material and a volume of the clot material may include correlating the first impedance signal and the second impedance signal. Estimating one or more of a flow rate of the clot material and a volume of the clot material may include determining a time difference between the correlation of the first impedance signal and the second impedance signal.

[0175]

[0187] Also described herein are catheters (and methods of using catheters to remove clot material) that are configured in very specific ways to reliably distinguish between clot material, blood, and / or wall with high accuracy. For example, described herein are devices and methods of using these devices in which two complementary sets of electrodes may be used to determine the type of material adjacent to a suction opening into the interior of the catheter. This configuration is experimentally shown to exhibit impedance signal separation between different tissue types that is greater than twice the impedance value. For example, any of these devices may include a flexible, elongate catheter having an aspiration lumen extending therethrough; a suction opening to the aspiration lumen at a distal end region of the flexible, elongate body; a first pair of sensing electrodes disposed at edges of the aspiration opening across a longitudinal axis of the flexible, elongate catheter; a second pair of sensing electrodes on either side of the aspiration opening in a proximal-to-distal line extending through the longitudinal midline of the aspiration opening; and a controller coupled to the first pair of sensing electrodes and the second pair of sensing electrodes and configured to distinguish clot material from blood and a vessel wall based on electrical impedance signals from both the first pair of sensing electrodes and the second pair of sensing electrodes.

[0176]

[0188] In some examples, the device includes a flexible, elongate catheter having an aspiration lumen extending therethrough, an aspiration opening to the interior of the aspiration lumen at a side of the tapered distal end region of the flexible, elongate body, and a first pair of sensing electrodes disposed across a longitudinal axis of the flexible, elongate catheter at a rim of the aspiration opening, wherein a first electrode of the first pair of sensing electrodes is located between the 2 o'clock and 4 o'clock positions on the rim of the aspiration catheter and a second electrode of the first pair of sensing electrodes is located between the 8 o'clock and 10 o'clock positions on the rim of the aspiration catheter. a second pair of sensing electrodes on either side of the suction opening in a proximal-to-distal line extending through the midline of the direction, wherein a first sensing electrode of the second pair of sensing electrodes has a surface area at least two times greater than a surface area of ​​a second sensing electrode of the second pair of sensing electrodes; and a controller coupled to the first pair of sensing electrodes and the second pair of sensing electrodes and configured to distinguish clot material from blood and a vessel wall based on electrical impedance signals from both the first pair of sensing electrodes and the second pair of sensing electrodes.

[0177]

[0189] In any of these devices, the second pair of sensing electrodes may include a first proximal electrode and a second distal electrode, the first proximal electrode having a surface area at least twice as large as the surface area of ​​the second distal electrode. The second distal electrode may be located at the edge of the suction opening. For example, the second distal electrode may be located at the edge of the suction opening at the 12 o'clock position of the suction opening. In some examples, the first proximal electrode is a ring electrode.

[0178]

[0190] The first pair of sensing electrodes may comprise a first electrode and a second electrode, the first electrode being at the 3 o'clock position of the suction opening and the second electrode being at the 9 o'clock position of the suction opening. In some examples, the suction opening is at a tapered side of the distal end region of the flexible elongate body. The first pair of sensing electrodes may be recessed from the lip.

[0179]

[0191] The above-described device may be used in real time to determine and output the identity of material at or near the suction opening and / or, in some instances, distal to the catheter distal end. For example, the method may include applying an electrical current (e.g., at one or more frequencies) to detect a first impedance from a first set of electrodes positioned along the longitudinal axis of the flexible, elongate catheter and across (and, in some instances, at the edge of) the suction opening. The method may also include applying an electrical current (e.g., at one or more frequencies) to detect a second impedance from a second pair of sensing electrodes on either side of the suction opening in a proximal-to-distal line. The proximal-to-distal line may extend through the longitudinal midline of the suction opening. The method may distinguish clot material from blood and a vessel wall based on the electrical impedance signals from both the first pair of sensing electrodes and the second pair of sensing electrodes. Generally, the method may be performed using a controller coupled to the first pair of sensing electrodes and the second pair of sensing electrodes. The controller may be local to the catheter (eg, part of the catheter or distal to the catheter), or the controller may be a remote processor.

[0180]

[0192] The set of impedance signals from the first pair or set of sensing electrodes and the second pair or set of sensing electrodes may be combined to determine a final estimate of the identity of the material near the suction opening (e.g., clot, blood, wall, etc.). This data may be combined with additional data, including, for example, baseline impedance values ​​from a second region isolated from other tissue types (e.g., in contact with only blood), from a previous time, or in real time. The data from the first pair of sensing electrodes and / or the second pair of sensing electrodes may be weighted and combined. The data from the first pair of sensing electrodes and / or the second pair of sensing electrodes may be normalized to provide a normalized impedance value. In some cases, the impedance value may be normalized to a known tissue type (e.g., blood) using the same or different sensing electrode pairs, including internal sensing electrodes (monopolar and / or bipolar).

[0181]

[0193] In some examples, data from the first pair and / or second pair of electrodes can be processed by the controller using a trained neural network that is trained with impedance values ​​from complementary pairs of these impedance values ​​(or normalized versions of the impedance values).

[0182]

[0194] Also described herein are methods and devices for determining blood vessel diameter using sensing electrodes. For example, the devices described herein include a flexible, elongate catheter having an aspiration lumen extending therethrough, a suction opening into the aspiration lumen at a distal end region of the flexible, elongate body, one or more sensing electrodes, and a controller coupled to the one or more sensing electrodes and configured to determine a change in blood vessel diameter based on a change in impedance measured by the one or more sensing electrodes.

[0183]

[0195] For example, the device may include a flexible, elongate catheter having an aspiration lumen extending therethrough; a suction opening to the interior of the aspiration lumen at a distal end region of the flexible, elongate body; one or more sensing electrodes on the distal end region of the flexible, elongate body; and a controller coupled to the one or more sensing electrodes and configured to determine a change in diameter of a blood vessel based on a change in impedance measured by the one or more sensing electrodes and output an indicator of the change in diameter of the blood vessel.

[0184]

[0196] Also described herein are methods of using any of these devices to detect or determine the size (eg, diameter) of a blood vessel in which the distal end of a catheter is positioned.

[0197] The one or more electrodes may be on the flexible elongate body. Alternatively, the one or more electrodes may be on an accessory device, e.g., a probe, associated with the flexible elongate body (e.g., one or more of a probe retriever, a guidewire, or a navigation catheter, etc.). Thus, a probe ("navigation probe") refers to a navigation catheter, guidewire, probe retriever, etc., and generally includes a second elongate flexible body configured to extend from a second opening at the distal end region of the aspiration catheter.

[0185]

[0198] The controller can be configured to output an indicator of a change in diameter of the blood vessel. In any of these methods and devices, the output may include a warning to the user. The output may include a command or signal to bend the distal end region of the flexible elongate body.

[0186]

[0199] In some examples, the controller is configured to determine that the vessel wall is greater than a predetermined threshold based on the impedance measured by the one or more sensing electrodes.

[0187]

[0200] Any of these methods may include determining the diameter of a blood vessel using a device described herein. The diameter may be a relative diameter (e.g., a change from a large vessel to a small vessel or from a small vessel to a large vessel) and / or an absolute diameter (e.g., within a diameter size range, greater than a threshold diameter, etc.). In some cases, the method or device may determine whether the diameter of the blood vessel is greater than or less than a threshold value based on the impedance sensed from one or more sensing electrodes (or sensing electrode pairs). In some cases, if the diameter of the blood vessel is outside the threshold value (e.g., greater than a maximum threshold value or less than a minimum threshold value), the controller may signal the user and / or adjust the operation of the device, such as by bending the tip region. The threshold value may be preset and / or determined and set at the beginning of the procedure, for example, using a jig or tool (e.g., an introducer) with a known diameter.

[0188]

[0201] Also described herein are methods and devices for detecting and / or removing clot material in large diameter blood vessels (e.g., blood vessels having a diameter greater than about 1.8 times the diameter of the catheter distal end region (e.g., about 2 times or more, 2.2 times or more, 2.5 times or more, 3 times or more, etc.). For example, the device includes a flexible, elongate catheter having an aspiration lumen extending therethrough; a suction opening at the distal end region of the flexible, elongate body to the interior of the aspiration lumen; one or more sensing electrodes on the flexible, elongate catheter; a bending region proximal to the aspiration opening; an actuator configured to enable bending of the bending region such that the distal end region of the flexible, elongate body bends the aspiration opening and the one or more sensing electrodes having the aspiration opening in a bending plane; and a controller coupled to the one or more sensing electrodes and configured to distinguish clot material from blood and a vessel wall based on electrical impedance signals from the one or more sensing electrodes.

[0189]

[0202] The controller may be further configured to determine that a diameter of a blood vessel containing the distal end region of the flexible elongate member is greater than a threshold value based on impedance measurements from the one or more electrodes.

[0190]

[0203] Any of these devices may include a handle at a proximal end of the flexible elongate body, with the actuator coupled to the handle. The device may include a pull wire configured to be actuated by the actuator to bend the flexible elongate body.

[0191]

[0204] In any of these devices and methods, the controller may be configured to emit an output that identifies whether clot material is present in the distal end region. The output may be emitted from any suitable region, including, but not limited to, emitting the output from a handle portion of the device.

[0192]

[0205] The methods and apparatus described herein are incorporated by reference in this PCT International Patent Application No. PCT / US2022 / 035392, filed June 28, 2022, entitled "APPARATUSES AND METHODS FOR CONTROLLING REMOVAL OF OBSTRUCTIVE MATERIAL," and U.S. Patent Application No. 17 / 858,053, filed July 5, 2022, entitled "APPARATUSES AND METHODS FOR CONTROLLING REMOVAL OF OBSTRUCTIVE MATERIAL," U.S. Patent Application No. 17 / 861,082, filed July 8, 2022, entitled "APPARATUSES AND METHODS FOR DISTINGUISHING CLOT MATERIAL FROM VESSEL WALL," and U.S. Patent Application No. 17 / 866,462, filed July 15, 2022, entitled "APPARATUSES AND METHODS FOR TRACKING OBSTRUCTIVE MATERIAL." The present invention may be used in conjunction with and / or modified by any of the methods and devices described in "MATERIAL WITHIN A SUCTION CATHETER," each of which is incorporated herein by reference in its entirety.

[0193]

[0206] All of the methods and apparatus described herein, in any combination, are contemplated herein to achieve and can be used to achieve the advantages as described herein.

[0194]

[0207] A better understanding of the features and advantages of the methods and apparatus described herein will be obtained by reference to the following detailed description and accompanying drawings that set forth illustrative embodiments, in which the principles of the invention are utilized. [Brief explanation of the drawings]

[0195] [Figure 1A]

[0208] FIG. 1 is a schematic diagram illustrating one example of a device for controlling a suction catheter. [Figure 1B]

[0209] FIG. 1B is an end view of one example of an aspiration catheter forming part of the device of FIG. 1A. [Figure 1C]

[0210] FIG. 10 is a schematic diagram of another example of an apparatus for controlling a suction catheter. [Figure 1D]

[0211] FIG. 1D shows an end view of the suction catheter portion of the device of FIG. 1C. [Figure 2]

[0212] FIG. 2 is an end view of one example of an elongate shaft of an aspiration catheter as described herein. [Figure 3]

[0213] FIG. 1 is an end view of an example elongated shaft of an aspiration catheter including a monopolar impedance sensor at the distal end of the catheter (showing a single electrode at the distal face of the aspiration catheter). [Figure 4]

[0214] FIG. 1 is an end view of an example elongate shaft of an aspiration catheter including a bipolar impedance sensor at the distal end of the aspiration catheter (including two adjacent electrodes at the distal portion of the catheter). [Figure 5]

[0215] FIG. 1 is an end view of an example elongate shaft of an aspiration catheter including multiple electrodes located circumferentially around the opening of the distal portion of the aspiration catheter (radially distal from the center and outer limits of the distal portion of the catheter). [Figure 6]

[0216] FIG. 10 is an end view of an example elongated shaft of an aspiration catheter including a bipolar impedance sensor in the aspiration catheter (showing the same circumferential distribution as in FIG. 4, with each monopolar electrode replaced by a closely spaced pair of bipolar electrodes). [Figure 7]

[0217] FIG. 12 is an end view of an example elongate shaft of an aspiration catheter including a bipolar impedance sensor in the distal portion of the aspiration catheter (including a pair of single electrodes, each electrode located on opposing semicircles of the distal portion of the catheter, radially distal to both the center and outer edge of the distal portion). [Figure 8]

[0218] FIG. 1 is an end view of an example elongate shaft of an aspiration catheter including a bipolar impedance sensor in a distal portion of the aspiration catheter (including two pairs of electrodes, each electrode in each pair located on opposing semicircles of the distal portion of the aspiration catheter, each pair rotated at a 90° angle relative to each other about the center of the distal portion). [Figure 9]

[0219] FIG. 1 is an end view of an example elongated shaft of an aspiration catheter including a monopolar impedance sensor in the impermeable wall portion of the aspiration catheter (including a single monopolar electrode attached to the exterior of the impermeable wall surrounding the inner region). [Figure 10]

[0220] FIG. 1 is an end view of an example elongate shaft of an aspiration catheter including a bipolar impedance sensor in the wall portion of the aspiration catheter (showing a single pair of adjacent electrodes attached to the exterior of the wall surrounding the interior region). [Figure 11]

[0221] FIG. 1 is an end view of an example elongate shaft of an aspiration catheter including a monopolar impedance sensor in a wall portion of the aspiration catheter (including multiple monopolar electrodes attached circumferentially to the exterior of the wall surrounding the interior region). [Figure 12]

[0222] FIG. 1 is an end view of an example elongated shaft of an aspiration catheter including a bipolar impedance sensor in the wall portion of the aspiration catheter (showing multiple closely spaced pairs of bipolar electrodes attached circumferentially to the exterior of the wall surrounding the interior region). [Figure 13]

[0223] FIG. 1 is an end view of an example elongate shaft of an aspiration catheter including a bipolar impedance sensor in the wall portion of the aspiration catheter (showing a single distal pair of bipolar electrodes positioned opposite each other on the exterior circumference of the wall surrounding the inner region). [Figure 14]

[0224] FIG. 10 is a schematic diagram illustrating an example of a device including an aspiration catheter, where the aspiration is controlled at least in part by a controller that receives input from one or more sensors at the distally facing portion of the catheter and one or more sensors within the lumen of the aspiration catheter to sense clot material at or near these regions. [Figure 15]

[0225] FIG. 10 is a schematic diagram illustrating an example of a device including a suction catheter and a macerator, each controlled by a controller that receives input from multiple sensors. [Figure 16]

[0226] 16 is a schematic diagram illustrating an example of a device including a suction catheter and a macerator, each controlled by a controller that receives input from multiple sensors, the example shown in FIG. 16 including positive as well as negative pressure. [Figure 17A]

[0227] 17A-17C illustrate the operation of a device similar to that shown in FIG. 16 to remove clot material from a blood vessel with minimal blood loss. [Figure 17B] 17A-17C illustrate the operation of a device similar to that shown in FIG. 16 to remove clot material from a blood vessel with minimal blood loss. [Figure 17C] 17A-17C illustrate the operation of a device similar to that shown in FIG. 16 to remove clot material from a blood vessel with minimal blood loss. [Figure 17D] 17A-17C illustrate the operation of a device similar to that shown in FIG. 16 to remove clot material from a blood vessel with minimal blood loss. [Figure 17E] 17A-17C illustrate the operation of a device similar to that shown in FIG. 16 to remove clot material from a blood vessel with minimal blood loss. [Figure 18A]

[0228] 17A-17C illustrate the operation of a device similar to that shown in FIG. 16, including a suction catheter, for removing clot material from a blood vessel. [Figure 18B] 17A-17C illustrate the operation of a device similar to that shown in FIG. 16, including a suction catheter, for removing clot material from a blood vessel. [Figure 18C]17A-17C illustrate the operation of a device similar to that shown in FIG. 16, including a suction catheter, for removing clot material from a blood vessel. [Figure 18D] 17A-17C illustrate the operation of a device similar to that shown in FIG. 16, including a suction catheter, for removing clot material from a blood vessel. [Figure 18E] 17A-17C illustrate the operation of a device similar to that shown in FIG. 16, including a suction catheter, for removing clot material from a blood vessel. [Figure 19]

[0229] FIG. 2 is an example of a state diagram for an apparatus as described herein. [Figure 20]

[0230] FIG. 1 shows one example of a macerator that may be used as part of any of the devices described herein. [Figure 21]

[0231] FIG. 1 is a diagram of an example of a macerator that may be used as part of any of the devices described herein. [Figure 22]

[0232] FIG. 1 is a diagram of an example of a macerator that may be used as part of any of the devices described herein. [Figure 23]

[0233] FIG. 1 is a diagram of an example of a macerator that may be used as part of any of the devices described herein. [Figure 24]

[0234] FIG. 1 is a diagram of another example of a macerator that may be used as part of any of the devices described herein. [Figure 25]

[0235] FIG. 1 illustrates one example of an aspiration catheter as described herein. [Figure 26]

[0236] FIG. 1 illustrates one example of a method for detecting clot material. [Figure 27A]

[0237] FIG. 1 shows one example of a device for removing clot material, including a macerator. [Figure 27B]

[0238] FIG. 1 shows an example of a device for removing clot material, including a macerator. [Figure 28]

[0239] 10A-10C illustrate examples of methods for detecting clot material using optical sensors. [Figure 29A]

[0240] Figure 29A shows an example of a device for removing clot material that uses an optical sensor to detect the clot material, and shows a cross section through the distal end region of the device. [Figure 29B] Figure 29B shows an example of a device for removing clot material that uses an optical sensor to detect the clot material. Figure 29B shows a longitudinal section through the device. [Figure 30A]

[0241] FIG. 30A illustrates a method of operating a device for removing clot material using an optical sensor. [Figure 30B] FIG. 30B illustrates a method of operating the device to remove clot material using an optical sensor. [Figure 30C] FIG. 30C illustrates a method of operating the device to remove clot material using an optical sensor. [Figure 31A]

[0242] 31A-31C show examples of devices for removing clot material. Figure 31A shows a device including an optical sensor. [Figure 31B] 31A-31C show examples of devices for removing clot material. Figure 31B shows a device that includes a contact sensor based on optical detection of contact. [Figure 31C]

[0243] FIG. 1 illustrates an example of an optical sensor. [Figure 31D] FIG. 1 illustrates an example of an optical sensor. [Figure 32]

[0244] FIG. 1 is a diagram illustrating an example of an optical sensor. [Figure 33]

[0245] 1 is a schematic diagram illustrating one example of an apparatus for removing clot material, including an optical sensor. [Figure 34]

[0246] 10A-10C illustrate examples of methods for detecting clot material, including detecting contact pressure. [Figure 35A]

[0247] 35A and 35B show examples of devices for removing clot material, including a contact sensor, and a distal end region of the device. [Figure 35B] 35A and 35B show an example of a device for removing clot material.FIG. 35B shows an example of the proximal end region of the device. [Figure 35C]

[0248] 10A-10C illustrate another example of a device for removing clot material that includes a contact sensor. [Figure 36]

[0249] FIG. 1 is a diagram illustrating an example of an optical contact sensor including an emitting fiber and a sensing fiber. [Figure 37A]

[0250] 10A-10C illustrate the operation of a device for removing clot material, including a contact sensor. [Figure 37B] 10A-10C illustrate the operation of a device for removing clot material, including a contact sensor. [Figure 37C] 10A-10C illustrate the operation of a device for removing clot material, including a contact sensor. [Figure 37D] 10A-10C illustrate the operation of a device for removing clot material, including a contact sensor. [Figure 38A]

[0251] FIG. 38A shows an example of an extraction inlet for a device that includes a sensor for detecting substances entering the extraction chamber region of the device. [Figure 38B] FIG. 38B shows an example of an extraction inlet for the device that includes a sensor for detecting substances entering the extraction chamber region of the device. [Figure 39A]

[0252] FIG. 1 illustrates a method of distinguishing clot material from the vessel lumen using a device as described herein. [Figure 39B] FIG. 1 illustrates a method of distinguishing clot material from the vessel lumen using a device as described herein. [Figure 39C] FIG. 1 illustrates a method of distinguishing clot material from the vessel lumen using a device as described herein. [Figure 39D]FIG. 1 illustrates a method of distinguishing clot material from the vessel lumen using a device as described herein. [Figure 39E] FIG. 1 illustrates a method of distinguishing clot material from the vessel lumen using a device as described herein. [Figure 40]

[0253] 10A-10C show an example of how suction can be used to detect clot material and confirm that it is drawn into the extraction chamber of the device. [Figure 41]

[0254] 1A-1C illustrate one example of a thrombectomy device that detects clot material within the extraction chamber area of ​​the device to control operation of the device. [Figure 42]

[0255] 10A-10C illustrate another example of a thrombectomy device configured to detect material within an extraction chamber by monitoring a macerator and / or pressure within the extraction chamber (e.g., using suction). [Figure 43]

[0256] FIG. 1 is a schematic diagram of an example of a macerator as described herein. [Figure 44]

[0257] FIG. 10 shows an example of a method for controlling the removal of a blood clot using a device configured to detect the opening of an opening through a cover over an extraction chamber. [Figure 45]

[0258] FIG. 10 is a schematic diagram illustrating one example of a thrombectomy device configured to detect clot material and distinguish between clot material and wall material, including a sensor for sensing the opening of an opening in a clot extraction region of the device. [Figure 46A]

[0259] FIG. 46A illustrates the operation of a thrombectomy device configured to detect the opening of an orifice into an extraction chamber. [Figure 46B] FIG. 46B illustrates the operation of a thrombectomy device configured to detect the opening of an orifice into the extraction chamber. [Figure 47]

[0260] FIG. 1 illustrates one example of a thrombectomy device as described herein. [Figure 48A]

[0261] FIG. 48A illustrates an example of a thrombectomy device including an obstacle sensor configured as a deflectable member as described herein. [Figure 48B] Figure 48B shows an example of a thrombectomy device including an obstacle sensor configured as a deflectable member as described herein. Figures 48B-48C show the device with a clot in the extraction chamber of the device. [Figure 48C] Figure 48C shows an example of a thrombectomy device including an obstacle sensor configured as a deflectable member as described herein. Figures 48B-48C show the device with a clot in the extraction chamber of the device. [Figure 49]

[0262] 1A-1C illustrate an example of a device (eg, a thrombectomy device) including an aspiration catheter and a macerator configured to include multiple deflectable members. [Figure 50]

[0263] 1A-1C show examples of devices (eg, thrombectomy devices) that include an aspiration catheter and a macerator that include multiple deflectable members. [Figure 51A]

[0264] 1A and 1B are schematic diagrams illustrating examples of deflection sensing circuits for deflectable members. [Figure 51B]

[0265] 1A and 1B are schematic diagrams illustrating examples of deflection sensing circuits for deflectable members. [Figure 52]

[0266] 10A-10C are graphs illustrating different scenarios of operation of a device using a deflectable member as an obstacle sensor as described herein. [Figure 53]

[0267] 10A-10C illustrate examples of methods for controlling the removal of a blood clot using a device including one or more deflectable members as described herein. [Figure 54A]

[0268] Figure 54A illustrates an example of a deflectable member configured as a spring element that extends longitudinally (axially) within the aspiration lumen to detect clot material. Figure 54A shows the deflectable member in a first (undeflected) configuration. [Figure 54B] Figure 54B illustrates an example of a deflectable member configured as a spring element that extends longitudinally (axially) within the aspiration lumen to detect clot material. Figure 54B shows the deflectable member in a second (deflected) configuration, such as when clot material is trapped within the distal end region of the aspiration lumen. [Figure 54C] FIG. 54C shows an example graph illustrating the change in electrical properties of a deflectable member in a deflected configuration. [Figure 55]

[0269] 1A-1C are schematic diagrams illustrating examples of deflectable members configured as optical shape sensing bend sensors. [Figure 56]

[0270] 1A and 1B are schematic diagrams illustrating an example of a flexible member configured as a resistive sensor whose resistance changes when the flexible member bends. [Figure 57]

[0271] 1A and 1B are schematic diagrams illustrating an example of an aspiration catheter including a deflectable member and a detection sensor (circuit) as described herein. [Figure 58A]

[0272] FIG. 1 is a schematic diagram illustrating an example of an aspiration catheter including a general impedance sensor similar to the impedance sensors described above. [Figure 58B]

[0273] 1A and 1B are schematic diagrams illustrating an example of an aspiration catheter including one variation of an impedance sensor. [Figure 58C]

[0274] 10A-10C are schematic diagrams illustrating an example of an aspiration catheter including a second variation of an impedance sensor. [Figure 59A]

[0275] FIG. 59A illustrates one example of an aspiration catheter device as described herein that includes a sensor (e.g., an impedance sensor) within the lumen to detect and / or track clot material within the lumen. [Figure 59B] 59B is a diagram showing one example of an aspiration catheter device as described herein that includes a sensor (e.g., an impedance sensor) within the lumen to detect and / or track clot material within the lumen. FIG. 59B shows a cross section through the distal end region of the catheter. [Figure 60]

[0276] 1A-1C are schematic diagrams illustrating examples of aspiration catheters that include a distal internal electrical (e.g., impedance) sensor. [Figure 61]

[0277] 1A-1C are schematic diagrams illustrating examples of pairs of ring electrodes that may be used as inner electrodes of any of the electrical sensors described herein. [Figure 62]

[0278] 1A-1C are schematic diagrams illustrating examples of aspiration catheters that include distal and proximal internal electrical (e.g., impedance) sensors, not drawn to scale. [Figure 63A]

[0279] FIG. 62 is a schematic diagram illustrating an example pair of annular ring electrodes similar to the ring electrodes of FIG. 61. [Figure 63B]

[0280] 10A-10C are schematic diagrams illustrating an example of a pair of ring electrodes that extend only partially around the annulus of the suction electrode's inner lumen. [Figure 63C]

[0281] 63A-63B.

[0082] FIG. 63C is a schematic diagram illustrating an example of a pair of spiral electrodes that can be functionally equivalent to the ring electrodes shown in FIGS. 63A-63B. [Figure 64]

[0282] 10A-10C are graphs showing impedance data over time from the operation of an aspiration catheter including an electrical sensor at the distal end of the catheter and an electrical sensor at the distal end as the aspiration catheter removes clot material. [Figure 65]

[0283] FIG. 10 is a schematic diagram illustrating an example of a device for sensing clot material, including a catheter (not shown to scale) with an aspiration lumen and an internal electrical impedance sensor as well as a pair of impedance sensors at the distal aspiration opening. [Figure 66]

[0284] 66 is a graph showing impedance signals over time from each of three sets of internal impedance sensors (e.g., electrode pairs) within the lumen of a device such as the device shown in FIG. 65. [Figure 67]

[0285] FIG. 1 is a schematic diagram of an example of a device including a suction opening sensor that includes two electrodes positioned on the edge of the suction opening of the suction catheter. [Figure 68]

[0286] FIG. 10 is a schematic diagram illustrating an example of a device including a suction opening sensor (including two electrodes positioned on the edge of the suction opening) and a set of internal impedance sensors slightly proximal to the suction opening sensor within the suction lumen. [Figure 69A]

[0287] FIG. 1 is a diagram of an example circuit diagram of an impedance sensor. [Figure 69B]

[0288] FIG. 10 shows example traces of alternating current that may be applied to sense impedance. [Figure 70]

[0289] 1A-1C are schematic diagrams illustrating examples of devices including suction opening sensors with piezoelectric transducers (e.g., shown as pairs of piezoelectric transducers). [Figure 71]

[0290] FIG. 10 is a schematic diagram illustrating an example of a device including a suction opening sensor with an optical sensor as described herein. [Figure 72]

[0291] FIG. 10 is a diagram illustrating a schematic example of a device including a suction opening sensor comprising an electromagnetic sensor as described herein. [Figure 73]

[0292] 1A-1C are schematic diagrams illustrating examples of devices including suction opening sensors with inductive sensors. [Figure 74]

[0293] 1A-1C are schematic diagrams illustrating examples of devices including suction opening sensors with thermal sensors. [Figure 75]

[0294] 1A-1C are schematic diagrams illustrating examples of devices including a suction opening sensor with a mechanical sensor. [Figure 76]

[0295] FIG. 1 shows an example of a quad detector with four electrodes (two electrode pairs) separated by a predetermined distance within the aspiration lumen of a catheter as described herein. [Figure 77A]

[0296] 77A shows example impedance signals measured using a first configuration of a suction aperture sensor comprising pairs of electrodes that measure electrical impedance at different frequencies as force is applied (e.g., by applying suction) against different materials (e.g., vena cava / wall or clot material). In FIG. 77A, the percentage change in relative impedance of the vena cava / wall (left side of each pair for each frequency) and the clot (right side of each pair for each frequency) compared to the impedance of the blood is shown. [Figure 77B] Figures 77B-77C show the impedance of the suction aperture sensor with respect to blood (left), vena cava / wall (center), or clot material (right) at different frequencies (120 Hz, 1 kHz, 10 kHz, 100 kHz, and 1 MHz) under different conditions. [Figure 77C] Figures 77B-77C show the impedance of the suction aperture sensor with respect to blood (left), vena cava / wall (center), or clot material (right) at different frequencies (120 Hz, 1 kHz, 10 kHz, 100 kHz, and 1 MHz) under different conditions. [Figure 78A]

[0297] FIG. 78A shows examples of impedance signals measured using a suction aperture sensor comprising a pair of electrodes that measure electrical impedance at different frequencies when force is applied (e.g., by applying suction) against different materials (e.g., vena cava / wall or clot material). [Figure 78B]FIG. 78B shows examples of impedance signals measured using a suction aperture sensor comprising a pair of electrodes that measure electrical impedance at different frequencies when force is applied (e.g., by applying suction) against different materials (e.g., vena cava / wall or clot material). [Figure 78C] FIG. 78C shows examples of impedance signals measured using a suction aperture sensor comprising a pair of electrodes that measure electrical impedance at different frequencies when force is applied (e.g., by applying suction) against different materials (e.g., vena cava / wall or clot material). [Figure 79A]

[0298] FIG. 79A is a diagram showing an example of an internal impedance sensor. [Figure 79B] FIG. 79B is a diagram showing an example of an internal impedance sensor. [Figure 80]

[0299] FIG. 10 is a diagram of an example of an internal impedance sensor including an internal ring. [Figure 81A]

[0300] FIG. 81A is a diagram of an example of an internal impedance sensor configured as a quad detector. [Figure 81B] FIG. 81B is a diagram of an example of an internal impedance sensor configured as a quad detector. [Figure 82]

[0301] 7A-7B show an example of an estimate of clot volume using impedance measurements obtained from various configurations of internal impedance sensors (similar to the internal impedance sensors shown in FIGS. 79A-79B, 80, and 81A-81B). [Figure 83]

[0302] FIG. 12 is a graph showing example impedance measurements over time from various internal impedance sensors tracking clot material moving through the aspiration lumen of the device, with the clot material remaining within the aspiration lumen. [Figure 84]

[0303] FIG. 10 is a graph showing example impedance measurements over time from various internal impedance sensors tracking clot material moving through the aspiration lumen of the device, where the clot material breaks down as it moves through the aspiration lumen. [Figure 85]

[0304] 10A-10C show an example of aspirating an aspirating material by identifying / detecting the material at the aspiration opening and tracking the material within the aspiration lumen of the device. [Figure 86A]

[0305] FIG. 86A is a side perspective view showing an example of an aspiration catheter assembly including multiple sensing electrodes positioned around the edge of the aspiration opening, proximal to the aspiration opening, on the nasal region of the catheter distal to the aspiration opening, and on a navigation catheter mated with the aspiration catheter. [Figure 86B] FIG. 86B is a top view showing an example of an aspiration catheter assembly including multiple sensing electrodes positioned around the edge of the aspiration opening, proximal to the aspiration opening, on the nasal region of the catheter distal to the aspiration opening, and on a navigation catheter mated with the aspiration catheter. [Figure 86C] FIG. 86C is a bottom view showing an example of an aspiration catheter assembly including multiple sensing electrodes positioned around the edge of the aspiration opening, proximal to the aspiration opening, on the nasal region of the catheter distal to the aspiration opening, and on a navigation catheter mated with the aspiration catheter. [Figure 87A]

[0306] FIG. 87A shows an example of an electric field generated by a pair of bipolar electrodes located on the edge of the suction opening transverse to the long axis of the suction opening and on the short axis across the suction opening (e.g., at the 3 o'clock and 9 o'clock positions relative to the suction opening). [Figure 87B]

[0307] FIG. 87B shows an example of an electric field generated by a pair of bipolar electrodes located proximal and distal to the lip of the suction opening. [Figure 88A]

[0308] FIG. 88A is a side perspective view showing an example of an aspiration catheter assembly including multiple sensing electrodes positioned around the edge of the aspiration opening. [Figure 88B] FIG. 88B is a top view illustrating an example of an aspiration catheter assembly including multiple sensing electrodes positioned around the edge of the aspiration opening. [Figure 88C] FIG. 88C is a bottom view illustrating an example of an aspiration catheter assembly including multiple sensing electrodes positioned around the edge of the aspiration opening. [Figure 89]

[0309] FIG. 89 is a schematic diagram of an example of an aspiration catheter including a first bipolar pair of electrodes and a second bipolar pair of electrodes at the end of the main shaft at the edge of the aspiration opening (e.g., approximately centered between the 12 o'clock and 6 o'clock positions). [Figure 90]

[0310] FIG. 90 is a schematic diagram of an example aspiration catheter that includes a pair of sensing electrodes distal to the aspiration opening on the tapered nosecone of the aspiration catheter. [Figure 91]

[0311] FIG. 91 is a schematic diagram of an example suction catheter that includes four bipolar pairs of sensing electrodes positioned around the edge of the suction opening (at 12, 3, 6, and 9 o'clock) at the end of the main axis on the edge of the suction opening, a pair of sensing electrodes distal to the suction opening on the tapered nose cone of the suction catheter, and a pair of sensing electrodes on the back of the suction catheter opposite the suction opening. [Figure 92A]

[0312] FIG. 92A is a side perspective view showing an example of an aspiration catheter assembly including multiple sensing electrodes positioned around the edge of the aspiration opening, a ring electrode proximal to the aspiration opening, and an electrode on the navigation catheter. [Figure 92B] FIG. 92B is a top view showing an example of an aspiration catheter assembly including multiple sensing electrodes positioned around the edge of the aspiration opening, a ring electrode proximal to the aspiration opening, and an electrode on the navigation catheter. [Figure 92C] FIG. 92C is a bottom view showing an example of an aspiration catheter assembly including multiple sensing electrodes positioned around the edge of the aspiration opening, a ring electrode proximal to the aspiration opening, and an electrode on the navigation catheter. [Figure 93]

[0313] FIG. 93 is a schematic diagram of an example of an aspiration catheter having electrodes inside the aspiration lumen that can provide a measure of blood impedance. [Figure 94]

[0314] FIG. 94 is a diagram schematically illustrating an example of an aspiration catheter that includes sensing electrodes on various optional accessory tools that may be part of the aspiration catheter assembly, including a guidewire accessory, a navigation catheter accessory, and a retriever probe ("go-getter") accessory. [Figure 95]

[0315] FIG. 95 is a schematic diagram of an example aspiration catheter having an articulating (bending) distal end region. [Figure 96A]

[0316] FIG. 96A is a schematic diagram illustrating the operation of an example aspiration catheter having an articulating distal end region, showing the aspiration catheter in a large vessel. [Figure 96B] FIG. 96B is a schematic diagram illustrating the operation of an example aspiration catheter having an articulating distal end region, taken through line A-A' of FIG. 96A. [Figure 96C] FIG. 96C is a schematic illustration of the operation of an example of an aspiration catheter having an articulating distal end region, showing the aspiration catheter and vessel of FIG. 96A in which the aspiration catheter is articulated upward to sense and / or remove a blood clot from the opposite side of the vessel. [Figure 97A]

[0317] 97A-97C illustrate the operation of an aspiration catheter similar to that shown in FIGS. 96A-96C, with FIG. 97A illustrating the aspiration catheter articulating inside a large blood vessel. [Figure 97B] FIG. 97B illustrates an example of a handle for the suction catheter that includes controls for articulating the suction catheter. [Figure 97C] FIG. 97C shows a cross section through the aspiration catheter of FIG. 97A. [Figure 98A]

[0318] FIG. 98A is a diagram that schematically illustrates the operation of an aspiration catheter to remove clot material from a pulmonary vessel using any of the aspiration catheters described herein. [Figure 98B] FIG. 98B is a diagram that schematically illustrates the operation of an aspiration catheter to remove clot material from a pulmonary vessel using any of the aspiration catheters described herein. [Figure 98C] FIG. 98C is a diagram that schematically illustrates the operation of an aspiration catheter to remove clot material from a pulmonary vessel using any of the aspiration catheters described herein. [Figure 99]

[0319] FIG. 99 is a schematic diagram of an example aspiration catheter that includes a reference sensor for sensing only blood and a sensor configured to detect only blood and clot material. [Figure 100]

[0320] FIG. 100 is a schematic diagram of an example aspiration catheter that includes an internal ring electrode for sensing clot material within the aspiration lumen. [Figure 101]

[0321] FIG. 101 is a schematic diagram of an aspiration catheter including a first pair of sensing electrodes spaced apart from each other across the longitudinal axis of the catheter and on the short axis of the aspiration opening (e.g., near the 3 o'clock and 9 o'clock positions), and a second pair of sensing electrodes positioned on the long axis of the catheter on either side of the aspiration opening. [Figure 102A]

[0322] FIG. 102A illustrates an example of an aspiration catheter having different sensing electrodes at different locations in the distal end region of the catheter. [Figure 102B] FIG. 102B illustrates an example of an aspiration catheter having different sensing electrodes at different locations in the distal end region of the catheter. [Figure 102C]

[0323] FIG. 102C shows an example of a test setup using an artificial blood clot. [Figure 102D] FIG. 102D shows an example of a test setup using a real blood clot. [Figure 102E]

[0324] FIG. 102E is an impedance diagram showing the impedance measured from the experimental setup of FIG. 102C using an electrode combination from a suction catheter (eg, similar to those shown in FIGS. 102A and 102B). [Figure 102F] FIG. 102F is an impedance diagram showing the impedance measured from the experimental setup of FIG. 102D using an electrode combination from a suction catheter (eg, similar to that shown in FIGS. 102A and 102B). [Figure 102G]

[0325] FIG. 102G shows a normalized version of an impedance measurement similar to those shown in FIGS. 102E and 102F. [Figure 102H] FIG. 102H shows a normalized version of impedance measurements similar to those shown in FIGS. 102E and 102F. [Figure 102i]

[0326] FIG. 102i shows the minimum and maximum impedance values ​​inside the experimental setup tube without the presence of a blood clot. [Figure 102J] FIG. 102J shows the minimum and maximum impedance values ​​inside the experimental setup tube in the absence of a blood clot, with the data normalized. [Figure 103A]

[0327] FIG. 103A illustrates an example of an aspiration catheter assembly that includes multiple sensing electrodes located at the distal end of the aspiration catheter, distal to the aspiration opening, on the nosecone region. [Figure 103B] FIG. 103B illustrates an example of an aspiration catheter assembly that includes multiple sensing electrodes located at the distal end of the aspiration catheter, distal to the aspiration opening, on the nosecone region. [Figure 104A]

[0328] FIG. 104A illustrates an example of an aspiration catheter assembly including multiple sensing electrodes disposed on a navigation catheter mated with an aspiration catheter configured to assume a curved configuration. [Figure 104B]FIG. 104B illustrates an example of an aspiration catheter assembly including multiple sensing electrodes disposed on a navigation catheter mated with an aspiration catheter configured to assume a curved configuration. [Figure 105A]

[0329] FIG. 105A illustrates an example of an aspiration catheter assembly including multiple sensing electrodes disposed on a navigation catheter mated with the aspiration catheter, where the aspiration catheter is configured to assume a helical (e.g., corkscrew) configuration. [Figure 105B] FIG. 105B illustrates an example of an aspiration catheter assembly including multiple sensing electrodes disposed on a navigation catheter mated with the aspiration catheter, where the aspiration catheter is configured to assume a helical (e.g., corkscrew) configuration. [Figure 106A]

[0330] FIG. 106A is a schematic diagram of an example aspiration catheter assembly including a pair of electrodes configured to sense the diameter of a blood vessel. [Figure 106B] FIG. 106B is a schematic diagram of an example aspiration catheter assembly including a pair of electrodes configured to sense the diameter of a blood vessel. [Figure 106C] FIG. 106C is a schematic diagram of an example aspiration catheter assembly including a pair of electrodes configured to sense the diameter of a blood vessel. DETAILED DESCRIPTION OF THE INVENTION

[0196]

[0331] Generally, methods and devices for removing clot material from a blood vessel are described herein. These methods and devices may be particularly well-suited for removing clot material while minimizing blood loss. These methods and devices may be used to track clots within and / or removed by an aspiration catheter, including, but not limited to, verifying that the clot has been removed, quantifying the amount of clot removed, estimating and / or quantifying the rate of clot removal, and / or determining and identifying blockages in the aspiration catheter. Furthermore, these methods and devices may allow for more precise control of clot aspiration and / or maceration, and may be useful for automating (or semi-automating) clot removal.

[0197]

[0332] Any of the methods and devices described herein may use one or more sensing modalities to detect the presence and / or proximity of clot material, and particularly to detect the presence and / or proximity of clot material within the aspiration catheter relative to the distal end opening of the aspiration catheter. These methods and devices may use any suitable type (e.g., mode) of sensor, including, for example, electrical properties (e.g., impedance such as bioimpedance, bioimpedance spectroscopy), light (e.g., color), and / or ultrasound. Other types of sensors may also be used. One or more sensors may be positioned at the distal end (e.g., distal end face) of the catheter and / or may reside within the lumen and / or macerator of the aspiration catheter. In some examples, the sensor may be configured as a deflection sensor that mechanically senses deflection of a deflectable member due to clot material contacting the deflectable member. In some examples, the sensor may extend radially around the lumen of the aspiration catheter, at least partially around the circumference (e.g., 30-360 degrees, 40-350 degrees, 60-350 degrees, 90-360 degrees, 45-360 degrees, etc.).

[0198]

[0333] Thus, the devices and methods described herein can assist a user (e.g., a doctor, surgeon, nurse, technician, etc.) in locating and engaging a thrombus to prevent unnecessary aspiration of whole blood or surrounding structures, such as a vessel wall or valve. These devices can improve spatial awareness of the distal end of the aspiration catheter and / or other areas of the aspiration catheter or the lumen of the aspiration catheter. Better spatial awareness at the treatment site at the distal end of the aspiration catheter during a thrombectomy procedure can be advantageous, for example, because it allows a user to establish proper engagement with clot material before initiating aspiration, during the performance of aspiration, and at the end of aspiration, thus reducing blood loss during the procedure.

[0199]

[0334] The devices described herein may typically include a suction catheter, which may include one or more sensors at the distal end of the suction catheter, and may include or be used in conjunction with a source of suction (negative pressure). The device may include a suction regulator, which may include a valve for regulating the source of suction, either as part of the controller or separately from the controller. In some examples, the device may include a source of positive pressure, and the controller may regulate the operation of the source of positive pressure.

[0200]

[0335] For example, FIG. 1A schematically illustrates one example of a device including a suction catheter 103 as described herein. FIG. 1A includes an elongated, flexible suction catheter (not shown to scale) 103. The suction catheter may be formed of any suitable material and may include a central (suction) lumen and a distal end opening. The suction catheter may be formed of any suitable material. One or more (e.g., two are shown in FIG. 1A) sensors 105, 105′ are included on the distal end face of the suction catheter. The sensors are connected to a controller 104 that can receive and process data from the sensors. One or more sensors (an internal sensor or set of sensors) 106 may be present within the lumen at the distal end region of the suction catheter and / or in more proximal regions. All of the sensors may provide data input to the controller 104. The connections may be hardwired through the suction catheter or may be connected to the controller via one or more connectors.

[0201]

[0336] The controller may control the suction applied through the suction catheter by regulating the pressure from the vacuum pump and reservoir 109 directly, or indirectly via a pressure regulator 111, which may include one or more valves, manifolds, etc. for controlling the pressure within the suction catheter.

[0202]

[0337] Figure 1B shows an end view of the aspiration catheter of Figure 1A, showing the sensors 105, 105' facing distally at the outer edge of the aspiration catheter, as well as the aspiration lumen 120 of the catheter. In Figure 1B, a pair of internal sensors 106 are shown from within the lumen; in reality, the sensors may be flush with the inner wall of the catheter and / or recessed within the catheter wall.

[0203]

[0338] The controller may include control circuitry for receiving and / or processing data from the sensors and for sending control signals to the pump regulator 111 or the pump 109. For example, the controller may include one or more processors, timing circuits, memory, etc. In some examples, the controller may include one or more outputs, such as a display, a speaker, etc. The controller may connect wirelessly or via a cable or wire to a remote processor or computer (e.g., a laptop, desktop, etc.). The controller may indicate, via the output, when clot material is present in front of or within the lumen of the aspiration catheter and / or when suction is applied.

[0204]

[0339] Any of these devices may include a macerator to help break up clot material and facilitate its removal from the blood vessel (through the lumen of the aspiration catheter). For example, FIGS. 1C and 1D schematically illustrate an example of a device including a macerator 129 that may be positioned (including removably and / or adjustably positioned) within the lumen of the aspiration catheter 103 as shown. The device shown in FIG. 1C is configured as a system that also includes a controller 104 that receives input from sensors 105, 105′ at the distal end face of the aspiration catheter and a sensor 106 within the catheter. As shown in FIG. 1C, a second set of sensors may include one or more sensors 143 in the macerator 129. In FIG. 1C, the macerator includes one or more windows through the elongated, flexible macerator body that expose a cutting member 133 (shown in FIG. 1C as a rotating thread). Any suitable cutting member may be used, including a wire, blade, or the like. The macerator may be actuated by a drive 131 (macerator driver) that rotates a flexible drive shaft 133 (macerator drive shaft). As described in more detail below, the controller 104 may control the actuation of the macerator in addition to, or instead of, controlling the suction through the suction catheter.

[0205]

[0340] FIG. 1D shows a distal end view of the aspiration catheter of FIG. 1C. As in FIG. 1B, the catheter may include one or more distally facing sensors (e.g., impedance electrodes in some examples). In FIG. 1D, a macerator 129 is shown in the aspiration lumen. In this example, the sensor is located within the lumen at or near the distal end portion. FIGS. 1A-1D show examples of aspiration catheters that include sensors. Sensors of different types, sizes, and sensitivities may be used.

[0206]

[0341] FIG. 2 shows a schematic diagram of the distal end region of an aspiration catheter. In FIG. 2, the distal end face of the catheter is covered by a membrane (e.g., a flexible, deformable polymer (e.g., silicone) cover 2). Sensors 5 in this example and in FIGS. 3-12 indicate the location and orientation of these sensors on the aspiration catheter. The aspiration catheter includes an inner wall (not visible) and an outer wall 4. The flexible cover may include small openings 3 that expand to allow clot material to pass through. In FIG. 2, pairs of sensors 5 are included and may provide inputs continuously or discretely.

[0207]

[0342] Figures 3-13 show alternative examples of the distal end of an aspiration catheter, including sensors disposed on its outer surface (including the distal-facing end) and its internal lumen. In all of Figures 3-13, the distal end of the aspiration catheter 4 includes a cover 2 that can be impermeable to blood but can include openings 3 (e.g., holes, slits, etc.) that can expand as suction draws clots into the lumen. This can limit blood loss into the aspiration catheter both before and during application of suction upon detection of clot material, as described in further detail below. Figure 3 shows a single sensor 1. This example may be, for example, a monopolar bioimpedance sensor. Figure 4 shows an example in which a bipolar bioimpedance sensor 8 is included on the distal surface of the cover. Figure 5 shows multiple sensors (e.g., eight sensors shown in this example) spaced equidistantly around the periphery of the cover. In Figure 5, sensor 1 is shown as a monopolar bioimpedance sensor (although other sensor types may be used), while in Figure 6, sensor 8 is a bipolar bioimpedance sensor. In Figure 7, a pair of radially spaced apart electrodes 8 (forming a larger bipolar bio-impedance sensor) is shown. Figure 8 shows two pairs of radially spaced apart bipolar bio-impedance sensors 8 (either opposing or adjacent electrodes may be used as a bipolar pair, or the partner electrodes may be swapped between these pairs).

[0208]

[0343] 9-13 illustrate examples in which the distal end region of the aspiration catheter includes one or more sensors within the lumen of the aspiration catheter. In FIG. 9, a single sensor 1 is shown within the lumen of the catheter. This sensor may be electrical (e.g., a bioimpedance sensor, which can be monopolar or bipolar). For example, FIG. 10 illustrates an example of a bipolar pair of electrodes forming a bioimpedance sensor 8 within the lumen of the distal end of the aspiration catheter. FIG. 11 illustrates an example of an aspiration catheter in which an annular ring of sensors is positioned within the lumen of the distal end of the aspiration catheter, at the sidewall of the lumen. As shown in FIGS. 11 and 12, the (longitudinally arranged) annular ring or rings of sensors may be continuous or discrete; for example, the annular rings of electrodes may be electrically connected to each other to form a single electrical sensor with multiple contact points. These sensors may be monopolar bioimpedance sensors or, as shown in FIG. 12, bipolar bioimpedance sensors 8. FIG. 13 illustrates an example in which a bipolar bioimpedance sensor is positioned with both electrodes positioned on opposite sides of the lumen of the aspiration catheter.

[0209]

[0344] 9-13 illustrate examples in which only a few sensors are shown and positioned within the distal end region of the aspiration catheter. In some examples, multiple sensors may be positioned along the length of the proximally extending lumen to allow tracking of the clot material as it passes through the lumen.

[0210]

[0345] While Figures 9-13 show sensors only within the lumen of the distal end of the aspiration catheter, in any of these examples, one or more sensors, including a bioimpedance sensor, may be positioned at the distally facing end of the aspiration catheter (as shown in Figures 3-8). In some of these examples, one or more sensors for detecting clot material may be positioned proximally along the length of the outer lateral side of the distal end of the aspiration catheter, which can help indicate when clot material is present on the lateral side of the aspiration catheter.

[0211]

[0346] As previously mentioned, any suitable sensor may be used, including, but not limited to, an impedance (e.g., bioimpedance) sensor. One example of a bioimpedance sensor (e.g., electrode) that may be used with the methods and devices described herein is described in Lei et al., 2013. For example, the bioimpedance sensor may have an electrode spacing of approximately 1.8 mm for a bipolar configuration, and a titanium aluminum alloy structure with a 1 mm PDMS coating is associated with all impedance values ​​and thresholds referred to herein. Other bioimpedance sensors may also be used with any of the methods and devices described herein.

[0212]

[0347] As previously described, the device may include a suction catheter having an elongate shaft including a lumen, a negative pressure source configured to be fluidly coupled to the lumen of the suction catheter, and a controller. The elongate shaft may be flexible and may include a proximal portion configured to be positioned outside the body during treatment and a distal portion configured to be positioned intravascularly adjacent to clot material at a treatment site within a vascular cavity, such as the lumen of a pulmonary or other blood vessel. The suction catheter may include one or more sensors (“sensing devices”) configured to sense and / or detect clot material. The sensors may be electrically coupled to the controller such that measurements obtained by the sensors can be processed by the controller. In some examples, the controller may be coupled to the negative pressure source and / or a connection between the negative pressure source (e.g., a pressure regulator) and the shaft of the suction catheter such that the controller can control the timing (and possibly the level) of suction applied through the shaft.

[0213]

[0348] Returning to FIG. 1A , the sensor may include multiple sensing elements (in some examples, electrodes, ultrasound transducers, optical transducers, optical fibers, etc.) in the distal end region of the elongate shaft. The sensing elements can be, for example, one or more electrodes. Any number of sensing elements (e.g., one, two, three, four, etc.) can be used, or multiple sensing elements (e.g., pairs of electrodes, etc.). The sensing elements can be positioned in the distal end portion of the elongate shaft such that the sensing elements have unimpeded access to the space distal to the elongate shaft and can therefore contact and / or accurately sense clot material located in the vascular lumen distal to the shaft, including clot material in contact with the distal end of the shaft or near (e.g., within 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 1 cm, etc.) the distal end of the shaft. For example, as shown in the end view of FIG. 1B , the sensing element may be positioned on the distally facing portion of the tubular sidewall forming the elongated shaft of the aspiration catheter. This may be true both in aspiration catheters that include a distal cover (e.g., a resiliently deformable cover) and in aspiration catheters that do not include a distal cover. In examples where the system includes a distal cover (e.g., as shown in FIG. 2 ), the sensing element may be positioned anywhere along the surface of the cover. The sensing element may be configured to sense the proximity of the tip of the elongated shaft of the aspiration catheter to clot material (e.g., a thrombus, an embolus, etc.) in the blood vessel and may be used in combination with existing positioning systems and methods, such as fluoroscopy, to manually or automatically control aspiration (suction) through the aspiration catheter. This can help reduce the volume of blood aspirated during clot removal. The sensing mechanism may provide signals and indications that allow the user to distinguish between clot material, whole blood, the vessel wall, and other surrounding structures in the treatment zone. In some cases, the device may initially achieve partial engagement with the clot material.The sensor may be a sensor array that may include multiple electrodes (e.g., impedance sensors) or optical sensors arranged circumferentially around the distal face of the funnel-shaped or tubular opening into the aspiration catheter to provide a point measurement of proximity to the clot material (and, in some cases, the lumen wall) and allow the practitioner to redirect the device within the blood vessel to more fully engage the clot material. In some examples, the distal end of the aspiration catheter (e.g., the cylindrical or funnel-shaped opening) may include one or more ultrasound transducers, which may be positioned to provide spatial awareness to the end of the aspiration catheter.

[0214]

[0349] The schematic diagrams shown in Figures 1A and 1C illustrate just one general configuration of several examples of the devices described herein. While the sensors shown in these examples and the examples shown in Figures 2-13 are shown as electrical (e.g., impedance) sensors, similar configurations and / or locations may be used for other sensor types (or combinations of sensor types), including ultrasonic and / or optical sensors. In some examples, the sensor may be an impedance sensing element including two electrodes in a dipole configuration electrically connected to a controller and / or other signal processing or power components, including a sensing unit, a signal processing unit, and a control unit.

[0215]

[0350] Optionally, the controller may be connected to one or more valves that regulate the pathway between the elongate shaft and a source of suction (e.g., a vacuum chamber) and / or, in some cases, a source of positive pressure (e.g., a pressure chamber). Alternatively, the controller may be connected directly to the source of suction and / or positive pressure. For example, the controller may control the operation of the source of suction (on / off, pumping rate, etc.) without requiring an additional valve between the pump (source of suction and / or positive pressure) and the suction catheter.

[0216]

[0351] Thus, during operation, the aspiration catheter may detect, via one or more distally facing sensors (e.g., at the distal end of the aspiration catheter), when its distal tip is in blood or near or in contact with clot material. For example, while these sensors are in contact with blood, using a bioimpedance sensor, an alternating current passing through the blood between a pair of sensing electrodes may detect a relatively low impedance, generally across the entire frequency spectrum. This relatively low impedance may be processed and classified in the sensing and signal processing units within the controller. If the impedance is low enough to statistically infer the absence of a thrombus proximal to the distal opening into the aspiration catheter, the control unit may maintain suction “off” or at a low level, preventing or limiting the aspiration of blood, by directly controlling the source of negative pressure or by adjusting a valve (to become or remain closed) so that negative pressure does not transmit (or increase) to the opening of the aspiration catheter. As clot material approaches the electrodes of the bioimpedance sensor, impedance increases and may converge to a range of values ​​indicative of the characteristic impedance (or impedance spectrum) of clot material. Values ​​indicative of a clot may be distinguished by the controller from values ​​indicative of the vessel wall or other structures that are not clot material. After the clot material fully engages the sensor (and thus the distal end of the aspiration catheter), the controller may turn on suction (or otherwise increase suction) when it determines that the sensor data indicates clot material. For example, in some cases (depending on the structure of the bioimpedance sensor), an impedance value of approximately 1,000,000 ohms or greater may indicate to the controller that clot material is near and / or in contact with the distal end of the aspiration catheter. The controller may increase or turn on suction through the aspiration catheter. In some examples, the system may initiate or increase vacuum pressure to aspirate clot material after the clot has fully contacted the sensor and the distal end of the aspiration catheter.As the clot material is aspirated, the impedance may remain above a threshold until all of the clot material has been aspirated from the front of the aspiration catheter. Importantly, a sensor within the lumen of the aspiration catheter may be used to configure and track the aspiration of clot material.

[0217]

[0352] The use of one or more sensors to detect clots within the lumen of the aspiration catheter is surprisingly effective in regulating the suction and operation of the aspiration catheter without relying on or requiring pressure or flow sensing. While pressure and / or flow sensing may be used within the aspiration catheter, the use of one or more sensors that directly detect clot material may be more robust and reliable with respect to controlling negative pressure and, as described in further detail below, with respect to controlling the disruption of clot material within the lumen of the aspiration catheter by controlling maceration within the lumen of the aspiration catheter.

[0218]

[0353] In some examples, the controller may continue to maintain suction (e.g., in an on state or higher) until the clot material is completely aspirated into the aspiration catheter and until a sensor within the lumen of the aspiration catheter indicates that the clot material has been removed from the distal end region of the aspiration catheter. After the clot material is removed, for example, when using a bioimpedance sensor, the sensed impedance (or impedance spectrum) again drops to a range of impedance values ​​consistent with blood alone (e.g., in some examples, less than 10,000 ohms, depending on frequency), and the controller turns off or reduces suction through the aspiration catheter (e.g., by setting one or more valves of the aspiration regulator to a closed state, turning off the aspiration pump, etc.).

[0219]

[0354] In some examples, the suction regulator and / or suction source (e.g., a pump) may be configured to have a standby / unpowered off state to prevent dangerous back-suction if the sensor is damaged or contaminated. For example, the valve on the suction regulator or suction source may be a normally closed solenoid. Fault detection (as known in the art) may be implemented in the controller to prevent unintentional and / or undesired application of suction in the absence of clot material. Generally, the controller may include sensing and signal processing to reliably confirm the presence of clot material from the sensor data.

[0220]

[0355] If the device includes bioimpedance sensors, these sensors may be configured to include bipolar or unipolar electrodes. While unipolar and bipolar electrodes may be used approximately equivalently, in a unipolar configuration, each electrode may represent a separate signal, and the controller may incorporate these additional signals. The respective ranges of sensing may vary depending on the electrodes. In any of these devices, the sensors may be distributed, for example, at locations along the distal portion of the aspiration catheter and may provide data (e.g., impedance values ​​of the bioimpedance sensors) from separate locations to provide spatial information about the clot material relative to the opening into the aspiration catheter. This information may be processed by the controller to further threshold the timing and / or level of suction applied. In some examples, the controller may establish multiple (e.g., n) dimensional impedance thresholds based on the number of available (unipolar or bipolar) impedance sensors. This multi-signal configuration may be processed in the controller and exported to an external display to provide the practitioner with additional spatial information about the medium proximal to the distal end of the aspiration catheter.

[0221]

[0356] Generally, as described above, the device may provide the user with output from the aspiration, including a visual display (e.g., video), a numerical value (e.g., some indication of the impedance at the distal end and / or within the aspiration catheter), etc.

[0222]

[0357] For example, the device may include a bioimpedance sensor operating as a dipole pair located on the surface of the aspiration catheter (such as the distally facing surface and / or distal membrane). In FIG. 2, for example, the sensor's dipole pair may include two separate dipole electrodes 5 located on opposite halves of the distal membrane 2, operating as a single dipole pair. In the dipole configuration, an AC current passes through the local tissue surrounding the distal membrane between both electrodes. The effective resistance of the tissue in direct contact with the electrodes is the tissue impedance. Different tissue types exhibit different impedance characteristics. The real-time impedance readings can be used to determine the type of tissue surrounding the distal face of the thrombectomy device and can be used to guide the user to the clot material after rough proximity has been established by non-invasive navigation, such as fluoroscopy. In this example, if the distal end of the aspiration catheter (e.g., in some cases, the distal membrane cover) is in contact only with blood (e.g., whole blood without significant clot material) and no clot material is present nearby, the impedance detected by the bipolar impedance sensor can be the effective resistance of the blood as current passes through the blood. The volume sensitivity of impedance measurements is a function of the square of the current density in a particular tissue volume, and the current arc in the two-electrode sensor can extend to a larger volume of whole blood than in the case of clot material. Thus, when a user guides the aspiration catheter toward clot material (e.g., using fluoroscopy or other guidance techniques), the impedance measurement can show a measurable increase in effective resistance, even though there is no contact with the clot material. In this way, the bioimpedance sensor can establish proximity in addition to contact with the clot material. In blood, at frequencies above 1 kHz, the impedance sensor can consistently show impedance values ​​below 10,000 ohms, while clot material returns values ​​above 1,000,000 ohms. It is noted that the actual values ​​of the impedance of the blood and / or clot and / or lumen wall may vary depending on the sensor configuration (e.g., electrode material, etc.), but the relative differences between these materials (blood, clot material, lumen wall, etc.) and the ability to distinguish between these materials may remain.The difference in magnitude between the impedance of whole blood and the impedance of the clot material can be about two orders of magnitude on average, more than enough to determine when complete contact with both electrodes is established. Similarly, the differences between the lumen wall and blood and the lumen wall and the clot material can vary, especially at various frequencies within the impedance spectrum.

[0223]

[0358] In any of these methods and devices, the device may include an aspiration catheter that includes a funnel carried by the distal end portion of the aspiration catheter. Thus, the distal end region of the aspiration catheter may be funnel-shaped or enlarged (having an enlarged diameter) relative to the more proximal portion of the aspiration catheter. The distal surface extending across the distal end of the aspiration catheter (including a funnel-shaped aspiration catheter) may be covered with an elastically deformable material, as described above. In some instances, the distal surface comprises a fluid-impermeable material (e.g., a sheet of elastically deformable material) with a single opening and / or slit. Suction may be used at the external proximal end of the aspiration catheter to aspirate clot material within the blood vessel, or the clot material may be removed (by suction) through the aspiration catheter and collected in an externally contained chamber (e.g., a vacuum chamber). Real-time photofluorography may be used to guide the aspiration catheter to the location of the clot material within the blood vessel and initiate aspiration. However, photofluorography cannot accurately reflect proximity, is not accurate enough to control the application of suction, and suffers from information loss due to dimensionality reduction, making it unhelpful for distinguishing between non-clot and clot material. For example, a user may appear to position the distal face of an aspiration catheter proximal to a target thrombus, but the distal face may be improperly engaged with the thrombus in an orthogonal plane. To accurately initiate suction, the user must be confident of proper engagement with the thrombus. To establish proper engagement, a measure of proximity must indicate that a majority of the area of ​​the distal face of the funnel is in contact with the thrombus, ensuring that a minimal amount of blood is aspirated before the thrombus enters the catheter.

[0224]

[0359] In some examples, the device may include an impedance sensor configured to measure impedance to distinguish between media adjacent to the distal end of the thrombectomy device. Each cell and tissue type in the human body exhibits unique impedance and conductivity characteristics. When blood clots, the normal-conducting plasma is trapped in a fibrin mesh, which provides clot coherence, thus transitioning the plasma from a conductive liquid to an insulated mass. Experimental results have shown a significant increase in impedance between whole blood and a clot, and this difference in impedance can be used to distinguish between a clot and whole blood at the treatment site. Using an impedance sensor located at the distal end of the aspiration catheter and / or within the lumen of the aspiration catheter can enable a user to distinguish between blood engagement and a clot engagement and accurately track the removal of thrombus material, for example, by relying solely on impedance, eliminating the need to aspirate blood before recognizing the engagement state between the catheter and the clot material.

[0225]

[0360] In some examples, the device may include an ultrasound sensor configured to obtain ultrasound measurements and distinguish between blood and clot material at the distal end of the aspiration catheter. The tissue densities of clot material, blood, and vessel walls vary significantly, due in part to the varying amounts of cells stored per unit volume of each tissue type, and can be controlled by the structure of the cells and the means by which the cells are bound. Blood, as a heterogeneous mixture of cells and liquid, behaves like a less dense fluid. However, clot material and vessel walls have a more compact, higher-elasticity cellular structure, allowing more cells to reside per unit space. Ultrasound can use cell density to distinguish between tissue types. Thus, any of these devices may include one or more ultrasound sensors, for example, at the distal end of the thrombectomy device, to distinguish between clot material, blood, and vessel walls. In some examples, the sensor at the distal end of the catheter includes one or more ultrasound sensors, while the intraluminal sensor is (or is only) a bioimpedance sensor. An ultrasonic sensor may be used to detect engagement with clot material before suction is activated.

[0226]

[0361] Alternatively or additionally, one or more optical sensors may be used, for example, to obtain one or more optical measurements. For example, optical measurements may be obtained from the distal end of the aspiration catheter to distinguish between clot material, blood, and the vessel wall, for example, by processing light reflection and absorption characteristics (and comparing them to known characteristics of each tissue). Blood, clot material, and vessel wall tissue typically have distinctly different optical qualities. This may be due to varying cellular structure, organization, and tissue cohesion within each type of material. A light emitter and a light detector, e.g., an optical sensor, may be coupled to the detection / emission sensor at the distal end of the aspiration catheter. In some examples, the optical component may include fiber optic material extending to the distal end of the aspiration catheter for emitting and / or detecting optical signals. Such signals may be processed by a controller, and the sensed signals may be used to distinguish between the clot and the surrounding medium without first using suction. Optical sensing may allow the user to establish proper engagement with the clot material before enabling suction.

[0227]

[0362] In any of these methods and devices, the device may include a controller (which may be configured to detect proximity to clot material), a suction catheter, a mounting surface (e.g., on the suction catheter), one or more electrodes, an oscillating voltage source, and a data processing unit. The voltage source and / or the data processing unit may be part of or coupled to the controller.

[0228]

[0363] 1A and 1C , respectively. In all of these examples, the device includes an elongated suction catheter 22 that includes one or more sensors 6 for sensing a blood clot at the distal end 31 of the suction catheter. The sensors provide data to a controller 7. The controller may include one or more processors and processing hardware, software, and / or firmware to process and analyze sensor data received from the sensors. The controller may control a suction regulator 13 that regulates suction from a suction source 14 (or, in some examples, may directly control the suction source 14). The suction catheter may be connected to the suction source and / or the suction regulator via one or more tubes 15.

[0229]

[0364] For example, in Figure 14, the device includes an aspiration catheter 2 with one or more sensors 6 positioned externally at its distal end 31. Any of these devices may alternatively include, or alternatively may include, one or more clot sensors positioned internally within the lumen of the catheter, for example, at a known distance d from the distal end of the catheter (not shown in Figure 14).

[0230]

[0365] These devices may be used to remove large or small clots, including clots smaller than the length d inside the lumen of the aspiration catheter. Upon engagement with a small clot at the distal end, one or more clot sensors 6 may be activated to indicate the presence of a clot. Because small clots may have a diameter equal to or smaller than the diameter of the catheter 2, not all clot sensors 6 used to establish proper engagement prior to aspiration may be activated, even though sufficient conditions for aspirating a small clot are met. In such cases, the controller may determine that suction should be initiated or increased in intensity based on a determination from the sensor data that the signal is persistent over time (not an artifact) and consistent with clot material. Alternatively, the user may decide to manually initiate suction by sending an override command signal to the controller.

[0231]

[0366] Accordingly, any of these devices may include a user interface including one or more inputs (e.g., buttons, touchscreens, knobs, dials, pedals, foot pedals, etc.) that allow a user to control and interact with the device, including the system. The user interface may be part of the controller 7 or may be separate from and coupled to the controller. For example, FIG. 15 shows an example including an external unit 33. This external unit (or external interface unit) may include user controls such as, but not limited to, a start suction (e.g., valve open) override input (e.g., button) and a stop suction (e.g., valve close) override input (e.g., button) that can allow a user to manually override control of the application of a signal and start suction despite an indication of insufficient engagement with the clot, or stop suction despite an indication of sufficient engagement with the clot. Other user inputs may be included as part of the controller and / or external unit. For example, user inputs may allow control of the operation of the device, including the level of suction, turning the macerator on / off, etc.

[0232]

[0367] Any of the devices described herein may include a power control circuit 19 integrated into the control unit 7. The power control circuit may receive power from a wall power line (e.g., a plug) and / or may include a battery. The power control circuit may provide power to the controller and, in some cases, to a source of pressure, e.g., a pump, and / or a suction regulator, and a drive unit (e.g., a motor) for driving the maceration. The power source may be part of and / or controlled by the controller.

[0233]

[0368] 15 also includes a macerator assembly including a cutting member 12 and a macerator drive shaft 11 and a macerator driver 10. The macerator assembly may be controlled by (or coupled to) a controller 7. Any of the devices described herein may include a macerator assembly and may be configured to be controlled by the controller using sensor data from sensors 6, including from sensors 6'', 6''' within the lumen of aspiration catheter 22.

[0234]

[0369] During operation, in some instances, a small clot may be proximal to the distal end 31 of the catheter 22 but not engaged with the distal end 31. (Optional) The one or more external clot sensors 6 may exhibit a slightly elevated proximity signal due to the presence of clot material in a manner characteristic of an approaching clot (e.g., when examining impedance or an impedance spectrum, including changes in impedance over time, bioimpedance may be elevated above the level of the wall and / or blood). In the engaged state, the distal end of the catheter may contact the clot material (even a small clot) such that it is within, e.g., half the diameter of, the distal end of the aspiration catheter and aligned with the opening of the aspiration catheter. In some cases, a small clot may remain proximal to the distal end of the aspiration catheter in the engaged state, but may be displaced, as previously described, so as to be in substantially closer contact with one portion of the distal end and not equally in contact with the entire distal end. In some examples, the system may wait until the clot material is aligned with the distal opening of the catheter before the controller triggers the application of suction, which can help prevent scraping, slicing, or expulsion of the clot at the treatment site. Alternatively, in some examples, the controller may be configured to initially apply a higher level of suction to center and position the clot. During improper or partial engagement of the clot material (e.g., when contacting a small clot), one or more sensors closest to the position of the small clot relative to the distal end of the catheter may exhibit a significantly higher proximity signal to the controller compared to the proximity signals of more distal sensors or other surrounding (forward-facing) sensors, the remaining sensors not contacting or in close proximity to the off-center (“misaligned”) small clot. In some cases, additional sensing, such as multiple sensors and / or fluoroscopy, may supplement the proximity sensor signal to guide repositioning of the distal end of the catheter relative to the clot material.

[0235]

[0370] The example shown in FIG. 16 shows a device similar to that shown in FIG. 15 that also includes a positive pressure source 18, such as a pump. Controller 7 may directly control positive pressure source 18, or the controller may indirectly control the positive pressure source by controlling positive pressure pressure regulator 13. Two different pressure regulators (e.g., including valves, outlets, manifolds, etc.) are shown in FIG. 16; in some examples, the same pressure regulator may be used to control both negative and positive pressure. Both negative pressure (e.g., suction) source 14 and positive pressure source 18 may individually include one or more sensors (e.g., pressure sensors 26, 26′) to monitor the pressure from or within the device. The controller may receive data from these sensors and adjust the pressure accordingly (including turning on / off, adjusting up / down). In some examples, the controller may adjust the final pressure or the rate of change of pressure by directly adjusting the source of negative and / or positive pressure and / or by controlling one or more pressure regulators 13.

[0236]

[0371] For example, the controller may adjust the amount of suction (and possibly positive pressure) when suction is being applied through the suction catheter. If a suction regulator 13 is used rather than directly adjusting the suction source, the controller may maintain a valve open so that the source of suction is in fluid communication with the suction catheter. When applying suction through the suction catheter (during suction), clot material may be located inside the catheter. In some examples, the controller may continuously monitor the reported status of the vacuum source and the status of the pressure source to confirm successful execution of open and close commands. If one or more sensed conditions do not match the conditions registered internally in the controller, an error may be generated, and the device may temporarily stop applying vacuum (and / or trigger a warning) as a safety measure. In some examples, the vacuum and pressure sources ("reservoirs" or pumps) may include purge valves that can be controlled by the controller so that, during a device error, the controller can automatically (or the user can manually) execute a purge command (e.g., the user presses a button located on an external unit) to activate purge valves located for the vacuum and / or pressure reservoirs.

[0237]

[0372] As previously described, the aspiration catheter may include an externally positioned clot proximity sensor at the distal end of the aspiration catheter and a clot detection sensor within the lumen of the aspiration catheter. During operation, these devices may detect clot entrapment (including complete entrapment) when the distally facing clot sensor no longer detects the clot. If the internal clot sensor within the lumen of the aspiration catheter still detects clot material, the clot has not been fully entrapped and removed, and suction may remain on. The macerator may also remain on. After a clot is no longer detected either outside the aspiration catheter or within the lumen of the aspiration catheter, the controller may turn off suction until additional clot material is detected. In either of these cases, the device may allow suction to be turned on (and possibly off) but may require manual input (e.g., via an input such as a switch, toggle, foot pedal, etc.) to turn suction on (or off). In some cases, the device may allow the user to select an automatic mode such that suction is automatically turned on (and / or off) as determined by the controller. For example, the device may include one or more distally facing external clot sensors and one or more internal clot sensors within the lumen of the aspiration catheter. The internal sensor may be, for example, a distance d from the distal opening of the aspiration catheter. The one or more external sensors may send a baseline signal (indicating the absence of clot material) to the controller, while the one or more internal sensors send a high proximity signal (indicating the presence of clot material) to the controller after the clot material is fully incorporated and is within distance d from the opening of the catheter. In some examples, proximity signals are communicated between the catheter lumen and the externally disposed sensors such that both the external and internal sensors send high proximity signals to the controller and the controller can analyze these signals together to determine the location of the clot material relative to the distal opening of the aspiration catheter.In some examples, if the controller determines that the location of clot material inside the catheter lumen has passed a known, predetermined distance (or is not present), the controller may send a close or off signal to the source of negative pressure (e.g., a pump) and / or the suction regulator when no further clot material is detected engaging the distal opening of the aspiration catheter. The controller may confirm successful release of suction. Following aspiration of the clot material, this sequence may be repeated again when additional clot material becomes engaged with the distal end of the aspiration catheter until no further clot material becomes engaged with the distal end of the aspiration catheter.

[0238]

[0373] The same general operation may be performed for large and small clot material. For example, an aspiration catheter including one or more distally-facing external clot sensors at its distal end and one or more clot sensors positioned inside the lumen (e.g., a distance d from the distal end) may control aspiration (and maceration) based on both internal signals sensing clot material (e.g., bioimpedance, ultrasound, optical, etc., even without sensing intraluminal pressure or flow) and one or more external signals sensing clots in contact with the distal opening. Either of these devices may determine the relative size of the clot. For example, a large clot may be defined as a clot with a length of d or greater while inside the aspiration catheter. Because large clots exhibit a narrow, elongated shape, some large clots may resemble small clots that engage the distal end of the catheter and interact with the clot proximity sensors. The controller may detect that a large clot has been fully engulfed when one or more external clot proximity sensors exhibit a baseline proximity signal. In examples including an intraluminal sensor, the controller may continue to operate suction (or a reduced level of suction, but not off) when the internal sensor indicates that a blood clot is still present within the lumen of the aspiration catheter. For example, one or more external sensors may send a baseline signal interpreted by the controller, indicating that no blood clots are in close proximity to the distal end of the device, while one or more internal sensors send a high proximity signal to the controller, indicating that a large blood clot has been fully entrapped and is present within a distance d from the opening of catheter 2. In some examples, both the external and internal sensors may indicate a high proximity signal to the controller, and the controller may determine the location of the large blood clot relative to the distal opening of catheter 2 (using both sets of signals) during entrapment and transport the clot material to a collection vessel.

[0239]

[0374] Although the devices described herein may be operated without sensing pressure within the catheter lumen, in some instances, a pressure sensor may be included. For example, one or more pressure sensors may be positioned inside the aspiration catheter, either distal or proximal to the distal end of the aspiration catheter. In such cases, the signals of one or more pressure sensors may be transmitted to a controller to complement one or more clot proximity sensors positioned either inside or outside the aspiration catheter. The pressure indicated at the proximal end of the aspiration catheter can be approximately equal to the pressure applied by the pressure regulator or aspiration source. For example, the pressure detected near the distal end of the aspiration catheter, within a known distance d from the distal opening, may indicate a slightly higher level when no clot is present in the catheter, but may indicate a higher pressure approximately equal to the pressure of the medium beyond the distal end of the aspiration catheter while clot material is passing past or between the distal and proximal pressure sensors. The pressure signal from the end of the catheter can allow the controller to calculate a more accurate representation of the location of the clot material within the aspiration catheter, which can signal to the pressure regulator or aspiration source, for example, to remain open in the event of insufficient movement of the clot along the aspiration catheter.

[0240]

[0375] As previously mentioned, in some examples, the controller may implement delayed signal processing or delayed signal response methods to prevent feedback interference with instantaneous or continuous control systems. In such examples, the controller may include a known delay (represented by t1) when stopping suction and / or when starting suction and / or when starting maceration and / or when stopping maceration. Separate start and stop delays may be used. The controller may also introduce an intentional delay before changing the macerator speed (e.g., turning the macerator on, turning the macerator off, increasing the macerator speed, decreasing the macerator speed, etc.). An intentional delay may be applied by the controller when updating a graphical user interface or external unit with status information. Adding an internal delay (e.g., 0.5 seconds, 1 second, 2 seconds, 3 seconds, etc., or more) may be beneficial. For example, if the controller uses an internal pressure-based sensor, changes in the intraluminal environment may initially cause features in the pressure signal, such as random noise or unusual spikes. In such cases, implementing an intentional delay can prevent the controller from reacting to nonexistent or anomalous conditions by allowing the controller to perform an action only after the data artifacts are expected to have subsided. The duration of the intentional delay may be varied by the controller. For example, the controller may vary the delay over time. In such an example, the controller may enable the controller to autonomously configure the delay duration using continuous analysis of data patterns and data buffering or recording. The controller may also autonomously configure the delay duration or any other variable mentioned herein through known statistical techniques, including, but not limited to, data signal processing, statistical analysis, thresholding, and artificial neural networks. For example, the value t1 may be adjusted to minimize the delay t1 while maximizing noise and data artifact reduction.In some examples, the controller may control a rotating macerator drive shaft disposed internally at the distal end of the aspiration catheter and a drive motor 10 coupled to the drive shaft via a mounting to drive the rotation (actuation) of the macerator. The controller may be responsible for regulating the speed of the macerator by supplying or withholding current to the motor and / or by applying control instructions (e.g., digital commands). In some examples, the controller may monitor variations in the current flowing to the motor 10 to measure clot attributes, including, but not limited to, volume, mass, density, or length. Based on such measurements, the controller may increase or decrease the speed and torque of the macerator to optimize maceration of a particular clot.

[0241]

[0376] Similarly, the controller may vary the speed of the macerator based on one or more sensors within the lumen of the aspiration catheter indicating the presence of clot material. The sensor output may be related to the integrity of the clot material, including how firm or compact it is. Thus, the controller may be configured to set the speed and / or torque of the macerator based on the strength of signals (e.g., bioimpedance, ultrasound, optical, etc.) from one or more sensors within the lumen of the aspiration catheter. In some examples, the controller may define time-dependent conditions, including, but not limited to, non-moving clot, rapid clot extraction, stagnant sensor input, and biased or contaminated sensor input, as determined by continuously analyzing the sensor input over a known interval t2 after any state change and using any selection of known analytical methods, including, but not limited to, statistical estimation, thresholding, signal enrichment analysis, noise detection, and data signal processing. For example, the controller may partially or fully base control the input to any component in electronic communication with the controller based on the aforementioned time-dependent conditions. Regulating the activity of components such as valves, motors, and user interfaces can enable treatment of blood clots according to continuously changing system attributes at the distal end of the catheter. In some examples, the controller may be in bidirectional communication with all of the components with which it can interface, including, but not limited to, sensors, valves, motors, and external user interfaces. The controller may monitor signals generated by the components it interfaces with and may include signals obtained by analysis and monitoring for activation of state-changing actions.In some examples, the controller may monitor components, peripherals, signals, or other electronic interfaces (including those not mentioned herein) so that the controller can continuously register received signals from all devices that interface with the aforementioned interfaces and controller; these interfaces and devices may continuously self-report status and data signals and update the controller with measured data or status at regular, known frequencies. By monitoring components including, but not limited to, clot proximity sensors, pressure sensors, valves, external unit controls, and / or additional user interface controls, the controller may include and incorporate additional information into control inputs for analysis, thresholding, state adjustment, state validation, state change validation, state override for emergency situations, and updating external indications of any status or measurement results mentioned herein. In some examples, vacuum and positive pressure reservoirs (e.g., pumps) may include internally located pressure sensors to continuously measure and report the pressure within each reservoir. The controller may use pressure signals from the vacuum and pressure reservoirs, for example, to adjust the pressure (negative and / or positive) applied to the suction catheter, change the state of the valves, adjust the amount of time the valves remain open during suction, and / or estimate the pressure inside the distal portion of the suction catheter's lumen. The controller may apply suction (e.g., by opening one or more valves) for a known time t2, then automatically stop suction (e.g., by closing any open valves) and reevaluate whether to reapply suction (e.g., reopen the valves) using any selection of available signals and states. This interval technique can guard against contaminated sensors, non-functioning sensors, stale commands, or other errors that may occur during operation and prevent the valves from operating.In some cases, in a system including a vascular region surrounding the distal tip of the aspiration catheter, the aspiration catheter, and a length d inside the distal tip of the aspiration catheter, the controller's potential failure to register a change in condition may result in poor aspiration, unauthorized aspiration, or excessive aspiration, or damage to the vessel wall and device components. The controller may determine when system requirements have been met using the method and an electronic peripheral in continuous data communication with the controller.

[0242]

[0377] 17A-17E illustrate the operation of a device such as those shown schematically in FIGS. 1A, 1C, and 14-16. For example, the device shown in FIG. 17A is similar to the device shown in FIG. 16 and includes a suction catheter 22 containing a central lumen with an opening at the distal end of the suction catheter into the lumen. The suction catheter may include a distal cover, as previously described. The device also includes a suction (e.g., vacuum or negative pressure) reservoir 14 and a pressure regulator (e.g., suction regulator) 13 including one or more valves disposed between the suction reservoir and the central lumen of the suction catheter. The central lumen of the suction catheter is fluidly connected to the vacuum reservoir and (in this example) the pressure regulator via connecting tube 15. One or more sensors 6 are disposed at the distal end 1 and may comprise, but are not limited to, a monopolar impedance sensor, a bipolar impedance sensor, a pressure sensor, an optical sensor, an acoustic sensor, or an applied force sensor. The aspiration reservoir may include a gas or fluid chamber and a pump for regulating the pressure within the chamber, and may communicate (e.g., periodic or periodic bidirectional reciprocal data communication) with a controller. The controller may then communicate (e.g., periodic or periodic bidirectional reciprocal data communication) with the aspiration regulator 13 and the sensor 6 located at the distal end. One or more sensors may be positioned within the lumen, for example, at the distal end region within the aspiration catheter. In some examples, the internal sensor is separated from the opening of the aspiration catheter by a distance d. The external sensor 6 may be configured in multiple locations, including, but not limited to, a forward-facing, single location; a forward-facing, closely paired location; a forward-facing, multiple location radially arranged around the opening of the catheter; and a forward-facing, multiple location radially arranged around the distal opening, where each radial location is configured with a closely paired sensor as described above. The internal sensors 6 may be configured in multiple arrangements including, but not limited to, an inwardly facing, singular arrangement, an inwardly facing, closely paired arrangement, an inwardly facing, multiple arrangement radially arranged around the catheter wall, and an inwardly facing, multiple arrangement radially arranged around the catheter wall, where each radial position is configured with a closely paired sensor as described above.The controller may provide power to various components of the system, including sensors. The addressable macerator motor 10 is fixedly mounted by a flexible drive shaft 11, with the macerator cutter 12 located at the distal end of the lumen. A user interface (e.g., external unit 13) may be coupled to the controller (or pair of controllers) and may include any selection of control interfaces and information displays, such as LED indicators, buttons, switches, and displays. The device of Figures 17A-17E also includes a positive pressure reservoir 18 and a pressure modifier 13 for positive pressure values, both of which are in fluid communication with the aspiration catheter lumen via connecting tubing 15.

[0243]

[0378] In FIG. 17A, device 1600 is shown within a blood vessel, such as the pulmonary artery. The distal end of the aspiration catheter lumen is immediately surrounded by blood 34. The blood vessel contains a large blood clot 13. A pair of forward-facing impedance sensors 6 located at the distal end of the aspiration catheter are monitored by controller 7. In this example, the sensors are bipolar and configured as bioimpedance sensors that operate by sending an electrical current 35 into the blood 14 in the blood vessel. In FIG. 17A, a large blood clot 36 is beyond the sensing range of clot sensor 6; therefore, the impedance value returned by the sensor is approximately that of blood, and suction and macerator 17 remain off (e.g., there is no negative pressure through the aspiration catheter).

[0244]

[0379] As shown in FIG. 17B , as the distal tip of the catheter approaches closer to the clot 26, the bioimpedance sensor 6 may detect clot material as it approaches closer to the distal end of the aspiration catheter and enters a region of relatively high emission current 35. Although the larger clot 36 is closer to the distal end, in this example, the clot material is closer to one sensor 6 of the pair, indicating that the clot 36 is not aligned relatively with the opening of the aspiration catheter. In some examples, the controller may turn on suction or may wait until the clot material is more optimally positioned relative to the distal end of the aspiration catheter, as can be detected by a signal from the sensor. In some examples, the controller may turn on short pulses of higher suction to help better position the clot material.

[0245]

[0380] In FIG. 17C, clot material 36 is proximal to the distal tip 1 and approximately equidistant to both forward-facing sensors 6. The distal opening is approximately aligned with the clot 13. In this example, current 35 from the sensor at the distal end of the aspiration catheter passes approximately symmetrically through the large clot in front of the distal opening. The controller may then apply suction through the lumen of the aspiration catheter. As previously mentioned, centering the clot can allow the clot material to be aspirated without requiring the absorption of excess blood into the lumen of the aspiration catheter.

[0246]

[0381] As shown in FIG. 17D, a clot is aspirated into the lumen of the catheter. The clot material is in contact with both the sensor inside the lumen and the forward-facing sensor 6. In this configuration, clot material may be detected by a bioimpedance signal from the internal sensor emitting a current 48 or field, in addition to the current emitted by the distally facing sensor. The controller may enable the macerator such that the driver 10 engages the macerator drive shaft 11 to drive rotation of the macerator cutter 12. In some instances, the macerator cutter may be positioned more distally within the lumen of the aspiration catheter to allow for improved absorption of clot material.

[0247]

[0382] In Figure 17E, the clot material has been aspirated completely into the lumen of the aspiration catheter. The clot material may no longer be detected by the sensors at the distal end of the aspiration catheter, and the signal from the first set of internal sensors 6 may decrease or cease as the clot is moved proximally through the lumen. In some examples, an additional sensor or set of sensors may be included to track the progress of the clot material down the lumen. The controller may continue to macerate the clot material and apply suction to pass the clot material proximally for collection.

[0248]

[0383] 18A-18E show another example of a device similar to that shown in FIGS. 1A, 1C, and 14-16, also within a pulmonary artery; in this example, a smaller amount of clot material may be aspirated into the device. In FIG. 18A, the distal end of the device is within the pulmonary artery, surrounded by blood 34. Small clot material 39 is outside the range of the sensor (shown here as a bioimpedance sensor emitting a current 25 to detect impedance). In FIG. 18B, the clot material is closer to the distal end of the aspiration catheter. The clot material 39 is shown proximal to the distal end but closer to one sensor 6 of the pair of distally facing sensors, and the resulting bioimpedance signal indicates that the clot material is not aligned with the opening of the catheter. As before, the controller may initiate aspiration or wait until the clot is closer (and the sensor indicates better centering) to minimize blood loss.

[0249]

[0384] In FIG. 18C, the clot material is proximal to the distal end and approximately equidistant to both forward-facing sensors 6, such that the distal openings are approximately aligned with the clot material. Current 25 from the sensors passes approximately symmetrically through a small clot 39 in front of the distal openings. The controller may then engage in suction of the clot material into the lumen, as shown in FIG. 18D. In FIG. 18D, the clot 21 is completely within the lumen and, as previously described, within range d of the first set of internal sensors. In FIG. 18D, the clot material, along with the forward-facing sensors 6, is in contact with the sensors 6 inside the lumen (for detection by emitted current 48). Thus, the controller may continue to use suction as clot material persists within the lumen.

[0250]

[0385] FIG. 18E shows that the clot material is entirely within the lumen and is out of range of the external, distally facing sensor, while still being within range of the internal sensor.

[0386] Figure 19 shows one example of a control loop model for a device such as those shown in Figures 1C, 15, 16, 17A-17E, and 18A-18E. In Figure 19, the controller may follow a control loop (1901) based on inputs from a clot detection sensor within the lumen of the aspiration catheter and from an external clot detection sensor at the distal end of the aspiration catheter. The sensor data may be analyzed to identify when the external sensor identifies only blood or the vessel wall ("external baseline"), when clot material is nearby ("proximal"), or when clot material is present at the catheter ("engaged"). Similarly, the internal sensor may be analyzed to determine when clot material is present ("engaged"), nearby ("proximal"), or not present and only blood is present ("baseline"). In this simple example of a state diagram, the results of the combined external and internal sensor data may set the state of the aspiration (on / off) or macerator (on / off). For example, if the external sensor indicates that clot material is fully present at the end of the catheter ("external engaged") and the interior is fully engaged with clot material ("internal engaged") (1903), suction may be turned "on" (1905), e.g., by opening a valve at the suction regulator and / or directly activating the suction source. If the external sensor indicates that clot material is not present ("external baseline") or is close but not yet in contact ("external proximal") (1907) while clot material is present at the internal sensor ("internal engaged"), suction may be applied to continue removing clot material from within the catheter (1909) while the macerator is actuated. If the external sensor indicates that clot material is present (“external engaged”) while the internal sensor indicates that clot material is nearby or absent (“internal proximal / baseline”) (1911), the controller may cause suction to be applied while the macerator is driven (1913).If the external sensor indicates the absence of a clot ("external baseline") while the internal sensor indicates the absence of a clot ("internal baseline") (1915), the controller may keep suction off (or at a low level in some instances) while drive of the macerator is also off (1917). If the external sensor indicates the presence of a clot nearby but not in contact ("external proximal") while the internal sensor indicates the absence of a clot ("internal baseline") (1919), the controller may set or keep suction off (or at a low level) while the macerator is kept off (1921). Finally, if the external sensor indicates the presence of a clot nearby ("internal proximal") while the internal sensor indicates the presence of a clot nearby ("internal proximal") (1923), the controller may slow or stop suction while continuing to drive the macerator (1925).

[0251]

[0387] In some examples, transitions between states (not shown in FIG. 19 ) may be predetermined, so that the states shown in FIG. 19 may be interconnected and the controller may base control the state of the aspiration and / or macerator based on the previous state. Thus, the state diagram shown in FIG. 19 is merely exemplary, and other state diagrams may be used and implemented by the controller. In some examples, the controller may use data (e.g., feedback) from other components that can inform the state diagram and control loop. For example, data from sensors on the negative or positive pressure source may be used, a pressure sensor from within the catheter lumen may be used, user input, including a user emergency override input, may be used, etc. The primary control layer (“Layer 1”) may include any preliminary data collection or analysis from peripheral components and exclusively includes the functions of the controller. A secondary control layer ("Layer 2") may include the establishment of known system states, including, but not limited to, out-of-range clot, clot proximal to the distal end, clot engaged with the distal end, clot within distance d, clot away from distance d, return to aspirated / out-of-range clot state, etc. Control layer 3 ("Layer 3") may exclusively include control loop operations, such as layer changes or repeated steps, which, in the case of the device shown above, may include returning to the primary control layer. The model control loops described herein function interchangeably for small and large clot examples.

[0252]

[0388] Any suitable macerator may be used. For example, Figures 20-24 show examples of macerators that may be used. Generally, the illustrated macerator (which may also be referred to as a shaver) includes an outer housing 201, shown in Figures 20-24 as an insulated cannula or an insulated cannula. The outer housing may be flexible to allow the macerator to move within a curved suction catheter. The macerator shown in Figures 20-24 may also include an inner housing 202; for example, in Figure 20, the inner housing is an insulated rotating sleeve. The rotating sleeve includes teeth that form an opening 203 and a macerator cutter 204. In some examples, the macerator may include a single housing within which a flexible macerator drive shaft (e.g., a wire) may rotate to drive the rotation of the macerator cutter. In some examples, only a single (e.g., outer) housing is used and may include a window (or multiple windows) exposing the rotating cutter. Alternatively, in some examples, the cutter extends from the distal end of the housing without being located within a window.

[0253]

[0389] Any of the macerators described herein may include one or more sensors for detecting clot material. In any of these examples, the sensor may form part (or a portion) of the aforementioned internal sensor. These sensors may be clot detection sensors and may include bioimpedance sensors, ultrasound sensors, optical sensors, etc. For example, in some examples, the sensor may be configured as a bipolar bioimpedance sensor. In FIG. 20, the macerator includes a monopolar impedance sensor 205 located radially outside the outer housing, proximal to an opening 203 (a window exposing the cutter) in the inner rotating sleeve 202. In this configuration, the impedance sensor may emit a current 206, shown in FIG. 20 by the dashed line representing the sensor's sensing field. The current transmitted from the monopolar impedance sensor 205 can return to the sensor 205 after being affected by the surrounding area. This sensor configuration therefore has lower spatial specificity, allowing for clot sensing throughout the volume within the distal end of the aspiration catheter (not shown in this example).

[0254]

[0390] Figure 21 shows another example of a macerator. In Figure 21, a second monopolar impedance sensor 205 is positioned radially outside of the outer housing 201, on an opposing side of the opening 203. In this example, the current 206 transmitted from each monopolar impedance sensor 205 also returns to each sensor 205. This sensor configuration combines lower spatial specificity with multiple measurement locations positioned radially relative to the opening 203, enabling clot sensing throughout the volume within the aspiration catheter (e.g., the distal end of the aspiration catheter), as well as multiplexed analyses including, but not limited to, clot proximity triangulation and signal denoising.

[0255]

[0391] Figure 22 shows another example of a macerator similar to that shown in Figure 20, except that a bipolar impedance sensor 205 replaces the monopolar sensor. In this example, current 206 transmitted from one electrode of bipolar impedance sensor 205 returns through the opposing sensor of pair 205'. This sensor configuration has higher spatial specificity, allowing for more accurate analysis of the clot near the window opening 203. Multiple sensors (including multiple bipolar sensors) may also be used.

[0256]

[0392] 23 shows another example of a macerator in which the sensor includes a pair of electrodes 205, 205′ forming a bipolar bioimpedance sensor that senses an area extending beyond the opening 202 exposing the window 203. In this example, current 206 transmitted from one electrode of each bipolar impedance sensor returns through the opposing sensor of each pair. This sensor configuration combines higher spatial specificity with multiple measurement locations radially positioned relative to the opening 203, allowing for sensing and positioning of the clot relative to the opening 203.

[0257]

[0393] FIG. 24 shows an example of a macerator inserted through the aspiration lumen into the distal end of an aspiration catheter. As shown in FIG. 24, the distal end of the aspiration catheter may include an enlarged distal end region within which the macerator may be positioned. As previously described, a cover 208 may be included, which may be elastically deformable and may include an opening or slit to allow passage of clot material. In FIG. 24, the macerator includes electrodes 207, with electrode 207′ located within the distal end region of the lumen, forming a sensing pair of bipolar bioimpedance sensors. Thus, a sensor pair 207, 207′ is created between a radially disposed electrode proximal to opening 202 in the macerator's outer housing and an electrode present in the wall of the aspiration catheter 209 (in this example, the expandable “funnel” region). In this example, the sensor may enable bipolar impedance sensing with high spatial specificity and a long-distance current path 206 to achieve sensing of the entire volume of the lumen at the distal end region of the aspiration catheter.

[0258]

[0394] FIG. 25 shows an example of a funnel distal end region as described herein, similar to the example shown schematically in FIG. 24 . In any of the devices described herein, the aspiration catheter may include an enlarged (larger diameter) distal end region. This distal end region may be expandable from a compressed, undeployed configuration and may be collapsible (to fit within the delivery catheter 305). The expandable distal end region 303 may be referred to as a funnel region and may be formed of a material that self-expands when released from the delivery catheter 305. For example, the distal end region may be formed of a braided or woven material, such as a polymer or metal (e.g., nitinol), and may be overlaid with a blood-impermeable material. In FIG. 25 , the aspiration catheter 300 is shown in an enlarged (deployed) configuration, with the distal funnel region shown expanded to a diameter 311 many times larger than the more proximal region 309.

[0259]

[0395] As previously described, the distal end surface of the expandable region may include a cover. The cover may be an elastically deformable material that can prevent blood from entering until suction is applied and can deform to allow clot material to enter. The cover may include one or more slits and / or holes that can elastically expand as clot material is drawn into the funnel region. As previously described, the outer distal surface (cover 307) may include one or more external sensors for detecting clots. As shown in FIG. 24, a macerator may be inserted into the proximal end of the aspiration catheter and slide axially into the distal enlarged (funnel) region. One or more internal sensors may be present within the funnel region of the aspiration catheter and / or the interior of the elongated body 309 to detect clot material within the aspiration catheter.

[0260]

[0396] FIG. 26 illustrates a method for detecting blood clots and distinguishing clot material from non-blood clots (e.g., blood vessel walls). Generally, the methods and devices described herein may electrically, optically, pneumatically, and / or acoustically interrogate the human vasculature and devices within the surgical field and notify the clinician during removal of obstructive material from a blood vessel (i.e., a pulmonary embolism). Current techniques for removing obstructive material from a blood vessel, such as a pulmonary embolism, require the clinician to travel through the heart and into the pulmonary artery, blindly searching for the obstructive material and attempting to remove it from the blood vessel. In some cases, when removing obstructive material from a blood vessel using the devices described herein, the clinician accesses the pulmonary vasculature using a tubular catheter and guidewire and continuously aspirates blood from the body proximal to the blood vessel in the hopes of drawing the obstructive material toward the catheter and ultimately passing it through the catheter and out of the body. This approach results in significant blood loss, prolonged surgical time, and increased safety risks, such as circulatory collapse and / or vascular dissection. In some cases, the clinician will pull a vacuum on the proximal end of the catheter and then pull nothing back through the catheter. At this point, the clinician does not know if they are stuck and causing trauma to the vessel wall, or if they are attached to a large obstruction and should wait and allow the suction to pull the obstruction through the catheter. Due to these limitations, there is a need for an improved thrombectomy system that tells the clinician where the obstruction is in the vessel, what is near and / or in the distal end of the system, and when to attempt to extract the obstruction. In the present invention, embodiments are described that address all of these limitations.

[0261]

[0397] The methods and devices described herein may use at least one sensing element mounted near or within a predetermined distance (e.g., within 10 cm, 7.5 cm, 5 cm, 4 cm, 3 cm, etc.) of the distal end of the system that identifies when the device encounters something stiffer than blood. If a stiffer object is sensed, the device may determine whether the obstruction is clot material, a vessel wall, or other obstruction. For example, the device may automatically and instantaneously apply negative pressure to the aspiration lumen or alert the clinician to do the same. As pressure is applied, the system may check (e.g., using at least one other sensor in the aspiration lumen or by otherwise detecting material in the extraction chamber of the device) to determine whether the system is contacting occlusive material (e.g., clot material) or a vessel wall. If occlusive material is sensed, the system then applies continuous negative pressure and initiates a maceration element to break down the occlusive material and extract it from the body. If no obstructive material is sensed in the aspiration lumen, the device may not apply additional negative pressure and may inform the clinician that the device did not encounter any obstructive material. In some embodiments, the device may reduce or stop the negative pressure being applied to the aspiration lumen to monitor the removal of obstructive material being morselized and removed, minimizing blood loss.

[0262]

[0398] For example, FIG. 26 illustrates one example method of operation of a thrombectomy device for detecting and removing clot material. For example, in FIG. 26, the overall method may include moving the thrombectomy device within a blood vessel (e.g., advancing or withdrawing it over a guidewire and / or diagnostic catheter) (2601) and positioning the device within the human body. The device may be guided with or without additional guidance (e.g., using fluoroscopy). The device may detect an obstruction within a region distal to the extraction inlet of the thrombectomy device (e.g., within 0-5 cm of the "extraction zone") (2603) using, for example, a contact sensor, a pressure sensor, an optical sensor, a bioimpedance sensor, etc. After the device determines that an obstruction is present, the device may determine whether the obstruction is clot material or the vessel wall (e.g., by applying suction to determine whether the obstruction is drawn into the extraction chamber, expanding an opening into the extraction chamber, etc.) (2605).

[0263]

[0399] If the device (e.g., a controller of the device) determines that the obstruction is clot material, either by directly sensing properties of the obstruction (e.g., electrical, optical, or tactile properties, etc.) or by determining that the obstruction can be sucked into the extraction chamber and / or cut by the macerator, which is typically only possible if the obstruction is clot material based on the device configuration described herein, the device may trigger a clot detection response, e.g., a warning / alarm, display, etc., either manually or automatically, and may turn on the extractor subsystem to extract, e.g., the device may turn on suction and / or mechanical extraction elements (e.g., stents, capture tools, etc.), and / or in some cases may turn on and / or increase macerator activity, etc. (2607). Alternatively, if the device determines that the obstruction is not clot material, the device may signal the user to indicate this and may continue moving the thrombectomy device.

[0264]

[0400] In any of these methods, the method may optimally include stopping the extractor subsystem from extracting material when the device determines that a clot is no longer detected (2609). For example, the device may stop the extractor subsystem (e.g., turn off the suction and / or mechanical extraction elements) (2611) when a clot is no longer detected in the extraction chamber, e.g., when one or more sensors configured to sense material in the extraction chamber no longer detect clot material, and / or when the device detects a change in the macerator response (e.g., current / power usage, vibration or acoustics, pressure within the suction lumen and / or extraction chamber area, etc.).

[0265]

[0401] 27A-27B show examples of thrombectomy devices that can be configured to perform any of these methods. For example, FIG. 27A shows one example of a device configured as an aspiration catheter including an elongated body 2713 with an aspiration lumen and an extraction chamber region 2703 at the distal end of the catheter. An opening 2721 into the extraction chamber region may be referred to as an extraction inlet and may include one or more forward-facing obstacle sensors 2708, 2708′ configured to detect or sense an obstacle within the distally-facing extraction zone 2704. The device also includes an internal sensor 2710 configured to detect material within the extraction chamber, in addition to a macerator 2717 within the extraction chamber region. The device also includes a macerator driver 2717, and optionally a suction regulator 2719, and a controller 2715. The controller may receive input from the device (e.g., from the obstacle sensor, the internal sensor and / or the macerator driver, the macerator sensor, and / or the aspiration sensor). The controller may include one or more inputs for a user to enter control commands and / or data.

[0266]

[0402] The controller may output one or more outputs 2723 to the user based on the operation of the device, which may include an output (warning).

[0403] In Figure 27A, the device may apply suction through and / or around the macerator. During operation, the device may control the application of suction and / or the operation of the macerator based on input from one or more sensors and / or evidence of resistance (e.g., by examining the drive of the macerator) indicative of material in the extraction chamber that may be affecting the operation of the macerator.

[0267]

[0404] FIG. 27B shows another example of an apparatus in which the device includes an elongate body 4513 with a lumen (e.g., aspiration lumen) extending along its length. The distal end region may include a tapered extraction chamber region 2703 that may include an extraction inlet 2721 at least partially covered by a cover 2729 that includes an opening 2743 (e.g., a slit) formed therethrough. The cover may be permanently positioned over the distally facing extraction inlet, and the opening may be formed to allow clot material to be aspirated. In the example shown in FIG. 27B, the apparatus includes a guide channel 2731 for passing a guidewire and / or guide 2735. The extraction chamber region 2711 may be configured to expand and collapse and may include an extraction chamber sensor 2748 that may be present within the extraction chamber or present outside the reaction chamber but configured to sense the chamber. The apparatus may include a macerator 2717 within the aspiration chamber. In this example, aspiration enters the aspiration chamber through the macerator. The device may include a macerator driver 2717 for driving the macerator, and in some examples, a suction regulator for regulating the suction applied by the device. A controller 2715 (including one or more inputs 2725 and outputs 2723) may be included, which may include one or more processors, communication circuitry, etc. The controller may include wireless circuitry and / or memory for storing and / or transmitting data regarding the operation of the device.

[0268]

[0405] 28 illustrates another example of a method (that may be performed by the devices described herein). In this example, the method may include moving a thrombectomy device within a blood vessel, for example, optionally advancing or withdrawing the device over a guidewire and / or diagnostic catheter while preparing to detect an obstruction, and then removing the clot material after the obstruction is detected and confirmed to be clot material by the device (2801).

[0269]

[0406] In FIG. 28 , which illustrates a specific example of the method of FIG. 26 , the apparatus and method may be configured to optically detect contact with an obstacle within the extraction zone of the thrombectomy device (e.g., at one or more locations around the extraction inlet) (2803) and determine whether the obstacle is clot material (2805). For example, the method or an apparatus configured to perform the method may include determining whether the obstacle is a clot or a wall (2805), e.g., by comparing reflected spectral values ​​obtained from one or more optical sensors configured to detect characteristics of material within the extraction chamber. If the obstacle is not clot material, the user may be alerted and the position of the device may be adjusted (e.g., withdraw the device away from the obstacle and continue advancing). However, if the obstacle is determined to be clot material, e.g., based on the reflected spectral values, a clot extraction response may be triggered (2807). For example, a warning / alarm, display, etc. indicating clot material may be triggered, the device may manually or automatically turn on / increase suction, manually or automatically turn on / increase the macerator, etc. A method or device configured to perform the method may stop suction when clot material is no longer detected (2809), for example, by stopping suction when clot material is no longer detected in the extraction chamber (e.g., a sensor in the suction chamber, resistance to rotation of the macerator, pressure in the suction lumen and / or extraction chamber, etc.). Suction and / or macerator may be stopped (or reduced) immediately and / or optionally, after a predetermined delay, for example, to allow clot material within the device to pass through the elongated suction channel.

[0270]

[0407] 29A-29B show one example of a device configured to detect clot material in an extraction region forward (distal to) the extraction inlet 2921 of the device. In this example, the device is shown as a catheter device including an elongated body 2913 and a distal end region. An optical sensor 2908 may be positioned distally forward at or near the distal end of the catheter. In some examples, the optical sensor may be formed with two (or more) optical fibers, an emitting fiber 2947 and a receiving fiber 2913. As shown in FIG. 29B, the device may include a sensing fiber 2913 coupled to a photodetector 2938 and an emitting fiber 2947 coupled to one or more light sources 2948. The catheter may include a hemostasis port 2942, a suction port 2940, and / or a port for coupling with a valve 2944. As previously mentioned, the device may include a controller (not shown), a suction regulator (not shown), and optionally, a macerator and / or macerator driver (not shown). Figure 29A shows a cross section through the distal end region (line A-A') of the device of Figure 29A, including the emitting fiber 2947 and sensing fiber 2913, shown positioned on the inner surface of the lumen (but may be within the wall of the catheter) and / or the outer surface.

[0271]

[0408] 20A-30C illustrate the operation of one example of such a device. In FIG. 20A, the device is guided over a guidewire 3022 through a blood vessel 3022 such that the distal end of the device may include a light emitter (or emitter / detector) that emits one or more wavelengths of light 3015, which can be used to distinguish between clot material and wall material, as previously described. In FIG. 30B, the device excavates only proximal to an obstruction 3020. In this example, the emitted / detected light may detect the obstruction (or contact with the obstruction), as shown in the figure, and suction may be applied (3030). The suction may remove the clot material. The device may then be advanced distally over the guidewire, only to encounter the obstruction again, as shown in FIG. 30C. In this case, one or more indicators may indicate that the obstruction is not clot material but may instead be due to the vessel wall, as shown in the figure.

[0272]

[0409] FIGS. 31A-31B show two example thrombectomy devices including an elongated body having an extraction chamber region 3111. A macerator 3117 and / or macerator subsystems (e.g., macerator driver, suction regulator, etc.) may be included. Suction may be applied through the macerator via a suction lumen 3171. The distal end face of the extraction inlet 3157 may be fully or partially covered by a cover (e.g., membrane 3159) including an opening therethrough. The distal end face may be slightly tapered. In FIG. 31A, the device may include an optical sensor 3159 for sensing and / or distinguishing clot material, as previously described. The optical sensor may include an emission fiber 3161 and a sensing fiber 3163 coupled to a photodetector 3146 and a light source 3148. A controller (not shown) may be used to coordinate sensing / detection and device response. FIG. 31A shows diffuse reflectance spectroscopy optimally positioned to monitor the extraction zone of the system while minimizing its impact on the cross-sectional area of ​​the system's aspiration opening.

[0273]

[0410] FIG. 31B shows a similar device in which the optical sensor 3169 is configured as a contact sensor that also includes an emitting fiber 3161 and a sensing fiber 3163. In this example, the contact sensor may protrude into the extraction zone 3104. FIG. 31B shows a distal region comprised of a flexible contact-sensing element protruding into the extraction zone distal to the suction opening and an interrogation sensor positioned to optically analyze objects entering the extraction zone. In this embodiment, the flexible contact-sensing element consists of two flexible polymer fibers made of PMMA glued adjacently together. This fiber assembly is then coated with a protective polymer jacket. In other embodiments, reduction to a single fiber may be envisioned by those skilled in the art. The use of two fibers was utilized to simplify and reduce the cost of processing the proximal end. The distal end of the fiber is cleaved and polished as described above, and a flexible optical finger is glued onto the distal end. The flexible optical finger is designed to be 1-5 mm long, have a diameter range of 0.0254-0.0508 cm (0.010-0.020 in), and have a soft, atraumatic distal tip. In this embodiment, the flexible optical finger is made of a low durometer 20-40 Shore A polymer, such as silicone, with a metal wire helically wrapped around the polymer. The proximal end of the fiber is cleaved and polished and attached to a light source and photon sensor. During use, the light source transmits light through the emission fiber into the flexible optical finger. This light shines into the flexible optical finger, and a portion of the light is reflected back through the sensing fiber, where the photon sensor detects a signal. When the finger is touched, the amount of light reflected back changes, causing a change in the signal at the photon sensor. The elongated body of the fiber assembly is positioned within the aspiration lumen of the device. In some embodiments, the fiber assembly can have a dedicated lumen running throughout the entire device. The interrogation sensor of this embodiment is constructed similarly to the sensor element in Figure 1 above. The investigative element is affixed to and positioned on the distal tapered portion of the maceration chamber so that the centerline of the optical lens traverses the extraction zone.This example also includes an integrated reinforced molded catheter with a guidewire lumen, an enlarged, collapsible maceration chamber with a conformable suction opening, a resilient distal taper, and a proximal end affixed to the catheter body fluidly connecting the maceration chamber to the suction lumen of the catheter body. Inside the maceration chamber, a macerator housing having a distal opening and at least one sidewall opening is positioned and affixed to the distal end of the catheter body shaft so that fluid communication still exists between the maceration chamber and the suction lumen. Inside the macerator housing, a macerator element having at least one sidewall opening is axially positioned so that the openings of the housing and element overlap. The macerator element is free to rotate within the macerator housing and has a metal wire affixed to its proximal end.

[0274]

[0411] During use, a clinician sets up the system, inserts the distal end of the system into a lumen within the body using standard minimally invasive procedures, and advances the system through the lumen toward the obstructive material under fluoroscopic guidance. When an object strikes the contact-sensing element, the element bends, altering the light intensity at the photon sensor. At this point, the system alerts the clinician that something is present in the system's extraction zone using either visible light, audible sound, or tactile feedback at a handle or base station outside the body. Simultaneously, the system interrogates the object using the interrogation-sensing element, as previously described in the previous embodiment. If the object is obstructive material and is present in the extraction zone, the system applies negative pressure to the aspiration lumen to draw the obstructive material into the maceration chamber and activates the maceration element to shred the material, allowing it to pass through the catheter body and out of the body. Aspiration and maceration continue until the material is removed from the extraction zone. This process can be repeated as many times as necessary.

[0275]

[0412] For example, Figure 31C shows one example of an optical sensor or optical sensor subsystem that may be used. In this example, the device includes an emission fiber, a sensing fiber, and an optical lens at the distal end, as well as a light source coupled to the emission fiber and a sensing element coupled to the sensing fiber. Figure 31D shows another example of an optical sensor configured as a contact fiber, similar to the contact fiber shown in Figure 31C, but with optical finger projections at the distal end that receive input from the emission fiber and output from the sensing fiber. The distal finger region may include a flexible member.

[0276]

[0413] FIG. 32 shows another example of an optical sensor configured to detect an obstruction as described herein. In this example, the sensor includes an emitting fiber 3105 and a sensing fiber 3107 that terminate at the center of a spherical region having a first refractive index 3113. A region having a second refractive index 3111 may be present in the outer region of the sphere, and the optical sensor may detect the difference between the first and second refractive indices; contact with an obstruction 3123 may change the shape of the spherical region and, therefore, the difference between the refractive indices. This may enable detection of contact with a substance. In some examples, the device may detect a change in refractive index from contact with the obstruction.

[0277]

[0414] 33 shows an example of a device where the emitting portion 3305 and sensing portion 3307 of the sensor are separated by more than the diameter of the elongate member 3325 at the distal opening into the extraction chamber. For example, the elongate member (elongate body) may be a suction catheter and suction 3309 may be controllably applied within the suction catheter.

[0278]

[0415] The methods and devices described herein may electrically, optically, pneumatically, and / or acoustically sense the contents of a human lumen and devices within the extraction region. As noted above, examples of these devices may include at least one sensing element to detect when an obstruction is located within the extraction zone of the suction opening and to interrogate the obstruction to determine whether it should be extracted or avoided (i.e., a blood clot versus a vessel wall). Other examples include at least two sensing elements to detect when an obstruction is located within the extraction zone of the suction opening and to interrogate the obstruction to determine whether it should be removed or avoided (i.e., a blood clot versus a vessel wall).

[0279]

[0416] In some examples, optical sensing may detect and interrogate obstructions within the extraction zone. An elongated, flexible catheter body having an internal lumen (aspiration lumen) may include a distal end and a proximal end, a handle with an aspiration port and a hemostasis valve, and a sensing fiber assembly including an emission fiber proximally connected to a light source, a sensing fiber connected to a photon sensor, and an optical lens attached to the distal end of the fiber assembly, as shown in Figures 29A-31B. The sensing fiber assembly may be affixed to the internal lumen of the catheter body so that the optical lens of the sensing fiber assembly is aligned (e.g., within 5 mm) with the distal end of the aspiration lumen, and then extends proximally throughout the catheter body and out the handle, where the connectorized proximal end of the fiber is connected to the light source and photon sensor. The optical lens of the sensing fiber assembly may be positioned relative to the distal opening of the aspiration lumen, so that occlusive material within this extraction zone may be carried into the aspiration lumen when negative pressure is applied to the lumen. The fiber assembly can move freely within a dedicated lumen in the catheter body or within the aspiration lumen of the catheter body, independent of the catheter body and handle. The fibers of the fiber assembly may be made of flexible glass or plastic, such as PMMA with a metal coating, with a diameter range of 50 to 500 microns, with a preferred diameter of 125 microns per fiber. The fibers are then combined and covered with an outer protective jacket. The distal ends of the two fibers are cleaved and polished to ensure that the distal ends are perpendicular to the centerline axis of the fibers. The distal ends are then potted together in a urethane or silicone material to create an optical lens. The optical lens has an abrasive distal shape. The proximal ends of the fibers are cleaved and polished, as are the distal ends, and the end of each fiber may be potted into an independent connector (i.e., SMA, ST, or MU connector). In some examples, the proximal end of the emitting fiber may be permanently affixed to a single LED and placed inside the handle along with a small electrical circuit and battery.The flexible catheter body in this example is a standard reinforced polymer shaft constructed similarly to a flexible elongate shaft, as disclosed in U.S. Patent Application No. 17 / 393,618, which is incorporated herein by reference in its entirety. The handle may be made of a rigid or semi-rigid plastic, such as nylon, ABS, or polycarbonate, which may be injection molded or machined. The hemostatic valve may be made of a resilient material, such as silicone.

[0280]

[0417] As shown in Figures 31C-31D and 32, optical sensing may utilize diffuse reflectance spectroscopy, using a fiber assembly to detect and interrogate obstructions within the extraction zone. The light source used may emit light in the 360-2500 nm range, and the sensing fiber may be connected to at least one spectrometer to analyze the reflected light. In another example, the emitting fiber may be affixed to an LED of a specific wavelength, such as 500 nm, and the sensing fiber may be permanently affixed to a sensing element, such as a silicon diode. Three or four fiber assemblies utilizing two specific wavelengths, such as 480-520 and 1530-1565 nm, may also be used.

[0281]

[0418] In use, a clinician sets up the system, inserts it into a lumen in the body according to standard minimally invasive procedures, and advances the system through the lumen toward the occlusive material. As occlusive material enters the extraction zone or the aspiration opening approaches the lumen wall, the intensity of the returning light changes, and the system displays this change graphically for the clinician or compares the intensity reading from the lookup to determine what is in the extraction zone and indicates to the clinician what is in the extraction zone and / or applies negative pressure to the aspiration lumen.

[0282]

[0419] The foregoing examples may use light to detect touch, and the touch sensing element may use a piezoelectric membrane or an electromechanical element that converts mechanical motion into an electrical signal, such as energizing a conductive element like a spring and monitoring the change in resistivity due to movement of a wire.

[0283]

[0420] Any of the methods and devices described herein may be configured to detect clot material based on contact pressure. For example, FIG. 34 illustrates a method of using contact sensing to identify clot material and distinguish it from the vessel wall or other material. In FIG. 34, the method may include inserting and / or advancing (e.g., over a guidewire, diagnostic catheter, etc.) a thrombectomy device into a patient's blood vessel (3401) and detecting contact with an obstruction at an extraction zone of an extraction inlet of the thrombectomy device based on contact pressure. The contact pressure may be detected by a contact sensor (3403), such as a pressure sensor using a contact balloon or other inflatable member that detects a change in pressure within the contact balloon at the material. Other contact sensors may include optical-based contact sensors, such as those previously described (see, e.g., FIGS. 31C, 32D, and 32). Other contact sensors may be based on impedance sensing, which can detect contact through a change in electrical impedance.

[0284]

[0421] After contact is identified, the device (e.g., using a controller portion of the device) may trigger an alert indicating the contact and may further identify the contact as contact with clot material or some other material, including the vessel wall (3405). The step of distinguishing between clot material and other (e.g., vessel wall) material may be performed in multiple ways. In some examples, as shown in FIG. 34 , the device may turn on suction (e.g., aspiration) through the device if suction is not already being applied, or may issue a pulse of suction, and may detect the presence of clot material in the extraction chamber that has entered from the extraction zone through the extraction inlet. In some examples, a closed or semi-closed extraction inlet, at least partially covered by a cover (e.g., a membrane), may allow clot material to pass through the opening but prevent the lumen wall or other material from entering the extraction chamber or beyond a predetermined depth. Thus, during the application (e.g., pulse) of suction / aspiration, the extraction chamber may be monitored to determine whether material presumed to be clot material has entered (3406). In some examples, one or more sensors may be present within the extraction chamber or oriented to sense within the extraction chamber (even if downstream and external from the extraction chamber) and may sense when a clot is present rather than the vessel wall (3408). In some examples, clot material within the extraction chamber may be optically detected (by one or more optical sensors within the extraction chamber), and generally, the internal sensor may be oriented to sense at a desired internal proximal location sufficiently far from the extraction inlet, e.g., 2 mm or more (e.g., 3 mm or more, 4 mm or more, 5 mm or more, 6 mm or more, 7 mm or more, 8 mm or more, 9 mm or more, 1 cm or more, etc.), to distinguish clot material within the extraction chamber from the vessel wall. In some examples, the method and apparatus may be configured to detect clot material within the extraction chamber by detecting a change in macerator activity.For example, the macerator may be activated continuously or upon sensing a clot (e.g., upon application of suction, including a pulse of suction), and the interaction between the clot material in the extraction chamber and the macerator may cause a detectable change in macerator behavior when compared to a baseline (e.g., operated without suction or operated before a clot is detected). In some examples, the device may detect contact between the macerator and clot material in the extraction chamber by detecting a change in driving energy (e.g., applied current) and / or a change in speed of activation (e.g., rotation, reciprocation, etc.) of the macerator's operation, and / or a change in vibration and / or sound. Macerator activity may be detected remotely, for example, at the proximal end of the device, by monitoring applied energy (e.g., current), resistance to actuation, etc.

[0285]

[0422] If clot material is detected in the extraction chamber, the method or device may trigger a clot detection response. If clot material is not detected, the method or device may indicate this. For example, if clot material is not detected, the device may decide to issue a warning that the blockage is likely in the vessel wall and / or turn off (or reduce) suction, allowing the device to be repositioned. Similarly, if clot material is determined to be present in the extraction chamber, the method and / or device may trigger a clot detection response that may include a warning / alarm (e.g., audible, visual, including, but not limited to, emitting or changing a tone, indicator light, display, etc.) indicating the presence of clot material, allowing manual or semi-manual operation of the device. Alternatively or additionally, the clot detection response may include manually or automatically turning on or increasing suction and / or turning on or increasing the macerator, etc., to remove the clot material (3407). The clot detection response may continue until clot material is no longer detected. For example, if a clot is no longer detected distally outside the extraction chamber and / or within the extraction chamber, the clot detection response (e.g., suction and / or macerator activity) may be paused or reduced (3411). In either of these cases, the clot detection response may be stopped or reduced immediately, or may be stopped or reduced after a delay. For example, the clot detection response may be stopped or reduced after a delay of several seconds, minutes, etc. to allow clot material to pass through the lumen of the device (e.g., the suction lumen).

[0286]

[0423] Figures 35A and 35B show examples of the distal portion (Figure 35A) and proximal portion (Figure 35B) of a device 3500 configured for contact sensing as described above. In this example, the device includes an expandable extraction chamber region 3511 at the distal end region of the device. The extraction inlet 3557 is covered by a cover (membrane 3559) in which there is an aperture (orifice) 3566 that allows the passage of clot material. In this example, the cover 3559 is flexible, and the aperture 3566 is configured as a cut or slit through the cover that can expand to pass (and retain) larger clots while closing to limit or prevent blood loss when no clot is present. The extraction chamber is formed at the distal end of an elongated catheter-like body that includes an aspiration lumen (aspiration lumen 3571). The macerator 3517 is positioned within the extraction lumen, and the macerator may fit through the catheter body region such that the macerator extends distally into the extraction chamber region 3511. A drive shaft 3588 extends proximally, and in this example, the macerator may be rotated by rotating the flexible, elongated drive shaft. The distal end of the extraction chamber, including the extraction inlet 3557, may be angled (wedge-shaped), concave, or convex. In FIG. 35, the device includes a guide channel 3531 for a guide element 3533 (e.g., a guidewire and / or diagnostic catheter 3537, which may include a pre-curved guide region).

[0287]

[0424] The device shown in Figure 35A also includes at least one contact sensor 3559. In this example, the contact sensor is a balloon element that can be connected to a pressure sensor to detect contact with the balloon area, where contact can increase the pressure of a fluid or other substance within the balloon and / or an elongate member (not shown) coupled to the balloon. The actual pressure sensor may be present at the proximal end of the device (e.g., near the proximal end (e.g., Figure 35B)).

[0288]

[0425] Any of these devices may include a proximal handle 3571 coupled to an outer shaft 3558 that surrounds the aspiration lumen 3571 and macerator drive 3588. In some examples that include a pressure sensor as part of the external contact sensor 3559, the contact sensor may be positioned within the extraction zone 3504 at the distal end of the device, while the pressure sensor coupled to the contact sensor may be part of or in communication with a controller 3780 at the proximal end of the device.

[0289]

[0426] Generally, the controller may include circuitry for controlling operation of the macerator, suction, and / or alerts to the user. For example, the controller may be coupled to any sensors for sensing clot material within the extraction chamber, in addition to external sensor 3559 in examples including an external sensor; in FIG. 35A , the device includes a pressure lumen 3560 that may be coupled to a pressure sensor in communication with controller 3780. The controller may control operation of the macerator driver (e.g., motor 3473, drive shaft 3588, etc.). The controller may regulate suction applied through suction lumen 3571, for example, by coupling to pump 3577, suction / aspiration tank 3375, and / or one or more valves (e.g., bleed valves, etc.). As previously mentioned, the controller may monitor operation of the macerator drive, for example, by monitoring the current applied to drive the macerator, and detect loads on the macerator that may indicate clot material within the extraction chamber area.

[0290]

[0427] Figure 35C shows an alternative version of the device including a contact sensor similar to the contact sensor shown in Figure 35A. In this example, the contact sensor 3559' is configured as an annular balloon surrounding the extraction inlet and opening 3566 into the extraction chamber 3511. This can allow for detection of contact around any portion of the extraction inlet 3557 within the extraction zone 3504. A pressure lumen (not shown) may couple the interior region of the contact-sensing balloon 3559' with a pressure sensor that can be monitored by the controller.

[0291]

[0428] FIG. 36 shows another example of a contact sensor. In this example, the contact sensor is an optical contact sensor that may be particularly well suited for detecting contact with a blood vessel wall or other tissue. For example, in FIG. 35, the sensor includes an emitting fiber 3605 coupled adjacent to a sensing fiber 3607 so that light 3611 emitted from the sensing fiber can be reflected from the tissue and detected by the sensing fiber. When the sensing fiber and emitting fiber are in contact with tissue 3613, a change in absorption characteristics indicative of tissue, including oxygenated tissue, may be detected depending on the wavelength of the emitted light. For example, the sensor may be configured to detect pulse oxygenation. This sensor may be positioned outside the extraction chamber and may detect contact with an obstruction. As previously described, any suitable contact sensor may be used.

[0292]

[0429] 37A-37D illustrate the operation of a device that detects an obstruction using a contact sensor similar to that shown in FIGS. 35A-35C. In FIG. 37A, the device 3720 is advanced forward until a contact sensor 3759 at an extraction region distal to the extraction inlet into the extraction chamber indicates contact with an obstruction 3720. The controller may detect contact by comparing the contact sensor (e.g., a pressure sensor, optical sensor, impedance sensor, etc. coupled to the balloon chamber at the distal end region of the device) to a baseline. For example, if the contact sensor is a pressure sensor, the controller may determine that the pressure indicates contact with an obstruction (e.g., an increase in pressure above a threshold). The controller may then trigger an alert indicating an obstruction and determine whether the obstruction is clot material, for example, by triggering a pulse of suction or requiring the user to trigger a pulse of suction, as shown in FIG. 37B. If the obstruction is clot material (as in this example), the material may be sucked into the extraction chamber 3711, as shown in the figure. The controller may detect the substance in the extraction chamber, for example, by one or more sensors configured to detect the substance in the extraction chamber, and may trigger a clot extraction response (e.g., suction, macerator, etc.).

[0293]

[0430] Figures 37C and 37D show another possibility that the obstruction 3720' is part of the vessel wall (e.g., a bifurcation). For example, Figure 37C may show the same device after removal of the clot material according to Figure 37B. After removing the clot material, contact pressure may decrease, a sensor sensing the interior of the extraction chamber may no longer register material (in some instances, chamber pressure may decrease), and / or the macerator drive current may decrease, indicating that the clot material has been removed. Suction may be reduced or discontinued, and the device may continue to advance. In this example, the contact sensor 3759 of Figure 37D may detect the obstruction 3720' and apply suction (e.g., a pulse of suction or a low level of suction), but not detect the obstruction within the extraction chamber 3711 (or very far within the extraction chamber 3711) because the wall material is not soft / supple enough to be drawn very far into the extraction chamber, even if drawn in. For example, the contact pressure at the contact sensor may increase, but the sensor in the chamber (e.g., chamber pressure) does not change above a threshold and / or the macerator driver does not show a significant change in drive energy (current), so the controller may conclude that no obstruction is present and alert the user that an obstruction other than a blood clot (e.g., a wall) is present.

[0294]

[0431] 38A-38C show another example of the distal end of the device, including an aspiration lumen 3803 containing an extraction chamber 3811. This device schematically illustrates an example in which a sensor 3859 is positioned to sense pressure from the distal face of the device (e.g., the extraction region). In this example, the sensor is a pressure channel coupled to a pressure-sensing element that can detect contact by sensing changes in pressure in this region. Alternatively, the sensor may detect a change in flow rate when a small amount of positive or negative pressure is applied, and pressure or fluid flow may be monitored to detect an occlusion. The device also includes a sensor (configured as a pair of electrical sensors 3860, 3860′, where impedance can be measured between the sensors to detect material within the extraction chamber 3811). The electrodes are positioned in a retracted position (distance x within the extraction chamber) so that suction applied through the extraction chamber can draw more pliable clot material into the chamber but is less likely to draw wall material. FIG. 38B shows another similar example in which a pair of distal electrodes 3859, 3859' can detect contact with an occlusion.

[0295]

[0432] 39A-39E illustrate the operation of another example of a device as described herein. In this example, the controller may monitor the pressure and / or flow rate around and through the device, and / or the impedance / resistance within the extraction chamber. For example, in FIG. 39A, the flow rate around the device is relatively high, while the pressure is relatively low, and the electrical impedance / resistance is consistent with an unobstructed channel (e.g., no material is blocking the chamber). As shown in FIG. 39B, as the device approaches the occlusion, the flow rate and / or pressure may increase, while the electrical impedance within the extraction chamber remains the same. This may trigger the application of suction (or a pulse of suction), drawing the occluding material into the extraction chamber and resulting in a change in electrical impedance, as shown in FIG. 39C. Distal and / or within the extraction chamber, the vacuum may be maintained high until an occlusion is no longer detected, resulting in an increase in flow rate and a decrease in pressure, and the electrical impedance returns to the blocked value. In contrast, as shown in FIG. 39E, if the obstruction is the blood vessel wall, the flow rate may decrease and the pressure may increase, but the electrical impedance sensed within the extraction chamber may remain essentially the same, indicating that the obstruction is likely the wall and not clot material.

[0296]

[0433] The methods and devices described herein may, for example, include or alternatively include detection using only one or more internal sensors that sense an area within the extraction chamber, without necessarily using a sensor that senses externally in front of the extraction chamber (e.g., within the extraction zone). Instead, suction may be applied periodically or on demand as the distal end of the device is advanced or positioned, and one or more sensors may detect material (e.g., clot material) within the extraction chamber. In some cases, resistance to suction may be monitored to infer an occlusion (e.g., high resistance to suction may indicate that the device is in contact with an occlusion). Alternatively, the device may only monitor material (clot material) within the extraction chamber.

[0297]

[0434] For example, FIG. 40 illustrates one method of controlling clot removal using suction pulses. The method may include moving a thrombectomy device within a patient's blood vessel, which may include advancing the device over a guidewire and / or diagnostic catheter (4001). Clot material may be detected within an extraction zone of the device's extraction inlet (e.g., in front of the extraction inlet) (4003) by activating a macerator within the extraction chamber (the macerator may be activated prior to applying suction to obtain a baseline of macerator behavior for subsequent comparison) (4005) and applying pulses of suction (the suction may be triggered manually or automatically, periodically or intermittently, etc.) (4007). The pulse length may be, for example, 100 ms to 10 seconds (e.g., 200 ms to 9 seconds, 200 ms to 8 seconds, etc.) or longer. Between suction pulses, the controller may determine whether clot material is present in the extraction chamber based on changes in the macerator response (e.g., vibration, sound, current / load, etc.) compared to a baseline (4009). If clot material is identified in the extraction chamber (4011), a clot extraction response (e.g., warning / alarm, display, etc., manually or automatically turning on a mechanical extractor (e.g., suction), turning on / controlling the macerator, etc.) may be triggered as previously described (4013).

[0298]

[0435] If, based on the macerator response, the clot is no longer present in the extraction chamber, either immediately or after a delay, the clot extraction response may be turned off, e.g., stopping the extraction (e.g., stopping or reducing suction or other mechanical extraction) (4015).

[0299]

[0436] FIG. 41 illustrates one example of an atherectomy device configured to perform methods as described above, including the method illustrated in FIG. 40. In FIG. 41, the device includes an elongate body having a distal end including an extraction chamber region 4103. The distal face of the elongate body may include an opening (extraction inlet 4121) into the extraction chamber region. Suction 4119 may be applied from the proximal end of the device under the control of a controller 4115, which may control the operation of a suction subsystem 4119, which may include a suction regulator, a pump, a suction tank, and / or a valve. The pump or suction source may be separate or may be coupled to and regulated by the controller. This control may control and receive input from (and provide output to) a macerator subsystem, which includes a macerator driver 4117 that operates a macerator 4107 positionable within the extraction chamber or extraction chamber region 4111 of the device. In this exemplary device, the controller may receive input 4125 from a user and provide the aforementioned output 4123, e.g., a notification.

[0300]

[0437] During operation, the device of FIG. 41 may periodically (e.g., every few seconds or even more frequently) apply pulses of suction to determine whether clot material has been drawn from the extraction inlet 4121 and extraction zone 4104 into the extraction chamber region. For example, clot material may be identified within the extraction chamber based on macerator behavior. For example, determining whether the macerator responds differently when suction is applied can indicate the presence of clot material by actuating the macerator, since a difference in response to the macerator when suction is applied versus when suction is not applied ma...

Claims

1. a flexible catheter body having an aspiration lumen extending therethrough; an aspiration opening into the aspiration lumen at the distal end region of the flexible catheter body; a first pair of sensing electrodes positioned at or adjacent to an edge of the suction opening transverse to a longitudinal axis of the flexible catheter body; one or more second sensing electrodes adjacent the suction opening in a proximal-to-distal line extending through the longitudinal midline of the suction opening; a controller coupled to the first pair of electrodes and the one or more second sensing electrodes and configured to determine that clot material is at or adjacent to the suction opening based on electrical signals from the first pair of sensing electrodes and the one or more second sensing electrodes.

2. The device of claim 1 , wherein the one or more second sensing electrodes comprise a pair of sensing electrodes.

3. 10. The device of claim 1, wherein the one or more second sensing electrodes comprise a first proximal electrode and a second distal electrode, the first proximal electrode having a surface area at least two times greater than a surface area of ​​the second distal electrode.

4. The device of claim 3 , wherein the second distal electrode is at or adjacent to the edge of the suction opening.

5. 4. The device of claim 3, wherein the second distal electrode is at or adjacent the edge of the suction opening at the 12 o'clock position of the suction opening.

6. The device of claim 3 , wherein the first proximal electrode is a ring electrode.

7. 2. The device of claim 1, wherein a first electrode of the first pair of sensing electrodes is located between the 1 o'clock position and the 5 o'clock position at the edge of the suction opening, and a second electrode of the first pair of sensing electrodes is located between the 7 o'clock position and the 11 o'clock position at the edge of the suction opening.

8. The device of claim 1 , wherein the suction opening is in a tapered side of the distal end region of the flexible catheter body.

9. The device of claim 1 , wherein the first pair of sensing electrodes are recessed from the edge.

10. The device of claim 1 , wherein the controller is further configured to determine that the suction opening is in a vessel wall.

11. 10. The device of claim 1, wherein the controller is configured to determine that clot material is present at or near the suction opening based on impedance electrical signals from the first pair of sensing electrodes and the one or more second sensing electrodes.

12. 10. The device of claim 1, further comprising one or more environmental sensing electrodes on an exterior surface of the distal end region of the flexible catheter body, the controller further configured to detect electrical signals from the one or more environmental sensing electrodes.

13. The device of claim 12 , wherein the controller is configured to determine whether the one or more environmental sensing electrodes are in contact with or adjacent to a blood vessel wall.

14. The device of claim 1 , further comprising a navigation probe configured to extend distally from a second opening distal to or adjacent to the suction opening.

15. The apparatus of claim 14 , further comprising a probe sensing electrode on the navigation probe.

16. a flexible catheter body having an aspiration lumen extending therethrough; an aspiration opening into the aspiration lumen at the tapered distal end region of the flexible catheter body; a first pair of sensing electrodes disposed at or adjacent to the edge of the suction opening; a second pair of sensing electrodes distal to the suction opening; a controller coupled to the first pair of sensing electrodes and the second pair of sensing electrodes and configured to determine, based on electrical signals from the first pair of sensing electrodes and the second pair of sensing electrodes, that clot material is in or adjacent to the first pair of sensing electrodes and / or the second pair of sensing electrodes.

17. 17. The device of claim 16, wherein the controller is configured to determine, based on impedance electrical signals from the first pair of sensing electrodes and the second pair of sensing electrodes, that clot material is in the first pair of sensing electrodes or the second pair of sensing electrodes, or that clot material is adjacent to the first pair of sensing electrodes or the second pair of sensing electrodes.

18. 17. The device of claim 16, wherein the second pair of sensing electrodes is at a distal tip region of the flexible catheter body.

19. 17. The device of claim 16, further comprising a navigation probe configured to extend distally from a second opening distal to the suction opening, the second pair of sensing electrodes being on the navigation probe extending from the second opening.

20. The device of claim 19 , wherein the navigation probe is configured to move proximally and distally relative to the second opening.

21. 20. The device of claim 19, wherein the navigation probe is one or more of a navigation catheter, a guidewire, and a probe retriever.

22. a flexible catheter body having an aspiration lumen extending therethrough; an aspiration opening into the aspiration lumen at the distal end region of the flexible catheter body; a first pair of sensing electrodes disposed at or adjacent to the edge of the suction opening; a second pair of sensing electrodes positioned at or adjacent to the edge of the suction opening; a controller coupled to the first pair of sensing electrodes and the second pair of sensing electrodes and configured to determine that clot material is at or adjacent to the suction opening based on electrical signals from the first pair of sensing electrodes and the second pair of sensing electrodes.

23. 23. The device of claim 22, wherein the suction opening is in a tapered side of the distal end region.

24. 23. The device of claim 22, further comprising one or more third sensing electrodes distal to the suction opening, wherein the controller is further configured to determine that clot material is at or adjacent to the one or more third sensing electrodes based on an electrical signal from the one or more third sensing electrodes.

25. 23. The device of claim 22, wherein the controller is configured to determine that clot material is at or adjacent to the suction opening based on impedance electrical signals from the first pair of sensing electrodes and the second pair of sensing electrodes.

26. 23. The device of claim 22, further comprising one or more environmental sensing electrodes on an exterior surface of the flexible catheter body opposite the suction opening, and wherein the controller is further configured to detect electrical signals from the one or more environmental sensing electrodes.

27. 27. The device of claim 26, wherein the controller is configured to determine whether the one or more environmental sensing electrodes are in contact with or adjacent to a blood vessel wall.

28. a flexible catheter body having an aspiration lumen extending therethrough; an aspiration opening into the aspiration lumen at the distal end region of the flexible catheter body; a second opening in the flexible catheter body distal to or adjacent to the suction opening; a navigation probe configured to extend distally from the second opening; a first one or more sensing electrodes at or adjacent to an edge of the suction opening; a second one or more sensing electrodes at a distal end region of the navigation probe; a controller coupled to the first one or more sensing electrodes and configured to determine, based on electrical signals from the first one or more sensing electrodes, that clot material is at or adjacent to the suction opening, and configured to determine, based on electrical signals from the second one or more sensing electrodes, that clot material is at or adjacent to the distal end region of the navigation probe.

29. 30. The apparatus of claim 28, further comprising a navigation lumen extending through the flexible catheter body, the navigation probe configured to extend through the navigation lumen.

30. 30. The device of claim 28, wherein the second opening opens into the interior of the aspiration lumen and the navigation probe is configured to extend through the aspiration lumen.

31. 30. The apparatus of claim 28, wherein the first one or more sensing electrodes comprise a pair of electrodes.

32. 30. The apparatus of claim 28, wherein the second one or more sensing electrodes comprise an electrode pair.

33. 30. The apparatus of claim 28, wherein the second one or more sensing electrodes comprise a ring electrode.

34. 30. The device of claim 28, further comprising one or more environmental sensing electrodes on an exterior surface of the distal end region of the flexible catheter body, the controller further configured to detect electrical signals from the one or more environmental sensing electrodes.

35. 35. The device of claim 34, wherein the controller is configured to determine whether the one or more environmental sensing electrodes are in contact with or adjacent to a blood vessel wall.

36. 29. The device of claim 28, wherein the suction opening is in a tapered side of the distal end region.

37. 30. The apparatus of claim 28, wherein the navigation probe comprises a navigation catheter, a guidewire, or a probe retriever.

38. 30. The apparatus of claim 28, wherein the navigation probe further comprises one or more contrast exit ports configured to release contrast material from a lumen extending through the navigation probe.

39. 30. The apparatus of claim 28, further comprising a guidewire configured to extend from a distal opening of the navigation probe.

40. a flexible catheter body having an aspiration lumen extending therethrough; a suction opening into the interior of said suction lumen at a distal end region of the flexible elongate body; one or more sensing electrodes; a controller coupled to the one or more sensing electrodes and configured to determine a change in diameter of a blood vessel based on a change in an electrical signal measured by the one or more sensing electrodes.

41. 41. The apparatus of claim 40, wherein the change in the electrical signal comprises a change in impedance.

42. 41. The device of claim 40, wherein the one or more sensing electrodes are on the flexible elongate body.

43. 39. The apparatus of claim 38, wherein the one or more sensing electrodes are on an accessory device associated with the flexible elongate body.

44. 44. The apparatus of claim 43, wherein the accessory device is one or more of a probe retriever, a guidewire, or a navigation catheter.

45. 41. The device of claim 40, wherein the controller is configured to output an indicator of the change in blood vessel diameter.

46. 46. ​​The apparatus of claim 45, wherein the output comprises a warning to the user.

47. 46. ​​The device of claim 45, wherein the output comprises a command or signal to bend the distal end region of the flexible elongate body.

48. 41. The apparatus of claim 40, wherein the controller is configured to determine that a vessel wall is greater than a predetermined threshold based on the impedance measured by the one or more sensing electrodes.

49. a flexible catheter body having an aspiration lumen extending therethrough; an aspiration opening into the aspiration lumen at the distal end region of the flexible catheter body; one or more contrast exit ports at a distal end region of the navigation probe configured to release contrast material from a lumen extending therethrough; a first one or more sensing electrodes at a distal end region of the flexible catheter body; a controller coupled to the first one or more sensing electrodes and configured to determine, based on an electrical signal from the first one or more sensing electrodes, that clot material is at or adjacent to the distal end region of the navigation probe.

50. a flexible catheter body having an aspiration lumen extending therethrough; an aspiration opening into the aspiration lumen at the distal end region of the flexible catheter body; a first one or more sensing electrodes at a distal end region of the flexible catheter body; one or more blood sensing electrodes positioned in an area of ​​the flexible catheter that is protected from contact with clot material; a controller coupled to the first one or more electrodes and configured to determine that clot material is at or adjacent to the first one or more sensing electrodes based on electrical signals from the first one or more sensing electrodes and the one or more blood sensing electrodes.

51. 51. The device of claim 50, wherein the one or more blood sensing electrodes are inside the aspiration lumen.

52. 51. The device of claim 50, wherein the one or more blood sensing electrodes are within the aspiration lumen distal to the aspiration opening.

53. 51. The device of claim 50, wherein the one or more blood sensing electrodes are positioned in a recess within the aspiration lumen.

54. 51. The device of claim 50, wherein the one or more blood sensing electrodes are on an exterior region of the flexible catheter body proximal to the suction opening.

55. 51. The device of claim 50, wherein the controller is configured to determine that the clot material is at or adjacent to the first one or more sensing electrodes based on a difference between the electrical signals from the first one or more sensing electrodes and the one or more blood sensing electrodes.

56. 51. The device of claim 50, wherein the first one or more sensing electrodes are at or adjacent to the suction opening.

57. 51. The device of claim 50, wherein the suction opening is in a tapered side of the distal end region of the flexible catheter body.

58. a flexible catheter body having an aspiration lumen extending therethrough; an aspiration opening into the aspiration lumen at the distal end region of the flexible catheter body; a first one or more sensing electrodes at a distal end region of the flexible catheter body; a retriever probe configured to extend distally from the flexible catheter body, the retriever probe including one or more clot grasping members configured to extend from the retriever probe; a controller coupled to the first one or more sensing electrodes and configured to determine, based on an electrical signal from the first one or more sensing electrodes, that clot material is at or adjacent to a distal end region of the navigation probe.

59. 59. The device of claim 58, wherein the retriever probe is configured to extend from the suction opening.

60. 59. The apparatus of claim 58, further comprising a second opening at a distal end region of the flexible catheter body, the retriever probe configured to extend distally from the second opening.

61. 59. The device of claim 58, further comprising one or more retriever electrodes at a distal end region of the retriever probe, and wherein the controller is further configured to determine, based on electrical signals from the one or more retriever electrodes, that clot material is at or adjacent to the distal end region of the retriever probe.

62. 59. The device of claim 58, wherein the first one or more sensing electrodes are at or adjacent to an edge of the suction opening.

63. 60. The device of claim 58, wherein the one or more clot grasping members comprise an expandable member.

64. 59. The device of claim 58, wherein the one or more clot grasping members comprise a hook, an arm, a basket, or a net.

65. 60. The device of claim 58, wherein the one or more clot grasping members comprise one or more suction ports.

66. a flexible catheter body having an aspiration lumen extending therethrough; an aspiration opening into the aspiration lumen at the distal end region of the flexible catheter body; one or more sensing electrodes at a distal end region of the flexible elongate catheter; a bending region proximal to the suction opening; an actuator configured to activate bending of the bending region such that the distal end region bends relative to a longitudinal axis of the flexible catheter body; a controller coupled to the one or more sensing electrodes and configured to determine that clot material is at or adjacent to the first one or more sensing electrodes.

67. 67. The apparatus of claim 66, wherein the controller is further configured to determine that a diameter of a blood vessel containing a distal end region of the flexible elongate member is greater than a threshold value based on impedance measurements from the one or more electrodes.

68. 67. The device of claim 66, further comprising a handle at a proximal end of the flexible elongate body, the actuator being coupled to the handle.

69. 67. The apparatus of claim 66, further comprising a pull wire configured to be actuated by the actuator to bend the flexible catheter body.

70. 67. The device of claim 66, wherein the controller is configured to emit an output identifying whether the clot material is at or adjacent to the one or more electrodes.

71. 71. The device of claim 70, wherein emitting the output comprises emitting the output from a handle portion of the device.

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