Clot detection systems and methods for thrombectomy catheters

Abstract

The present technology relates to systems and methods for removing a thrombus from a blood vessel of a patient. In some embodiments, the present technology is directed to systems including an elongated catheter having a distal portion configured to be positioned within the blood vessel of the patient, a proximal portion configured to be external to the patient, and a lumen extending therebetween. The system can also include a fluid delivery mechanism coupled with a fluid lumen and configured to apply fluid to at least partially fragment the thrombus. Intermediate pinch valve closing steps and aspiration modes may be configured to control pressure spikes and hydraulic shock experienced with high aspiration flow rates and rapid valve closure.

Description

CLOT DETECTION SYSTEMS AND METHODS FOR THROMBECTOMY CATHETERSCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims priority to U.S. provisional patent application no. 63 / 733,264, titled “CLOT DETECTION SYSTEMS AND METHODS FOR THROMBECTOMY CATHETERS,” and filed on December 12, 2024, which is herein incorporated by reference in its entirety.INCORPORATION BY REFERENCE

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

[0003] The present technology generally relates to medical devices and, in particular, to systems including aspiration and fluid delivery mechanisms and associated methods for removing a thrombus from a mammalian blood vessel.BACKGROUND

[0004] Thrombotic material may lead to a blockage in fluid flow within the vasculature of a mammal. Such blockages may occur in varied regions within the body, such as within the pulmonary system, peripheral vasculature, deep vasculature, or brain. Pulmonary embolisms typically arise when a thrombus originating from another part of the body (e.g., a vein in the pelvis or leg) becomes dislodged and travels to the lungs. Anti coagulation therapy is the current standard of care for treating pulmonary embolisms, but may not be effective in some patients. Additionally, conventional devices for removing thrombotic material may not be capable of navigating the tortuous vascular anatomy, may not be effective in removing thrombotic material, and / or may lack the ability to provide sensor data or other feedback to the clinician during the thrombectomy procedure. Existing thrombectomy devices operate based on simple aspiration which works sufficiently for certain clots but is largely ineffective for difficult, organized clots. Many patients presenting with deep vein thrombus (DVT) are left untreated as long as the risk of limb ischemia is low. In more urgent cases, they are treated with catheter-directed thrombolysis or lytic therapy to break up a clot over the course- 1 -SG Docket No.: 10844-737.672of many hours or days. More recently other tools like clot retrievers have been developed to treat DVT and pulmonary embolism (PE), but these tools are not being widely adopted because of their limited effectiveness and additional costs versus aspiration or the standard of case. Other recent developments focus on slicing or macerating the clot, but these mechanisms are designed to reduce the risk of the catheter clogging and do not address the problem of tough, large, organized clots. There remains the need for a device to address these and other problems with existing venous thrombectomy including, but not limited to, a fast, easy-to-use, and effective device for removing a variety of clot morphologies.

[0005] Problematically, excess blood can be aspirated if aspiration is running when a clot is not present or not captured. Furthermore, high aspiration flow rates with certain catheters can cause spikes in pressure resulting in hydraulic shock and damage to pressure sensors when valves are rapidly closed.

[0006] What is needed is efficient and controlled valve closing with intermediate steps configured to shorten transition times between open and closed valve states while controlling pressure spikes.SUMMARY OF THE DISCLOSURE

[0007] A method for detecting clot engagement with a thrombus removal device is provided, the method comprising: introducing a distal portion of an elongate catheter to a thrombus location in a blood vessel; opening a valve in an aspiration lumen of the elongate catheter to a first open position; operating an aspiration source of the elongate catheter to provide aspiration to the aspiration lumen with the valve in the first open position; partially closing the valve from the first open position to a second open position; measuring a pressure distal to the valve while the valve is in the second open position; comparing the measured pressure to a known clot engagement pressure; and determining that a clot is engaged with the distal end if the measured pressure is less than the known clot engagement pressure.

[0008] In some aspects, the first open position comprises a fully opened valved position.

[0009] In some aspects, the valve remains in the first open position for a first predetermined time period.

[0010] In some aspects, the valve remains in the second open position for a second predetermined time period.

[0011] In some aspects, the second pre-determined time period is shorter than the first pre-determined time period.- 2 -SG Docket No.: 10844-737.672

[0012] In some aspects, the method includes receiving a user input prior to opening the valve to the first open position, the user input comprises actuation of a button on a console or a handle of the elongate catheter.

[0013] In some aspects, the known clot engagement pressure is a pressure expected to be sensed within the elongate catheter when the elongate catheter is engaged with clot.

[0014] A method is also provided for determining when a clot has been removed from a patient with a thrombus removal device, the method comprising: determining that a clot is engaged with a distal end of an elongate catheter; while the clot is engaged with the distal end, opening a valve in an aspiration lumen of the elongate catheter to a first open position; operating an aspiration source of the elongate catheter to provide aspiration to the aspiration lumen with the valve in the first open position; delivering two or more intersecting fluid streams from a distal end of the elongate catheter towards the clot engaged with the distal end to at least partially cut or break up the clot; partially closing the valve from the first open position to a second open position; measuring a pressure distal to the valve while the valve is in the second open position; comparing the measured pressure to a known clot clearance pressure; and determining that the clot has been cleared from the distal end if the measured pressure is more than the known clot clearance pressure.

[0015] In some aspects, the first open position comprises a fully opened valved position.

[0016] In some aspects, the valve remains in the first open position for a first predetermined time period.

[0017] In some aspects, the valve remains in the second open position for a second predetermined time period.

[0018] In some aspects, the second pre-determined time period is shorter than the first pre-determined time period.

[0019] In some aspects, the method includes receiving a user input prior to opening the valve to the first open position.

[0020] In some aspects, the user input comprises actuation of a button on a console or a handle of the elongate catheter.

[0021] In some aspects, the known clot clearance pressure is a pressure expected to be sensed within the elongate catheter when the elongate catheter is no longer engaged with clot.

[0022] In some aspects, the method includes, after determining that the clot has been cleared, closing the valve to a closed position.

[0023] In some aspects, closing the valve comprises partially closing the valve to a third open position, followed by fully closing the valve.- 3 -SG Docket No.: 10844-737.672

[0024] In some aspects, partially closing the valve to the third open position at a first closing velocity, followed by fully closing the valve at a second closing velocity.

[0025] In some aspects, the first closing velocity is higher than the second closing velocity.

[0026] In some aspects, partially closing the valve to the third open position is configured to prevent a pressure spike within the aspiration lumen that can damage one or more components of the thrombus removal device.

[0027] In some aspects, the one or more components comprise a pressure transducer.

[0028] A thrombus removal device is provided, comprising: an elongate catheter having a distal end configured to be advanced to a thrombus location in a blood vessel, the elongate catheter comprising an aspiration lumen that extends to the distal end; a vacuum source operatively coupled to the aspiration lumen; a valve disposed in the aspiration lumen; a pressure sensor disposed in the aspiration lumen; and one or more processors operatively coupled to the valve and / or the vacuum source, the one or more processors being configured to: open the valve to a first open position; control the vacuum source to provide aspiration to the aspiration lumen with the valve in the first open position; partially close the valve from the first open position to a second open position; evaluate a pressure reading from the pressure sensor while the valve is in the second open position; compare the pressure reading to a known clot engagement pressure; and determine that a clot is engaged with the distal end if the measured pressure is less than the known clot engagement pressure.

[0029] In some aspects, the one or more processors are further configured to indicate to a user that the clot is engaged with the distal end.

[0030] In some aspects, the device includes a display configured to indicate to the user that the clot is engaged with the distal end.

[0031] In some aspects, the first open position comprises a fully opened valved position.

[0032] In some aspects, the one or more processors are configured to control the valve to remain in the first open position for a first pre-determined time period.

[0033] In some aspects, the one or more processors are configured to control the valve to remain in the second open position for a second pre-determined time period.

[0034] In some aspects, the second pre-determined time period is shorter than the first pre-determined time period.

[0035] In some aspects, a user input device is provided that is configured to control opening of the valve.

[0036] In some aspects, the user input device comprises actuation of a button on a console or a handle of the elongate catheter.- 4 -SG Docket No.: 10844-737.672

[0037] In some aspects, the known clot engagement pressure is a pressure expected to be sensed within the elongate catheter when the elongate catheter is engaged with clot.

[0038] A thrombus removal device is also provided, comprising: an elongate catheter having a distal end configured to be advanced to a thrombus location in a blood vessel, the elongate catheter comprising an aspiration lumen that extends to the distal end; a vacuum source operatively coupled to the aspiration lumen; at least two fluid ports disposed near the distal end; a fluid source configured to provide a flow of fluid to the at least two fluid ports to produce intersecting fluid streams or jets within the distal end; a valve disposed in the aspiration lumen; a pressure sensor disposed in the aspiration lumen; and one or more processors operatively coupled to the valve, the fluid source, and / or the vacuum source, the one or more processors being configured to: open the valve to a first open position; control the vacuum source to provide aspiration to the aspiration lumen with the valve in the first open position; control the fluid source to deliver fluid to the at least two fluid ports to produce two or more intersecting fluid streams from towards a clot engaged with the distal end to at least partially cut or break up the clot; partially close the valve from the first open position to a second open position; evaluate a pressure reading from the pressure sensor while the valve is in the second open position; compare the pressure reading to a known clot clearance pressure; and determine that a clot is cleared from the distal end if the measured pressure is more than the known clot clearance pressure.

[0039] In some aspects, the one or more processors are further configured to indicate to a user that the clot is engaged with the distal end.

[0040] In some aspects, the device includes a display configured to indicate to the user that the clot is engaged with the distal end.

[0041] In some aspects, the first open position comprises a fully opened valved position.

[0042] In some aspects, the one or more processors are configured to control the valve to remain in the first open position for a first pre-determined time period.

[0043] In some aspects, the one or more processors are configured to control the valve to remain in the second open position for a second pre-determined time period.

[0044] In some aspects, the second pre-determined time period is shorter than the first pre-determined time period.

[0045] In some aspects, a user input device configured to control opening of the valve.

[0046] In some aspects, the user input device comprises actuation of a button on a console or a handle of the elongate catheter.

[0047] In some aspects, the known clot engagement pressure is a pressure expected to be sensed within the elongate catheter when the elongate catheter is engaged with clot.- 5 -SG Docket No.: 10844-737.672BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The novel features of the invention are set forth with particularity in the claims that follow. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

[0049] FIGS. 1-1 A illustrate various views of a portion of a thrombus removal system including a distal portion of an elongated catheter configured in accordance with an embodiment of the present technology.

[0050] FIGS. 2A-2C illustrate various embodiments of a thrombus removal system including a saline source, an aspiration system, and one or more controls for controlling irrigation and / or aspiration of the system.

[0051] FIG. 3 A is a system schematic diagram of a thrombus removal system.

[0052] FIG. 3B is one embodiment of a thrombus removal system including one or more sensors configured to detect a clot.

[0053] FIGS. 4A-4B illustrate a method for determining if a clot is engaged with a thrombectomy catheter.

[0054] FIGS. 5A-5B illustrate a method for determining if a clot has been cleared from the patient with the thrombectomy catheter.

[0055] FIG. 6A shows gulp aspiration mode.

[0056] FIG. 6B illustrates hydraulic shock assessment.

[0057] FIG. 7 shows a table illustrating valve closing velocities corresponding to peak pressures within the system and valve closing times.

[0058] FIG. 8A illustrates a flowchart of a high-flow aspiration mode.

[0059] FIG. 8B shows a table of various sequences of commanded angles and corresponding velocities in the high-flow aspiration mode.

[0060] FIG. 9A shows a low-flow aspiration mode.

[0061] FIG. 9B is a table comparing interval time, pinch valve actual open time, total volume of aspiration and volumes during initial sip and subsequent sips in the low-flow aspiration mode.

[0062] FIG. 9C shows a flow chart for an initial sip aspiration.

[0063] FIG. 9D shows a table with sequence of command angles and corresponding velocities to rotate to the commanded angle for the initial sip aspiration.

[0064] FIGS. 9E-9F show a flow chart for subsequent sip aspiration.- 6 -SG Docket No.: 10844-737.672

[0065] FIGS. 10A-10D show examples of a damper or pressure control mechanism that can be implemented in a thrombectomy device to dampen hydraulic shock or pressure spikes within the device when an aspiration valve is rapidly closed.DETAILED DESCRIPTION

[0066] This application is related to disclosure in International Application No. PCT / US2021 / 020915, filed March 4, 2021 (the ‘915 application), the disclosure of which is incorporated by reference herein for all purposes. The ‘915 application describes general mechanisms for capturing and removing a clot. By example, the catheter may include a capture element such as an auger to break up and draw in a clot material into an aspiration lumen. In another example, multiple fluid streams are directed toward the clot to fragment the material.

[0067] The present technology is generally directed to thrombus removal systems and associated methods. A system configured in accordance with an embodiment of the present technology can include, for example, an elongated catheter having a distal portion configured to be positioned within a blood vessel of the patient, a proximal portion configured to be external to the patient, a fluid delivery mechanism configured to fragment the thrombus with pressurized fluid, an aspiration mechanism configured to aspirate the fragments of the thrombus, and one or more lumens extending at least partially from the proximal portion to the distal portion..

[0068] The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the present technology. Certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section. Additionally, the present technology can include other embodiments that are within the scope of the examples but are not described in detail with respect to the figures.

[0069] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present technology. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features or characteristics may be combined in any suitable manner in one or more embodiments.- 7 -SG Docket No.: 10844-737.672

[0070] Reference throughout this specification to relative terms such as, for example, "generally," "approximately," and "about" are used herein to mean the stated value plus or minus 10%.

[0071] Although some embodiments herein are described in terms of thrombus removal, it will be appreciated that the present technology can be used and / or modified to remove other types of emboli that may occlude a blood vessel, such as fat, tissue, or a foreign substance. Additionally, although some embodiments herein are described in the context of thrombus removal from a pulmonary artery (e.g., pulmonary embolectomy), the technology may be applied to removal of thrombi and / or emboli from other portions of the vasculature (e.g., in neurovascular, coronary, or peripheral applications). Moreover, although some embodiments are discussed in terms of maceration of a thrombus with a fluid, the present technology can be adapted for use with other techniques for breaking up a thrombus into smaller fragments or particles (e.g., ultrasonic, mechanical, enzymatic, etc.).

[0072] The headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed present technology.Systems for Thrombus Removal

[0073] As provided above, the present technology is generally directed to thrombus removal systems. Such systems include an elongated catheter having a distal portion positionable within a blood vessel of the patient (e.g., an artery or vein), a proximal portion positionable outside the patient's body, a fluid delivery mechanism configured to fragment the thrombus with pressurized fluid, an aspiration mechanism configured to aspirate the fragments of the thrombus, and one or more lumens extending at least partially from the proximal portion to the distal portion. In some embodiments, the systems herein are configured to engage a thrombus in a patient's blood vessel, break the thrombus into small fragments, and aspirate the fragments out of the patient's body. The pressurized fluid streams (e.g., jets) function to cut or macerate thrombus, before, during, and / or after at least a portion of the thrombus has entered the aspiration lumen or a distal end of the system. Fragmentation helps to prevent clogging of the aspiration lumen and allows the thrombus removal system to macerate large, firm clots that otherwise could not be aspirated. As used herein, “thrombus” and “embolism” are used somewhat interchangeably in various respects. It should be appreciated that while the description may refer to removal of “thrombus,” this should be understood to encompass removal of thrombus fragments and other emboli as provided herein.

[0074] According to embodiments of the present technology, a fluid delivery mechanism can provide a plurality of fluid streams (e.g., jets) to fluid apertures of the thrombus removal - 8 -SG Docket No.: 10844-737.672system for macerating, cutting, fragmenting, pulverizing and / or urging thrombus to be removed from a proximal portion of the thrombus removal system. The thrombus removal system can include an aspiration lumen extending at least partially from the proximal portion to the distal portion of the thrombus removal system that is adapted for fluid communication with an aspiration pump (e.g., vacuum source). In operation, the aspiration pump may generate a volume of lower pressure within the aspiration lumen near the proximal portion of the thrombus removal system, urging aspiration of thrombus from the distal portion.

[0075] FIG. 1 illustrates a distal portion 10 of a thrombus removal system according to an embodiment of the present technology. FIG. 1 A Section A-A illustrates an elevation sectional view of the distal portion 101. The example section A-A in FIG. 1A depicts a funnel 20 that is positioned at the distal end of the distal portion 10, the funnel adapted to engage with thrombus and / or a tissue (e.g., vessel) wall to aid in thrombus fragmentation and / or removal. The funnel can have a variety of shapes and constructions as would be understood by one of skill from the description herein. In some embodiments, the distal portion 10 of the thrombus removal system does not include a funnel, but instead aspirates directly into the aspiration lumen. The example section A-A in FIG. 1 A depicts a double walled thrombus removal device construction having an outer wall / tube 40 and an inner wall / tube 50. An aspiration lumen 55 is formed by the inner wall 50 and is centrally located. A generally annular volume forms at least one fluid lumen 45 between the outer wall 40 and the inner wall 50. The fluid lumen 45 is adapted for fluid communication with the fluid delivery mechanism. One or more apertures (e.g., nozzles, orifices, or ports) 30 are positioned in the thrombus removal system to be in fluid communication with the fluid lumen 45 and an irrigation manifold 25. In operation, the ports 30 are adapted to direct (e.g., pressurized) fluid toward thrombus that is engaged with the distal portion 10 of the thrombus removal system.

[0076] In various embodiments, the system can have an average flow velocity within the fluid lumen of up to 20 m / s to achieve consistent and successful aspiration of clots. In some embodiments, the fluid source itself can be delivered in a pulsed sequence or a preprogrammed sequence that includes some combination of pulsatile flow and constant flow to deliver fluid to the jets. In these embodiments, while the average pulsed fluid velocity may be up to 20 m / s, the peak fluid velocity in the lumen may be up to 30 m / s or more during the pulsing of the fluid source. In some embodiments, the jets or apertures are no smaller than 0.0100” or even as small as 0.008” to avoid undesirable spraying of fluid. In some embodiments, the system can have a minimum vacuum or aspiration pressure of 15 inHg, to- 9 -SG Docket No.: 10844-737.672remove target clots after they have been macerated or broken up with the jets described above.

[0077] The thrombus removal system can be sized and configured to access and remove thrombi in various locations or vessels within a patient’s body. It should be understood that while the dimensions of the system may vary depending on the target location, generally similar features and components described herein may be implemented in the thrombus removal system regardless of the application. For example, a thrombus removal system configured to remove pulmonary embolism (PE) from a patient may have an outer wall / tube with a size of approximately 11-13 Fr, or preferably 12 Fr, and an inner wall / tube with a size of 7-9 Fr, or preferably 8 Fr. A deep vein thrombosis (DVT) device, on the other hand, may have an outer wall / tube with a size of approximately 9-11 Fr, or preferably 10 Fr, and an inner wall / tube with a size of 6-9 Fr, or preferably 7.5 Fr. Applications are further provided for ischemic stroke and peripheral embolism applications.

[0078] FIGS. 2A-2C illustrate various configurations of a thrombus removal system 600, including a thrombus removal device, 602, a vacuum source and cannister 604, and a fluid source 606. In some embodiments, the vacuum source and cannister and the fluid source are housed in a console unit that is detachably connected to the thrombus removal device. A fluid pump can be housed in the console, or alternatively, in the handle of the device. The console can include one or more CPUs, electronic controllers, or microcontrollers configured to control all functions of the system. The thrombus removal device 602 can include a funnel 608, a flexible shaft 610, a handle 612, and one or more controls 614 and 616. For example, in the embodiment shown in FIG. 2 A, the device can include a finger switch or trigger 614 and a foot pedal or switch 616. These can be used to control aspiration and irrigation, respectively. Alternatively, as shown in the embodiment of FIG. 2B, the device can include only a foot switch 614, which can be used to control both functions, or in FIG. 2C, the device can include only an overpedal 616, also used to control both functions. It is also contemplated that an embodiment could include only a finger switch to control both aspiration and irrigation functions. As shown in FIG. 2A, the vacuum source can be coupled to the aspiration lumen of the device with a vacuum line 618. Any clots or other debris removed from a patient during therapy can be stored in the vacuum cannister 604. Similarly, the fluid source (e.g., a saline bag) can be coupled to the fluid lumens of the device with a fluid line 620.

[0079] Still referring to FIG. 2 A, electronics line 622 can couple any electronics / sensors, etc. from the device to the console / controllers of the system. The system console including the CPUs / electronic controllers can be configured to monitor fluid and pressure levels and - 10 -SG Docket No.: 10844-737.672adjust them automatically or in real-time as needed. In some embodiments, the CPUs / electronic controllers are configured to control the vacuum and irrigation as well as electromechanically stop and start both systems in response to sensor data, such as pressure data, flow data, etc.

[0080] As is described above, aspiration occurs down the central lumen of the device and is provided by a vacuum pump in the console. The vacuum pump can include a container that collects any thrombus or debris removed from the patient. One or more valves can be disposed along or within the aspiration lumen between the vacuum pump / source and the distal end of the aspiration catheter. Actuation of the valve can fluidly couple or decouple the vacuum source to the aspiration catheter. When aspiration is activated, the valve can be opened to allow the vacuum source to generate vacuum within the aspiration catheter. When the valve is closed, the aspiration is “turned off’ and no aspiration or suction is applied at the distal end of the aspiration catheter.

[0081] FIGS. 3A-3B are schematic diagrams of the thrombus removal system and the thrombus removal device, respectively. Referring to FIG. 3 A, the system can include pulmonary artery pressure (Ppa), pressure vacuum source (Pvs), pressure jet source (Pjs), fluid resistance of vacuum system (Rvs) and fluid capacitance (Cvs) of the aspiration / vacuum portion of the device, fluid resistance (Rjs) and capacitance (Cjs) of the jet portion of the device, and multiple test points T1-T7 for testing pressure or flow of the system. Any number or type of pressure and / or flow sensors can be implemented in the system. Additionally, other types of sensors can be used. For example, electrodes or impedance sensors can be used to measure an impedance at the distal end of the system (e.g., to characterize changes in electrical impedance associated with clots vs. blood). In other embodiments, temperature sensors (e.g., one or more thermistors) may be used to sense a temperature of the device or target tissue. In additional embodiments, the vacuum source or jet source can be configured as sensors, such as using back emf or a fluid column sensor connected to the aspiration lumen or jet lumen.

[0082] The pressure vacuum source (Pvs) can be a vacuum source (a trap in which a low pressure gas is maintained above the aspirant) or a positive displacement source, both of which induce a negative pressure distal to the CNTs (when present as it may not be required with a positive displacement pump). Engagement, such as with a clot, can be characterized by either the difference between an expected flow or rate in change of flow and a measured flow where that difference is of great enough magnitude.

[0083] Referring to FIG. 3B, CNTs represents the junction or connection between the pressure vacuum source and the thrombus removal device, and CNTj represents the junction - 11 -SG Docket No.: 10844-737.672or connection between the pressure jet source and the thrombus removal device. A valve in CNTs and CNTj can isolate the capacitance of the vacuum / jet source from the rest of the system such that the amount of blood drawn into the system when the vacuum system is stopped or shut down is minimized. Referring to FIG. 3 A, testing points T1 and T2 can represent pressure or flow sensor locations configured to provide pressure / flow readings at a location between the pressure vacuum source and the device, and between the pressure jet source and the device, respectively. Testing points T4 and T3, similarly, can represent pressure or flow sensor locations configured to provide pressure / flow readings at a location near the junction or connection between the device and the pressure vacuum source and pressure jet source, respectively. Additionally, testing points T5, T6, and T7 can represent pressure or flow sensor locations configured to provide pressure / flow readings at a location near a distal end of the device. For example, testing point T5 can provide flow / pressure readings at or near where the jet fluid exits the jet ports or nozzles at the distal end of the device. Similarly, testing points T6 and T7 can provide pressure / flow readings of the aspiration system at or near the distal end of the device, such as within the funnel (T6 in FIG. 3B) or within the thrombus removal device just proximal to the funnel (T7 in FIG. 3B). The locations of the test points within the system schematic illustrate potential test / sensor locations for pressure sensors, flow sensors, or other sensors that could be used in real time to control operation of the device, detect system operating parameters, detect clogs, etc.

[0084] Referring to FIG. 3B, an embodiment of the thrombus removal device is shown which includes test points T6 and T7 for sensing flow and / or pressure in the funnel and the aspiration lumen of the device, and also haptic sensors Hl and / or H2 for detecting contact with a clot or other debris in the patient. In some embodiments, the haptic sensors can comprise pressure sensors (positive or negative), optical sensors, electrical impedance sensors (de, single frequency, or spectral) or other sensors useful for the operation of the system.

[0085] Generally, the thrombus removal system can include a searching for clot / no clot engaged state, an engaging clot state, a clot engaged state, a clogged jet lumen state, a clogged aspiration lumen state, and a clot initially engaged / leak state. As described above, sensors can be disposed throughout the system, including at or near a distal end of the device (e.g., at or within the funnel and / or within the aspiration lumen), at or near a proximal end of the device, and / or at or within the pressure and / or jet / fluid source outside of the device. The readings of these groupings of sensors can generally be used to determine which state the thrombus removal system is in, and can be further used to inform and control the device into subsequent states throughout the therapy. When the sensors are in a nominal or (+) state it reflects a signal indicative of engagement with a clot, and when the sensors are in a non-- 12 -SG Docket No.: 10844-737.672nominal or (-) state it reflects a signal indicative that the device is not in engagement with a clot. In some embodiments, the nominal state can correspond to a sensed parameter within a given range (e.g., a specific pressure or flow rate range) and the non-nominal state can correspond to a sensed parameter (e.g., pressure or flow rate) beyond a threshold pressure. In one embodiment, a nominal range for pressure can be between approximately +4 to -25 inHg.

[0086] FIGS. 4A-4B illustrate a schematic diagram and a pressure plot, respectively, of one implementation for searching for or identifying when a clot is engaged with a thrombectomy system. FIGS. 4A-4B can employ any of the thrombectomy systems described above. Referring to FIG. 4A, the thrombectomy system can default to a standby state 402, in which jetting and / or aspiration are de-activated. However, a user can provide an input 404 (e.g., via a button press on a console or handle of the system) to initiate a clothunting procedure. Upon receiving this input, the system activate aspiration 406 (e.g., activate the vacuum or aspiration source) and fully open a valve between the distal end of the thrombectomy catheter and the vacuum source (e.g., a valve within CNTs described above). This valve can be, for example, within or fluidly coupled to the aspiration lumen of the thrombectomy catheter. The system can hold this system state (e.g., valve fully open, vacuum source on) for a pre-determined time period 407, such as 1 second. While the time period 407 is described and illustrated as being 1 second, it should be understood that any preset or user-set time period can be used, such as 0-5 seconds, 0-10 seconds, etc. During this time, the thrombectomy catheter will be applying aspiration to the distal end of the catheter, potentially pulling blood and / or clot into the distal end of the device. If aspiration time is greater than a timeout 403, the system may return to the standby state 402.

[0087] After this pre-determined time period 407 has passed, the system can adjust the valve between the distal end of the thrombectomy catheter and the vacuum source. For example, the system can partially close 408 the valve. It should be understood that, when partially closing the valve in this step from the fully open valve position of step 406, the valve will still be partially opened. In some embodiments, the valve is partially closed such that the valve is only 75% open, 80% open, 85% open, 90% open, 95% open, or anywhere from 75-99% open (relative to 100% fully opened). Once again, the system can hold this system state (e.g., valve partially open, vacuum source on) for a pre-determined time period 409 such as 1 second or 0.25 seconds. In some examples, this second pre-determined time period 409 is shorter than the first pre-determined time period 407. During this time, the thrombectomy catheter will be applying aspiration to the distal end of the catheter, potentially pulling blood and / or clot into the funnel of the device. It should be noted that the pre-- 13 -SG Docket No.: 10844-737.672determined time period for this system state (partially open valve) can be the same or different than the time period for the fully open state described above.

[0088] After this second pre-determined time period has passed, the system can compare 410 a pressure measured by the system distal to the valve (e.g., with a pressure sensor in the aspiration lumen or in the funnel, such as T1 above) with a threshold pressure, referred to herein as a “clot captured pressure” which is a pressure known by the system to be indicative of a clot being captured by the distal end of the thrombectomy device.

[0089] If the pressure measured by the system distal to the valve is less than the “clot captured pressure”, then the system can determine at step 412 that a clot is engaged with the system (e.g., in the funnel of the device). The system can automatically re-enter the standby mode 402, waiting for further input from the user. In some embodiments, upon detecting engagement with a clot, the system can automatically enter a jetting and clot removal mode in which the valve in the aspiration lumen is fully opened, jetting is turned on, and the clot is macerated and removed from the patient’s body via aspiration. In other embodiments, the system will wait for a further input from the user (e.g., another button press) to initiate this jetting and clot removal mode.

[0090] If the pressure measure by the system distal to the valve is more than the “clot captured pressure”, then after another pre-determined time period 411 (e.g., 1 second, 0-5 seconds, 0-10 seconds, etc.), the system may repeat step 406 and return the valve to the fully opened position with the vacuum pump turned on to repeat the clot engagement and detection process.

[0091] FIG. 4B plots a vacuum pressure (inHg) 414 distal to the pinch valve over time 421, and is discussed in this section with respect to the steps described above in FIG. 4A. In the standby state 402, the pressure sensor can read an atmospheric pressure within the aspiration catheter. A pressure drop of approximately 30 inHg is seen at 0.5 seconds. This can correspond, for example, to step 406 in FIG. 4A in which the valve is fully opened and the vacuum pump is activated to generate vacuum in the aspiration catheter. After a predetermined time period 407, the valve can be partially closed at step 408 (so that it is in a partially open state) with the vacuum pump operating, resulting in the pressure returning closer to atmospheric since less aspiration is being applied to the catheter. In this partially open valve state, the system can compare the measured pressure to the “clot captured pressure” which indicates when clot is engaged with the catheter. If the measured pressure is less than the “clot captured pressure”, as shown at 412, the algorithm can indicate that a clot is captured or engaged with the distal end of the thrombectomy device.- 14 -SG Docket No.: 10844-737.672

[0092] When the thrombus removal system is actively searching for clot, the system is monitoring various sensors (such as flow or pressure sensors) to determine if / when the thrombus removal system has engaged with a thrombus or thrombi at the target tissue location. While in this clot searching state, the system can operate the aspiration source to pull vacuum and assist in capturing clots in the funnel of the device. In some embodiments, the aspiration can run at a normal level (e.g., the same level of aspiration that runs when a clot is being removed) and in other embodiments the aspiration can run at a lower level or some minimal level. In this state, the jets can be completely off or can also run at a lower or minimal level to assist with clot capture. As described above, the system can include any number of pressure and / or flow sensors located at several locations on or within the system. The system can also use the jet ports / jet lumens as sensors, which can inform the system about the particular state and guide the therapy process.

[0093] It should be noted that the amount of partially opening / closing the valve during the clot-hunting can affect the aspiration ability of the device. If the valve is closed too much (e.g., below 75%, it may dramatically reduce the effectiveness of the device to pull clot into the thrombectomy device, and / or the responsiveness of the device for engaging / removing clot when the valve is fully opened again. If no clot is detected, then the system can cycle back to the fully open valve state, which increases the vacuum pressure in the aspiration lumen.

[0094] FIGS. 5A-5B illustrate another schematic diagram and a pressure plot, respectively, of one implementation for identifying when a clot has been cleared or removed from the patient with a thrombectomy system. This sequence can follow, for example, the clot detection technique described above in FIGS. 4A-4B.

[0095] As described above, after a clot is detected by the system or determined to be engaged with the system, the system can enter standby mode 502 in which it is awaiting a user input. The user can initiate a clot removal procedure by, for example, providing an input 504 into a console of the system or pressing a button on a handle of the device. Upon receiving this input, the system can turn on aspiration at step 506 (e.g., activate the vacuum or aspiration source) and fully open a valve between the distal end of the thrombectomy catheter and the vacuum source (e.g., a valve within CNTs described above). After a pre-determined time period 507, the system can activate jetting 509 to deliver two or more intersecting fluid streams into an intersection region within the device to interact with and cut or break up the clot. While jetting and aspiration are active, at step 508 the system can once again partially close the valve between the distal end of the thrombectomy catheter and the vacuum source, such that the valve assumes a partially open state (e.g., between 75-99% open).- 15 -SG Docket No.: 10844-737.672

[0096] After another pre-determined time period 511 has passed, at step 512 the system can compare a pressure measured by the system distal to the valve (e.g., with a pressure sensor in the aspiration lumen or in the funnel, such as T1 above) with a “clot cleared pressure” which is a pressure known by the system to be indicative of a clot being cleared from the funnel of the device. If the pressure measured by the system distal to the valve is greater than the “clot cleared pressure”, then at step 514 the system can determine that a clot has been removed or cleared from the system (e.g., from the distal end of the device). The system can automatically return to the standby mode 502 after clearing the clot, waiting for further input from the user. If the system determines that the clot has not been cleared or removed, the process can repeat starting again at step 506. If, however, the amount of irrigation / jetting time exceeds a threshold value, the system can return to the standby mode 502 to prevent excessive jetting / irrigati on from being delivered to the patient.

[0097] FIG. 5B plots a vacuum pressure (inHg) 514 distal to the pinch valve over time 521, and is discussed in this section with respect to the steps described above in FIG. 5 A.

[0098] FIG. 5B illustrates vacuum pressure 514 distal to the tip of the pinch valve (inHg) 521. In the standby 502 and input 504 states, a clot is captured by the device which results in vacuum pressure being sensed inside the thrombectomy catheter between the clot and the valve. It can be seen here that the pressure sensed within the device at standby is the same as the pressure within the device at the end of the plot in FIG. 4B after the clot has been captured. At step 508, the valve is partially closed while jetting and aspiration are active, and the pressure within the device is monitored. At about 2 seconds in the illustrated plot, the clot clearing algorithm did not detect that the clot was cleared, so step 506 is repeated in which the valve is fully opened with jetting active. After a pre-determined time period, at around 3 seconds in this plot, the valve is partially closed again, and the clot clearing algorithm is repeated. When the system still detects the presence of a clot, the valve is fully opened again, repeating step 506 at around 4 seconds in the plot. At about the 5 second mark, the valve is partially closed again, and the clot clearing algorithm is run again. The system compares the vacuum pressure to the “clot cleared pressure” or threshold, allowing the system to determine that the clot has finally been cleared as shown at step 514. With the clot cleared, the sensed pressure is seen returning back to atmospheric.

[0099] In certain embodiments, the system may allow a user to choose between two different aspiration modes when the distal end of the device state is clear or open flow (e.g., no clot engaged with the device). For example. There may be a high-flow mode in which the system performs a single, full open aspiration with a pre-determined timeout period (e.g., up to 1 second, up to 2 seconds, up to 5 seconds, etc.). There may also be a low flow or “sip”- 16 -SG Docket No.: 10844-737.672mode in which the system performs periodic or limited aspiration with a separate predetermined timeout period (e.g., up to 5 seconds, up to 10 seconds, etc.). In some examples, the pre-determined timeout period in the high-flow mode is shorter than the pre-determined timeout period in the low-flow mode, since the high-flow mode aspirates / removes blood much faster than the low-flow mode. Generally, the high-flow mode can be used when searching for clots, or when the device is positioned near a clot to ensure that the clot is pulled into the device. The low-flow mode can be used when trying to limit the amount of blood aspirated from the patient. The low-flow mode can still be used to pull clots into the device, but in general the device may need to be closer to the clots to engage with the clots.

[0100] FIG. 6A shows pressure diagram of a high-flow aspiration mode and the corresponding open / closed angles of a pinch valve used to open and close off the thrombectomy catheter to the vacuum source. When the pinch valve is actuated to its fully open angle 604 to allow vacuum to be generated within the thrombectomy catheter, pressure drops from atmospheric 603 to the free flow pressure 601 as shown in the plot. After the predetermined timeout period for this high-flow mode, the valve is actuated to a minimum open angle 606, as shown around 1.25 seconds into this plot. The valve is still partially opened at this stage, but not fully opened. After this transition, the valve is slowly closed to the minimum closed angle 608 (or all the way to the fully closed angle 610) to turn off aspiration. It is noted that since the valve acts upon flexible tubing, the valve does not need to rotate all the way to the fully closed position to create a complete seal.

[0101] The step of closing the valve to the minimum open angle 606 in can result in hydraulic shock in high-flow systems that can be transmitted through the device as transient pressure spikes and damage vacuum pressure sensors within the device. For example, some pressure sensors typically used for this type of application have a maximum rated specification of 30 PSIA. The transient pressure spikes caused by rapidly closing the valve under high-flow aspiration can damage these pressure sensors. FIG. 6B illustrates this hydraulic shock phenomenon. For example, in plot 620 when the valve is fully opened at step 623, the pressure can drop from atmospheric 603 to free flow pressure 601 as previously described. If the valve is fully closed at step 624, the pressure can spike within the device above the sensors maximum rated specification 625, potentially resulting in damage to the sensor. Additionally, as shown in plot 626, the pressure spike can also result in the sensed pressure being clipped at the max rated pressure of the sensor.

[0102] To address the potential for pressure sensor damage and / or clipping, hydraulic shock in the system can be mitigated, reduced, or eliminating by adjusting or actuating the speed with which the valve is closed, and also introducing intermediate closing steps to- 17 -SG Docket No.: 10844-737.672shorten the t transition time while still controlling pressure spikes. Put another way, the valve closing speed can be reduced, in combination with partially closing the valve as the valve transitions from open to closed. FIG. 7 shows a table illustrating how the closing velocity 706 for one embodiment of a thrombectomy catheter affects the peak pressure 708 in the system, and also the closing time 710 of the valve. For example, if the valve is closed at 0.1 Hz, the peak pressure is reduced to 3.9 inHg, but the closing time from fully open to fully closed is 3.2s, which may be longer than the desired aspiration time, resulting in more blood being removed from the patient than desired. At faster closing speeds, e.g., anything above 1 Hz in this example, the peak pressure is too large and can result in damage to the system.

[0103] FIG. 8A illustrates a flowchart of a high-flow aspiration mode that includes intermediate closing steps to prevent or limit hydraulic shock. Step 802 beings with the pinch valve closed in standby mode. An input 804 such as a button press may be activated to rotate 806 the pinch valve to the fully open angle and at a first rotation velocity (e.g., 10 Hz). If the input 804 is not activated, the pinch valve remains closed in standby 802.

[0104] The valve remains fully open for a pre-determined time period 808, during which the system is operating in a high-flow aspiration mode. At step 810, the system can introduce an intermediate closing step in which the pinch valve is rotated to the minimum open angle at a second rotation velocity. In this example, the second rotation velocity of this intermediate closing step is less than the first rotation velocity at the fully opening step.

[0105] At step 812, the system checks the closing angle of the valve, and if the angle is less than the minimum open angle, then at step 814 the pinch valve is rotated to the minimum closed angle at a third rotation velocity. In this example, this third rotation velocity is a velocity that will result in pressures within the system being below a threshold pressure, such as a pressure that would damage components in the system. The system continuously monitors the closing angle of the valve at step 816 and continues to rotate the valve at the third rotation velocity in step 814 until the minimum close angle is achieved. Finally, at step 820, the pinch valve is rotated to the fully closed angle at a fourth rotation velocity.

[0106] FIG. 8B shows a table of various sequences of commanded angles 822 and corresponding velocities 824 needed to rotate to the commanded angle in the high-flow aspiration mode for one specific embodiment. While the individual closing velocities can be adjusted or tailored to a specific device, in this example the first rotation velocity to fully open the valve is the highest velocity, followed by the second rotation velocity moving the valve to the minimum open position, followed by the third rotation velocity moving the valve to the minimum closed position, followed by the fourth rotation velocity moving the valve to the fully closed position.- 18 -SG Docket No.: 10844-737.672

[0107] FIG. 9A shows a pressure diagram of a low-flow aspiration mode, also referred to herein as a “sip” aspiration mode. As discussed above, this low-flow aspiration mode can generate aspiration with a partially closed (or partially open) valve to limit the amount of blood removed from a patient when hunting or looking for clots. As shown in FIG. 9A, the closed valve pressure 908 can be at atmospheric pressure, and when the valve is partially opened during an initial sip 902 for a first pre-determined time period (e.g., up to 0.5 seconds, up to 1 second, etc.) the pressure in the device reduces to the open valve pressure 912. After the first pre-determined time period has passed, the valve can be closed allowing the pressure within the device to return to atmospheric. The low-flow aspiration mode can employ subsequent “sips” 903, 904, 905, and 906 in which the valve is partially opened for first, second, third, fourth, etc. pre-determined time periods as shown. In this example, these the valve is partially opened for shorter time periods in these subsequent sips than in the initial sip. As a result, the pressure within the device is lowered only to the threshold pressure 910, not all the way to the open valve pressure 912. This results in less suction in the device, and therefore less blood removed from the patient during these subsequent sips.

[0108] FIG. 9B is a table comparing one example of the duration and volume of aspiration during the low-flow aspiration mode described above. As shown in the chart, the low-flow aspiration mode has a total 920 interval time of 5 seconds, with 30mL aspiration volume. The initial sip 902 has an interval time 914 of 1.5 seconds, with the pinch valve open 916 for 0.5 seconds and a 20mL aspiration volume. Each subsequent sip 903-906 has an interval time 914 of 1 second, pinch valve open time 916 of 0.1 seconds, and 3-5mL of aspiration per cycle. This example is merely one implementation, and intended to show that the initial sip can remove more volume of blood / clot than the subsequent cycles.

[0109] FIG. 9C shows a flow chart of a low-flow aspiration mode that includes intermediate closing steps to prevent or limit hydraulic shock. The system begins with the pinch valve closed in standby 922. An input 924 such as a button press may then be activated to rotate 926 the pinch valve to fully open angle and a first open velocity. If the input is not activated, then the pitch valve remains closed in standby.

[0110] The valve remains fully opened for a pre-determined time period 928, during which the system is operating in the low-flow aspiration mode during the initial sip. At step 930, the system can introduce an intermediate closing step in which the pinch valve is rotated to the minimum open angle at a second rotation velocity. In this example, the second rotation velocity of this intermediate closing step is less than the first rotation velocity at the fully opening step.- 19 -SG Docket No.: 10844-737.672

[0111] At step 932, the system checks the closing angle of the valve, and if the angle is less than the minimum open angle, then at step 934 the pinch valve is rotated to the minimum closed angle at a third rotation velocity. In this example, this third rotation velocity is a velocity that will result in pressures within the system being below a threshold pressure, such as a pressure that would damage components in the system. The system continuously monitors the closing angle of the valve at step 936 and continues to rotate the valve at the third rotation velocity in step 938 until the minimum close angle is achieved. Finally, at step 940, the pinch valve is rotated to the fully closed angle at a fourth rotation velocity.

[0112] FIG. 9D shows a table of various sequences of commanded angles 950 and corresponding velocities 952 needed to rotate to the commanded angle in the low-flow aspiration mode for one specific embodiment. While the individual closing velocities can be adjusted or tailored to a specific device, in this example the first rotation velocity to fully open the valve is the highest velocity, followed by the second rotation velocity moving the valve to the minimum open position, followed by the third rotation velocity moving the valve to the minimum closed position, followed by the fourth rotation velocity moving the valve to the fully closed position.

[0113] FIG. 9E shows a flow chart for subsequent sip aspirations corresponding to subsequent sips 903, 904, 905, and 906 in FIG. 9A. The pitch valve begins at the minimum closed angle 962. After a wait time of, at step 966 the pinch valve is rotated to the minimum open angle at a first rotation velocity. If, at step 968, pressure is less than a threshold, then the pinch valve is rotated at step 970 to the minimum closed angle at a second rotation velocity. If pressure is not less than a threshold, then at step 971 the system can determine if the angle is greater than a minimum open angle. If yes, then the pinch valve is rotated to the minimum closed angle at a velocity in step 970. If no, then the pinch valve is rotated to the minimum open angle at step 966.

[0114] After step 970, if the system determines at step 972 that the angle is less than halfway from the minimum closed angle toward the maximum closed angle, the pinch valve may be rotated at step 980 to the minimum close dangle at a third rotation velocity. The system can then determine at step 982 if total aspiration time is greater than or equal to a predetermined time. If yes, then at step 984 the pinch valve may be rotated to the fully closed angle at a fourth rotation velocity of, at which point the system enters standby mode 986. If total aspiration time is not greater than or equal to the threshold, then the flow of any subsequent sip may reset with the pinch valve at the minimum closed angle.

[0115] FIG. 9F shows a table of various sequences of commanded angles 990 and corresponding velocities 992 needed to rotate to the commanded angle in the high-flow- 20 -SG Docket No.: 10844-737.672aspiration mode for one specific embodiment. While the individual closing velocities can be adjusted or tailored to a specific device, in this example the first rotation velocity to fully open the valve is the highest velocity, followed by the second rotation velocity moving the valve to the minimum open position, followed by the third rotation velocity moving the valve to the minimum closed position, followed by the fourth rotation velocity moving the valve to the fully closed position.

[0116] As discussed above, slowly and / or partially closing the valve can prevent pressure spikes resulting from rapid closing of the valve to prevent damage to sensitive components in the system. FIGS. 10A-10C show another embodiment in which a damper or pressure control mechanism is implemented in a thrombectomy device to dampen hydraulic shock or pressure spikes within the device when an aspiration valve is rapidly closed. In FIG. 10 A, a schematic diagram of a thrombectomy device is shown which includes a valve 1002, a damper or pressure control mechanism 1004 disposed distally of the valve, and a thrombectomy catheter 1006. When the valve opens and vacuum is applied from the pressure source to the catheter, there is no compliance or damping function provided by the damper or pressure control mechanism, but when the valve closes, any positive pressure generated as a result of the valve closing is dampened because there is compliance provided in the system by the damper or pressure control mechanism.

[0117] FIG. 10B shows one example of a damper or pressure control mechanism, which in this example can be a spring loaded syringe. The syringe can include a chamber or reservoir 1008 having some amount of available volume, a spring 1010, and a stop 1012. When the valve opens and vacuum is applied from the pressure source to the catheter, there is no compliance or damping function provided by the spring, but when the valve closes, any positive pressure generated as a result of the valve closing is dampened within the reservoir 1008 as the spring allows the volume to expand until it reaches stop 1012. The syringe provides compliance in the system when the valve closes.

[0118] FIGS. 10C-10D shows another example of a damper or pressure control mechanism. The damper can comprise a flexible or elastic section of tubing 1014 disposed over a rigid tube 1016. The portion of the rigid tubing covered by the flexible or expandable tubing can include windows or openings 1018. The elastic tubing can include sealed ends 1020 against the rigid tube. A portion of the rigid tube can include perforations or openings 1018. When the valve opens and vacuum is applied from the pressure source to the catheter, there is no compliance or damping function provided by the tubing set, but when the valve closes, any positive pressure generated as a result of the valve closing is dampened by- 21 -SG Docket No.: 10844-737.672passing through the openings 1018 into the elastic section of tubing 1014. The damper provides compliance in the system when the valve closes.

[0119] The dampers of FIGS. 10B-10D provide a damper control function that, when the pressure is below zero, provides a change in volume over change in pressure of zero, but when the pressure is greater than zero, provides a change in volume over change in pressure of greater than zero (e.g., the damper provides compliance in the system only when the pressure increases in the system.

[0120] While the embodiments herein have been described as being intended to remove thrombi from a patient’s vasculature, other applications of this technology are provided. For example, the devices described herein can be used for breaking up and removing hardened stool from the digestive tract of a patient, such as from the intestines or colon of a patient. In one embodiment, the device can be inserted into a colon or intestine of the patient (such as through the anus) and advanced to the site of hardened stool. Next, the aspiration system can be activated to engage the hardened stool with an engagement member (e.g., funnel) of the device. Finally, the jets or irrigation can be activated to break off pieces of the hardened stool and aspirate them into the system. Any of the techniques described above with respect to controlling the system or removing clots can be applied to the removal of hardened stool.

[0121] As one of skill in the art will appreciate from the disclosure herein, various components of the thrombus removal systems described above can be omitted without deviating from the scope of the present technology. As discussed previously, for example, the present technology can be used and / or modified to remove other types of emboli that may occlude a blood vessel, such as fat, tissue, or a foreign substance. Further, although some embodiments herein are described in the context of thrombus removal from a pulmonary artery, the disclosed technology may be applied to removal of thrombi and / or emboli from other portions of the vasculature (e.g., in neurovascular, coronary, or peripheral applications). Likewise, additional components not explicitly described above may be added to the thrombus removal systems without deviating from the scope of the present technology. Accordingly, the systems described herein are not limited to those configurations expressly identified, but rather encompasses variations and alterations of the described systems. Conclusion

[0122] The above detailed description of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise forms disclosed above. Although specific embodiments of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology as those skilled in the relevant art will recognize. For example, although steps are - 22 -SG Docket No.: 10844-737.672presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments.

[0123] From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the technology. Where the context permits, singular or plural terms may also include the plural or singular term, respectively.

[0124] Unless the context clearly requires otherwise, throughout the description and the examples, the words "comprise," "comprising," and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to." As used herein, the terms "connected," "coupled," or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling of connection between the elements can be physical, logical, or a combination thereof. Additionally, the words "herein," "above," "below," and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. As used herein, the phrase "and / or" as in "A and / or B" refers to A alone, B alone, and A and B. Additionally, the term "comprising" is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and / or additional types of other features are not precluded. It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with some embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.- 23 -SG Docket No.: 10844-737.672

Claims

CLAIMS:What is claimed is:

1. A method for detecting clot engagement with a thrombus removal device, the method comprising: introducing a distal portion of an elongate catheter to a thrombus location in a blood vessel; opening a valve in an aspiration lumen of the elongate catheter to a first open position; operating an aspiration source of the elongate catheter to provide aspiration to the aspiration lumen with the valve in the first open position; partially closing the valve from the first open position to a second open position; measuring a pressure distal to the valve while the valve is in the second open position; comparing the measured pressure to a known clot engagement pressure; and determining that a clot is engaged with the distal end if the measured pressure is less than the known clot engagement pressure.

2. The method of claim 1, wherein the first open position comprises a fully opened valved position.

3. The method of claim 1, wherein the valve remains in the first open position for a first pre-determined time period.

4. The method of claim 3, wherein the valve remains in the second open position for a second pre-determined time period.

5. The method of claim 4, wherein the second pre-determined time period is shorter than the first pre-determined time period.

6. The method of claim 1, further comprising receiving a user input prior to opening the valve to the first open position.

7. The method of claim 6, wherein the user input comprises actuation of a button on a console or a handle of the elongate catheter.- 24 -SG Docket No.: 10844-737.6728. The method of claim 1, wherein the known clot engagement pressure is a pressure expected to be sensed within the elongate catheter when the elongate catheter is engaged with clot.

9. A method for determining when a clot has been removed from a patient with a thrombus removal device, the method comprising: determining that a clot is engaged with a distal end of an elongate catheter; while the clot is engaged with the distal end, opening a valve in an aspiration lumen of the elongate catheter to a first open position; operating an aspiration source of the elongate catheter to provide aspiration to the aspiration lumen with the valve in the first open position; delivering two or more intersecting fluid streams from a distal end of the elongate catheter towards the clot engaged with the distal end to at least partially cut or break up the clot; partially closing the valve from the first open position to a second open position; measuring a pressure distal to the valve while the valve is in the second open position; comparing the measured pressure to a known clot clearance pressure; and determining that the clot has been cleared from the distal end if the measured pressure is more than the known clot clearance pressure.

10. The method of claim 9, wherein the first open position comprises a fully opened valved position.

11. The method of claim 9, wherein the valve remains in the first open position for a first pre-determined time period.

12. The method of claim 11, wherein the valve remains in the second open position for a second pre-determined time period.

13. The method of claim 12, wherein the second pre-determined time period is shorter than the first pre-determined time period.

14. The method of claim 13, further comprising receiving a user input prior to opening the valve to the first open position.- 25 -SG Docket No.: 10844-737.67215. The method of claim 14, wherein the user input comprises actuation of a button on a console or a handle of the elongate catheter.

16. The method of claim 9, wherein the known clot clearance pressure is a pressure expected to be sensed within the elongate catheter when the elongate catheter is no longer engaged with clot.

17. The method of claim 9, further comprising, after determining that the clot has been cleared, closing the valve to a closed position.

18. The method of claim 17, wherein closing the valve comprises partially closing the valve to a third open position, followed by fully closing the valve.

19. The method of claim 18, wherein further comprising partially closing the valve to the third open position at a first closing velocity, followed by fully closing the valve at a second closing velocity.

20. The method of claim 19, wherein the first closing velocity is higher than the second closing velocity.

21. The method of claim 18, wherein partially closing the valve to the third open position is configured to prevent a pressure spike within the aspiration lumen that can damage one or more components of the thrombus removal device.

22. The method of claim 21, wherein the one or more components comprise a pressure transducer.

23. A thrombus removal device, comprising: an elongate catheter having a distal end configured to be advanced to a thrombus location in a blood vessel, the elongate catheter comprising an aspiration lumen that extends to the distal end; a vacuum source operatively coupled to the aspiration lumen; a valve disposed in the aspiration lumen; a pressure sensor disposed in the aspiration lumen; and- 26 -SG Docket No.: 10844-737.672one or more processors operatively coupled to the valve and / or the vacuum source, the one or more processors being configured to: open the valve to a first open position; control the vacuum source to provide aspiration to the aspiration lumen with the valve in the first open position; partially close the valve from the first open position to a second open position; evaluate a pressure reading from the pressure sensor while the valve is in the second open position; compare the pressure reading to a known clot engagement pressure; and determine that a clot is engaged with the distal end if the measured pressure is less than the known clot engagement pressure.

24. The device of claim 23, wherein the one or more processors are further configured to indicate to a user that the clot is engaged with the distal end.

25. The device of claim 24, further comprising a display configured to indicate to the user that the clot is engaged with the distal end.

26. The device of claim 23, wherein the first open position comprises a fully opened valved position.

27. The device of claim 23, wherein the one or more processors are configured to control the valve to remain in the first open position for a first pre-determined time period.

28. The device of claim 27, wherein the one or more processors are configured to control the valve to remain in the second open position for a second pre-determined time period.

29. The device of claim 28, wherein the second pre-determined time period is shorter than the first pre-determined time period.

30. The device of claim 23, further comprising a user input device configured to control opening of the valve.- 27 -SG Docket No.: 10844-737.67231. The device of claim 30, wherein the user input device comprises actuation of a button on a console or a handle of the elongate catheter.

32. The device of claim 23, wherein the known clot engagement pressure is a pressure expected to be sensed within the elongate catheter when the elongate catheter is engaged with clot.

33. A thrombus removal device, comprising: an elongate catheter having a distal end configured to be advanced to a thrombus location in a blood vessel, the elongate catheter comprising an aspiration lumen that extends to the distal end; a vacuum source operatively coupled to the aspiration lumen; at least two fluid ports disposed near the distal end; a fluid source configured to provide a flow of fluid to the at least two fluid ports to produce intersecting fluid streams or jets within the distal end; a valve disposed in the aspiration lumen; a pressure sensor disposed in the aspiration lumen; and one or more processors operatively coupled to the valve, the fluid source, and / or the vacuum source, the one or more processors being configured to: open the valve to a first open position; control the vacuum source to provide aspiration to the aspiration lumen with the valve in the first open position; control the fluid source to deliver fluid to the at least two fluid ports to produce two or more intersecting fluid streams from towards a clot engaged with the distal end to at least partially cut or break up the clot; partially close the valve from the first open position to a second open position; evaluate a pressure reading from the pressure sensor while the valve is in the second open position; compare the pressure reading to a known clot clearance pressure; and determine that a clot is cleared from the distal end if the measured pressure is more than the known clot clearance pressure.

34. The device of claim 33, wherein the one or more processors are further configured to indicate to a user that the clot is engaged with the distal end.- 28 -SG Docket No.: 10844-737.67235. The device of claim 34, further comprising a display configured to indicate to the user that the clot is engaged with the distal end.

36. The device of claim 33, wherein the first open position comprises a fully opened valved position.

37. The device of claim 33, wherein the one or more processors are configured to control the valve to remain in the first open position for a first pre-determined time period.

38. The device of claim 37, wherein the one or more processors are configured to control the valve to remain in the second open position for a second pre-determined time period.

39. The device of claim 38, wherein the second pre-determined time period is shorter than the first pre-determined time period.

40. The device of claim 33, further comprising a user input device configured to control opening of the valve.

41. The device of claim 40, wherein the user input device comprises actuation of a button on a console or a handle of the elongate catheter.

42. The device of claim 33, wherein the known clot engagement pressure is a pressure expected to be sensed within the elongate catheter when the elongate catheter is engaged with clot.- 29 -SG Docket No.: 10844-737.672

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