Thrombectomy system, algorithm, and method

Abstract

The present technology relates to systems and methods for removing thrombi from a patient's blood vessels. In some embodiments, the present technology relates to a system that includes an elongate catheter having a distal portion configured to be positioned within a patient's blood vessel, a proximal portion configured to be located external to the patient, and a lumen extending between the distal portion and the proximal portion. The system can also include a fluid delivery mechanism coupled to the fluid lumen and configured to apply fluid to at least partially fragment the thrombus, and a suction mechanism fluidly coupled to the suction lumen and configured to suction the fragmented thrombus.

Description

Technical Field

[0001] Claims of Priority

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 368,444, filed Jul. 14, 2022, and U.S. Provisional Application No. 63 / 373,386, filed Aug. 24, 2022, which are hereby incorporated by reference in their entirety for all purposes.

[0002] Related Applications

[0002] This application is related to International Application No. PCT / US2021 / 020915 and International Application No. PCT / US2022 / 033024, the disclosures of which are hereby incorporated by reference.

[0003] Incorporation by Reference

[0003] All publications and patent applications mentioned in this specification are hereby 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.

[0004]

[0004] This technology generally relates to medical devices, and in particular, systems and methods for removing blood clots, e.g., from the venous system, using mechanical thrombectomy.

Background Art

[0005]

[0005] Thrombotic material can lead to the occlusion of blood flow in the vascular system of mammals. Such occlusions can occur in various regions of the body, such as the pulmonary system, peripheral vascular system, deep vascular system, or within the brain. Pulmonary embolism typically occurs when a blood clot that has formed in another part of the body (e.g., the veins of the pelvis or leg) becomes dislodged and travels to the lungs. Anticoagulant therapy is the current standard treatment for treating pulmonary embolism, but it may not be effective in some patients.

[0006]

[0006] Conventional mechanical thrombectomy devices for treating venous thromboembolism (VTE) utilize suction and / or rotary pulverizers. Such conventional devices may not be able to proceed through tortuous vascular anatomies and / or effectively remove thrombus material. Devices designed to treat deep vein thrombosis (DVT) need to proceed through tortuous paths and small blood vessels and thus do not permit large suction lumens and rotating or moving physical mechanisms. Due to these and other limitations, most DVT patients are left untreated as long as the risk of limb ischemia is low. In more urgent cases, patients are treated by catheter thrombolysis or thrombolytic therapy to dissolve the blood clot over many hours or days. In clinical use, conventional DVT devices temporarily reduce the blood clot burden but do not effectively treat the patient, so patients often relapse later due to recurrence of DVT. Devices for treating pulmonary embolism (PE) typically have a relatively larger profile (in other words, profile or contour), which provides more suction or a larger suction catheter bore to better remove organized, hard blood clots, but cannot proceed beyond the trunk of the body.

[0007]

[0007] More recently, the treatment of VTE has trended towards suction catheters. However, these devices require a trade-off between effectiveness (more suction) and blood loss. More suction removes more blood, which exposes the patient to risk. As a result, clinicians stop the procedure after a set amount of time or blood removal, even if the patient has more blood clots that would otherwise be selected for removal.

[0008]

[0008] Systems developed to address the trade-off between suction and blood loss have had little success. One approach requires conserving blood by recirculating purified blood back to the patient. This limits blood loss but adds numerous clinical and technical complexities. Another approach currently in use requires automated, physician-guided control of the suction mechanism to reduce its use. Such systems are capable of detecting when a blood clot has engaged the catheter tip and either cycling down suction or stopping it completely, allowing the vacuum in the catheter to draw in material. In use, these systems have demonstrated several problems. First, it takes a long time to detect blockage by occluding material (e.g., engagement with a blood clot). Such systems detect a "blocked state" based on pressure in the catheter, for example, when full vacuum is achieved in the catheter or the differential pressure between the vacuum and ambient pressure approaches and reaches a maximum. Due to compliance (i.e., flexibility), fluid turbulence, and other factors in the catheter system, the catheter system can take a long time for the "blocked state" parameters to settle. Thus, the system may need to wait several more seconds to confirm the state. In fact, such a system can take about 20 seconds to detect occluding material trapped in the catheter, which is not in line with the goal of limiting suction time during use. Second, such systems often fail to detect a blocked state. The pressure in the catheter is accompanied by significant mechanisms (noise and / or ringing sounds) that make it difficult to identify a blocked state based on absolute pressure. Third, even if the system successfully detects that an occluding material has been trapped, conventional systems cannot remove a hard blood clot through the catheter without high vacuum pressure or cannot remove the blood clot at all (in which case, the operator may attempt to remove the blood clot by using the vacuum to hold the blood clot at the distal end of the catheter and slowly removing the catheter with the clot attached, which is often referred to as "lollipopping" the blood clot).

Summary of the Invention

Problems to be Solved by the Invention

[0009]

[0009] There remains a need for devices and methods to solve these and other problems associated with existing thromboectomy systems. There remains a need for a rapid, easily used, and effective device for removing various clot morphologies with limited blood loss.

Means for Solving the Problems

[0010]

[0010] An elongated catheter having at least one suction lumen configured to remove thrombus material, a suction mechanism fluidly coupled to the suction lumen and configured to reduce the pressure in the suction lumen, a pressure sensor configured to monitor the pressure within the suction lumen, a valve disposed between the pressure sensor and the suction mechanism, and an electronic control device operably coupled to the pressure sensor and the valve, the electronic control device configured to open and close the valve and to monitor the pressure within the suction lumen to determine whether a blood clot is engaged with the elongated catheter or whether the blood clot has been at least partially removed, is provided.

[0011]

[0011] In one aspect, the electronic control device is configured to close the valve every 3 to 5 seconds of treatment.

[0012] In one aspect, the cycle time for opening and closing the valve is about 300 ms or less.

[0012]

[0013] In another aspect, the electronic control device is configured to determine that a blood clot is engaged with the elongated catheter when the monitored pressure does not substantially increase after the valve is closed.

[0013]

[0014] In some aspects, the electronic control device is configured to determine that a blood clot has been at least partially removed when the monitored pressure increases after the valve is closed.

[0015] In one aspect, the system is configured to remove 45 ml or less of blood from the patient before detecting that the blood clot has been at least partially removed.

[0014]

[0016] In some aspects, the valve has a valve state including an open state, a closed state, a state of opening, or a state of closing.

[0017] In some aspects, the electronic control device is configured to determine that a blood clot is engaged when the valve moves from a closed state to an open state and the pressure in the suction lumen does not exceed a blood clot engagement threshold.

[0015]

[0018] In one aspect, the electronic control device is configured to determine that a blood clot is engaged when the valve moves from a closed state to an open state and the gradient of the pressure in the suction lumen does not exceed a blood clot engagement threshold.

[0016]

[0019] In some aspects, the electronic control device is configured to determine the change in pressure in the suction lumen over time to determine whether a blood clot is engaged with an elongate catheter or whether the blood clot has been at least partially removed.

[0017]

[0020] In one aspect, the change in pressure in the suction lumen over time is an input to a correlation function for a predetermined blood clot detection profile.

[0021] In some aspects, the change in pressure in the suction lumen over time is filtered and normalized.

[0018]

[0022] In some aspects, the electronic control device is configured to provide the pressure in the suction lumen and the valve state to a trained machine learning model to determine whether a blood clot is engaged with an elongate catheter or whether the blood clot has been at least partially removed.

[0019]

[0023] An elongated catheter having at least one suction lumen configured to remove thrombus material, a suction mechanism fluidly coupled to the suction lumen and configured to reduce the pressure in the suction lumen, a valve coupled to the suction mechanism and having a valve state including an open state or a closed state, a first pressure sensor disposed distal to the valve and configured to monitor a first pressure in the suction lumen, a second pressure sensor disposed proximal to the valve and configured to monitor a second pressure in the suction lumen, and an electronic control device operably coupled to the pressure sensors and the valve, the electronic control device being configured to open and close the valve and monitor the first pressure and the second pressure in the suction lumen to determine whether a blood clot is engaged with the elongated catheter or whether the blood clot has been at least partially removed. A system for removing thrombus is provided.

[0020]

[0024] In one aspect, the electronic control device is configured to close the valve at most every 3 - 5 seconds of treatment.

[0025] In another aspect, the cycle time for opening and closing the valve is about 300 ms or less.

[0021]

[0026] In some aspects, the electronic control device is configured to determine that a blood clot is engaged with the elongated catheter when the pressure monitored after closing the valve does not substantially increase.

[0022]

[0027] In one aspect, the electronic control device is configured to determine that a blood clot has been at least partially removed from the elongated catheter when the pressure monitored after closing the valve has increased.

[0023]

[0028] In some aspects, the system is configured to remove 45 ml or less of blood from the patient from when the blood clot is at least partially removed until it is detected that the blood clot has been at least partially removed.

[0024]

[0029] In one aspect, the electronic control device is configured to determine that a blood clot is engaged when the valve moves from a closed state to an open state and the first and second pressures in the suction lumen do not exceed a blood clot engagement threshold value.

[0025]

[0030] In another aspect, the electronic control device is configured to determine that a blood clot is engaged when the valve moves from a closed state to an open state and the gradient of the first and second pressures in the suction lumen does not exceed a blood clot engagement threshold value.

[0026]

[0031] In some aspects, the electronic control device is configured to determine a change in pressure within the suction lumen over time to determine whether a blood clot is engaged with an elongate catheter or whether the blood clot has been at least partially removed.

[0027]

[0032] In one aspect, the change in pressure within the suction lumen over time is an input to a correlation function against a predetermined blood clot detection profile.

[0033] In another aspect, the change in pressure within the suction lumen over time is filtered and normalized.

[0028]

[0034] In some aspects, the electronic control device is configured to provide the first and second pressures and the valve state within the suction lumen to a trained machine learning model to determine whether a blood clot is engaged with an elongate catheter or whether the blood clot has been at least partially removed.

[0029]

[0035] A non - transitory computer - readable medium storing instructions for determining the blood clot engagement state of a thrombectomy device, the instructions being executable by a processor to cause the computing device to receive the valve state of the thrombectomy device, which indicates an open state when the distal end of the thrombectomy device is in fluid communication with a suction source or a closed state when the distal end is not in fluid communication with the suction source, receive one or more pressure measurements within the suction lumen, and evaluate the one or more pressure measurements and the valve state to determine the blood clot engagement state with the distal end of the thrombectomy device.

[0030]

[0036] In some embodiments, the instructions cause the computing device to close the valve at least every 3 - 5 seconds of treatment.

[0037] In one embodiment, the cycle time for opening and closing the valve is about 300 ms or less.

[0031]

[0038] In some embodiments, the blood clot engagement state is determined to be engaged with the distal end of the thrombectomy device when the pressure measurement does not increase after the valve state changes from the open state to the closed state.

[0032]

[0039] In another embodiment, the blood clot engagement state is determined to be at least partially removed from the distal end of the thrombectomy device when the pressure measurement increases after the valve state changes from the open state to the closed state.

[0033]

[0040] In some embodiments, the computing device is configured to detect the blood clot engagement state before the thrombectomy device removes more than 45 ml of blood from the patient.

[0034]

[0041] In another embodiment, the computing device is configured to determine the blood clot engagement state as engaged when the valve state transitions from the closed state to the open state and one or more pressures within the suction lumen do not exceed a blood clot engagement threshold.

[0035]

[0042] In one aspect, the computing device is configured to determine an engaged state of a blood clot when the valve state transitions from a closed state to an open state and the gradient of the first and second pressure measurements from within the suction lumen does not exceed a blood clot engagement threshold.

[0036]

[0043] In another aspect, the computing device is configured to determine a change in the pressure measurement within the suction lumen over time to determine when the blood clot is engaged with or at least partially removed from the elongate catheter.

[0037]

[0044] In one aspect, the change in the pressure measurement within the suction lumen over time is an input to a correlation function against a predetermined blood clot detection profile.

[0045] In another aspect, the change in the pressure measurement within the suction lumen over time is filtered and normalized.

[0038]

[0046] In another aspect, the computing device is configured to provide one or more pressure measurements and the valve state within the suction lumen as inputs to a trained machine learning model to determine the blood clot engagement state with the distal end of the thrombectomy device.

[0039]

[0047] A non - transitory computer - device - readable medium storing instructions for determining a blood clot engagement state of a thrombectomy device, the instructions being executable by a processor to cause the computing device to receive a valve state of the thrombectomy device, which indicates valve opening when the distal end of the thrombectomy device is in fluid communication with a suction source or valve closing when the distal end of the thrombectomy device is not in fluid communication with the suction source, receive one or more pressure measurements within the suction lumen, provide the valve state and the one or more pressures as inputs to a trained machine - learning model, and cause the machine - learning model to output a blood clot engagement state.

[0040]

[0048] In one aspect, the output includes a probability of the blood clot engagement state.

[0049] In another aspect, the output includes a binary blood clot engagement state.

[0050] In one aspect, the output includes an individual blood clot engagement state.

[0041]

[0051] In another aspect, the individual blood clot engagement state indicates when the blood clot is not engaged, when the blood clot is engaged, or when the blood clot has been removed.

[0052] In some aspects, the output is indicated using auditory, visual, and / or tactile feedback.

[0042]

[0053] In one aspect, the computing device is configured to disable the suction source when the blood clot engagement state indicates that the blood clot has been removed.

[0054] In another aspect, the valve state further indicates valve opening when the distal end of the thrombectomy device transitions from a state of not being in fluid communication with the suction source to a state of being in fluid communication with the suction source.

[0043]

[0055] In another aspect, the valve state further indicates valve closure when the distal end of the thrombectomy device is transitioning from a state of being in fluid communication with a suction source to a state of not being in fluid communication with the suction source.

[0044]

[0056] A method for removing a thrombus is provided, comprising introducing a distal portion of an elongate catheter into a patient's body, the catheter including a suction lumen in fluid communication with a distal end for removing a thrombus; positioning the distal end of the catheter in the region of the target thrombus; reducing the pressure in the suction lumen to generate a vacuum at the distal end of the catheter; closing or opening a valve in the suction lumen; monitoring at least the pressure in the suction lumen; and identifying engagement of the target thrombus with the distal end based on the monitored pressure and the valve state of the valve.

[0045]

[0057] A method for removing a thrombus is provided, comprising introducing a distal portion of an elongate catheter into a patient's body, the catheter including a suction lumen in fluid communication with a distal end for removing a thrombus; positioning the distal end of the catheter in the region of the target thrombus; applying a vacuum to the suction lumen; changing the valve state of a valve in fluid communication with the suction lumen to open or close the suction lumen; monitoring one or more pressures in the suction lumen; providing the valve state and the one or more monitored pressures to a trained machine learning model; and outputting a clot engagement state from the trained machine learning model.

[0046]

[0058] Receiving the valve state of the thrombectomy device, which indicates valve opening when the distal end of the thrombectomy device is in fluid communication with a suction source and indicates valve closure when the distal end is not in fluid communication with the suction source; receiving one or more pressure measurements within the suction lumen; providing the valve state and the one or more pressures as inputs to a machine learning model trained thereon; and outputting a clot engagement state using the machine learning model. A method performed by a computer for a thrombectomy system is provided.

[0047]

[0059] In one aspect, the method further includes presenting the output to a user.

[0060] In one aspect, the method further includes displaying the output on a display of the thrombectomy system.

[0048]

[0061] In one aspect, the method further includes changing an operating mode of the thrombectomy device in response to the output.

[0062] In one aspect, changing the operating mode further includes ending suction.

[0049]

[0063] In another aspect, changing the operating mode further includes initiating delivery of fluid flow at the distal end.

[0064] In one aspect, changing the operating mode further includes ending delivery of fluid flow at the distal end.

[0050]

[0065] A more complete understanding of the features and advantages of the methods and apparatuses described herein can be obtained by reference to the following detailed description and the accompanying drawings that illustrate exemplary embodiments.

Brief Description of the Drawings

[0051]

Figure 1A

[0066] FIG. 1A is a diagram illustrating an example of a thrombectomy system.

Figure 1B

Figure 2A

[0067] Figure 2A is a diagram showing one embodiment of a blood clot detection waveform.

Figure 2B

Figure 3A

[0068] It is a diagram showing another embodiment of a blood clot detection waveform.

Figure 3B

Figure 4

[0069] It is a diagram showing another embodiment of a blood clot detection waveform.

Figure 5

[0070] It is a diagram showing yet another embodiment of a blood clot detection waveform.

Figure 6

[0071] It is a diagram showing yet another embodiment of a blood clot detection waveform.

Figure 7A

[0072] Figure 7A is a diagram of another thrombectomy system.

Figure 7B

Figure 8A

[0073] It is a diagram showing waveforms and analyses used by a blood clot detection algorithm to determine the system and / or blood clot detection state of a thrombectomy system.

Figure 8B

Figure 8C

Figure 8D

Figure 8E

Figure 8F

Figure 8G

DETAILED DESCRIPTION OF THE INVENTION

[0052]

[0074] Various aspects of the present application relate to devices such as those disclosed in International Application No. PCT / US2021 / 020915 ('915 application), filed on March 4, 2021, the disclosure of which is incorporated herein by reference for all purposes. The '915 application describes general mechanisms for capturing and removing blood clots. For example, a catheter may include a capture element such as an auger for breaking up clot material and drawing it into a suction lumen. In another example, multiple fluid flows are directed at the clot to break up the material.

[0053]

[0075] The present technology generally relates to thrombectomy systems and related methods. A system configured according to an embodiment of the present technology may include, for example, a distal portion configured to be positioned within a patient's blood vessel, a proximal portion configured to be located outside the patient, a fluid delivery mechanism configured to fragment a blood clot with pressurized fluid, a suction mechanism configured to aspirate fragments of the blood clot, and one or more lumens extending at least partially from the proximal portion to the distal portion, and may include an elongate catheter.

[0054]

[0076] The terms used in the following description are intended to be construed in the broadest reasonable form, even if used in connection with a detailed description of certain embodiments of the present technology. Some terms may even be emphasized below. However, any terms intended to be construed in any restricted form are clearly and specifically defined in sections of this detailed description and the like.

[0055]

[0077] In addition, the present technology can include other embodiments that are within the scope of the examples but not described in detail with respect to the drawings.

[0078] References throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with that 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 form in one or more embodiments.

[0056]

[0079] Throughout this specification, references to relative terms such as, for example, "generally", "substantially", and "about" are used herein to mean plus or minus 10% of the recited value.

[0057]

[0080] Although some embodiments herein are described from the perspective of thrombus removal, the present technology can be used and / or modified to remove other types of emboli that can occlude blood vessels, such as fat, tissue, or foreign bodies. Additionally, although some embodiments herein are described in relation to thrombus removal from the pulmonary artery (e.g., pulmonary embolectomy), the present technology can be applied to the removal of thrombi and / or emboli from other parts of the vascular system (e.g., at neurovascular locations, coronary artery locations, or peripheral locations). Further, although some embodiments are described from the perspective of maceration of thrombi by fluid, the present technology can be adapted to be used with other techniques for breaking down thrombi into smaller fragments or particles (e.g., aspiration-only systems, ultrasound, mechanical, enzymatic).

[0058]

[0081] The headings provided herein are for convenience only and do not interpret the scope or meaning of the claimed technology.

[0082] The present technology generally relates to a system for removing undesirable materials from a patient. Although described from the perspective of thrombus removal, it will be appreciated from the description herein that the systems and methods can be equally applicable to other uses, such as the removal of benign tumors, kidney stones, etc.

[0059]

[0083] Suction systems typically remove blood while suctioning. Some systems have proposed blood conservation techniques, such as filters for "cleaning" the blood for reinsertion, but to date those techniques have found limited practicality and are accompanied by additional complexity.

[0060]

[0084] Referring to FIGS. 1A and 1B, various aspects of the present disclosure relate to systems and methods for rapidly detecting the operating state of a thrombectomy system 100 and / or an improved control system. An exemplary venous thrombectomy system 100 includes a distal portion positionable within a patient's blood vessel (e.g., artery or vein), a proximal portion positionable outside the patient's body, a suction mechanism including a suction lumen 104 in an elongate catheter coupled to a suction source 106 configured to aspirate fragments of a thrombus, and a selective fluid system configured to generate a high-speed jet 109 to disrupt a blood clot so that it can be aspirated. The thrombectomy system can optionally include an expandable funnel (in other words, a funnel-shaped portion) 108 disposed at the distal end of the elongate catheter. In some embodiments, the systems herein are configured to engage a thrombus in a patient's blood vessel, disrupt the thrombus into small fragments, and aspirate the fragments from the patient's body. As used herein, "thrombus" and "embolus" are used somewhat interchangeably in various respects. Although this description may refer to the removal of a "thrombus," it should be recognized that this is to be understood to include the removal of thrombus fragments and other emboli as provided herein.

[0061]

[0085] In various embodiments, the system includes a high - speed intersecting fluid flow 109 (e.g., a saline jet) in or near the funnel to disrupt the thrombus, whereby the thrombus can be passed through the aspiration lumen and removed through the low - profile catheter lumen. The high - speed jet flow can be configured to macerate, cut, fragment, pulverize, and / or feed into the aspiration lumen and remove from the proximal portion of the catheter. The jet flow can also serve to enable debris of the thrombus to be removed from the catheter even when the distal end / funnel is blocked or sealed by the thrombus, enabling treatment of large, hard blood clots that would otherwise pose a risk of clogging the catheter, such that the catheter would have to be removed from the patient, cleaned, and re - introduced to the target site.

[0062]

[0086] The aspiration lumen 104 may extend at least partially from the distal portion to the proximal portion of the catheter and may be in fluid communication with an aspiration source 106 (e.g., a vacuum source). In various embodiments, the aspiration source is disposed at the proximal end of the system and creates a pressure that extends to the distal end of the aspiration lumen 104. Due to the pressure or vacuum within the lumen, the clot material is drawn into the catheter and through the aspiration lumen to the proximal end outside the patient's body.

[0063]

[0087] In some embodiments, the pressure sensor 110 can be disposed within the suction lumen 104 or in fluid communication with the suction lumen 104. The pressure sensor can be any conventional pressure sensor known in the art. In one particular embodiment, the suction lumen itself can be configured as a fluid column, and the pressure sensor can be disposed proximal to the suction lumen (e.g., at or near the suction source). In the embodiments shown in FIGS. 1A and 1B, the pressure sensor is shown proximal to the pinch valve 112. However, it should be understood that the pressure sensor can be disposed anywhere within the system in fluid communication with the suction lumen, including distal to the pinch valve, the catheter 102 or the funnel 108, the handle of the device, or the suction source. It should also be understood that multiple pressure sensors can be used in the system at any of the above-described locations or in fluid communication with the suction lumen. This configuration allows the pressure within the suction lumen to be accurately monitored by the pressure sensor 110.

[0064]

[0088] An exemplary system includes one or more pinch valves 112 in communication with a suction pump. As will be appreciated by those skilled in the art from the description herein, when the pinch valve is closed (as shown in FIG. 1B), the pressure drops in the volume between the suction pump and the valve. Thus, the pressure in the suction lumen, as measured by the pressure sensor 110, can be rapidly affected by opening the pinch valve (as shown in FIG. 1A). A typical system relies on the suction pump to slowly form the pressure in the system. In an exemplary embodiment, the pressure is already formed and is precisely controlled by one or more pinch valves 112.

[0065]

[0089] The systems described herein can include one or more processors or electronic control devices configured to control the operation of the thrombus system. The one or more processors or electronic control devices can be further configured to execute instructions, algorithms, or methods implemented by a computer, such as an algorithm for detecting or outputting a system state or a thrombus detection / thrombus engagement state of the system. In some embodiments, the system includes one or more processors and a memory coupled to the one or more processors, the memory being configured to store computer program instructions, algorithms, software, firmware, or machine learning models / AI algorithms that implement methods implemented by a computer, such as for detecting a system or thrombus engagement state of the thrombectomy system, when executed by the one or more processors.

[0066]

[0090] In an exemplary embodiment, pressure is cycled within the suction lumen by opening and closing one or more pinch valves. FIGS. 2A and 2B show the results for an exemplary system for removing a thrombus from a subject. FIG. 2A shows the pressure waveform when the thrombectomy system interacts with only blood, and FIG. 2B shows the pressure waveform when the thrombectomy system interacts with the thrombus and blood, including before engagement, when the thrombus is engaged, and after the thrombus has been removed by the thrombectomy system. As shown in FIG. 2B, the pressure within the suction lumen does not return to the original pre-engagement level (not a complete recovery) and takes longer for each cycle when the catheter engages the thrombus to create a vacuum.

[0067]

[0091] Figures 3A and 3B show the pressure waveforms of the state of the suction lumen with and without a blood clot during one cycle when pulling a vacuum. In Figure 3A, when there is no blood clot, the suction lumen is open to the blood flow and drops to a pressure level P1. When a blood clot is engaged in the thrombectomy system (e.g., in the funnel or the suction lumen), the suction lumen is partially or completely closed, and the pressure drops to a pressure level P2 lower than the pressure level P1, as shown. As time passes and the blood clot is further engaged, the pressure continues to drop. However, in both cases, it takes time (e.g., up to 20 seconds or more) to reach the maximum pressure and detect blood clot engagement. This explains why conventional systems that detect blood clots based on pressure thresholds take so much time to detect a blood clot. The delay in blood clot detection can be caused by compliance in the thrombectomy system itself, such as compliance in the tube connecting the suction lumen to the suction source, or compliance in the suction lumen, the funnel, or other aspects of the system.

[0068]

[0092] Figure 3B shows pressure waveforms for multiple cases when the blood clot is engaged with the funnel and when the blood clot is not engaged with the funnel. As shown in Figure 3B, when the blood clot is not engaged with the funnel, the pressure waveform rapidly recovers to a higher pressure when the pinch valve of the thrombectomy system is open. When the blood clot is engaged with the funnel, the pressure waveform remains relatively static or unchanged and does not rapidly recover to the levels seen when the blood clot is not engaged. For example, in one embodiment, the blood clot detection algorithm evaluates the aspiration lumen pressure when the valve is open and determines that the blood clot is engaged when the aspiration lumen pressure does not exceed a blood clot engagement threshold (e.g., the pressure level before engagement). As can be seen in the chart, the slope of the pressure waveform when no blood clot is present is significantly greater than the slope of the pressure waveform when the blood clot is engaged. This is because when the pinch valve is open and the blood clot is engaged, there is relatively little pressure change. In one embodiment of the blood clot detection algorithm, the blood clot detection algorithm evaluates the slope of the aspiration lumen pressure when the valve is open and determines that the blood clot is engaged when the aspiration lumen pressure does not exceed a blood clot engagement slope threshold. As described herein, the engaged blood clot acts to close or block the aspiration lumen, which prevents rapid pressure recovery.

[0069]

[0093] Referring back to FIGS. 2A and 2B, a significant amount of ringing is observed, such that the downslope (i.e., the gradient) in the aspiration lumen pressure measurement is not readily recognizable. In contrast, the upslope has a more distinct pattern. Recovery (up to 103 kPa (15 psi) in an exemplary test) is more consistent and represents a clear signal at the peak of the waveform. In various embodiments, the system identifies a blood clot (i.e., enters a "blood clot engagement" state) based on these signature features. In various embodiments, the system identifies a blood clot based on the form in which the peak decreases in each cycle. In various embodiments, the system produces a maximum vacuum even when not at maximum duty cycle (e.g., by forming pressure while the blood clot is occluding the aspiration lumen).

[0070]

[0094] An exemplary system can include a fluid jet and an aspiration lumen. During operation, prior to a blood clot being engaged, the system aspirates at least a portion of the jet fluid. Bench tests demonstrate that the system can detect the capture of a blood clot regardless of whether the fluid jet is on or off. However, in some embodiments, even when the jet is off, fluid can still be drawn into the aspiration lumen through the jet lumen.

[0071]

[0095] Compliance in the system makes it more difficult to identify blood clot engagement. However, bench tests have demonstrated that the system can detect a blood clot despite compliance in the system. In fact, unlike conventional systems, in various aspects, the system according to the present invention utilizes compliance in the system to detect a blood clot.

[0072]

[0096] Here, a method of using the system to search for and detect blood clot engagement will be described with reference to FIGS. 2-4. In use, the clinician has already identified the approximate region of the target blood clot using imaging. The clinician positions the funnel of the blood clot excision catheter over the region of the target blood clot before turning on the system. When in position, the system enters the blood clot search mode. In this mode, the vacuum (suction) line (e.g., suction lumen 104) is open but is clamped relatively quickly by a pinch valve (e.g., pinch valve 112). This reduces the blood loss associated with vacuuming and thrombus search and also provides a good pressure signature of when the system engages the blood clot. The problem with conventional systems and algorithms is that it is difficult to differentiate based on vacuuming by an open vacuum that simply sucks at the end of the device. This is because there is a very large resistance caused by the smaller diameter of the catheter and the hysteresis of the tubing.

[0073]

[0097] However, in this system, it has been found that when the vacuum line is clamped or closed and there is no blood clot, the columns of vacuum and fluid are relieved. Referring to FIG. 4, two pressure waveforms are shown. The solid line pressure waveform shows the pressure in the suction lumen when no blood clot is engaged with the system, and the dashed line pressure waveform shows the pressure in the suction lumen when a blood clot is engaged. When the pinch valve is cycled between the open and closed states, the pressure in the suction lumen rapidly recovers to atmospheric pressure when no blood clot is present. In contrast, when a blood clot is present, the pressure in the suction lumen does not return to atmospheric pressure (e.g., about 103 kPa (15 psi)). When the vacuum line is opened (e.g., by opening the pinch valve), the blood clot closes the lumen and the pressure is not relieved by the anatomical structure. Thus, the pressure in the suction lumen remains lower and as the vacuum line is opened and closed, the system generates an increasingly large suction pressure on the blood clot. Thereby, a pressure sensor (in fluid communication with the suction lumen) detects engagement in the closed position based on whether the suction pressure rapidly recovers to a threshold pressure (e.g., atmospheric pressure).

[0074]

[0098] The specific implementation of the "blood clot hunting" algorithm is also described. First, as described above, the system can obtain blood clots in the funnel by suction. As described above, the pressure in the suction lumen approaches vacuum when the blood clot is engaged in the funnel and suction is on. Next, the system can be configured to constrict or close the suction lumen by closing a pinch valve disposed between the suction source and the pressure sensor. The system can initiate jet generation and wait for the pressure waveform to recover rapidly while being monitored by the pressure sensor. If the pressure waveform remains down, this indicates to the user that a blood clot is still present in the funnel of the device. However, if the pressure waveform rises, this indicates to the user that the blood clot has been cleared (in other words, removed) or partially cleared. This "blood clot hunting" process can be repeated through the blood clot removal procedure. In some embodiments, this process can be repeated every 3 - 5 seconds. The thrombus removal device of the present disclosure is configured to remove approximately 15 ml of material / blood / fluid per second. Thus, by repeating this algorithm and process every 3 - 5 seconds, the system can detect blood clot removal at least every 3 - 5 seconds, during which only 45 ml to 75 ml of blood is aspirated in the event that the blood clot is removed. It should be understood that this process can be performed even more rapidly, potentially reducing the blood clot removal detection time. The overall blood clot hunting algorithm can be executed in 300 ms or less. Detecting blood clot removal this quickly advantageously limits the amount of blood removed from the patient after blood clot removal.

[0075]

[0099] Figure 4 shows each of two scenarios starting from the state where the lumen is open. The open scenario is similar to the solid line graph in Figure 4 or similar to the time stamps (single cycle) in Figures 2A and 2B. When the system is clamped without the presence of a blood clot, the vacuum pressure rapidly recovers completely and quickly to a threshold pressure such as atmospheric pressure plus blood pressure (e.g., about 103 kPa (15 psi)). An exemplary system can return to atmospheric pressure fairly quickly by pinch valve control. In an exemplary embodiment, the system closes slowly (e.g., 100 milliseconds), and the system quickly recovers and returns to the threshold pressure easily. In Figure 4, the system may not have enough time between cycles to fully return, but with more time, the system can fully and quickly recover and stabilize in each cycle. This depends on various factors such as the resistance and compliance of the suction system. The system is then clamped again, whereby the system can rapidly recover to atmospheric pressure again. In the absence of a blood clot, the system rapidly recovers and returns to 103 kPa (15 psi). In the presence of a blood clot, the system does not rapidly recover and vacuum pressure remains in the catheter. This is because the blood clot is obstructing the end face of the system. The suction lumen is no longer open as a result of the engaged blood clot. In the exemplary graph, the maximum pressure is 103 kPa (15 psi), and the cycle time of the pinch valve is about 30 milliseconds. It should be understood that the threshold / maximum pressure and / or the open / close cycle time of the pinch valve can be adjusted.

[0076]

[0100] Accordingly, an exemplary blood clot hunting algorithm does not rely solely on absolute vacuum pressure. Instead, the algorithm looks at the snap-back pressure, velocity, and / or waveform after the system has clamped the suction lumen. When the system is clamped (e.g., the suction lumen is closed), the system evaluates whether (a) the pressure relaxes and returns to atmospheric pressure or some other threshold pressure, or (b) the pressure remains mostly the same or gradually decreases. In the latter case, i.e., when the pressure gradually decreases, the system identifies an occlusion in the suction system that correlates with blood clot engagement. As shown in FIG. 4, a line engaged by a blood clot is less responsive and the system cannot pull a full 103 kPa (15 psi) vacuum again. Instead, the measured suction pressure gradually decreases, indicating that the blood clot is well engaged.

[0077]

[0101] A method for detecting blood clot engagement according to the present invention will now be described with reference to FIG. 4. This method includes creating a pressure behind (proximal to) a pinch valve and then generating a vacuum in a thrombectomy system by opening the pinch valve. The pinch valve is then closed. This process is repeated for successive cycles and the pressure in the suction lumen is monitored. The system monitors to see if the vacuum remains stable or returns more quickly to atmospheric pressure. Based on the rate and / or pressure of the pressure change (also known as snap-back) in the lumen by successive cycles, the system detects blood clot engagement.

[0078]

[0102] In various embodiments, if blood clot engagement is not detected within a predetermined period or within the number of duty cycle revolutions of the suction source, the system turns off the suction. The step of turning off the suction can help prevent or reduce the amount of blood removed from the subject by the thrombectomy system.

[0079]

[0103] The systems and methods described herein have been found to be able to accurately detect blood clot engagement in less than just a few seconds. Generally, the system can detect blood clot engagement through several duty cycles. In comparison, conventional systems and algorithms simply aspirate until the pressure in the aspiration lumen drops below a threshold value, which can take a significant amount of time and expose the patient to risk. In use, such conventional systems take over 20 seconds and the results are unpredictable.

[0080]

[0104] In various embodiments, the system uses the above techniques in relation to other parameters. In various embodiments, the method includes the use of a pressure threshold.

[0105] In various embodiments, the system adjusts the control of jetting and aspiration. In various embodiments, the system transitions to actuate the jet when the blood clot is well engaged. In this format, the aspiration time is limited and then the system can quickly remove the blood clot when it is found. In various embodiments, the system utilizes advanced techniques such as machine learning to identify parameters, pressure thresholds, etc. to improve system control.

[0081]

[0106] The system can be designed to operate at a vacuum level lower than the target pressure at the working end of the catheter. The above graph can be shifted up, and when the system generates a target blood clot engagement signature when closed at a lower vacuum pressure, the amount of vacuum required is reduced. Thus, the vacuum pump can be configured to operate at a lower speed / pressure, but the system can still distinguish the "blood clot engagement" signature pattern. When the system is clamped, the vacuum remains at the blood clot. Since the suction lumen is closed, the vacuum generated at the blood clot can drop to a lower level, e.g., 14 kPa (2 psi). During algorithm hunting, a higher level of vacuum can be formed, and when the blood clot is trapped, the pressure is reduced. The system can automatically reduce the pressure or generate a signal to instruct the clinician. The reduced vacuum pressure in the engagement mode reduces blood loss.

[0082]

[0107] FIG. 5 shows the pressure in the aspiration lumen over multiple cycles using the system and method described above. As shown, the vacuum pump is controlled to generate the same pressure profile, but instead of pulling a full vacuum, the system is configured to pull a reduced vacuum (e.g., a half or quarter duty cycle). The vacuum pump is then stopped and the pinch valve is opened. When the catheter is engaged with a blood clot, the lumen becomes blocked and a vacuum begins to form in the catheter even though the vacuum pump is not operating at a full duty cycle. Generally, the system is configured such that the vacuum pump generates the vacuum pressure in small amounts and periods instead of operating at a sudden high pressure. In other words, the system pulls the vacuum in small amounts over the course of one or several large cycles. Even though the system is not applying much absolute pressure, the pressure rises increasingly in the blood clot and the actual pressure in the lumen drops, so the system can still generate sufficient vacuum when the catheter is engaged with the blood clot. In this case, it can be seen that the overall step function shifts downward in pressure towards absolute vacuum and weakens when the catheter is engaged with the blood clot. The result is that the system removes even less blood because the pump operates at a lower vacuum, and further, the pump requirements are reduced because the pump does not need to generate a high vacuum pressure.

[0083]

[0108] The benefits of an exemplary valve system are to reduce the capacitance difficulties of the fluid canister from operation. The collection canister has an air volume, and the air volume has capacitance. Therefore, it usually takes time to reach absolute vacuum in the system. However, the exemplary pinch valve avoids this problem by allowing the vacuum pump and the canister to reach equilibrium, and then the pinch valve can be opened. An exemplary system with a valve allows even a smaller pump load to generate a higher vacuum with a higher vacuum hammer effect. This also allows for an immediate or nearly immediate vacuum at the desired level. Conventional systems may have a 60 cc (60 mL) syringe, and the user has to draw a full vacuum. The exemplary system provides the same and / or higher levels of vacuum with more control and fewer additional requirements in the components.

[0084]

[0109] The valve configuration also allows for a more rapid and improved control over pressure. Compared to conventional systems, the user does not have to wait for the capacitance in the system to be overcome. The clinician can accurately and rapidly control the pressure with the valve. As understood from the above description, a more responsive control of pressure also allows the system to more rapidly detect blood clot engagement based on pressure recovery. The system does not require extra time to wait for the capacitance in the system.

[0085]

[0110] Referring to FIG. 6, the system enables "digital control" with accurate and reliable control of pressure at any desired location in the fluid / pressure system. This digital control allows the vacuum pump to be adjusted with a throttle, reducing the duty cycle, power demand, and pump RPM. Bench tests have shown that reducing the vacuum pressure by half or even 75% still provides sufficient pressure to engage and detect blood clots. For example, in some embodiments, the pump can be configured to generate 48 kPa (7 psi) and 69 kPa (10 psi), respectively. By controlling the pinch valve to tighten and release the suction lumen, additional vacuum can be drawn on the blood clot when engaged. The pressure sensor and control device can then identify a pressure drop similar to FIG. 5 with less blood / fluid removal.

[0086]

[0111] FIGS. 7A and 7B show another embodiment of a thrombectomy system 700 that can include some or all of the previously described features, including an aspiration mechanism including an aspiration lumen 704 in an elongated catheter coupled to a proximal portion positionable outside the patient's body and a distal portion positionable within a patient's blood vessel (e.g., artery or vein), and an aspiration source 706 configured to aspirate fragments of a blood clot into an aspiration canister 707, and a selective fluid system (not shown) configured to form a high-speed jet to break up the blood clot so that it can be aspirated. The thrombectomy system can optionally include an expandable funnel 708 disposed at the distal end of the elongated catheter. The pinch valve 712 can be configured to selectively open or close the aspiration lumen as previously described. In some embodiments, the systems herein are configured to engage a blood clot in a patient's blood vessel, break the blood clot into small fragments, and aspirate the fragments from the patient's body.

[0087]

[0112] In the embodiment of FIG. 7A, the system includes a pressure sensor P disposed within or fluidly coupled to a suction lumen (e.g., at the handle of the device). h a pressure sensor P disposed within or fluidly coupled to the suction lumen at the pinch valve ex and a pressure sensor P disposed within or fluidly coupled to the suction source in and may include two or more pressure sensors configured to measure the pressure within the suction lumen or suction source.

[0088]

[0113] FIG. 7B is a diagram of a thrombectomy system 700 showing the resistance and capacitance in the system corresponding to the locations of pressure sensors P h , P ex and P in .

[0114] FIGS. 8A - 8G show additional charts of pressure waveforms used for blood clot detection using the system of FIG. 7. In FIGS. 8A - 8G, the blood clot detection algorithm can be a conventional algorithm or alternatively an artificial intelligence algorithm or alternatively an output from a trained machine learning model. FIG. 8A shows the pressure waveforms for each of the pressure sensors described in FIG. 7A, including the pressure waveforms corresponding to P h , P ex and P in . The irrigation (i.e., washing or perfusion) pressure (e.g., jet or fluid flow pressure) is also shown in FIG. 8A. The chart of FIG. 8A shows the opening and closing of the pinch valve and the resulting measured pressures P h , P ex and P inShows various system states corresponding thereto. For example, system state 1 in FIG. 8A represents pinch valve opening where the blood clot is not engaged with the thrombectomy device. System state 2 in FIG. 8A represents pinch valve closing where the blood clot is not engaged with the thrombectomy device. System state 3 represents pinch valve closing in a state where the blood clot is engaged with the thrombectomy device. System state 4 in FIG. 8A represents pinch valve opening where the blood clot is not engaged with the thrombectomy device. Finally, system state 5 represents the blood clot aspirated from the thrombectomy device.

[0089]

[0115] In a first embodiment, conventional algorithms can be used to evaluate or determine various pressure waveforms to determine whether a blood clot is engaged or not engaged with a thrombectomy system. In one embodiment, the algorithm can determine the change in the pressure waveform over time (dP / dt) to determine whether a blood clot is engaged. The dP / dt waveform is shown in FIG. 8A. In some examples, the dP / dt waveform is calculated as a linear fit filter over a continuous set of points (e.g., points collected over a set time period such as 10 msec, 20 msec, 30 msec, 40 msec, 50 msec, or longer). However, other filters such as median filters, linear filters, Fourier filters, etc. can be used. In one embodiment, after priming the system, the valve can be cycled between on / off to set / normalize dP / dt due to compliance variations between individual catheters. Comparing system state 1 and system state 3, it can be seen that the dP / dt waveform has a large negative peak in system state 1 (valve open without blood clot) compared to system state 3 (valve closed with blood clot engaged). Further, lower frequency ringing is present in system states 1 (valve open without blood clot) and 2 (valve closed without blood clot) compared to states 3 (valve closed with blood clot engaged) and 4 (valve open with blood clot engaged). These pressure waveform behaviors and parameters can be used by the algorithm to determine whether a blood clot is engaged.

[0090]

[0116] In some embodiments, the initial opening and closing of the pinch valve when no blood clot is engaged can be used to calibrate or normalize the pressure readings of the thrombectomy device to an initial state. Subsequent openings and closings of the valve can then be compared to this initial state to determine blood clot engagement, no blood clot engagement, blockage, and / or blood clot clearing.

[0091]

[0117] For example, referring to FIG. 8A, at time reference 800, the valve is opened (e.g., transitions from a closed state to an open state), no blood clot is detected, and a large peak negative response with a low frequency occurs. This large peak negative can be the basic peak negative, and the low frequency can be the basic low frequency to which future peak negatives and frequency responses are compared to determine the system state. Similarly, at time reference 801, the valve is closed (e.g., transitions from an open state to a closed state), no blood clot is detected, and a large peak positive response with a low frequency occurs. This large peak positive can be the basic peak positive, and the low frequency can be the basic low frequency to which future peak positives and frequency responses are compared to determine the system state.

[0092]

[0118] For example, in one embodiment, the blood clot detection algorithm identifies a large negative peak (e.g., a negative pressure greater than the blood clot detection threshold, or alternatively, up to 50% / 75% / 85% / 95% of the maximum of the basic peak negative, similar to or included in the accepted ratio of the basic peak negative) when the valve is open to determine that no blood clot is engaged with the system, and also identifies a low frequency response similar to the basic low frequency response in the dP / dt waveform (system state 1). Alternatively, the blood clot detection algorithm identifies a peak positive that is higher than the blood clot detection threshold or lower than the ratio of the basic peak positive when the valve is open to determine that a blood clot is engaged with the system, and also identifies a high frequency ringing in the dP / dt waveform that is at a frequency higher than the basic frequency (system state 4).

[0093]

[0119] In another embodiment, the clot detection algorithm identifies a large positive peak (e.g., a positive pressure greater than the clot detection threshold or similar to the baseline positive peak) and / or a low frequency response similar to the fundamental frequency response in the dP / dt waveform when the valve is closed to determine that a clot is not engaged with the system (system state 2). Alternatively, the clot detection algorithm identifies a positive peak lower than the clot detection threshold and / or a high frequency response higher than the fundamental frequency response in the dP / dt waveform when the valve is closed to determine that a clot is engaged with the system (system state 3).

[0094]

[0120] The clot detection algorithm can determine that a clot has been aspirated by identifying a spike (positive or negative) in the dP / dt waveform while the valve is in the open state (system state 5). This can also be said to detect that the clot has been cleared.

[0095]

[0121] In another embodiment, to determine when the system has cleared or removed a previously engaged blood clot, the real-time blood clot clearance detection algorithm can use a pressure signal. The algorithm can employ a parametric approach that uses a correlation function against an averaged "blood clot removal signature" to detect when a blood clot has been cleared. In one embodiment, the pressure signal can be filtered by a low-pass filter to clean the signal, and then the algorithm can log, differencing, and normalizing the vacuum signal. The algorithm can then perform a correlation with a predetermined profile. The sensitivity can be controlled by a correlation threshold and a sampling window size, and the accuracy of the detection can be increased as the window size increases. Another parametric approach is to pass the vacuum signal through a low-pass filter, double-differentiate the signal, apply blanking times around the valve open and valve closed states, and then apply a threshold detector. In yet another parametric approach, the algorithm can low-pass filter an external vacuum signal, double-differentiate the signal, apply blanking times around valve opening and closing (valve motion gives large artifacts in this signal), and then apply a threshold detector to determine engagement or blood clot clearing.

[0096]

[0122] Referring further to FIG. 8A, in the second embodiment, the thrombectomy system can employ a trained machine learning model to determine the system state (blood clot engaged, blood clot not engaged, blood clot aspirated). In some embodiments, the machine learning model can be trained by tagging the system state, while pressure measurements are obtained during the procedure or by the training data set. The training can include inputs of valve state (e.g., open / closed, transition from open to closed, transition from closed to open), blood clot engagement state (not engaged, engaged), pressure values from any pressure sensors, and other system parameters (e.g., jet on / off, suction on / off, etc.). In one example, the training has three inputs: 1) pinch valve state, 2) suction source and / or suction cannister pressure, and 3) pinch valve pressure. Optionally, pressure readings from the handle can be added as an input during training to increase accuracy. For example, the user can tag the system state of blood clot not engaged, blood clot partially engaged, or blood clot engaged / clogged during the procedure or by the training data set, and the machine learning model can be trained to correlate the data with any system state. The trained model can then be used as described above to determine the system state and / or blood clot engagement during the procedure. The machine learning model can provide an output indicating the system state and / or blood clot state. For example, the machine learning model can output that the system is not engaged with the blood clot, engaged with the blood clot, clogged, or has cleared the blood clot. Further, the machine learning model can output the probability of blood clot engagement (e.g., 25% / 50% / 75% / 100% probability of blood clot engagement). Alternatively, the machine learning model can provide a binary output of blood clot engagement (e.g., 0 = blood clot not engaged, 1 = blood clot engaged).

[0097]

[0123] In FIG. 8A, at time reference 800, the pinch valve opens and Ph and P ex causes a drop in the pressure measurement value stored by, while P in remains relatively stable. A large negative peak is shown in the dP / dt waveform, indicating that no blood clot was engaged when the valve was first opened. Since the AI model does not detect engagement at this point, the "engagement" line representing the AI model remains at a value of 0. FIG. 8B is an enlarged view of the waveform that occurs after time reference 800. This corresponds to system state 1.

[0098]

[0124] Returning to FIG. 8A, at time reference 801, the pinch valve closes, and P h and P ex causes an increase in the pressure measurement value recorded by, while P in remains relatively stable. A positive peak is shown in the dP / dt waveform, indicating that no blood clot was engaged when the valve was first opened. Since the AI model does not detect engagement at this point, the "engagement" line representing the AI model remains at a value of 0. FIG. 8C is an enlarged view of the waveform that occurs after time reference 800. This corresponds to system state 2.

[0099]

[0125] Referring further to FIG. 8A, an AI model is shown that identifies a blood clot engaged immediately after the valve was opened as identified by the AI engagement line indicated by time reference 802. FIG. 8D is an enlarged view of this time period following time reference 802. In FIG. 8D, immediately after the valve is opened, both P h and P ex begin to drop, while P in remains relatively stable. A large negative peak is shown in the dP / dt waveform, indicating that no blood clot was engaged when the valve was first opened. However, the AI model detects engagement immediately thereafter, as shown in FIG. 8D. Since the blood clot was not yet engaged when the valve was open, this is associated with system state 1, but it can be seen that the engagement is detected by the AI model immediately thereafter.

[0100]

[0126] Figure 8A shows the time reference 803, at which the valve is closed and the blood clot engagement has not yet been detected by the AI model. This corresponds to system state 3. Figure 8E is an enlarged view of a time period following the time reference 803. P h and P ex The pressure measurements recorded by P in do not recover as rapidly as they did in Figure 8C when the blood clot was not engaged, whereas P

[0101]

[0127] Figure 8F shows the time period around the time reference 804 when the valve is open again and the blood clot is still engaged with the device. The AI model continues to indicate blood clot engagement. All sensed pressures remain relatively stable. This corresponds to system state 4.

[0102]

[0128] Figure 8G shows the period around the time reference 805 in Figure 8A, with the valve closed immediately after the AI model has identified that the blood clot is no longer engaged with the thrombectomy device. In some examples, this can be associated with a system state indicating that the blood clot has been cleared. The system can sense a transient signal via various pressure sensors (particularly P h ). In one example, the system can look at the vacuum relief curve (e.g., the time constant of pressure recovery and / or flow rate) to determine that a blood clot previously engaged with the system has been cleared. In Figure 8G, immediately after the AI model has determined that the blood clot is no longer engaged, an increase or peak in the dP / dt waveform and both P h and P ex can be seen. After the valve closes while P in remains relatively stable, further rapid recovery or spikes in P h and P ex are present.

[0103]

[0129] Although described from the perspective of a pinch valve, one of ordinary skill in the art will recognize from the description herein that other elements may be used to achieve the described clamping effect and pressure control.

Claims

1. An elongated catheter having at least one suction lumen configured to remove thrombus material, A suction mechanism is fluidly coupled to the suction lumen and configured to reduce the pressure in the suction lumen, A pressure sensor configured to monitor the pressure within the suction lumen, A valve is disposed between the pressure sensor and the suction mechanism, An electronic control device operably coupled to the pressure sensor and the valve, configured to open and close the valve and to monitor the pressure in the suction lumen to determine whether the blood clot is engaged with the elongated catheter or whether the blood clot has been at least partially removed, and A system equipped with a mechanism for removing blood clots.

2. The system according to claim 1, wherein the electronic control device is configured to close the valve every 3 to 5 seconds during treatment.

3. The system according to claim 2, wherein the cycle time for opening and closing the valve is approximately 300 ms or less.

4. The system according to claim 1, wherein the electronic control device is configured to determine that a blood clot is engaged with the elongated catheter when the monitored pressure does not substantially rise after the valve has been closed.

5. The system according to claim 1, wherein the electronic control device is configured to determine that the blood clot has been removed at least partially when the monitored pressure rises after the valve has been closed.

6. The system according to claim 1, wherein the system is configured to remove 45 ml or less of blood from the patient before detecting that the blood clot has been at least partially removed.

7. The system according to claim 1, wherein the valve has valve states including an open state, a closed state, a state in the process of opening, or a state in the process of closing.

8. The system according to claim 7, wherein the electronic control device is configured to determine that a blood clot is engaged when the valve moves from a closed state to an open state and the pressure in the suction lumen does not exceed a blood clot engagement threshold.

9. The system according to claim 7, wherein the electronic control device is configured to determine that a blood clot is engaged when the valve moves from a closed state to an open state and the pressure gradient in the suction lumen does not exceed a blood clot engagement threshold.

10. The system according to claim 1, wherein the electronic control device is configured to determine changes in pressure within the suction lumen over time in order to determine whether the blood clot is engaged with the elongated catheter or whether the blood clot has been removed at least partially.

11. The system according to claim 10, wherein the change in pressure within the suction lumen over time is an input to a correlation function for a predetermined blood clot detection profile.

12. The system according to claim 10, wherein the change in pressure within the suction lumen over time is filtered and normalized.

13. The system according to claim 7, wherein the electronic control device is configured to provide the pressure in the suction lumen and the valve state to a trained machine learning model in order to determine whether the blood clot is engaged with the elongated catheter or whether the blood clot has been removed at least partially.

14. An elongated catheter having at least one suction lumen configured to remove thrombus material, A suction mechanism is fluidly coupled to the suction lumen and configured to reduce the pressure in the suction lumen, A valve coupled to the suction mechanism, having valve states including an open state and a closed state, A first pressure sensor is positioned distal to the valve and configured to monitor the first pressure in the suction lumen, A second pressure sensor is positioned near the valve and configured to monitor the second pressure within the suction lumen. An electronic control device operably coupled to the pressure sensor and the valve, the electronic control device being configured to open and close the valve and to monitor the first and second pressures in the suction lumen to determine whether the blood clot is engaged with the elongated catheter or whether the blood clot has been at least partially removed, and A system equipped with a mechanism for removing blood clots.

15. The system according to claim 14, wherein the electronic control device is configured to close the valve at intervals of up to 3 to 5 seconds during treatment.

16. The system according to claim 15, wherein the cycle time for opening and closing the valve is approximately 300 ms or less.

17. The system according to claim 14, wherein the electronic control device is configured to determine that a blood clot is engaged with the elongated catheter when the pressure monitored after the valve is closed does not rise substantially.

18. The system according to claim 14, wherein the electronic control device is configured to determine that the blood clot has been at least partially removed from the elongated catheter when the pressure monitored after the valve has been closed rises.

19. The system according to claim 14, wherein the system is configured to remove 45 ml or less of blood from the patient from the time it detects that the blood clot has been at least partially removed.

20. The system according to claim 14, wherein the electronic control device is configured to determine that a blood clot is engaged when the valve moves from a closed state to an open state and the first and second pressures in the suction lumen do not exceed a blood clot engagement threshold.

21. The system according to claim 14, wherein the electronic control device is configured to determine that a blood clot is engaged when the valve moves from a closed state to an open state and the gradients of the first and second pressures in the suction lumen do not exceed a blood clot engagement threshold.

22. The system according to claim 14, wherein the electronic control device is configured to determine changes in pressure within the suction lumen over time in order to determine whether the blood clot is engaged with the elongated catheter or whether the blood clot has been removed at least partially.

23. The system according to claim 22, wherein the change in pressure within the suction lumen over time is an input to a correlation function for a predetermined blood clot detection profile.

24. The system according to claim 22, wherein the change in pressure within the suction lumen over time is filtered and normalized.

25. The system according to claim 14, wherein the electronic control device is configured to provide the first and second pressures in the suction lumen and the valve state to a trained machine learning model in order to determine whether the blood clot is engaged with the elongated catheter or whether the blood clot has been removed at least partially.

Images