Aspiration-type thrombectomy system and method for dynamic system state monitoring

Abstract

Aspiration thrombectomy system for use with a vacuum source and aspiration catheter includes a connecting conduit configured to selectively connect the aspiration catheter to the vacuum source via a controllable vacuum valve. A distal pressure sensor is configured to detect pressure at a distal end within the connecting conduit. An automatic controller can operate the vacuum valve to generate a fluid pressure change in the connecting conduit and detect the pressure distribution in the connecting conduit in relation to the generated pressure change via the distal pressure sensor. The automatic controller can determine one or more system states of the aspiration catheter or connecting conduit based on the detected pressure distribution and can operate the vacuum valve based on the determination of the system state.

Description

[0001] priority

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 426688, filed November 18, 2022, pursuant to Section 119(e) of 35 U.S. SC, which is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to the field of medical devices and methods. More specifically, the specific embodiments described herein relate to apparatus and methods for controlling the removal of clots from a patient's vascular system via aspiration thrombectomy. Background Technology

[0004] Stroke is a leading cause of disability and death and a growing problem in global healthcare. In the United States alone, more than 700,000 people suffer a stroke each year, and more than 150,000 die from it. Among stroke survivors, approximately 90% experience long-term motor, sensory, memory, or reasoning impairments ranging from mild to severe. The total cost to the U.S. healthcare system is estimated to exceed $50 billion annually.

[0005] Stroke can be caused by a blockage of a cerebral artery due to a blood clot (called an ischemic stroke) or by a ruptured cerebral artery (called a hemorrhagic stroke). A hemorrhagic stroke causes bleeding within the skull, restricting blood supply to brain cells and putting harmful stress on fragile brain tissue. Blood loss, swelling, protrusion of brain tissue, and the pooling of blood leading to clots within the skull all rapidly damage brain tissue. A hemorrhagic stroke is a life-threatening medical emergency with limited treatment options.

[0006] Besides stroke, thromboembolism throughout the vascular system, in the arterial and venous circulation, is characteristic of many common life-threatening conditions. Examples of potentially fatal conditions caused by thrombus occlusion include pulmonary embolism, deep vein thrombosis, and acute limb ischemia. Acute pulmonary embolism is a leading cause of death in the United States, causing approximately 300,000 deaths annually. Pulmonary embolism can be a complication of deep vein thrombosis, with an annual incidence of 1% in patients aged 60 and older. All of the above conditions are examples of conditions for which treatment may involve aspiration or drainage of clots and / or blood.

[0007] Of particular interest is Penumbra The Mechanical Thrombectomy System is a fully integrated system specifically designed for mechanical thrombectomy via aspiration. It is suitable for revascularization in patients with acute ischemic stroke secondary to intracranial large vessel occlusion. The system is a similar system designed specifically for peripheral and coronary vascular systems, and is also a mechanical thrombectomy and aspiration system designed for revascularization in patients with peripheral vascular system thromboembolism. Both the Penumbra and Indigo systems were commercially available at the time of filing of this provisional patent application and include aspiration or reperfusion catheters, aspiration tubing, other accessories, and aspiration pump (sold under the trade name: Pump MAX). TM Suction pump or Penumbra Engine TM A suction pump is used to connect the suction tubing and suction cannula. As shown in Figure 1, the Pump MAX™ suction pump 10 includes a base unit 12 that encapsulates an offline voltage-operated vacuum pump (not shown). The base unit has an on / off switch 14 and a separate knob 16 for adjusting the vacuum level provided by the pump. The vacuum level can be read on a pressure gauge 18. Blood and clots are drawn into a collection container 20 from a suction line 22 (shown in dashed lines), which is connected to a reperfusion catheter (not shown) that has been inserted into the patient's vascular system to remove clots. Blood and clots are drawn into the collection container under partial vacuum provided by a vacuum connector 28 connected to the base unit 12 (not shown) of the vacuum pump. Vacuum from the vacuum connector 28 is applied to a vacuum port 24 on a removable cap 26. The vacuum connector 28 is connected to the vacuum port 24 via an external vacuum line 30.

[0008] Despite its effectiveness, clot aspiration using the Indigo system mechanical thrombectomy device or other similar vacuum-assisted thrombectomy systems sometimes must be discontinued due to the risk of excessive blood loss in patients, especially when using large aspiration catheters. During aspiration thrombectomy, when the catheter tip disengages from contact with a thrombus or other occlusive material, it is exposed to healthy blood and subsequently undergoes sufficient flow. In this situation, the blood loss rate can be excessive, and in some cases, may lead to premature termination of the procedure. In specific implementations, during the procedure, when the catheter enters healthy blood and subsequently undergoes sufficient flow, the blood loss rate is in the range of 20-25 cc per second for an 8 French size catheter. The maximum tolerable blood loss is 300-1000 mL, and the catheter should not be operated in unrestricted mode for more than approximately 20 to 50 seconds. When the physician operates the system manually, the total blood loss may reach unacceptable levels before sufficient clots are removed. Furthermore, reliably identifying whether the catheter tip has come into contact with a clot or whether healthy, clot-free blood has been accidentally aspirated is an important issue, and such manual control is not optimal.

[0009] During other surgeries using the penumbra system, such as neurovascular surgery for ischemic stroke, the risk of excessive blood removal may be lower, and the primary focus of the procedure can be maximizing the removal of occlusive material. Optimized technique and aspiration control are crucial for successful removal of the occlusive material.

[0010] Therefore, there is a need for improved methods and apparatus for controlling the aspiration of thrombi and clots using a combination of aspiration catheters and a pumping console. Systems and methods for limiting blood loss during such aspiration procedures would be particularly useful, for example, by automatically stopping aspiration when the aspiration catheter is no longer in contact with the clot or thrombus. Additionally, systems and methods for optimizing system performance, as well as procedures for removing occlusive material, are desirable. At least some of these objectives will be achieved through the specific embodiments described below.

[0011] At the time of filing this provisional patent application, PenumbraS Commercially available, in the article titled "Science of Aspiration: The Penumbra" The "Approach" is described in the brochure. Relevant patents and publications include: US4574812; US5624394; US6019728; US6283719; US6358225; US6599277; US6689089; US6719717; US6830577; US8246580; US8398582; US8465467 US8668665; US9248221; US2003 / 0050619; US2010 / 094201; US2014 / 323906; US2014 / 276920; US2016 / 0220741; US2017 / 0238950; US2017 / 049470; WO2014 / 151209; and WO2010 / 045178. Summary of the Invention

[0012] The specific embodiments described herein provide systems and methods for improving catheter aspiration by enabling longer procedures, by enhancing the uptake of occlusive material, or both. In specific embodiments, the amount of fluid flowing through the aspiration catheter under vacuum aspiration is monitored to determine whether the flow is unrestricted, restricted, or blocked. Depending on the determined flow state, different techniques and methods can be employed to improve catheter aspiration in specific embodiments. In one specific embodiment, unrestricted flow is detected, and aspiration is automatically and temporarily restricted for blood-saving purposes. This can advantageously extend the time available to perform the procedure, thereby allowing for more complete removal of occlusive material. In another embodiment, restricted flow is detected, and full vacuum aspiration is automatically applied. In yet another specific embodiment, a blocked catheter is detected, and pulsed aspiration is automatically applied. This can advantageously enhance the uptake of strong, hard, or other troublesome occlusive material. Alternatively, users of specific embodiments can apply pulsed aspiration, full aspiration, or restricted aspiration as needed.

[0013] In one specific embodiment, the described system and method address the problem of excessive blood loss through dynamic extraction cycles. Monitoring the properties and flowability of the material extracted by the aspiration catheter allows the system to permit continuous aspiration even when clots are present, or sampling the extraction rate to determine if the catheter tip is in contact with the clot, thereby reducing the risk of excessive blood loss. While the determination and monitoring of blood flow rate are disclosed in the exemplary embodiments below, other measurements of the flowability and / or structural composition of the aspirated effluent may also be used, such as monitoring the volume of the collection chamber, monitoring the filling rate of the collection chamber, visually monitoring the aspiration tubing (where clots are darker in color than fresh blood), or placing strain gauges on the aspiration tubing.

[0014] The specific implementation of the system and method can respond to changes in flow rate, pressure, differential pressure, or other parameters of material composition inside or adjacent to the aspiration catheter in a sub-second time range to limit unnecessary blood aspiration during thrombectomy. The specific implementation can be used in any thrombectomy, embolectomy, atherosclerotic plaque resection, or other catheter or probe system in which blood and clots are completely or partially extracted by applying a vacuum to the proximal end of any reperfusion, aspiration catheter, or probe for clot extraction purposes.

[0015] Specific embodiments provide a vacuum aspiration control system for use with a vacuum source and aspiration catheter. The system includes a flexible connecting conduit, switching valves, a sensing unit, and a controller. The connecting conduit is linear in an unconstrained configuration and is configured to connect a vacuum source to a suction lumen in the aspiration catheter. The switching valves are configured to be operatively connected to the connecting conduit, and the sensing unit is configured to determine the flow velocity within the connecting conduit and generate a signal representing this flow rate, typically unrestricted flow, restricted flow, or blockage. The controller is connected to receive the signal representing flow through the connecting conduit and, in response to the signal, opens and closes one or more switching valves. In one embodiment, when the signal indicates unrestricted flow, for example, primarily healthy blood or blood without clots obstructing blood vessels flowing through the connecting conduit, and / or the catheter is substantially not in contact with clots or other obstructing material, the controller is configured to automatically close the switching valves to stop flow through the connecting conduit. In another embodiment, the controller is configured to initiate pulsed aspiration when the signal indicates blockage, which may be caused by some obstructing material in or near the catheter or connecting conduit.

[0016] The controller is also typically configured to automatically open a switch valve at predetermined intervals to sample the effluent material through the connecting tubing, and the valve usually remains open only when a signal indicates a return to the clot. The controller algorithm is able to interpret the differences between healthy blood and clots, regardless of the aspiration source and the inner diameter of the attached catheter.

[0017] The sensing unit may include any one or more of a variety of sensors, including: differential pressure sensors, acoustic (including ultrasonic) flow sensors, optical flow sensors, thermal flow sensors, magnetofluid sensors, sensors that detect circumferential expansion of the connecting pipe, etc. Although differential pressure is described in more detail below, it should be understood that any sensing unit capable of detecting when the flow rate or extraction rate through the connecting pipe is excessive and / or blocked will be suitable for use in a particular embodiment.

[0018] In an exemplary embodiment, the sensing unit includes a pair of pressure sensors located at spaced-apart positions along the connecting pipe to measure differential pressure. The controller can calculate the flow rate based on the differential pressure and determine whether the calculated flow rate indicates unrestricted flow, restricted flow, or blockage.

[0019] In another embodiment, the sensing unit uses an optical sensor that measures the transmission, absorption, or both of light to characterize the contents flowing through the connecting pipe. In a specific embodiment, visible light is used to determine whether the flow contains clumps or is predominantly clump-free. Typically, flow containing clumps is darker in color and can be detected by an optical sensor. Alternatively, the optical sensor can use infrared, ultraviolet, visible light, or a combination of such light to analyze the contents within the connecting pipe.

[0020] In other embodiments, the sensing unit uses a circumferential expansion sensor to determine the contents flowing through the connecting conduit. The internal pressure of the connecting conduit and the contents flowing through it affect the circumference of the connecting conduit. Under strong vacuum, such as during a blockage, the conduit may contract maximally. During high-speed flow of predominantly clot-free blood, the conduit may contract only slightly. During periods of restricted flow, clots and blood may cause relative changes in the circumference of the connecting conduit.

[0021] On / off valves can also take many specific forms. Typically, regardless of form, an on / off valve will include an actuator, such as a solenoid actuator, which is powered to open the valve. The valve itself can take many forms, including pinch valves, angle valves, or any of a variety of other valves that provide actuation. Alternatively, a manually operated on / off valve can be provided, allowing the user to initiate and / or terminate the functions and features of the specific implementation.

[0022] In another exemplary embodiment, the controller can be configured to open the valve and remain open until a flow pattern indicating unrestricted flow is detected, at which point the controller closes the valve. The controller can also be configured to automatically reopen the valve. In a specific embodiment, in what may be referred to as a “sampling mode,” the controller can also be configured to periodically sample or test the flow to recharacterize the flow and determine whether it is safe to restart aspiration. For example, in a specific embodiment, the controller can cyclically test the flow by opening the valve for a fixed time interval—150 milliseconds in one embodiment—to establish a “test” flow. The test flow is characterized, and if such an indication is found, the valve can be reopened to a “treatment” mode to allow continued aspiration treatment. If the system characterizes the flow as unrestricted, such as excessive, the system will remain in a closed configuration for a fixed time interval before performing additional differential pressure sampling; in one embodiment, this fixed time interval is between a quarter second and two seconds.

[0023] However, in other implementations, the controller may not be configured to automatically re-establish flow when safe conditions are met. For example, in one embodiment, the controller may be configured to allow the user to reposition the aspiration catheter and, after repositioning, manually open the on / off valve (typically by actuating a switch that causes the controller to open the valve) to resume aspiration treatment. However, in this case, the controller can immediately return to "sampling mode," and if the re-established flow is characterized as unrestricted flow, the controller will close the on / off valve again, and the user can then reposition the aspiration catheter back into sampling mode to engage the clot and manually resume aspiration. Such systems typically provide a manual switch that allows the user to manually open the on / off valve.

[0024] The controller can be configured to control two or more valves. In a specific embodiment, the controller controls a first switching valve between the suction conduit and a vacuum source, and a second switching valve between the suction conduit and a pressure source having a pressure at least higher than that of the vacuum source. The controller can alternately open the first and second switching valves to create pressure changes within the suction conduit or adjacent piping. When the first switching valve is open, the controller can sample the flow to determine whether the attached conduit is still clumped or otherwise blocked. If no blockage or occlusion is detected, the controller can keep the first switching valve open and the second switching valve closed.

[0025] In a specific embodiment, the vacuum suction system includes a base unit that incorporates at least one on / off valve and a controller. The base unit is typically configured to be mounted directly on or near a vacuum pump or control console and typically includes a connecting cable to receive power from the vacuum control console or line and optionally exchange information with the controller and vacuum control console. The connecting tube typically has a proximal end configured to connect to a vacuum source and a distal end configured to connect to a suction conduit. In this case, the vacuum suction system typically also includes an external unit configured to be fixed to the connecting tube at a location between the distal and proximal ends. An exemplary external unit includes at least a portion of a sensing unit. For example, in a specific embodiment, the sensing unit may include a first pressure sensor in the base unit and a second pressure sensor in the external unit. In these cases, the controller is typically configured to determine the presence of a pressure differential based on signals from the first and second pressure sensors.

[0026] In a second aspect, a vacuum aspiration method is provided. The vacuum aspiration method involves attaching the distal end of an aspiration catheter to an occlusion in a blood vessel. A vacuum is applied through the aspiration lumen of the aspiration catheter using a vacuum source connected to the proximal end of the aspiration lumen via a connecting tube. In this manner, portions of clots and other occlusive material can be aspirated through the connecting tube into the aspiration lumen and drawn into a collection container by the vacuum source. Flow through the connecting tube is sensed, and when the sensed flow exceeds a predetermined value while the vacuum source remains open, a valve automatically closes to stop flow through the connecting tube. Flow through the connecting tube is then re-established by opening the valve, and these steps are repeated until the desired amount of clot is aspirated.

[0027] In a third aspect, a specific embodiment provides an assembly for generating a pressure differential that can cause pressure pulses to perform an extraction cycle. This assembly may include a fluid injection device, a mechanical displacement device, a gravity-induced pressure head, or a combination thereof. The fluid injection device can provide a relatively positive pressure source for a conduit currently or previously under vacuum suction. For example, the fluid may be at a pressure higher than the vacuum suction system pressure, a pressure between full vacuum pressure and ambient pressure, at ambient pressure, a pressure between ambient pressure and contraction pressure, at contraction pressure, or a pressure higher than contraction pressure. The fluid injection device may utilize orifices, valves, pumps, pressure chambers, or combinations thereof. The mechanical displacement device can physically displace the volume of the conduit system to provide a relative increase or decrease in pressure depending on the direction of displacement. In a specific embodiment, the mechanical displacement assembly assists in vacuum recovery after the pressure in the conduit increases to above the pressure of the vacuum source.

[0028] In a specific implementation, the controller may include an algorithm for interpreting pressure sensor signals to determine whether the contents flowing through the catheter should be characterized as unrestricted, restricted, or blocked. Generally, unrestricted flow is high flow, which may be excessive and may consist primarily or entirely of healthy blood, clot-free blood, or blood without vascular clots that would hinder aspiration. Restricted flow may include a mixture of healthy blood and clots or other occlusive material, and blockage may be caused by clots or other occlusive material within the aspiration catheter, part of the aspiration catheter, adjacent to the aspiration catheter, or in other connecting tubing attached to the aspiration catheter. In some instances, healthy blood may be blood with a sufficiently low proportion of cross-linked fibrin so that it does not adequately integrate to cause localized ischemia or other similar vascular occlusion. When the algorithm detects unrestricted flow, it may cause the system to initiate a sampling mode. When the algorithm detects restricted flow, it may cause the system to activate full vacuum aspiration. When the algorithm detects blockage, it may cause the system to generate various pressure pulses during the extraction cycle. The algorithm can respond to and adapt to changing environmental conditions, such as changing catheters of different sizes during surgery. If the catheter status remains static, changes too quickly, changes too slowly, or improves as expected, the algorithm can adjust the sampling mode and pressure pulse amplitude.

[0029] In specific aspects of this method, embodiments may remove clots and other occlusive substances from blood vessels, including veins or arteries. Flow sensing may include one or more of differential pressure measurement, acoustic flow measurement, optical flow measurement, thermal flow measurement, circumferential expansion measurement of connected pipes, etc.

[0030] In a preferred aspect of the method, sensing the flow rate includes measuring the pressure difference using a first sensor located near the vacuum source and a second sensor located on or near the connecting pipe between the vacuum source and the suction conduit.

[0031] In another embodiment of the method, restoring flow through the connecting pipe includes opening the valve for sub-second intervals, detecting when the sensed flow is characterized as acceptable, and automatically restoring the flow. Automatic flow restoration typically involves automatically detecting when the sensed flow can be characterized as acceptable, and keeping the valve open as long as the flow is so characterized. Alternatively, restoring flow may include manually opening the on / off valve.

[0032] In another embodiment of the method, a pressure differential is generated by closing the valve of the vacuum pump and opening the valve of the pressure source, wherein the pressure is at least higher than the vacuum pressure, and then the valve to the vacuum pump is reopened. Alternatively or in combination, the pressure differential is generated by mechanical displacement, wherein the volume of the chamber decreases to increase the pressure within the conduit, and the volume of the chamber increases to decrease the pressure within the conduit, thereby generating a pressure differential through the actuation of the mechanical displacement chamber. The pressure differential can be tailored to have a specific or dynamic amplitude and frequency that facilitates the removal of clots or other obstructing substances.

[0033] In a specific implementation, regarding dynamic system state detection, the controller can generate pressure level changes in the connecting pipes by operating a vacuum valve, for example, by selectively opening and closing the vacuum valve. In a second step, the controller can detect the pressure level using a remote pressure sensor, where the detected pressure level change is correlated with the generated pressure level change. In a third step, the controller can determine one or more system states in the suction conduit or connecting pipes based on the detected pressure level change. In a fourth step, the controller can operate the vacuum valve to take action based on one or more determined system states.

[0034] In specific embodiments, the system state may include the flow state within the suction conduit and / or connecting pipes. Specifically, the flow state may include open flow, closed flow, and / or partially closed flow. More specifically, the system state may include the presence of a particular fluid within the suction conduit and / or connecting pipes.

[0035] In specific embodiments, the controller can be configured to detect the presence of brine fluid in the system based on dynamic system state detection, for example, for perfusion, flushing, or reperfusion of the system, or to detect brine loss during pulses. In specific embodiments, the controller can be configured to detect the presence of gas (e.g., air bubbles) in the system based on dynamic system state detection. In specific embodiments, the controller can be configured to detect the absence of conduits attached to the system based on dynamic system state detection. In specific embodiments, the controller can be configured to detect the engagement of clots with conduit tips based on dynamic system state detection.

[0036] In specific embodiments, dynamic system status detection may utilize pressure sources and / or valves other than vacuum valves, either alone or additionally. In specific embodiments, the system may use vacuum valves, pressure valves (e.g., brine vent valves), and / or multiple other pressure valves.

[0037] Specific implementations of this dynamic system state detection method may use sensors other than distal pressure sensors, either alone or additionally. In specific implementations, the system may use one or more pressure sensors associated with connecting pipes and / or suction conduits, as well as other pressure sensors, such as vacuum pressure sensors and saline pressure sensors. The sensors used in specific implementations are not limited to pressure sensors. In some implementations, multiple sensors may be used, for example, to detect pressure, acoustic energy, ultrasonic energy, and / or flow rate.

[0038] In a specific implementation, one or more system scores can be determined to determine the system state, wherein each system score, independently or in combination with other system scores, can indicate the probability of a particular system state in the suction conduit or connecting tubing. In this respect, system scores can serve as a measure for quantifying the corresponding probability of a particular system state.

[0039] In specific implementations, system scores can be derived directly or indirectly from sensor data (e.g., pressure distribution). In specific implementations, system score determination can be based on automatically identifying specific features from the detected pressure distribution, extracting pressure parameters based on values ​​and trends derived from those specific features, and calculating one or more system scores based on the pressure parameters of those features. In specific implementations, determining system scores based on pressure parameters may also include the use of appropriate weighting and / or correction factors for the parameters. In specific implementations, pressure parameters may include one or more of the following: initial pressure level, difference between initial and final pressure levels, final pressure level, difference between final and final pressure levels, peak pressure level, and change in pressure level.

[0040] In a specific implementation, the system score can be determined based on machine learning. In a specific implementation, the training dataset can be assembled from detected stress distribution data acquired across a wide range of scenarios, combined with statistical variations and corresponding to the system states of interest. The trained machine learning model can then be used to predict the system states in new situations. In a specific implementation, the machine learning algorithm can employ semi-supervised and unsupervised learning. The algorithm can employ clustering, dimensionality reduction, and reinforcement learning to further improve prediction accuracy. In a specific implementation, an algorithm combining the above-described algorithmic flow analysis techniques can be used.

[0041] In a specific embodiment, one or more of the system state scores may be based on one or more geometric characteristics of the aspiration catheter, wherein one or more geometric characteristics of the aspiration catheter may be determined based on one or more detected pressure levels. In a specific embodiment, one or more of the system state scores may be based on one or more environmental parameters of the aspiration thrombectomy system. In a specific embodiment, one or more of the system state scores may be based on one or more material parameters associated with the aspiration thrombectomy system, wherein one or more material parameters may be determined based on one or more detected pressure levels. In a specific embodiment, one or more of the system state scores may be based on one or more thrombus parameters associated with one or more thrombi in the aspiration catheter or connecting tubing, wherein one or more thrombus parameters may be determined based on one or more detected pressure levels. In a specific embodiment, one or more of the system state scores may be based on one or more fluid parameters associated with one or more fluids in the aspiration catheter or connecting tubing, wherein one or more fluid parameters may be determined based on the one or more detected pressure levels.

[0042] In specific implementations, an escalation feature can be used, where the controller maintains a continuously determined escalation count for the same system state, and a specific action can be taken if the count exceeds a threshold. In specific implementations, the count can be reset in iterations following threshold crossover iterations. In a particular aspect, the action taken if the count exceeds the threshold could be generating a notification, such as a user notification. In specific implementations, the action taken if the count exceeds the threshold could involve the controller operating one or more valves.

[0043] The embodiments disclosed herein are merely examples, and the scope of this disclosure is not limited thereto. Specific embodiments may include all, some, or none of the components, elements, features, functions, operations, or steps of the embodiments disclosed herein. Embodiments of the invention are particularly disclosed in the appended claims for methods and systems, wherein any feature mentioned in one claim class, such as methods, may also be claimed in another claim class, such as systems. Relevance or reference in the appended claims is chosen solely for formal reasons. However, any subject matter arising from the deliberate reference to any prior claim (especially multiple references) may be claimed, such that any combination of the claims and their features disclosed may be claimed, regardless of the dependent relationship chosen in the appended claims. Claimable subject matter includes not only combinations of features set forth in the appended claims but also any other combination of features in the claims, wherein each feature mentioned in the claims may be combined with any other feature or combination of other features in the claims. Furthermore, any embodiments and features described or depicted herein may be claimed in a separate claim and / or in any combination with any embodiments or features described or depicted herein or with any features of the appended claims. Attached Figure Description

[0044] Figure 1 illustrates the Penumbra as described in detail in the background section. Vacuum control console and collection vessel of a mechanical thrombectomy system.

[0045] Figure 2 It is a perspective view of a vacuum control console and blood and clot collection containers, with the collection containers being housed within the mounting area of ​​the vacuum control console.

[0046] Figure 3A This is a view of the vacuum control console, with the collection tank removed.

[0047] Figure 3B yes Figure 3A A detailed view of the on / off switch and vacuum display area on the top surface of the vacuum control console, shown with the power off.

[0048] Figure 3C Figure 1 to Figure 3A A schematic representation of the internal components of the vacuum control console.

[0049] Figure 4 The collection tank is shown.

[0050] Figure 5 Shown in an inverted or "flipped" view Figure 4 Implementation method of the collection tank.

[0051] Figure 6 yes Figure 4 and Figure 5 Exploded view of the vacuum tank.

[0052] Figure 7A and Figure 7B A vacuum control console and a collection tank are shown, similar to those previously shown, with a vacuum suction control system attached thereto.

[0053] Figure 8A and Figure 8B External units of a type suitable for use in specific embodiments are shown.

[0054] Figure 9 An exemplary base unit of a closed-loop switching valve and a type of controller suitable for use in a vacuum suction control system is shown in cross-section.

[0055] Figure 10 An exemplary external unit is shown, which depicts internal components including fittings and a pressure sensor (depicted in dashed lines).

[0056] Figure 11 An angle valve, shown in cross-section, is a type of valve that can be used as a switching valve in a specific embodiment.

[0057] Figure 12 This is an isometric view of the angle valve connected to the coil, each end of which has a pressure sensor mounted on the top of the tank.

[0058] Figure 13 An implementation of an algorithm suitable for use with differential pressure is shown.

[0059] Figures 14 to 18 An exemplary pulsed fluid injection assembly suitable for use in a specific embodiment is shown.

[0060] Figure 19 A mechanical displacement assembly for manipulating pressure is shown in a specific embodiment.

[0061] Figure 20 A graphical representation of a specific implementation of pulsed aspiration is shown, in which the pressure inside the catheter changes over time.

[0062] Figure 21 This is a schematic representation of a specific implementation configured for dynamic system state detection.

[0063] Figure 22 A specific implementation of an algorithm suitable for implementing dynamic system state detection is shown in the embodiments.

[0064] Figure 23A specific implementation of the distal pressure distribution detected over time is shown, along with some pressure parameters.

[0065] Figures 24 to 31 A specific implementation of the distal pressure distribution of a series of system state fractions is shown.

[0066] Figure 32 A specific implementation of the evolution of the distal pressure distribution and the corresponding system state fraction is shown.

[0067] Figure 33 A specific implementation of continuous system scores and upgrades is shown.

[0068] Figures 34 to 35 The pressure distribution during preparation is shown in the specific implementation.

[0069] Figures 36 to 50 The pressure distribution characteristics of a specific implementation for dynamic system state detection during preparation are shown.

[0070] Figures 51 to 52 The pressure distribution characteristics of a specific implementation for catheter detection during flushing are shown.

[0071] Figures 53 to 55 The pressure distribution characteristics of a specific implementation method for verifying the presence of liquid during rinsing are shown.

[0072] Figures 56 to 58 The pressure distribution characteristics of a specific implementation for verifying the presence of liquid during re-preparation are shown.

[0073] Figures 59 to 60 The pressure distribution characteristics of a specific implementation for brine detection during a pulse sequence are shown.

[0074] Figures 61 to 65 The pressure distribution characteristics of a specific implementation for clot detection corresponding to a pulse sequence are shown.

[0075] Figures 66 to 70 The pressure distribution of a specific implementation is shown, detected using multiple pressure sensors for dynamic system state detection. Detailed Implementation

[0076] Aspiration Thrombectomy System

[0077] Specific implementation methods are described below. For clarity, not all features of every actual implementation are described in this specification. In the development of actual devices, modifications may be made to produce implementations that still fall within the scope of this disclosure.

[0078] Figure 1 illustrates the Penumbra as described in detail in the background section. Vacuum control console and collection vessel of a mechanical thrombectomy system.

[0079] Reference Figures 2 to 6 Specific embodiments of a vacuum system 40 of the type used with devices and methods for controlled clot extraction will be described. Figure 2 This is a perspective view of a vacuum control console and a blood and clot collection container, wherein the collection container is received in the mounting area of ​​the vacuum control console. The vacuum system 40 includes a vacuum control console 42 and a blood / clot collection container 44. The vacuum control console 42 includes a housing with a recess 48 shaped to removably receive the collection container 44, as will be described in more detail below.

[0080] Reference Figures 3A to 3C The illustration shows a specific embodiment of the vacuum control console 42, in which the vacuum tank 44 is removed. Figure 3B yes Figure 3A A detailed view of the on / off switch and vacuum display area on the top surface of the vacuum control console, shown with the power off. Figure 3C Figure 1 to Figure 3A A schematic representation of the internal components of the vacuum control console. A pillar 50, forming a continuous portion of the outer surface or wall of the housing 46, is formed within a recess 48 and extends upward from a bottom plate 56. The bottom plate 56 acts as a support for the collection can 44 when it is received within the recess. A vacuum connector 52 and a pressure sensing connector 54 are formed in or on the upper surface of the pillar 50, and are positioned such that when the vacuum can 44 is received within the recess 48, the vacuum connector 52 and the pressure sensing connector 54 will engage with the pressure sensing port 104 and the vacuum port 102 on the vacuum can 44. Figure 5 Alignment. One lamp 58 is located on the wall surface of the housing 44 within the recess 48, and one lamp 5 is positioned such that it illuminates the contents of the collection tank 44 when the system is in use. The second lamp (in...) Figure 3A (Not visible in the middle) It exists on the opposite wall of the recess 48. The vacuum control console 42 also has an on / off switch 60 on its upper surface. The on / off switch 60 provides illumination (e.g., when the on / off switch is open) Figure 2 and Figure 3A (As shown) and no lighting is provided when the system is off. Figure 3B Additionally, a pressure indicator 62 is disposed on the upper surface of the housing 46. (For example...) Figure 2 and Figure 3A As shown, the display can be a circular lamp, for example, with four sections, which are illuminated sequentially as the vacuum level inside the tank increases. Each quadrant represents the percentage of the measured vacuum relative to ambient pressure.

[0081] The internal components of the vacuum control console 42 are schematically shown. Figure 3C The main internal components of the vacuum control console include a pressure sensor 64, a pump 68, a power supply 72, and a microprocessor controller 74. The pump 68 has an inlet connected to a vacuum connector 52 on a column 50 of the housing 46. Similarly, the pressure sensor 64 is connected to a pressure sensing connector 54 on the column 50. The pump can be turned on by a switch 60, which draws a vacuum through connector 52 and releases the removed gas into the interior of the console. The console is ventilated through vents 70 on the bottom surface of the housing 46.

[0082] In this specific implementation, the pump's function is controlled by a microprocessor controller 74, and the pressure output from sensor 64 also passes through the microprocessor controller 74. Each of the lamp 58, switch 60, and display 62 is connected to the microprocessor controller 74, which is powered by a power supply 72. The power supply 72 is powered via a line current connector 72A. The USB connector 72B is powered by the microprocessor controller 74. The pump is plugged into a wall socket via a power cord supplied with the pump. The power supply converts alternating current from the wall socket into direct current, which the microprocessor controller uses to power the pump, switch, lamp, USB connector, etc.

[0083] In a specific embodiment, pressure sensor 64 is connected to microprocessor controller 74 and measures the vacuum pressure in the tank via pressure sensing connector 54. A second pressure sensor (not shown) is also connected to microprocessor controller 74 and measures the ambient pressure outside the pump housing via internal tubing connected to a vent at the bottom of the pump. The microprocessor controller acquires the vacuum pressure reading from pressure sensor 64 and divides it by the ambient pressure reading from the second pressure sensor to calculate the vacuum pressure in the tank as a percentage of the ambient pressure.

[0084] Now for reference Figures 4 to 6 The specific embodiment of the collection tank 44 has a body 78, which is typically formed of a polished transparent plastic material molded into the shape shown. Figure 4 The collection tank is shown. Figure 5 The image depicted is shown in an inverted or "flipped" view. Figure 4 Implementation method of the collection tank. Figure 6 yes Figure 4 and Figure 5 An exploded view of the vacuum tank.

[0085] The body 78 has an open upper end 76, which can be covered by a removable transparent plastic cover 80. The transparent plastic cover 80 is typically attached via a bayonet connector 82, and a structure or other gasket 84 will seal the cover to the open end of the body 78.

[0086] In a specific embodiment, a groove 94 is formed in one side of the body 78 and shaped such that the groove 94 can be placed above the post 50 in the recess 48 of the housing 46 of the vacuum control console 42. Figure 5 As shown, the pressure sensing port 104 and the vacuum port 102 are located at the upper end of the recess 94, such that when the can 44 is positioned in the recess 48, the pressure sensing port 104 and the vacuum port 102 are aligned and connected with the vacuum connector 52 and the pressure sensing connector 54 on the post 50.

[0087] In a specific embodiment, the pressure sensing port 104 is connected to a conduit or lumen that extends upward within the body 48 of the can 44 and terminates at an upper opening or orifice 106. Similarly, the vacuum port 102 extends upward through a much larger lumen or conduit and terminates at an opening 108 at the upper end of the vacuum port 102. Orifices 106 and 108 are located near the top inside the body 78, but will be located below the bottom of the lid 80 when the lid is in place on the can 44. Therefore, both orifices 106 and 108 will be exposed to the interior of the can 44, but will remain far above the center and bottom of the clot and blood pool. In this way, the risk of blood and clot contamination is minimized.

[0088] In a specific embodiment, the filter plate 86 (shown as a perforated screen but may also be a woven screen or other separating element) is held in the middle portion of the interior of the body 78 of the canister 44. Clots are drawn into the interior of the canister via a connector 110 attached to the proximal end of a conduit or other tubing. Clots and blood are drawn into the interior of the body 78 by a vacuum drawn through a vacuum port 102 by a vacuum control console 42, as previously described. As clots and blood fall downwards from the connector 110 into the canister 44, the clots collect on the upper surface of the filter plate 86, while the blood flows through the perforations in the plate and collects at the bottom of the canister. Excess blood can flow through an open bypass area 100 as the plate tilts downwards from the sleeve 88 mounted on a column 90 inside the canister. Figure 4 The open bypass area 100 is formed on the back of the plate and allows blood to flow directly to the bottom of the canister. The filter body 92 occupies the interior of the column 90 and the orifice 108 and prevents extracted material from contaminating the interior of the housing 42. The filter body 92 occupies the interior of the column 90 and extends into the orifice 108. Therefore, the filter body can prevent extracted material from contaminating the interior of the housing 42. A groove 94 is formed on one side of the body 78 of the canister 44 and is received in the recess 48 of the housing 46 above the column 50 for alignment with the vacuum and pressure sensing connector and the vacuum port. A gasket 96 is also provided at the seal between the vacuum port and the vacuum connector.

[0089] Although Figure 7 to Figure 19The exemplary apparatus and method for controlled clot aspiration shown in the detailed embodiments can be used with the vacuum system 40 just described; however, it should be understood that the detailed embodiments described and claimed herein are not limited to use with any particular vacuum console, but can be used with any clot or other vascular thrombectomy or aspiration system, including thrombectomy or other vascular aspiration catheters, combined with a vacuum pump or other source, where there is a risk of excessive blood aspiration, blockage, or both.

[0090] In a specific implementation, Figure 7A and Figure 7B Vacuum control consoles and collection tanks, similar to those previously shown, are illustrated, with a vacuum suction control system attached thereto. They illustrate specific embodiments of an exemplary system 200 for performing controlled clot suction according to the described principles. The exemplary system 200 includes a base unit 210 and an outer unit 204. A proximal end of a connecting conduit 206 is connected to the base unit 210, and the outer unit is fixed to or attached to the connecting conduit at a location spaced apart from the proximal end, typically at a distance sufficient to allow conclusions about the flow. The outer unit 204 may be configured to connect directly to the hub or other proximal end of the suction conduit, or it may be configured to connect in the middle of the connecting conduit. In an unconstrained configuration, the connecting conduit is linear and flexible along its length.

[0091] In a specific embodiment, the base unit 210 may be configured to be located directly on top of the cover 26 on the collection tank 44 of the previously described vacuum control console 40. Typically, a communication cable extends from the base unit 210 through a portion of the connecting conduit 206 to a connection socket on the vacuum control console 40, allowing the base unit to be powered by the vacuum control console and optionally to transmit data with a controller within the vacuum control console.

[0092] like Figure 7B As shown, in a specific embodiment, external unit 204a may include a switch for initiating treatment using vacuum console 40 and controlled clot aspiration system 200. The switch can also shut down the system, thereby providing manual over-control of the algorithm to ensure the system is shut down and flow-free. When the switch is open, the system can immediately enter algorithm mode, in which it decides to remain open, enter sampling mode, or initiate an extraction cycle in response to pressure sensor readings. Further details of external unit 204a are provided in... Figure 8A and Figure 8B As shown in the image.

[0093] Figure 9An exemplary base unit depicted in cross-section is shown, representing a closed-loop valve and a controller of a type suitable for use in a vacuum suction control system. In a specific embodiment, the exemplary base unit 200b may include a base unit housing 216 having an open internal cavity 218 accommodating multiple components. For example, a controller 220, typically including a microprocessor on a printed circuit board, may be mounted within the cavity 218 along with a pressure sensor 224, which is attached to the proximal end of a pipe segment 228 and a connecting pipe 206 via a pressure fitting 226. The pipe segment 232 may be foldable and positioned within a pinch valve 228 driven by a solenoid 230. The pinch valve 228 may be biased to a closed position by a compression spring (not visible) unless it is opened by the solenoid 230. The base unit 200b also includes a connection fitting 222 configured to be removably secured to a vacuum fitting (not shown) on the lid 26 of the canister 44. The controller 220 is configured to open and close the pinch valve 228 to allow and prevent clots and blood from flowing through the tubing segment 232 from the aspiration catheter into the collection tank, respectively. Optionally, the base unit 200b may include buttons (not shown) that are electronically communicated with the printed circuit board 220 for advanced user control of various system parameters. In specific embodiments, the base unit may house or communicate with a pressure chamber, a fluid source, an additional switching valve, or a combination thereof.

[0094] In specific embodiments, on / off valves and controllers of the type suitable for use in aspiration control systems can be used to apply mechanical force to clots, thrombi, or other occlusive material. During impregnation cycles, the mechanical action of the on / off valve on the occlusive material can be used to cut, shear, chop, split, soften, impregnate, or otherwise alter the shape, consistency, and / or deformability of the occlusive material. Changing the form or consistency of clots, thrombi, or other occlusive material through mechanical action can advantageously enable more efficient aspiration of the occlusive material through the aspiration catheter. For example, large thrombi can be broken into smaller fragments for more efficient aspiration. For example, hard or dense thrombi can be mechanically softened or made more flexible through mechanical action for more effective aspiration. In specific embodiments, clamp valve 228 can be used to apply mechanical force and action to clots, thrombi, or other occlusive material. In specific embodiments, other types of valves can be used, including but not limited to valves specifically designed to improve the mechanical action on occlusive material. In a specific implementation, the parameters used for selectively operating the valve by the controller, including but not limited to timing, frequency, and / or duty cycle parameters, can be optimized to provide improved mechanical action of the valve against occlusive substances.

[0095] Figure 10An exemplary external unit is shown, depicting internal components including fittings and a pressure sensor (shown in dashed lines). In a specific embodiment, the exemplary external unit 204 includes an external unit housing 240, within which a flow fitting 242 is located. The flow fitting 242 can be connected to portions 206a and 206b of a connecting conduit 206, such as... Figure 7B , Figure 8A and Figure 8B The specific implementation is shown in the diagram. The second pressure sensor 246 can be mounted on a printed circuit board 248 and also inside the housing 240. The output of the pressure sensor can be transmitted to the controller 220 via a connecting cable (not shown). This connecting cable can be connected via a signal / power connector 250 and a mating signal-power connector 252, which can be a conventional USB port and plug. The connecting cable 206 can have a dual-cavity design, such as... Figure 9 As shown in the specific embodiments, one of the lumens can be used to route a communication cable between the external unit and the base unit, while the other lumen accommodates fluid flow. In another embodiment, the external unit may accommodate or be in communication with a pressure chamber, a fluid source, an additional switching valve, or a combination thereof.

[0096] By providing a first pressure sensor 224 in the base unit and a second axially separated pressure sensor 246 in the outer unit 240, in a specific embodiment, the material flow rate through the connecting pipe can be calculated based on the pressure differential measured by the controller. The controller can analyze the pressure differential and flow rate to determine the contents flowing through the suction conduit, connecting pipe, or both.

[0097] In an exemplary embodiment, the controller characterizes the state of the catheter contents as unrestricted flow, restricted flow, or occlusion. In a specific embodiment, a high pressure differential between spaced-apart pressure sensors indicates unrestricted flow, which may consist of predominantly healthy, clot-free blood or blood without vascular occlusion clots. In some instances, healthy blood is blood with a sufficiently low proportion of cross-linked fibrin so that it does not adequately integrate to cause local ischemia or other similar vascular occlusion. Complete aspiration of such healthy blood may result in excessive blood loss, potentially requiring premature termination of the aspiration procedure. In another specific embodiment, variable and intermediate or low pressure differentials indicate restricted flow, which may consist of clots, occlusive material, and blood. Such flow may benefit from complete aspiration. In yet another specific embodiment, small or near-zero pressure differentials may indicate occlusion. Such flow, or the absence of such flow, may benefit from extraction cycles. However, using pressure differentials to detect increased flow and occlusion is exemplary, and other flow measurement and material property measurement techniques may be used within the scope of this specific embodiment.

[0098] Figure 11 An angle valve 260, depicted in cross-section, is shown. This type of angle valve 260 can be used as a switching valve in a specific embodiment, rather than the pinch valve 228 shown in base unit 200. The angle valve has a connector (not shown) for attachment to a vacuum vessel and a fitting 266 that can be connected to a connecting pipe 206, which in turn connects to a suction conduit. A solenoid 268 is typically present to open and close the valve stem 270 and valve seat 272. In a specific embodiment, the valve can open to allow suction and close to prevent suction. Alternatively, the valve in the specific embodiment can open to allow fluid into the suction pipe and / or suction conduit and close to block fluid.

[0099] Figure 12 This is an isometric view of an angle valve connected to a coiled conduit, each end of which has a pressure sensor mounted on the top of the tank. In a specific embodiment, the pressure sensors may be integrated into a single base unit 276, which may be fixedly attached to the tank cover 278. In this specific embodiment, a first pressure sensor 282 and a second pressure sensor 284 are attached to opposite ends of the coiled flow conduit 280 to allow for differential pressure measurement. Angle valve 286 may be directly fixed to the outlet of the coiled flow conduit 280 to provide desired on / off flow control.

[0100] In a specific implementation, the controller 220 in the base unit 200 can implement an algorithm for receiving and analyzing pressure sensor data to open and close a switching valve, such as a pinch valve 228. Figure 9 ) or angle valve 286 ( Figure 12 ) or 260 ( Figure 11 The algorithm receives and analyzes input pressure data multiple times per second. The collected data determines the diameter of the attached conduit, the contents flowing through the conduit and suction tubing, and the flow rate.

[0101] In a specific implementation, controller 220 implements an algorithm that uses pressure sensor data to analyze the contents flowing through the aspiration catheter and characterize them as unrestricted flow, restricted flow, or blockage. Unrestricted flow catheters primarily aspirate healthy, clot-free blood, or blood without obstructive material. Mixed flow catheters aspirate a combination of clots, obstructive material, and blood. Catheters with little or no flow are blocked or occluded. If the algorithm determines that excessive blood has been aspirated (which is often the case for unrestricted flow catheters), it may restrict aspiration to reduce blood loss. If the algorithm determines that flow in the catheter is restricted, it typically allows complete aspiration. If the algorithm determines that there is almost no flow in the catheter, it may initiate an extraction cycle to help clear any blockages or obstructions. As used herein, the term "clot" should be understood to encompass any obstructive material found in the vascular system, such as thrombi, emboli, plaques, occlusive material, vascular occlusion, or any other obstructive substance. For brevity, "clot" refers to all such obstructive substances.

[0102] Figure 13 An implementation of an algorithm suitable for use with differential pressure (“ΔP”) to determine flow rate and control on / off valves based on the determined flow rate is shown. In the algorithm logic tree shown, the first step is to measure the maximum and minimum differential pressure windows within a given evaluation period. After the evaluation period, the instantaneous differential pressure is acquired and compared with these maximum and minimum differential pressure windows, which are incrementally updated. If the instantaneous differential pressure is lower than the minimum differential pressure of the evaluation period, the algorithm determines that the system is in a clot and instructs the system to continue full aspiration. On the other hand, if the instantaneous differential pressure is higher than the minimum differential pressure, the algorithm determines whether the instantaneous differential pressure is higher than the product of the maximum differential pressure and a confidence interval. If not, the algorithm allows full aspiration; if so, the algorithm restricts aspiration to limit blood loss and enters a sampling state, where aspiration is limited to brief fluctuations to acquire new instantaneous differential pressure readings. In either case, as long as aspiration is allowed, the algorithm continuously acquires instantaneous differential pressure readings and compares them with the maximum and minimum differential pressures collected throughout the procedure. In one implementation, the algorithm triggers a sampling state when unrestricted flow (e.g., open flow) is detected. In another implementation, the algorithm initiates full aspiration or an extraction cycle with pulsed aspiration when clots are detected.

[0103] In a specific implementation, correlation algorithms are used to determine whether the conduit has unrestricted flow, restricted flow, or blockage, for example, based on the correlation between flow velocity and such states. In another implementation, a windowing algorithm is used to analyze the discrete portions of the pressure sensor data to establish local minimum and local maximum pressure sensor readings. These windowed minimums and maximums are compared with the global maximum and global minimum in the dataset. Considering sudden large changes in pressure readings, the system prioritizes determining the conduit state based on local minimums and maximums. Pressure readings below the minimum and above the maximum indicate changes in the conduit state; for example, below the minimum indicates conduit blockage, and above the maximum indicates unrestricted flow.

[0104] In a specific implementation, an algorithm is used that emphasizes the analysis of the standard deviation of a discrete window across data points. The flow rate is compared to the average flow rate. A small standard deviation indicates conduit blockage or unrestricted flow, while a large standard deviation indicates restricted flow.

[0105] In a specific implementation, a learning algorithm is used to determine the contents flowing through the aspiration catheter. Training data is generated by collecting pressure readings along the catheter length under various conditions, such as unrestricted flow, restricted flow, or blockage. A large number of pressure readings for each catheter condition are recorded, and the algorithm then refers to these datasets to interpret previously unseen pressure readings to predict the catheter's condition.

[0106] In this specific implementation, an Artificial Neural Network (ANN) is utilized, employing a multinomial logistic regression algorithm. The ANN is trained to predict answers by considering a large training dataset. The training data includes observed data as input and actual outputs. The input propagates through the ANN, which consists of hierarchical nodes, each representing a linear transformation within the solution space. The ANN then "learns" by analyzing the difference between its calculated output and the actual output. This difference is translated into an error function. The error function is backpropagated through the ANN, thereby modifying the weights of each node based on its contribution to the error function. Weighting is a mathematical optimization process that determines which nodes best map the input to their correct output. A large training dataset is iteratively propagated through the ANN until the error function converges, i.e., reaches an acceptable tolerance level. When nodes are correctly weighted, the error function has converged, and the ANN can accurately predict the output of previously unseen inputs. Here, this means that a learned ANN can take novel pressure sensor data inputs and accurately predict catheter size and whether the catheter contents should be classified as unrestricted, restricted, or blocked.

[0107] In specific implementations, the algorithm employs semi-supervised and unsupervised learning to continuously update node weights. Clustering, dimensionality reduction, and reinforcement learning can be used to further improve prediction accuracy. In a preferred embodiment, the algorithm can accurately interpret pressure fluctuations associated with switching between catheters of different diameters and filters out pressure fluctuations caused by manual movement of the separator within the suction catheter by determining and considering the rhythm of movement. Alternatively, specific implementations can employ an algorithm combining the aforementioned algorithmic flow analysis techniques.

[0108] In a specific implementation, the algorithm can initiate a sampling mode when unrestricted flow is detected. In an exemplary implementation, the algorithm can detect flow changes indicating unrestricted flow within milliseconds. In one implementation of the sampling mode, the algorithm cycles through stopping aspiration and then opening and closing the switching valve at a predetermined frequency. When the valve is briefly open, the sampling state generates a suction surge and evaluates the pressure sensor readings. Based on this suction fluctuation, the algorithm determines whether the system should return to full aspiration, with the switching valve in the open position or remaining in the sampling state. These sampling surges occur on the order of milliseconds and ensure that full aspiration only occurs when the system comes into contact with clots, thereby minimizing blood loss.

[0109] In this implementation, the system is powered on and there is a brief delay before the algorithm evaluates the flow in the suction line. If the sensor indicates unrestricted flow, an appropriate delay is calculated for the on / off valve to remain closed. After the delay, the on / off valve opens, briefly allowing suction, and pressure readings are sampled in the suction line to assess whether the system still has unrestricted flow or has been located in agglomerates or other blockages. If the sampling detects unrestricted flow, a new delay is calculated (in some cases, the delay time for each consecutive reading gradually increases until a threshold is reached). If the sampling detects agglomerates, such as restricted flow or blockage, an appropriate delay is calculated for the valve to remain open. While open, the system periodically evaluates the pressure sensor readings to determine if the system's location would result in unrestricted flow. These processes are repeated until the procedure is complete.

[0110] In specific implementations, extraction cycles can be used to clear blockages in the aspiration catheter or to facilitate the aspiration of large or otherwise difficult-to-aspirate clots. The extraction cycle establishes a pressure differential between the aspiration catheter and a vacuum source to generate pressure pulses. Generally, these pressure pulses can employ a variety of mechanisms to promote thrombus uptake into the aspiration catheter. In one mechanism, the pressure pulse introduces an accelerating component that promotes the extraction of the blockage material. In another mechanism, the pressure pulse generates a force pulse that instantaneously breaks static friction, thereby allowing for lower kinetic friction to take up the thrombus. In yet another mechanism, the pressure pulse pulls the thrombus away from the distal tip of the catheter and then rapidly forces the thrombus into contact with the catheter, thereby impregnating the thrombus.

[0111] In a specific implementation, the extraction cycle can alternate between providing vacuum aspiration and relative positive pressure. The extraction cycle typically begins when the aspiration catheter is already under complete vacuum. When the extraction cycle begins, the vacuum switch valve between the catheter and the aspiration source closes, increasing the pressure in the aspiration catheter, which may result in a positive pressure pulse and establish a pressure differential between the vacuum source and the catheter. Subsequently, the switch valve opens, and the contents and the distal end of the aspiration catheter experience a pressure differential as a negative pressure pulse, which negatively impacts the structural integrity of any occlusion to the extent that static pressure can only be achieved with a greater energy supply. The amplitude or magnitude of these pressure pulses is directly related to the pressure differential between the evacuation catheter and the pressure source (for positive pressure pulses) and between the pressurization catheter and the vacuum source (for negative pressure pulses). The frequency of opening and closing the switch valve can be predetermined or responsive to pressure sensor data. The pressure pulses of the extraction cycle can have optimized amplitude and frequency to extract thrombi and similar occlusions from the vascular system.

[0112] Pressure differential in a conduit can be generated in several ways. In one embodiment, pressure can be generated by closing the conduit's connection to a vacuum source. In another embodiment, pressure can be generated by introducing fluid into the conduit, wherein the fluid is at a pressure between full vacuum and ambient pressure, ambient pressure, systolic pressure, or higher than systolic pressure. Figures 14 to 17 In a specific implementation, the pressure difference can be generated by the mechanical displacement of the pressure chamber. Figure 18 ).

[0113] In a specific implementation, the extraction cycle can be automatically initiated when the algorithm of controller 220 detects a blocked conduit, an obstructed conduit, or a conduit located in a clot. A conduit can be identified as blocked when the differential pressure approaches zero. In a specific implementation, the controller automatically initiates the extraction cycle after the system detects a blockage lasting longer than 5 seconds. Alternatively, the extraction cycle can be started or terminated according to user requirements. The extraction cycle can provide pressure pulses for a predetermined period of time. Alternatively, in a specific implementation, the extraction cycle can evaluate pressure sensor data each time the valve is opened to assess the flow rate and determine whether the extraction cycle should continue or terminate. If the extraction cycle fails to clear the blockage, the amplitude and frequency of the pressure pulses may be changed. In a specific implementation, the algorithm on controller 220 consults a library of different pressure pulses and selects from that library. If a specific amplitude and frequency begins to clear the blockage, the algorithm can continue generating pressure pulses of that frequency and amplitude until the blockage is cleared.

[0114] Figures 14 to 18 An exemplary pulsed fluid injection assembly suitable for use in a specific embodiment is shown. Figure 14 A fluid system that can be used in a specific embodiment to generate a pressure differential and thus a pressure pulse is illustrated. In this embodiment, a fluid introduction unit 290 is attached along the length of a connecting conduit 206 via a three-point joint 292. The three-point joint 292 may be located between a base unit 210 and an outer unit 204, or it may be located at the distal end of both the base unit 210 and the outer unit 204—i.e., near the attached suction conduit. A fluid injection switch valve 296 controls the flow of fluid (liquid or gas) to inject a pressure pulse into the clot flow path, which can facilitate the extraction of clots or other obstructing substances. In this embodiment, the fluid flow is introduced directly into the connecting conduit 206. In this embodiment, the fluid flow first passes through an injection line 294 before entering the connecting conduit 206. The injection line 294 can direct the pressure pulse toward the conduit, which can optimize the pressure pulse. In this embodiment, the three-point joint 292 has, for example, Figure 13 The T-shaped connector structure is shown. Alternatively, in a specific embodiment, the three-point joint may have a Y-shaped connector structure (not shown). The Y-shaped connector can advantageously guide fluid from the fluid inlet unit to the conduit, which can optimize pressure pulses in a manner similar to the injection tubing of the previous example.

[0115] Figure 15Another fluid system is illustrated, in which, in a specific embodiment, a pump 398 can be connected between a fluid reservoir 390 and an injection valve 396. In one embodiment, the pump 398 is cyclically activated when the injection valve 396 is open. The pump provides work by forcefully injecting fluid from the fluid reservoir 390 through the injection switch valve 396 into the injection line 394 and / or connecting line 306. In a specific embodiment, the magnitude of the positive pressure pulse is directly related to the throughput (e.g., size) of the pump 398. In a specific embodiment, a pressure chamber 397 is positioned between the pump 398 and the injection valve 396. The pressure chamber 397 allows the pump 398 to provide work even when the injection valve 396 is closed. When the injection valve 396 is closed, the pump 398 forcibly injects fluid from the reservoir 390 into the pressure chamber 397, thereby pressurizing the pressure chamber 397. When the injection valve 396 is open, the pressure is released from the pressure chamber 397 into the injection line 394 and / or connecting line 306. In this embodiment, since pump 396 can accumulate pressure over time, the magnitude of the positive pressure pulse is not directly related to the throughput (e.g., size) of pump 398, thus allowing for a smaller pump. To provide even better control over the duration or amplitude of the positive pressure pulse, in this embodiment, the injection valve can be throttled or manipulated to open and close to regulate the injection rate. In this embodiment, a pressure sensor can be included in pressure chamber 297 to monitor and control pressure accumulation.

[0116] Figure 16 Another three-point joint 492 attached along connecting conduit 406 is shown. In a specific embodiment, three-point joint 492 may be located between base unit 210 and outer unit 204, or it may be located at the distal end of both base unit 210 and outer unit. Pressure valve 496 controls the generation of a positive pressure pulse from fluid chamber 490. Fluid from fluid chamber 490 may flow directly into connecting conduit 406 or may first pass through injection line 494 before entering connecting conduit 406. Suction valve 499 controls the application of vacuum suction from the attached vacuum source. In a specific embodiment, three-point joint 492 has valves that control both vacuum force and positive pressure pulse. This allows three-point joint 492 to alternate between applying vacuum suction and pressure pulse, where the pressure is higher than the pressure of the vacuum source. In a specific embodiment, suction valve 499 and pressure valve 496 may open alternately, simultaneously, delayedly, or in some overlapping sequence. In an overlapping sequence, one valve begins to open as the other begins to close, resulting in a brief period during which both valves are at least partially open. In other overlapping sequences, there are sometimes periods where both valves are open and both valves are closed for at least a short time.

[0117] In a specific embodiment, a suction valve 499 is positioned between the conduit and the suction source to regulate suction, and a pressure valve 496 is positioned between the conduit and the fluid source to regulate fluid injection. In a specific embodiment, both the suction valve 499 and the pressure valve 496 can be selectively opened and closed to create a pressure differential within the conduit and / or suction line, which can generate pressure pulses of desired amplitude and frequency.

[0118] Figure 17 A perspective view of the tee connector and the components connected to it is provided. In a specific embodiment, the connecting conduit 706 serves as a common passage between the vacuum source 700, the pressure source 790, and the aspiration catheter 750. The connecting conduit 706 may have a first end configured to attach to or be positioned in fluid communication with the vacuum source and a second end configured to attach to or be in fluid communication with the aspiration catheter. In a specific embodiment, the second end is attached to the aspiration catheter via a rotary hemostatic valve. A tee connector 792 may be positioned near the second end to provide a pulse of relatively positive pressure near the aspiration catheter 750. In a specific embodiment, the tee connector 792 is an angled connector or a Y-connector, thereby directing fluid from the pressure source toward the aspiration catheter 750. In some specific embodiments, the tee connector 792 includes an injection conduit 794 that directs fluid from the pressure source to the aspiration catheter 750. In a specific embodiment, the injection conduit 794 extends from the tee connector to the aspiration catheter, thereby allowing fluid to flow from the pressure source into the aspiration catheter 750. In another embodiment, the injection tubing 794 extends from the tee fitting to a position near the distal end of the aspiration catheter, as shown in perspective view 751, which provides a magnified view of the distal end of the aspiration catheter 750. In this embodiment, a pressure source can cause fluid to flow according to directional arrow 761, and a vacuum source can cause fluid to flow according to directional arrow 760. In this embodiment, a controller can adjust a vacuum valve 799 and a pressure valve 796, whereby closing the vacuum valve 799 and opening the pressure valve 796 can result in a relative increase in pressure at the distal end of the aspiration catheter.

[0119] Alternatively, in a specific embodiment, opening the vacuum valve 799 and closing the pressure valve 796 can result in a relative decrease in pressure at the distal end of the suction conduit 750. In a specific embodiment, these pressure changes are transmitted as pressure pulses along the length of the suction conduit. In a specific embodiment, the controller can close the vacuum valve 799 and open the pressure valve 796 for a short period of time, thereby allowing a minimum volume of fluid from the pressure source 790 to be introduced into the proximal end of the suction conduit 750 to increase the relative pressure at the distal end of the suction conduit 750 before restoring vacuum by reopening the vacuum valve 799 and closing the pressure valve 796.

[0120] Similarly, in a specific embodiment, the controller can close the vacuum valve 799 and open the pressure valve 796 for an extended period, allowing a larger volume of fluid from the pressure source 790 to be introduced into the suction conduit 750. This facilitates the movement of obstructive material away from the distal end of the suction conduit 751 before restoring vacuum by reopening the vacuum valve 799 and closing the pressure valve 796. In another embodiment, the connecting conduit 706 may have a dual-lumen design along a portion of its length, whereby one lumen contains fluid and the second lumen contains wiring. This allows the controller to regulate both the vacuum valve 799 and the pressure valve 796.

[0121] Figure 18 A valve structure for controlling suction force and positive pressure pulses is shown. In a specific embodiment, a three-point joint 592 is attached to a connecting conduit 506 and a pressure chamber 590. A gate valve 550 translates along axis 570 to block suction at position 550A and to block fluid introduction at position 550B. The gate valve 550 can provide pulsed suction by oscillating back and forth at a predetermined or responsive frequency controlled by an algorithm in controller 220. In a specific embodiment, a three-way gate valve is present at the joint between the suction source, the pressure source, and the conduit. The gate valve 550 translates between blocking the suction source and blocking the pressure source to achieve pressure pulses of desired amplitude and frequency.

[0122] In a specific embodiment, fluid injection does not occur at the three-point junction, but rather in a more distal region closer to the catheter tip. The location of the relative pressure injection can be used to optimize pressure pulse variations to facilitate clot removal. In one embodiment, the distal region of the aspiration catheter includes an openable and closable valve, such as a distal valve. In this embodiment, the aspiration valve is closed, and the distal valve is opened to allow blood to rush into the catheter, increasing the pressure within the catheter and amplifying the pressure differential between the catheter lumen and the vacuum source. Typically, the distal valve is then closed, and the aspiration valve is opened, where the pressure differential between the vacuum source and the catheter results in a pressure pulse. In another embodiment, fluid is transferred from another adjacent catheter to the aspiration catheter. For example, an inner catheter can deliver fluid to an outer aspiration catheter. In a specific embodiment, the outer catheter can deliver fluid to the inner aspiration catheter via a valve structure. In either case, fluid is delivered along the length of the aspiration catheter, rather than proximally. Similarly, in this embodiment, adjacent catheters can provide additional connections to a vacuum source.

[0123] Figure 19A mechanical displacement assembly for manipulating pressure is shown. In a specific embodiment, a mechanical piston 699 may replace the injection valve, pressure chamber, pump, and fluid reservoir of a previous embodiment. The stroke of piston 699 or the mechanical device may be controlled to adjust the volume of the conduit, resulting in negative pressure in one stroke and positive pressure in another. Generally, mechanical actuators actuate back and forth to increase and decrease the overall volume of the system. When the device actuates to increase volume, the pressure decreases, and when the device actuates to decrease volume, the pressure increases. These pressure changes may generate, amplify, or assist in the pressure pulses of the extraction cycle. In a specific embodiment, piston 699 may be disposed in a three-point junction 692 attached to connecting conduit 606. Other mechanical devices for controlling the volume or pressure of the conduit include linear motors, stepper / servo motors, cam follower actuators, solenoids, audio exciters, voice coil actuators, diaphragms, peristaltic pumps, rotary vanes, gears, screws, syringes, etc. (not shown).

[0124] In a specific implementation, high-frequency pressure pulses can be achieved through mechanical methods, such as... Figure 19 The method shown. To provide high-frequency pressure pulses, the catheter must be rapidly pressurized and rapidly emptied. In a specific implementation, Figures 14 to 18 Fluid injection systems can easily provide rapid pressure inflow; however, a vacuum source may require a considerable amount of time to restore the conduit to a complete vacuum. If the next pressure inflow occurs too early, the conduit will not have time to reach or approach a complete vacuum. In this case, the pressure differential between the incompletely emptied conduit and the pressure source will be low, and the resulting pressure pulse will have a low amplitude, which may not be optimal in some situations. In specific implementations, to avoid low-amplitude pressure pulses caused by high frequencies, a vacuum recovery system can be used to reduce the time required to return the conduit to a complete vacuum after a positive pressure inflow. Using a vacuum recovery system, high-amplitude and high-frequency pressure pulses can be achieved.

[0125] Figure 19Another device is shown that can be used as a vacuum recovery system by generating a pressure differential. In a specific embodiment, the vacuum recovery system may utilize a syringe, a vacuum chamber, a second suction pump, or some combination of these options. The syringe is a piston-driven device that retracts to increase the volume of the system (thus reducing pressure) and advances to decrease the volume of the system (thus increasing pressure). The syringe-like device can not only advantageously aid in vacuum recovery but also advantageously aid in the generation of positive pressure pulses. In a specific embodiment, the syringe is used during the extraction cycle. In such an embodiment, the conduit begins under complete vacuum. The vacuum source is closed, the syringe advances (to reduce the system volume), and fluid is optionally injected, all of which contribute to the formation of positive pressure pulses. Next, the vacuum source is opened, and the syringe retracts (to increase the system volume) to generate negative pressure pulses, thereby accelerating the return of the conduit to near complete vacuum. In a specific embodiment, the suction pump is configured to selectively infuse the evacuation chamber leading to the conduit, in addition to the suction pump, after each pressure pulse. The suction pump and the evacuation chamber together restore the conduit to complete vacuum more rapidly. When the suction pump approaches the conduit, it can open to the evacuation chamber to further infuse the evacuation chamber between pressure pulses. In a specific embodiment, an auxiliary suction pump assists the main suction pump to facilitate vacuum recovery after each pressure pulse.

[0126] Figure 20 A graphical representation of a specific implementation of pulsed aspiration is shown, where the pressure inside the catheter varies over time. The extraction cycle can use a pulsating scheme to systematically manipulate the amount of pressure within the catheter to facilitate the extraction of occlusive material. The pressure within the catheter can be manipulated by various methods. For example, vacuum aspiration can be used to reduce the pressure within the catheter, and the removal of fluid by vacuum aspiration and / or the introduction of fluid can be used to increase the pressure within the catheter. In other cases, mechanical actuation devices can alternate between increasing and decreasing the pressure within the catheter. In a specific implementation, such as Figure 20 As shown, at time 0, the conduit is not subject to any suction and is at atmospheric pressure. From time 0 to time 1, the conduit loses pressure, surging from atmospheric pressure to near-vacuum (i.e., close to -29.9 inches of mercury). From time 1 to time 2, the conduit pressure increases, thus reducing the vacuum level. From time 2 to time 3, the conduit loses pressure, allowing it to return to near-vacuum. From time 3 to time 4, the conduit gains pressure and returns to ambient pressure. From time 4 to time 5, the conduit loses pressure, rising again from atmospheric pressure to near-vacuum. From time 5 to time 6, the conduit pressure increases, causing a surge from near-vacuum to above ambient pressure. From time 6 to time 7, the conduit loses pressure, jumping from a pressurized state above atmospheric pressure to near-vacuum.

[0127] Figure 20The pulsation scheme shown can be executed once or repeated multiple times. In specific embodiments, the pulsation scheme may include additional time periods with additional pressure variations and pressure patterns. Generally, the system pressure may vary between near vacuum and above average systolic pressure. The cycle of the duration pulsation scheme can be predetermined or adapted to pressure sensor readings. In specific embodiments, the controller can extend or shorten the pulsation scheme based on pressure sensor readings. In some specific embodiments, the system can maintain a stable pressure state for one or more time periods. For example, the controller can keep the system in a near-vacuum state. The residence time at each pressure state and the frequency of system transitions between pressure states can be optimized to take up different clotted or occlusive material compositions. Although Figure 20 A pulsation scheme with a stable and consistent frequency is shown; in other embodiments, the frequency of the pulsation scheme may be variable or a combination of partially stable and partially variable. High-amplitude (or high-amplitude) pressure pulses can be generated by producing a large pressure differential. For example, Figure 20 A high-amplitude pressure pulse between times 5 and 7 is shown. In a specific implementation, a lower-amplitude pressure pulse can be generated by oscillating between less extreme high and low pressures. For example, the lower end of the pressure pulse may not reach near-complete vacuum, and the higher end of the pressure pulse may not reach ambient pressure, or both, resulting in a lower-amplitude pressure pulse, which may be desirable in some cases. Figure 20 The time unit can be seconds, milliseconds, microseconds, etc.

[0128] In some specific embodiments, the extraction cycle employs a predetermined series of pressure pulses with near-full vacuum suction before the extraction cycle, between pulses of relative positive pressure, and after the extraction cycle. The pressure pulses can be selected from a library of pressure pulses with amplitudes and frequencies that promote the extraction of clots and other occlusive substances. The series of pressure pulses can differ from each other in frequency, amplitude, or both. For example, a pulsation scheme can use a series of pressure pulses with the following trends: one of the amplitudes or frequencies increases while the other decreases; both the amplitude and frequency increase or decrease; or one of the amplitudes or frequencies increases or decreases while the other remains constant.

[0129] In a specific implementation, the extraction cycle provides specific pressure pulses based on pressure sensor readings. One such response extraction cycle measures the pressure within the catheter and then selects one or more pressure pulses optimized for the catheter with those pressure readings. In another response extraction cycle, the system can cycle through a library of pressure pulse patterns, where each individual pressure pulse is followed by a period of static or full aspiration and occlusion detection. After the library has been cycled, the system can repeat the pressure pulse that was measured as the most successful. The success of a particular pressure pulse is typically proportional to the amount of increased flow rate following the pressure pulse. The system can continue cycling until only a few pressure pulse patterns remain in the cycle. If the effectiveness of the cycle begins to diminish, the system can return to a complete library and begin a new cycle.

[0130] In a specific implementation, the response extraction cycle can have three modes: upward cycle, where the continuous pressure pulses are stronger in amplitude and / or frequency; downward cycle, where the continuous pressure pulses are weaker in amplitude and / or frequency; and sustaining pressure pulses, where the pressure pulses have a consistent frequency and amplitude. The system enters the cycle mode when it detects a blockage. It enters the sustaining mode when it detects a restricted flow state. When the system detects an unrestricted flow state, it enters the downward cycle mode. In this way, the system tends to apply pressure pulses with amplitudes and frequencies that promote restricted flow, which is beneficial for removing clots and other blockage materials.

[0131] Alternative approaches may be useful in situations where maximum removal of occlusive material is possible without concern for blood loss, such as in neurovascular stroke surgery. In these cases, the preferred technique may include positioning the distal end of the catheter within the clot, applying a complete vacuum, and waiting for a predetermined period before proceeding to the next step. The aim may be to completely or nearly completely engage the catheter tip with a large amount of occlusive material, essentially blocking the distal end of the catheter and sometimes referred to as “catheter plugging.” If the clinician successfully “plugs the catheter,” the catheter system can be removed from the blood vessel, along with the large amount of clot or occlusion. Alternatively, in specific embodiments, an extraction cycle may be used to aspirate the occlusion through the catheter lumen or to lock the clot deep within the catheter. After completing the extraction cycle, in specific embodiments, the clot may be removed or plugged into the attached catheter, allowing the catheter to be safely removed from the patient along with the clot.

[0132] In a specific implementation, the extraction cycle can be automatically or manually stopped when a clot or other obstructing material blocks the catheter. For example, the clot or obstructing material may be too large or hard to pass through the aspiration catheter but is still partially trapped within it. In a specific implementation, the system can switch to full aspiration to allow the user to remove the blocked catheter while simultaneously pulling the clot or obstructing material out along with the catheter. In some cases, the clot or obstructing material may still block the catheter when the extraction cycle is initiated. In a specific implementation, the controller can then return to full aspiration and notify the user of the blockage event, thereby prompting the user to remove the catheter. In a specific implementation, the user can manually shut off the extraction cycle, returning the system to full vacuum and removing the catheter.

[0133] In a specific implementation, the system can be switched to an impregnation cycle to allow mechanical forces, such as pinch valves or different types of valves, to be applied to clots or other occlusive materials. This mechanical action can be used to substantially alter the form and / or consistency of the clots or other occlusive materials to achieve more efficient suction.

[0134] To indicate that a specific implementation is performing work to remove clots or other obstructing material, one implementation may include visual and / or auditory signals indicating the progress of a given extraction cycle. In one implementation, the start of an extraction cycle is signaled by a flashing blue light that flashes until the cycle is complete, and upon completion, the light turns green to indicate completion. In another implementation, base unit 216 may include a light bar. The light bar gradually fills, i.e., the light bar gradually “fills” the light, proportional to the progress of the cycle. Alternatively, base unit 216 may include a small screen for displaying images. The small screen may display an animation indicating loading. The loading animation may perform a repetitive pattern (e.g., rotating a circular object) or a single loop of extended animation (e.g., slowly filling a circle). In conjunction with or as an alternative to visual progress indication, the system may use auditory cues in an implementation to indicate the start, pulsating phase, and completion of an extraction cycle. Such auditory cues may include musical notes, beeps, and / or speech. Auditory cues may include updates (e.g., “extracted”) or suggestions (e.g., “advance / retract catheter”).

[0135] In a specific implementation, the algorithm can also control lighting mechanisms, such as indicator lights 210. Figure 7A and Figure 7BThis allows the system to communicate to the user whether it is in a fully aspirated state, an unrestricted flow state, a restricted flow state, a blocked state, a sampling state, or an extraction state. Specific lights may illuminate to indicate that a bubble or overshoot switch has been triggered. In a specific embodiment, an algorithm may control a piezoacoustic chip that communicates auditory information to the physician regarding the status of the exudate and the overshoot switch. In one embodiment, the piezoelectric element is a 4kHz monotone mounted at 10cm for 65dB. The signal may include sounds and phrases such as pitch / tone variations, beep patterns, "blockage," "occlusion," "clotting," "blood," "open flow," etc. Specific embodiments utilize dynamic beep rhythms, where the beep pattern steadily increases as the duration of the unrestricted flow state increases. The speed of the beep indicates the length of time the system has been in an unrestricted flow state, alerting the physician to the increasing severity of system positioning problems. In a specific embodiment, the system may also include multi-position switches or buttons to specifically enable different algorithms, mute audio cues, or the fluid perfusion system. Such a feature can be enabled by inserting a pin in the base unit 210, which will enable the customizable feature.

[0136] In a specific implementation, the system can be manually powered on and aspirated for a predetermined period of time. If the system detects unrestricted flow, the switching valve is closed to stop the flow. The attending physician must then reposition the catheter tip into the clot and manually trigger a mechanism (e.g., a foot pedal or manual switch) to initiate further aspiration. This manual trigger can override the algorithm and allow aspiration to continue. Once the manual trigger is released, the algorithm can again monitor the flow to allow aspiration, as long as the flow is acceptable. In a specific implementation, if and when the system detects unrestricted flow again, the switching valve can be closed again until the physician repositions the aspiration catheter and manually overrides the controller. This process can be repeated until the physician completes the procedure.

[0137] In some embodiments, the catheter may need to be perfused with an incompressible fluid before it can be used to remove clots and other obstructing material. In some embodiments, the catheter may be filled with saline fluid to remove all air from the catheter lumen. In some embodiments, the catheter is automatically perfused, thereby filling the catheter with fluid to expel all compressible fluids (e.g., air). In some embodiments, sensors may monitor the catheter contents during use. If compressible fluid (e.g., air bubbles) is detected, the system may alert the user. In some embodiments, the system may indicate that the procedure needs to be stopped so that the catheter can be prepared again to remove air bubbles.

[0138] Dynamic system state detection

[0139] Figure 21This is a schematic diagram of a specific implementation configured for dynamic system state detection, illustrating alternative methods for detecting one or more system states (e.g., unrestricted or blocked flow in a suction conduit). The proximal end of connecting conduit 2110 may be fluidly connected to a vacuum source 2120. The distal end 2130 of connecting conduit may be fluidly connected to the proximal end of suction conduit 2140. Figure 21 In this case, the distal end of the suction catheter is shortened, i.e., not shown in the schematic diagram.

[0140] In a specific embodiment, controller 2150 can selectively open and close vacuum valve 2160 to control fluid communication or corresponding isolation of the connecting pipe relative to the vacuum pressure of the vacuum source. Based on parameters used to operate the vacuum valve, such as the number, sequence, frequency, and / or duty cycle of triggering valve open / close states, many operating states of the vacuum valve are possible. A distal pressure sensor 2170 may be located near the distal end of the connecting pipe. In a specific embodiment, an external unit, such as previously... Figure 8A , Figure 8B and Figure 10 The unit described and illustrated can exist as a connection module between the distal end of the connecting pipe and the proximal end of the suction catheter. In a specific embodiment, the external unit may also include a distal pressure sensor.

[0141] In a specific implementation, the controller may operate a vacuum valve to generate one or more pressure level changes in the connecting pipe, thereby drawing in the contents of the connecting pipe and / or suction conduit system. Furthermore, the controller may use a distal pressure sensor to detect the pressure level at the distal end of the connecting pipe, wherein the detected pressure level changes are correlated with the pressure level changes generated by operating the vacuum valve.

[0142] In a specific implementation, based on a detected pressure distribution, which includes a time-correlated sequence of detected pressure levels, the controller can dynamically determine one or more system states in the suction conduit and / or connecting pipes. Based on the determination of one or more flow states, the controller can also initiate one or more actions.

[0143] Figure 21 The general approach, along with the specific implementations described above, can be considered as dynamic detection of system state. This paper will further discuss some specific implementations of this method. It should be understood that the specific implementations of dynamic detection of system state can vary between implementations and can be customized based on specific configurations and applications.

[0144] Figure 22A specific implementation of an algorithm suitable for realizing dynamic system state detection and detecting the system state in the aspiration catheter or connecting tubing of an aspiration thrombectomy system is shown. In the first step 2210 of the illustrated algorithm, the controller can generate one or more pressure level changes in the connecting tubing by operating a vacuum valve in a first operating mode, for example by selectively opening and closing the vacuum valve. In the second step 2220, the controller can detect one or more pressure levels associated with the distal end of the connecting tubing via a first pressure sensor. In the third step 2230, the controller can determine one or more system states in the aspiration catheter or connecting tubing based on one or more detected pressure level changes. In the fourth step 2240, the controller can operate the vacuum valve in a second operating state based on one or more determined system states.

[0145] In certain implementations or situations, based on inferring the system state present in the suction conduit or connecting pipe through detected pressure distribution, the controller can determine that additional vacuum valve operation is not immediately required. For example, the controller can create a pressure level change in the connecting pipe by opening and then closing the vacuum valve. In another implementation, if the controller subsequently determines that there is unrestricted or open flow in the suction conduit, the controller can continue to keep the vacuum valve closed until the next action step is required.

[0146] The system status may include a qualitative and / or quantitative description of the flow state within the aspiration catheter and / or connecting tubing. In specific embodiments, the flow state may be an unrestricted or open flow state, wherein the distal end or tip of the aspiration catheter may be in contact with healthy blood, and there may be little or no occlusive material in the catheter and / or connecting tubing. In specific embodiments, for example due to Figure 21 The clot 2180 may present a blocked flow state in the suction conduit. As will be discussed further, in specific embodiments, the flow state may also include "intermediate" states, such as partially blocked flow, which may require specific actions to follow the determination of the system state.

[0147] System status may also include a qualitative and / or quantitative description of the presence of specific fluids and / or other materials in the aspiration conduit and / or connecting pipes. In a specific embodiment, the presence or absence of a flushing or perfusion fluid, such as brine, may define one or more system statuses. In a specific embodiment, the presence or absence of a gas, such as trapped air, may define one or more system statuses.

[0148] The system status may also include qualitative and / or quantitative descriptions related to the presence, absence, and / or other characteristics of components of the aspiration thrombectomy system. In specific embodiments, as will be further discussed, the disclosed method can be used to detect when the aspiration catheter is not attached to the thrombectomy system. In specific embodiments, the system status may also include qualitative and / or quantitative descriptions related to specific aspects of the operational importance of the aspiration thrombectomy system. In specific embodiments, as will be further discussed, the disclosed method can be used to detect when a clot has been distally engaged by the aspiration catheter. In specific embodiments, such determination can be used to further automatically initiate regulated aspiration. In specific embodiments, such determination can be used to further automatically initiate immersion cycles.

[0149] The contents of a system including connecting tubing and / or aspiration catheters may include blood, including healthy blood, as well as clots and other occlusive substances found in the vascular system, such as thrombi, emboli, plaques, occlusive materials, and / or vascular occlusion materials. Additionally, the system contents may include other fluids and materials used for preparing and operating the aspiration thrombectomy system. In a specific embodiment, saline fluid may be used for flushing and / or perfusion of the aspiration thrombectomy procedure. In a specific embodiment, gas bubbles, such as air bubbles, may be trapped in the connecting tubing and / or aspiration catheters and may be part of the system contents. In a specific embodiment, pressure level changes generated by operating a vacuum valve can be considered as generating pressure waves in the system including the contents of the connecting tubing and / or aspiration catheters.

[0150] Although this disclosure describes the use of specific sensors and / or valves to detect a specific system state in a specific manner, this disclosure is intended to provide any suitable sensor, actuator, or method for detecting system state or taking further action in any suitable manner.

[0151] Specific implementations of the dynamic system state detection method may utilize pressure sources and / or valves, in addition to the aforementioned vacuum sources and vacuum valves, either alone or additionally. In specific implementations, as previously disclosed, the pressure source may be connected in fluid communication with a connecting pipeline via a controllable pressure valve, wherein the reference pressure level of the pressure source can vary from vacuum (i.e., very low absolute pressure) to an absolute pressure significantly higher than ambient pressure or systolic pressure. By way of example and not limitation, in specific implementations, a brine supply system may be used as such a pressure source. These individual or additional pressure sources and / or pressure valves may be used in different combinations to generate pressure level changes and / or to initiate actions as a result of determining a particular system state.

[0152] Specific embodiments of this dynamic system state detection method may use sensors other than the aforementioned distal pressure sensor, either alone or additionally. In a specific embodiment, as previously discussed, a vacuum pressure sensor monitoring the vacuum level at the tank may be used. In a specific embodiment, a brine pressure sensor monitoring the pressure level of the brine fluid may be used. Furthermore, the sensors used in specific embodiments of this method are not limited to pressure sensors. In specific embodiments, data may be derived from various sensors, including, for example, sensors for detecting pressure, acoustic energy, ultrasonic energy, and flow rate.

[0153] In a specific implementation, one or more system scores can be determined to identify the system state, wherein each system score, independently or in combination with other system scores, can indicate the probability of a particular system state in the suction conduit or connecting tubing. In this respect, system scores can serve as a measure for quantifying the corresponding probability of a particular system state.

[0154] System scores can be derived directly or indirectly from sensor data, such as the detected pressure distribution discussed above. In specific embodiments, system score determination can be based on automatically identifying specific features from the detected pressure distribution, extracting pressure parameters based on values ​​and trends derived from those specific features, and calculating one or more system scores based on the pressure parameters of those features. In specific embodiments, system scores can be determined as the sum of specific parameter indices (e.g., pressure parameters). By way of example, and not limitation, one or more pressure parameters indicating the open flow state of a system can return, for example, system scores of 1, 2, or 3, depending on the specific pressure parameters and specific thresholds used in the system combination, application, and / or implementation. The pressure parameters and specific thresholds can be directly summed to calculate a quantitative value of one or more system scores, such as the open flow score. In specific embodiments, determining system scores can involve further processing. In specific embodiments, determining system scores based on pressure parameters can also include the use of appropriate weighting and / or correction factors for the parameters. By way of example, and not limitation, the weights of the pressure parameters can be determined empirically. Maximum and minimum values, thresholds, and other characteristics associated with system scores can be determined and / or adjusted based on specific system combinations and / or applications. For example, the specific threshold for the system score can vary based on the specific combination of the catheter and the aspiration system. Several examples and specific implementations with specific characteristics involving the detected pressure distribution and the corresponding system score will be discussed further. It should be understood that deriving the system score from sensor data can vary depending on the implementation and can be customized for specific configurations and applications.

[0155] In a specific implementation, the system score can be determined based on machine learning. In a specific implementation, the intermediate quantities used to determine the system score can be determined based on machine learning. As an example, and not a limitation, the intermediate quantities of interest may include thresholds and / or weighting factors. In a specific implementation, the training dataset can be assembled from detected stress distribution data acquired across a wide range of scenarios, combined with statistical variations, and corresponding to the system states of interest. The trained machine learning model can then be used to predict the system states of new situations. In a specific implementation, the machine learning algorithm can employ semi-supervised and / or unsupervised learning. The algorithm can employ clustering, dimensionality reduction, and / or reinforcement learning to further improve prediction accuracy. Additionally, in a specific implementation, an algorithm using a combination of the above-described algorithmic flow analysis techniques can be employed.

[0156] It is important to note that specific sensor parameters and distributions, such as pressure distribution, parameter selection, thresholds, and other criteria, and / or all other quantities, such as valve states illustrated herein, are exemplary and not limiting. For example, those discussed further below... Figures 23 to 70 Provided as an example only, not as a restriction.

[0157] Figure 23 The distal pressure distribution detected over time for a specific embodiment is shown, illustrating some pressure parameters. The distal pressure distribution 2310 is based on the pressure changing over time as detected by the distal pressure sensor. The corresponding vacuum valve state distribution 2320 indicates the state of the vacuum valve over time, where the open state of the vacuum valve is indicated as a relatively elevated stable level on the y-axis, for example in 2320a, and the closed state of the vacuum valve is indicated as the vacuum valve being at a relatively low stable level, for example in 2320b. Similar to the vacuum valve states described above, the open or closed states of vacuum valves or other valves shown in other figures and illustrations herein can also be indicated by the relative levels of the corresponding valve distributions on the y-axis.

[0158] As a result, in specific implementations, the detected pressure distribution (e.g.) can be used to... Figure 23 The system's response to pressure level changes caused by the cycle of the vacuum valve (i.e., rapid opening and closing) was observed in the diagram. Figure 23 Some specific exemplary features of the detected pressure distribution, previously referred to as pressure parameters, are also shown.

[0159] For example, in Figure 23 In the specific implementation shown, and corresponding to situations where flow is generally unrestricted or open, when the vacuum valve is first opened, the distal pressure may experience a significant drop as the contents of the connecting pipe and suction conduit are exposed to the very low absolute pressure level of the vacuum source and accelerate toward the low pressure.

[0160] For example, the value of the distal pressure corresponding to the initial value before the sudden decrease in distal pressure can be identified as the initial (or initial) distal pressure, as shown in the figure. For example, in a specific embodiment, the initial distal pressure can indicate the patient's blood pressure and the time history of the system status. Furthermore, in a specific embodiment, the rate of change of the initial distal pressure can be correlated with blood viscosity and / or the presence of clots in the catheter. After the vacuum valve is subsequently closed, the contents of the connecting tubing and aspiration catheter may experience a sudden deceleration and eventually return to a new pressure equilibrium in the system disconnected from the vacuum source.

[0161] One or more peak pressure levels can be pressure parameters of interest used to determine system fraction and / or system state. In a specific implementation, the maximum recorded overshoot corresponding to the distal pressure when the vacuum valve is closed in this condition can be identified as the maximum absolute rebound pressure, such as... Figure 23 As an example, not a limitation, the maximum absolute rebound pressure may also be related to blood viscosity.

[0162] In a specific implementation, one or more pressure levels and / or time intervals corresponding to the restoration of pressure level equilibrium following a pressure change event, such as a vacuum valve cycle, can be pressure parameters of interest for determining system fraction and / or system state. For example, a time window can be established based on pressure and / or time measures corresponding to the cessation of the effect of pressure disturbances related to the opening and closing sequence of the vacuum valve. In a specific implementation, as shown, the distal pressure value at that moment can be identified as the final distal pressure. For example, in a specific implementation, the final distal pressure can correspond to the distal pressure value at a predetermined time interval (e.g., 80 ms) after the vacuum valve closes, or it can be based on a time interval determined according to other parameters.

[0163] It should be understood that, based on the requirements of specific configurations and applications, the specific definitions and thresholds of sensor parameters may vary between implementations. The pressure parameters and related characteristics disclosed below are intended to be exemplary and not limiting.

[0164] In a specific implementation, the measurement of pressure change can be further extracted as a pressure parameter. For example, for this extraction, the pressure change between the marked start and end times of distal pressure can be considered. In a specific implementation, as shown in the figure, the mean absolute deviation (“MAD”) of pressure with respect to the median (“Med”) pressure can be identified as a measurement of the pressure change between the vacuum valve closing and the end of distal pressure. The mean absolute deviation (“MAD / med”) of pressure with respect to the median pressure can also be correlated with blood viscosity.

[0165] In a specific implementation, the differential pressure level can be a pressure parameter of interest used to determine the system fraction and / or system state. In a specific implementation, for two consecutive vacuum valve cycle sequences, the difference between the second initial distal pressure and the first initial distal pressure can be identified as the differential pressure level of interest, such as... Figure 23 As shown. Such an initial distal pressure differential can remain stable throughout the viscosity range.

[0166] As previously discussed, the system fraction can be determined based on detected pressure parameters. In a specific implementation, the open fraction can be determined based on the detected pressure parameters. By way of example, and not by limitation, the value of the open fraction can vary between 0 and 7, and can indicate at least the probability of an open flow state. Similarly, in a specific implementation, the occlusion fraction can be determined based on detected pressure parameters. By way of another example, and not by limitation, the value of the occlusion fraction can vary between 0 and 7, and can indicate at least the probability of an occluded flow state. Furthermore, in a specific implementation, various combinations of the open and occlusion fractions can indicate the probability of one or more additional system states of interest (e.g., partially occluded flow states).

[0167] In specific implementations, thresholds can be established to determine the system state based on system scores. As examples, rather than by constraint, in specific implementations, if the occlusion score is equal to or greater than 3 (within the maximum possible score of 7), the system can be determined to be in an occluded state. In specific implementations, if the open score is equal to or greater than 3 (again, within the maximum possible score of 7), the system can be determined to be in an open-flow state. In specific implementations, if both the open and occlusion scores are less than 3, the system can be determined to be in a partially occluded state. In specific implementations, this partially occluded state may indicate the presence of a clot or thrombus that is sufficiently flexible or deformable to be extracted by continuous aspiration and does not necessarily require pulsed or modulated aspiration.

[0168] Although this disclosure describes establishing specific thresholds for determining the system state based on a particular system score in a particular manner, this disclosure contemplates providing any suitable threshold for determining the system state based on any system score in any suitable manner.

[0169] Figures 24 to 31 Specific embodiments of distal pressure distributions for a series of system state fractions are illustrated. In these examples of specific embodiments, specific portions of each detected distribution are highlighted, and occlusion and open fractions determined based on the detected pressure parameters are indicated to correspond to the highlighted portions of each detected pressure distribution. These illustrations are exemplary and are not provided in a limiting manner.

[0170] For example, Figure 24 The distal pressure distribution detected under generally open or unrestricted flow conditions in a specific embodiment is shown. The detected distribution in the specific embodiment shows a relatively rapid pressure change 2310 in response to a change in vacuum valve state 2320. The highlighted areas show relatively large overshoot or maximum rebound pressure, as well as high pressure changes detected when the flow vacuum valve closes immediately. Based at least on these pressure parameters, the occlusion fraction in this example is determined to be 0, while the open fraction is determined to be 5.

[0171] As another example, Figure 25 The diagram illustrates the distal pressure distribution detected under partially occluded flow conditions in a specific embodiment. This distribution exhibits relative damping rebound, with the detected pressure level not recovering to its initial distal pressure level. Based at least on these pressure parameters, the occlusion fraction in this example is determined to be 0, while the open fraction is determined to be 1. Figure 26 A specific implementation is shown, wherein the occlusion fraction is determined to be 3 and the open fraction is determined to be 1.

[0172] Figure 27 An example is shown where, for a specific embodiment, the occlusion fraction is determined to be 4 and the open fraction is determined to be 1. In this example, based on the pressure distribution detected in response to a first vacuum valve cycle that begins shortly after a timemark of 1367.5 s, the system can initially be determined to be in an open flow state. Based on the determination of open flow, the system can operate in an intermittent aspiration manner, i.e., the vacuum valve can remain closed for a period of time to prevent the aspiration of healthy blood. During this intermediate time interval, in some embodiments, the catheter can be repositioned to engage with the clot. The vacuum valve curve shows that it cycles again shortly after a timemark of 1368.5 s. Based on the corresponding detected pressure distribution, the system can be determined to be in a flow state that is at least partially occluded, which is reflected in the system fraction determined in this example. In some embodiments, as shown here, the system can trigger regulated or pulsed aspiration in response to this condition. In this specific embodiment, regulated aspiration can be observed as alternating cycles of vacuum valve distribution (2320) and pressure valve portions (2710), each distribution indicating the state of the corresponding valve over time. In some implementations, high-pressure brine fluid can act as a pressure source via a pressure valve. At the end of the sequence, as shown in the distal distribution, blockages can be aspirated, and the exemplary pressure distribution indicates that the system is once again in an open flow state.

[0173] Figures 28 to 31 An example is shown where, in a specific implementation, progressively more distinct markings can indicate occlusion, with correspondingly larger occlusion scores and / or lower (or zero) open scores determined by the controller. Figure 28An example is shown where the occlusion fraction is 5 and the open fraction is 1. Figure 29 An example is shown where the occlusion fraction is 6 and the open fraction is 0. Figure 30 An example is shown where the occlusion fraction is 7 and the open fraction is 0. Figure 31 Different examples are shown where the occlusion fraction is 7 and the open fraction is 0. Figure 32 The illustrations show open flow and the corresponding intermittent suction evolving into occluded or partially occluded flow in specific embodiments, which may require regulated or pulsed suction. These illustrations are exemplary and not intended to be limiting.

[0174] In a specific implementation, a particular combination of occlusion fraction, open fraction, and / or other system fractions can be used to trigger an impregnation cycle to apply mechanical force to the occluded material. This mechanical action can be used to substantially alter the form and / or consistency of the clot or other occluded material to achieve more efficient suction.

[0175] In specific implementations, an escalation feature can be used, wherein a continuously determined escalation count is maintained by the controller to maintain the same system state, and a specific action can be taken if the count exceeds a threshold. In specific implementations, the count can be reset in iterations following threshold crossover iterations. In specific implementations, the action taken if the count exceeds the threshold can be generating a notification, such as a user notification. In specific implementations, the action taken if the count exceeds the threshold can involve the controller operating one or more valves. In specific implementations, parameters for regulated suction or pulse suction can be adjusted based on a combination of occlusion fraction and escalation count.

[0176] Figure 33 The progression of the escalation counting scenario in a specific implementation is illustrated. The occlusion fraction determined at a specific moment indicated by the arrow is shown as an example, but not as a limitation: it fluctuates between 5 and 7 during the time interval spanning the first five such moments (arrows), but this can generally indicate a persistent occlusion flow state. Accordingly, the escalation count is shown to increment in each consecutive identical determination of the occlusion flow until a threshold escalation count of 5 is reached, at which point, in the specific implementation, the adjusted pumping parameters can be modified based on a combination of the occlusion fraction and the escalation count. When determining the system fraction for the next time, as... Figure 33 As indicated by the last arrow, the upgrade count can be reset to zero. In this example, the occlusion score is significantly reduced to 3.

[0177] In a specific implementation, one or more system scores relative to a threshold can be used to initiate action based on the operation of one or more valves. Such action may also depend on the previous or current system state and / or the suction pattern performed via valve operation.

[0178] In a specific embodiment of an aspiration-based thrombectomy system performing intermittent aspiration, an increase in the occlusion fraction exceeding a threshold can trigger the initiation of a modulated aspiration mode. In another specific embodiment of the same system, an increase in the open fraction exceeding a threshold can trigger a mode involving continuous intermittent aspiration. In yet another embodiment, if neither the open nor the occlusion fraction increases beyond a threshold, continuous aspiration can be initiated. In a specific embodiment of a modulated aspiration-based thrombectomy system, a decrease in the occlusion fraction below a threshold can trigger a mode change to intermittent aspiration.

[0179] As previously discussed, additional system conditions can be determined based on sensor data detected in relation to changes in the generated pressure level. For example, in a specific implementation, the presence of brine and / or air in the system can be detected through such dynamic system condition detection. Figure 34 and Figure 35 Examples are shown in specific embodiments of detecting successful and unsuccessful infusion operations by using detected pressure distributions related to pressure changes resulting from valve operation. These illustrations are exemplary and are not provided in a limiting manner.

[0180] Figure 34 and Figure 35 The diagram illustrates a distal pressure distribution 2310 based on a specific embodiment, a brine pressure distribution 3410 associated with a brine pressure source, and a vacuum pressure distribution 3420 associated with pressure in a vacuum tank. An exemplary vacuum valve distribution 2320 illustrates the open / closed operating states of a vacuum valve over time. An exemplary pressure valve distribution 2710, also known as a vent valve distribution, illustrates the open / closed operating states of a pressure valve for a brine pressure source over time. Specific characteristics and pressure parameters that may allow the detection of brine and / or air will be discussed further.

[0181] Figures 36 to 50 Pressure distribution characteristics are illustrated in specific embodiments for dynamic system state detection during infusion. These illustrations are exemplary and not intended to be limiting. Figure 36 The diagram illustrates the pressure distribution at the start of the infusion sequence when both the vacuum valve and the brine pressure valve are open in a specific embodiment. It explains how the slope of the vacuum pressure distribution can indicate air in the distal connection pipe and in the absence of confinement. Figure 37 The nature of the change or variation in the slope of the vacuum pressure distribution at the start of the infusion sequence, still in the specific embodiment, is shown, such as a bend from a positive slope to a negative slope, which can indicate the transition from an aeration system to a restricted system due to the entry of brine liquid into the vacuum tank. Figure 38This illustrates, in a specific embodiment, how the time interval between initiating infusion and identifying a bend or change in the slope of the vacuum pressure distribution can indicate the relative balance of air and / or brine, as well as limitations at the distal connection pipe.

[0182] Figure 39 This diagram illustrates how the mean absolute deviation (“MAD”) of vacuum pressure acquired during the start, middle, and end time windows / intervals of a perfusion operation—which can be expressed as “MAD / med”—can be used in a specific embodiment to identify brine and to detect successful perfusion. High levels of variation may indicate slugging due to liquid brine; this variation may increase as a successful start-up operation progresses, indicating that air is gradually being replaced by liquid. In contrast, Figure 40 The illustration shows the characteristics of the vacuum distribution corresponding to an unsuccessful perfusion operation in a specific embodiment. In the early stages of perfusion, a high slope may indicate the presence of air, and a delayed or absent significant and timely slope change may indicate the absence of liquid brine. An excessively long time required for a slope change may indicate excessive air in the system. Furthermore, a change in level from the beginning may indicate the presence of liquid in the pipes rather than a dry pipe. A decreasing vacuum pressure change over time may indicate a decrease in liquid in the pipes over time, rather than an increase.

[0183] Figure 41 The diagram illustrates the evolution of brine pressure changes during the start, middle, and end of a successful infusion operation in a specific embodiment. For example, the median absolute deviation of pressure, or MAD / med, can be used as a measure of change. Similarly, high levels of change may indicate slugging due to the presence of brine. For a successful start-up in this specific embodiment, low initial change may indicate a dry start, while a significant and increased pressure change at the end of the operation indicates the potential presence of brine. In contrast, Figure 42 The illustration shows a significant pressure change in brine pressure at the start of the perfusion sequence in a specific embodiment, indicating that the tubing may not yet have begun to dry out. A decrease in pressure change may indicate the presence of a small amount of fluid in the tubing, resulting in minimal slugging.

[0184] Figure 43 The distal pressure distribution 2310, obtained during the middle of a successful perfusion sequence in a specific embodiment, is shown. The significantly high maximum and low minimum distal pressures, along with the high variability, may indicate an inertial "water hammer" effect of the liquid relative to air, which could further suggest the presence of liquid brine. Similarly, Figure 44The diagram illustrates the saline pressure distribution 3410 obtained during a successful perfusion sequence in a specific embodiment. The significantly high maximum saline pressure and low minimum saline pressure, along with the high variability, may indicate an inertial "water hammer" effect of the liquid relative to air, which could further suggest the presence of liquid saline. In contrast, Figure 45 The distal pressure distribution and saline pressure distribution obtained in the middle of an unsuccessful perfusion sequence are shown in a specific embodiment. Both exemplary pressure distribution plots show small deviations and low variations in maximum and minimum pressures, which can indicate low-inertia "water hammer" effects and minimal fluid flow when the vacuum valve is closed.

[0185] Figure 46 The diagram illustrates the vacuum pressure distribution obtained during a successful infusion sequence in a specific embodiment. Little or no change in vacuum pressure can be observed at the vacuum tank, which could indicate no flow and / or high viscosity, further suggesting that the tubing may be filled with liquid, resulting in a very low flow rate at the vacuum valve. In contrast, Figure 47 The diagram illustrates the vacuum pressure distribution obtained during an unsuccessful infusion sequence in a specific embodiment. The increased pressure at the vacuum tank may indicate a high flow rate, and / or low viscosity may indicate that the tubing is filled with air rather than liquid brine.

[0186] Figure 48 The distal pressure distribution obtained near the end of a successful perfusion sequence in a specific embodiment is shown. The significantly high maximum distal pressure and low minimum distal pressure, along with high variability and ringing or oscillation, may indicate an inertial "water hammer" effect of the liquid relative to air due to the large fluid flow when the pressure valve closes, possibly due to the presence of liquid brine. In contrast, Figure 49 The distal pressure distribution obtained near the end of an unsuccessful perfusion sequence in a specific embodiment is shown. Little or no change in distal pressure can be observed, which may indicate a lack of fluid flow when the pressure valve is closed, and little or no inertial "water hammer" effect is observed due to the relative lack of brine.

[0187] Figure 50 The diagram illustrates the saline pressure distribution obtained near the end of a successful perfusion sequence in a specific embodiment. The intermediate final saline pressure exceeds the intermediate final distal pressure, which may indicate a head-on or pressure differential between the two pressures. This could be due to the saline column being higher than the distal sensor.

[0188] While this disclosure describes the use of specific sensor distributions, specific parameters, and / or specific actuators (e.g., vacuum valves) to dynamically detect system status and / or take further action based on that determination, this disclosure is intended to provide any suitable sensors, actuators, and / or methods for detecting system status or taking further action in any suitable manner.

[0189] As previously discussed, system states such as open flow state, closed flow state, or "intermediate" state are determined based on system scores such as open and closed fractions. In specific embodiments, the controller can be configured to detect system states associated with the relative presence or absence of liquids and gases (e.g., brine and air). For example, each feature (e.g., those disclosed above) can be weighted, and the weighted sum of the features can be used to determine one or more corresponding system states. The above and following aspects are exemplary and not limiting. It should be understood that the methods for dynamic system state detection can vary with implementation and can be customized based on specific configurations and / or applications.

[0190] In a specific implementation, dynamic system status detection can be used to determine whether the catheter is attached to the aspiration thrombectomy system. In another specific implementation, the catheter must not be connected to the system for flushing with saline. Additionally, other factors indicating the presence of saline may be used subsequently. This is provided as an example, not a limitation. Figures 51 to 52 The pressure distribution characteristics of a specific implementation for catheter detection during flushing are shown.

[0191] Figure 51 The distal pressure distribution obtained at the start of the flushing sequence in a specific embodiment is shown, where no catheter is attached to the system. Large variations or ringing of the distal pressure can be observed based on the circulation of the vacuum valve within the time interval or window of interest. Additionally, the median distal pressure 5110 during this time interval can be determined to be close to the local ambient pressure. This combination of characteristics may indicate that no catheter is attached to the system. In contrast, Figure 52 The distal pressure distribution obtained at the start of the flushing sequence in a specific embodiment is shown, with the catheter attached to the system. Based on the circulation of the vacuum valve, changes in distal pressure or a significant reduction in ringing can be observed, and the median distal pressure is significantly lower than the local ambient pressure during this time interval, indicating that the catheter can be attached to the system.

[0192] Figures 53 to 55 The pressure distribution characteristics of a specific implementation method for verifying the presence of liquid during rinsing are shown. Figure 53 The brine pressure distribution at the start of the flushing sequence in a specific embodiment is shown. A higher brine pressure relative to the distal or ambient pressure indicates the presence of sufficient liquid in the brine conduit to begin flushing. Figure 54 The brine pressure distribution during the middle of the rinsing sequence in a specific embodiment is shown. The maximum brine pressure, which is higher than the median brine pressure at the beginning, illustrates the inertial "water hammer" effect due to the presence of liquid. Furthermore, the time taken to reach the maximum brine pressure may be sufficient to indicate ringing in this particular example. Figure 55 The brine pressure distribution at the end of the flushing sequence is shown in a specific embodiment. The brine pressure at the end of the flush is greater than the distal pressure at the start of the flush, which may indicate the presence of a standing head in the brine tubing due to the liquid being at a considerable height above the distal end of the tubing. These illustrations are provided by way of example and not limitation.

[0193] In a specific implementation, dynamic system state detection can be used to determine the presence or absence of saline during the reperfusion sequence. This is, by way of example, but not limitation. Figures 56 to 58 The pressure distribution characteristics of a specific implementation for verifying the presence of fluid during reperfusion are shown. Figure 56 and Figure 57 The diagram illustrates the saline pressure distribution obtained at the end of a successful reperfusion sequence in a specific embodiment. (See diagram for reference.) Figure 56 As shown, significant changes in brine pressure detected during the time interval window after valve closure (using a metric such as MAD / med) can be used to verify the presence of liquid. Figure 57 As shown, a brine pressure exceeding ambient pressure at the end of reperfusion (5710) can indicate a standing head in the brine line due to sufficient fluid height. In contrast, Figure 58 The diagram illustrates the saline pressure distribution corresponding to an unsuccessful reperfusion sequence in a specific implementation. Low variations in saline pressure detected during the time interval window following valve closure (using a metric such as MAD / med) may indicate a lack of inertial "water hammer" effect, which could further suggest a lack of liquid saline. Furthermore, the observation that the saline pressure at the end of reperfusion is the same as ambient pressure also likely indicates a lack of saline.

[0194] In a specific implementation, dynamic system state detection can be used to determine the presence or absence of brine during a pulse sequence. This is provided as an example, but not as a limitation. Figures 59 to 60 The pressure distribution characteristics of a specific implementation for brine detection during a pulse sequence are shown. Figure 59 The brine pressure distribution during the pulse sequence in a specific embodiment is shown. High variations in brine pressure detected during a time interval window based on the operating pressure valve (using a metric such as MAD / med) can indicate the presence of brine. Furthermore, a high ratio of maximum to minimum brine pressure may also indicate the presence of brine. Figure 60The detection of brine loss during pulsation is illustrated in a specific embodiment. While the early time interval window during the pulse illustrates high variations in brine pressure and a large ratio of maximum to minimum brine pressure, all of which indicate the possible presence of brine, the later time interval window illustrates significantly lower variations in brine pressure and a significantly reduced ratio of maximum to minimum brine pressure, all of which indicate that brine loss may occur during the pulse.

[0195] In a specific embodiment, dynamic system status detection can be used to determine whether clots have been bonded. In a specific embodiment, the initiation of regulating suction can be performed after this determination of clot bonding. In a specific embodiment, such determination can be used alone or additionally to initiate an impregnation cycle for applying mechanical force to the occlusive material. This mechanical action can be used to substantially alter the form and / or consistency of the clot or other occlusive material to achieve more efficient suction.

[0196] This is an example, but not a limitation. Figures 61 to 65 The pressure distribution characteristics of a specific implementation for clot detection corresponding to a pulse sequence are shown. Figure 61 The distal pressure distribution during the pulse sequence in a specific embodiment is shown. A comparison of the median distal pressure obtained during the midpoint of the time interval between vacuum valve cycle events illustrates a decrease in the median during two consecutive such measurements, which can indicate the presence of occlusion or clots.

[0197] Figure 62 The distal pressure distribution during the pulse sequence in a specific embodiment is shown. In the first case, corresponding to the first cycle of the vacuum valve around the 1105.9s timemark, the median distal pressure obtained at the beginning is compared with the median distal pressure obtained in the middle of the pulse cycle. As observed in the first case, the large difference between these median pressures may indicate the presence of open or unrestricted flow. In the second case, corresponding to the second cycle of the vacuum valve starting around the 1106.1s timemark, a small difference between the median pressures is observed, which may indicate the presence of occlusion or agglomeration.

[0198] Figure 63The distal pressure distribution during the pulse sequence in a specific embodiment is shown. In the first case, corresponding to a short time window around the 1105.9s timemark at the start of the first cycle of the vacuum valve, the distal pressure variation (using metrics such as MAD / med) is large due to the inertial "water hammer" effect, which may indicate open, free, or unrestricted flow. In the second case, corresponding to a short time window at the start of the second cycle of the vacuum valve around the 1106.1s timemark, the distal pressure variation (using metrics such as MAD / med) is small, which may indicate the presence of occlusion or agglomeration.

[0199] Figure 64 The distal pressure distribution during the pulse sequence in a specific embodiment is shown. In the first case, corresponding to the first cycle of the vacuum valve around the 1105.9 s timemark, the median distal pressure at the start of the pulse cycle is compared to the mean absolute deviation of the distal pressure during the middle of the pulse cycle. A large deviation observed may indicate open flow conditions and a corresponding pressure increase. In the second case, corresponding to the second cycle of the vacuum valve starting around the 1106.1 s timemark, the median distal pressure at the start of the second pulse cycle is again compared to the mean absolute deviation of the distal pressure during the middle of the second pulse cycle. A small deviation observed may indicate low flow conditions and a pressure decrease due to the possible presence of blockage or agglomeration.

[0200] Figure 65 The distal pressure distribution during the pulse sequence in a specific embodiment is shown. In the first case, corresponding to the large time interval window taken in the middle of the first cycle of the vacuum valve starting around the 1105.9s time mark, the change in distal pressure (using a metric such as MAD / med) is large due to the inertial "water hammer" effect, which may indicate open, free, or unrestricted flow. In the second case, corresponding to the large time interval window taken in the middle of the second cycle of the vacuum valve starting around the 1106.1s time mark, the change in distal pressure (using a metric such as MAD / med) is small, which may indicate the presence of occlusion or agglomeration.

[0201] In specific implementations, dynamic system state detection may involve the use of multiple sensors, such as multiple pressure sensors, including interactions between the multiple sensors. This is provided as an example, but not as a limitation. Figures 66 to 70 The pressure distribution of a specific implementation using multiple pressure sensors P1 and P2 for dynamic system condition detection is shown. It should be understood that the use of multiple sensors for dynamic system condition detection can vary depending on the implementation and can be customized based on specific configurations and / or applications.

[0202] Figure 66The illustration shows the use of pressure distributions P1 and P2 in a specific embodiment to detect open flow conditions. For example, for the event corresponding to the first valve cycle. Figure 66 For the initial time interval window, based on the valve cycle, both P1 and P2 pressure changes are significant, which can indicate an open flow condition. Based on this determination, the valve can remain closed. For example, an open flow determination can be made separately or additionally based on comparing the median pressure levels at the beginning and end and / or based on comparing the median pressure level at the end relative to ambient pressure. In a specific embodiment, if the P1 change multiplied by the P2 change is large, and the initial median P1 pressure is less than the final median P1 pressure, and if the final median P1 pressure is approximately equal to ambient pressure, then open flow can be determined. In a specific embodiment, if the P1 change multiplied by the P2 change is large, and the initial median P2 pressure is less than the final median P2 pressure, and if the final median P2 pressure is approximately equal to ambient pressure, then open flow can be determined.

[0203] In a specific implementation, for the event corresponding to the second valve cycle... Figure 67 Within the intermediate time interval window, the pressure changes of both P1 and P2 are relatively smaller, which can indicate a lower flow rate. Furthermore, the median of the P1 and P2 pressure levels acquired during this intermediate time interval window also decreases, which may indicate that flow is restricted due to the presence of clumps. Based on this determination, the valve can be opened. In a specific embodiment, if the product of the P1 change and the P2 change is small, it can indicate a lower flow rate. In a specific embodiment, if the product of the P1 change and the P2 change is large and the system is determined to be not in free flow, it can indicate a lower flow rate and / or restricted flow, and the valve can be opened due to the presence of clumps.

[0204] Figures 68 to 70 The illustration shows a specific implementation of system status detection using P1 and P2 in an open valve state without valve circulation. For example... Figure 68 As shown, in a specific embodiment, at the start of the valve opening state, pressure P1 is close to pressure P2, and the product of P1 and P2 is small, which can indicate a low flow rate. In a specific embodiment, if pressure P1 is approximately equal to pressure P2, and if pressure P1 is approximately equal to ambient pressure, and if the product of pressure P1 and pressure P2 is small, it can indicate low flow. Based on the determination of low flow, the valve may remain open without sampling. Figure 69The diagram illustrates an increase in flow in a specific embodiment. As shown, P1 increases to a value much greater than P2, resulting in a large product of P1 and P2, which may indicate a high flow rate potentially leading to a sampling cycle and possibly valve operation. If no open flow is detected in the sampling cycle, the valve may remain open. In this embodiment, a high flow rate can be indicated if the pressure P1 is greater than the pressure P2, and if the product of the pressures P1 and P2 is large, and if the P1 and P2 environments are available, thus inducing a sampling cycle. If no open flow is detected in the sampling cycle, the valve may remain open. In this embodiment, a high flow rate can be indicated if the pressure P1 is much greater than the pressure P2, and if the P1 and P2 environments are unavailable, leading to a sampling cycle. If no open flow is detected in the sampling cycle, the valve may remain open. In this embodiment, a high flow rate can be indicated if the product of the pressures P1 and P2 is large, and if the P1 and P2 environments are unavailable, leading to a sampling cycle. If no open flow is detected in the sampling cycle, the valve may remain open.

[0205] Figure 70 The diagram illustrates a comparison of the changes in P1 and P2 pressures observed during time interval windows, in the middle and near the end of the distribution shown in the illustration. Small changes in P1 and P2 pressures (e.g., changes observed approximately in the middle of the distribution sequence shown in the figure) may indicate low flow conditions and the possible presence of agglomerates. In this case, the valve may remain open. Conversely, large changes in P1 and P2 pressures, as observed near the end of the pressure distribution sequence shown in the figure, may indicate high flow rates and the absence of agglomerates. In this case, the valve may be closed. In the illustration, if the square of the P1 change (i.e., the P1 change multiplied by itself) multiplied by the P2 change is large, a high flow rate can be determined, indicating the absence of agglomerates. Based on this determination, the valve may be closed.

[0206] In specific implementations, physical parameters can be extracted from sensor data. Specific characteristics and pressure parameters detected during dynamic system state monitoring may depend on, depend differently on, or be independent of specific physical parameters. For example, as previously discussed, in specific implementations, the initial distal pressure and / or maximum absolute rebound pressure may be correlated with blood viscosity. Conversely, in specific implementations, the initial distal pressure differential may be stable with changes in blood viscosity. Based on other known parameters, in specific implementations, physical parameters such as blood viscosity, clot or thrombus characteristics such as elasticity or deformability, catheter and / or connecting tubing dimensions, geometry, configuration, and other characteristics can be determined by detecting sensor distributions (e.g., pressure distributions) based on comparisons with known databases and / or selectively generating pressure changes in the system. In specific implementations, parameters such as clot or thrombus characteristics determined by detecting sensor distribution maps can be used to determine the selective application of specific operating modes (such as extraction, conditioning, and / or immersion modes).

[0207] As already discussed, system state determination can be based on determining one or more system state scores. In specific implementations, the algorithms and thresholds used to determine and interpret system state scores can be adjusted based on: physical conditions, such as ambient temperature and other temperatures and pressures; material parameters, such as the elasticity of connecting tubing or the viscosity of blood; geometric and configuration parameters, such as the length or diameter of the aspiration catheter; characteristics of the thrombus, such as elasticity or deformability; and / or other detected parameters, such as pressure parameters.

[0208] other

[0209] In this document, unless otherwise expressly indicated or the context otherwise indicates, "or" is inclusive rather than exclusive. Therefore, "A or B" in this document means "A, B, or both," unless otherwise expressly indicated or the context otherwise indicates. Furthermore, "and" is both consequential and separate, unless otherwise expressly stated or the context otherwise indicates. Therefore, "A and B" in this document means "A and B, together or separately," unless otherwise expressly indicated or the context otherwise indicates.

[0210] The scope of this disclosure covers all changes, substitutions, variations, alterations, and modifications to the exemplary embodiments described or illustrated herein that will be understood by those skilled in the art. The scope of this disclosure is not limited to the exemplary embodiments described or illustrated herein. Furthermore, while this disclosure describes and illustrates various embodiments herein as including specific components, elements, features, functions, operations, or steps, any of these embodiments may include any combination or arrangement of any component, element, feature, function, operation, or step that will be understood by those skilled in the art as described or illustrated anywhere herein. Additionally, the device or system mentioned in the appended claims, or a component of a device or system adapted, arranged, capable, constructed, operable, or operatively to perform a specific function, covers: the device, system, or component, whether or not it or the specific function is enabled, turned on, or unlocked, provided that the device, system, or component is so adapted, arranged, capable, constructed, operable, or operatively performed. Furthermore, while this disclosure describes or illustrates specific embodiments that provide particular advantages, these embodiments may not provide these advantages, or may provide some or all of these advantages.

Claims

1. A suction-type thrombectomy system, comprising: A suction catheter having a proximal end and a distal end, wherein the suction catheter is configured to contain fluid; A controllable vacuum valve is in fluid communication with a vacuum source, wherein the vacuum valve is configured to operate in multiple operating states, and wherein one or more of the operating states include selectively opening the vacuum valve and selectively closing the vacuum valve; A connecting conduit having a proximal end and a distal end, wherein the connecting conduit is configured to serve as a common channel for fluid communication between the suction conduit and the vacuum source via the vacuum valve; A first pressure sensor, the first pressure sensor being associated with the distal end of the connecting pipe; and An automatic controller, the automatic controller being configured to: The vacuum valve is operated in a first operating state among the plurality of operating states to produce one or more changes in the pressure level of the fluid in the connecting pipe; One or more pressure levels associated with the distal end of the connecting pipe are detected via the first pressure sensor, wherein changes in the detected pressure levels are related to changes in one or more resulting pressure levels; Based on one or more detected changes in pressure levels and based on one or more system state scores according to the detected pressure levels, one or more system states of the aspiration catheter or the connecting tubing are determined from a plurality of predetermined system states, wherein each system state score indicates the probability of a corresponding state in the aspiration catheter or the connecting tubing; and The vacuum valve is operated in a second operating state based on one or more defined system states.

2. The aspiration-type thrombectomy system according to claim 1, wherein, The second operating state of the vacuum valve is the same as the first operating state.

3. The aspiration-type thrombectomy system according to claim 1, wherein, Based on the determination that at least one system state score corresponding to the occluded flow state has decreased to below a threshold score, the second operating state is an intermittent suction operating state.

4. The aspiration-type thrombectomy system according to claim 1, wherein, Based on the determination that at least one system state score corresponding to the occluded flow state has increased above a threshold score, the second operating state is an adjusted suction operating state.

5. The aspiration-type thrombectomy system according to claim 1, wherein, One or more of the system state scores are also based on one or more geometric features of the aspiration catheter, wherein the one or more geometric features of the aspiration catheter are determined based on one or more detected pressure levels.

6. The aspiration-type thrombectomy system according to claim 1, wherein, One or more of the system state scores are also based on one or more environmental parameters of the aspiration thrombectomy system.

7. The aspiration-type thrombectomy system according to claim 1, wherein, One or more of the system state scores are also based on one or more material parameters associated with the aspiration thrombectomy system, wherein the one or more material parameters are determined based on one or more detected pressure levels.

8. The aspiration thrombectomy system according to claim 1, wherein, One or more of the system state scores are also based on one or more thrombus parameters associated with one or more thrombi in the aspiration catheter or the connecting tubing, and wherein the one or more thrombus parameters are determined based on one or more detected pressure levels.

9. The aspiration-type thrombectomy system according to claim 1, wherein, One or more of the system state scores are also based on one or more fluid parameters associated with one or more fluids in the suction conduit or the connecting conduit, and wherein the one or more fluid parameters are determined based on one or more detected pressure levels.

10. The aspiration thrombectomy system according to claim 1, wherein, Determining the one or more system state scores includes determining one or more pressure parameters based on the detected pressure levels.

11. The aspiration thrombectomy system according to claim 10, wherein, The pressure parameters include one or more of the following: initial pressure level, difference between initial pressure levels, final pressure level, difference between final pressure levels, peak pressure level, and change in pressure level.

12. The aspiration thrombectomy system according to claim 1, wherein, The system further includes a pressure source in fluid communication with the connecting pipe via a controllable pressure valve, and wherein operating in the first operating state and operating in the second operating state includes operating one or both of the vacuum valve and the pressure valve.

13. The aspiration thrombectomy system according to claim 1, wherein, One of the system states is determined to be an open flow state, and the second operating state is an intermittent suction operating state based on the determination of the open flow state.

14. The aspiration thrombectomy system according to claim 1, wherein, One of the system states is determined to be an open flow state, and based on the determination of the open flow state, the second operating state is a state in which the vacuum valve is closed.

15. The aspiration thrombectomy system according to claim 1, wherein, One of the system states is determined to be a partially blocked flow state, and the second operating state is a continuous suction operating state based on the determination of the partially blocked flow state.

16. The aspiration thrombectomy system according to claim 1, wherein, One of the system states is determined to be a clogging flow state, and the second operating state is an regulated suction operating state based on the determination of the clogging flow state.

17. The aspiration thrombectomy system according to claim 1, wherein, One of the system states is determined to be a blocked flow state, and the second operating state is, based on the determination of the blocked flow state, the vacuum valve is open.

18. The aspiration thrombectomy system according to claim 1, wherein, The automatic controller is also configured to: For each determined system state, determine whether the system state is the same as a previously determined system state; and Determine whether the number of identical consecutive system states exceeds a threshold.

19. The aspiration thrombectomy system according to claim 18, wherein, The automatic controller is also configured to: In response to determining that the threshold number has been exceeded, a notification indicating that the threshold number of consecutive identical system states has been exceeded is generated.

20. The aspiration thrombectomy system according to claim 18, wherein, The second operating state is selected based on the determination that the number of identical consecutive system states exceeds the threshold number.

21. The aspiration thrombectomy system according to claim 1, wherein, The aspiration thrombectomy system includes one or more second pressure sensors associated with one or more corresponding locations of the aspiration catheter or the connecting tubing, and wherein the automatic controller is further configured to detect one or more pressure levels associated with the corresponding location for each second pressure sensor.

22. The aspiration thrombectomy system according to claim 1, wherein, The one or more detected pressure levels are associated with one or more pressure wave distributions.

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