Systems and methods for aspiration thrombectomy

Abstract

Systems and methods for aspiration thrombectomy are provided. An aspiration thrombectomy system for use with a vacuum source and an aspiration catheter includes a connection tube configured to function as a fluid conduit between the aspiration catheter, a fluid source, and the vacuum source. The system may be provided with a controllable valve and a pressure sensor associated with the connection tube. The controller may detect a pressure profile in the connection tube via one or more pressure sensors. The controller may determine whether the connection tube is occluded based on the detected pressure profile, and may determine a location of the occlusion. The controller may operate one or more valves to introduce a fluid medium into the connection tube.

Description

Field of the Technology

[0001] The present disclosure generally relates to the field of medical devices and methods. More particularly, the specific embodiments described herein relate to devices and methods for controlling the removal of clots from a patient's vasculature by aspiration thrombectomy. Background Art

[0002] Stroke is a major cause of disability and death and an increasingly serious problem for healthcare globally. Stroke can be caused by the occlusion of a cerebral artery due to thromboembolism (referred to as "ischemic stroke") or by the rupture of a cerebral artery (referred to as "hemorrhagic stroke"). Hemorrhagic stroke can lead to bleeding within the skull, restricting the blood supply to brain cells and causing harmful pressure on the delicate brain tissue. Blood loss, swelling, herniation of brain tissue, and blood pools can lead to the formation of clot masses within the skull and can rapidly damage brain tissue. Hemorrhagic stroke is a life-threatening medical emergency with limited treatment options.

[0003] In addition to stroke, thromboembolism throughout the vasculature of the arterial and venous circulations is characteristic of many common, life-threatening conditions. Examples of potentially fatal diseases caused by thrombotic occlusion include pulmonary embolism, deep vein thrombosis, and acute limb ischemia. In the United States, acute pulmonary embolism is a major cause of death. Pulmonary embolism can be a complication of deep vein thrombosis. The foregoing are some non-limiting examples of conditions in which treatment can include aspirating or draining clots and / or blood. Summary of the Invention

[0004] The specific embodiments described herein provide systems and methods for improving catheter aspiration by achieving a more efficient procedure, by enhancing the uptake of occlusive material, or both. In certain embodiments, the amount of fluid flowing through an aspiration catheter under vacuum aspiration is monitored to determine whether the flow is unrestricted, restricted, or blocked. Depending on the determined flow state, certain embodiments can employ different techniques and methods to improve catheter aspiration. In certain embodiments, unrestricted flow is detected and aspiration is automatically and temporarily restricted for the purpose of conserving blood. Blood loss is minimized and the ratio of occlusive material to healthy blood removed is increased, thereby allowing for a more complete removal of the occlusive material. In certain embodiments, restricted flow is detected and full vacuum aspiration is automatically applied. In another specific embodiment, a blocked catheter is detected and pulse aspiration is automatically applied. This can beneficially enhance the uptake of large, hard, or otherwise troublesome occlusions. Alternatively, the user of certain embodiments can apply pulse aspiration, full aspiration, or restricted aspiration as needed.

[0005] In certain embodiments, the described systems and methods address the problem of excessive blood loss through a dynamic aspiration cycle. The properties and fluidity of the material removed by the aspiration catheter are monitored so that the system can allow continuous aspiration when in a clot, or sample the extraction rate to determine if the end of the catheter is in contact with a clot, in order to reduce the risk of excessive blood loss. Although the determination and monitoring of blood flow rate are disclosed in the exemplary embodiments below, other measurements of the fluidity and / or structural composition of the aspirate 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 tube (clots are darker in color than fresh blood), or placing a strain gauge on the aspiration tube.

[0006] The systems and methods of certain embodiments can respond to changes in the flow rate, pressure, differential pressure, or other metrics of the material composition inside or adjacent to the aspiration catheter within a sub-second time frame to limit unnecessary blood aspiration during thrombectomy. Certain embodiments can be used in any thrombectomy, embolectomy, atherectomy, or other catheter or probe system in which blood and clots are removed in whole or in part by applying a vacuum to the proximal end of any reperfusion, aspiration catheter, or probe for the purpose of clot extraction.

[0007] Certain embodiments can provide a vacuum aspiration control system for use with a vacuum source and an aspiration catheter. In certain embodiments, the system includes a flexible connecting tube, a switching valve, a sensing unit, and a controller. In certain embodiments, the connecting tube is linear in an unconstrained configuration and is configured to connect the vacuum source to the aspiration lumen in the aspiration catheter. In certain embodiments, the switching valve is configured to be operably connected to the connecting tube, and the sensing unit is configured to determine the flow rate within the connecting tube and generate a signal representative of such flow, such as unrestricted flow, restricted flow, or blocked flow. In certain embodiments, the controller is connected to receive the signal representative of the flow through the connecting tube and opens and closes one or more switching valves in response to the signal. In certain embodiments, when the signal indicates unrestricted flow, e.g., primarily healthy blood or blood from an unobstructed vascular clot flows through the connecting tube, and / or the catheter is substantially not in contact with a clot or other occlusive material, the controller is configured to automatically close the switching valve to stop the flow through the connecting tube. In certain embodiments, the controller is configured to initiate pulsed aspiration when the signal indicates a blockage, which may be caused by some occlusive material in or adjacent to the catheter or connecting tube.

[0008] In certain embodiments, the controller may be configured to automatically open the switching valve at a predetermined interval to sample the effluent material through the connecting tube, and the valve generally remains open only when a signal indicates a return to a clot. In certain embodiments, the controller algorithm may be configured to determine the difference between healthy blood and a clot, independent of the suction source and the inner diameter of the attached catheter.

[0009] In certain embodiments, 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, magnetic flow sensors, sensors that detect circumferential expansion of the connecting tube, rotary suction pump torque sensors, and the like. 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 tube is excessive and / or blocked is suitable for and contemplated in certain embodiments.

[0010] In certain embodiments, the sensing unit may include a plurality of pressure sensors at spaced positions along the connecting tube to measure differential pressure. In certain embodiments, the controller may calculate the flow rate based on the differential pressure and may determine whether the calculated flow rate indicates unrestricted flow, restricted flow, or blockage.

[0011] In certain embodiments, the sensing unit may use an optical sensor that measures light transmission, absorption, or both to characterize the contents flowing through the connecting tube. In certain embodiments, visible light is used to determine whether the flow contains a clot or is primarily clot-free. By way of example and not limitation, flow with a clot may be darker in color, which can be detected by the optical sensor. Additionally or alternatively, in certain embodiments, the optical sensor may sense infrared, ultraviolet, visible light, or a combination thereof to analyze the contents within the connecting tube.

[0012] In certain embodiments, the sensing unit may use a circumferential expansion sensor to determine the contents flowing through the connecting tube. In certain embodiments, the internal pressure of the connecting tube and / or the contents flowing through the connecting tube may affect the circumference of the connecting tube. By way of example and not limitation, under strong vacuum, such as during a blockage, the tube may experience a relatively large contraction and / or a relatively large reduction in circumferential extent. By way of example and not limitation, during periods of high blood flow that is primarily clot-free, the tube may experience a relatively low contraction and / or a relatively low reduction in circumferential extent. By way of example and not limitation, during restricted flow, a clot and / or blood may cause relative expansion of the connecting tube.

[0013] In certain embodiments, the sensing unit can be integrated into a rotationally driven inline suction pump. In certain embodiments, the consistency of the effluent in the tube may affect the torque required to pump the effluent. By way of example and not limitation, when removing occlusive material, the torque can approach a relatively large value. By way of example and not limitation, during removal of mostly clot-free blood, the torque required can be relatively low.

[0014] In certain embodiments, the switching valve can take various specific forms. In certain embodiments, the switching valve can include an actuator, such as a solenoid actuator, that is powered to open the valve. In certain embodiments, the valve can take various forms, such as a pinch valve, an angle valve, or any one or combination of various other valves that can provide suitable actuation. Additionally or alternatively, in certain embodiments, a manual switching valve can be provided that allows a user to initiate and / or terminate the functions and features of certain embodiments.

[0015] In certain embodiments, the controller can be configured to open the valve and keep the valve open until a flow pattern indicating unrestricted flow is detected, at which point the controller closes the valve. In certain embodiments, the controller can further be configured to automatically reopen the switching valve. In certain embodiments, in what can be referred to as a "sampling mode", the controller can further be configured to periodically sample, or test the flow to re-characterize the flow and determine if it is safe to resume suction. By way of example and not limitation, in certain embodiments, the controller can periodically test the flow by opening the switching valve for a fixed time interval, such as 150 milliseconds, to establish a "test" flow. In certain embodiments, the test flow is characterized and, if there is such an indication, the switching valve can be reopened to a "treatment" mode to allow continued suction treatment. In certain embodiments, if the system characterizes the flow as unrestricted, e.g., excessive, the system can remain in a closed configuration for a fixed time interval, such as between one-quarter of a second and two seconds, before taking an additional pressure differential sample.

[0016] In certain embodiments, the controller can be configured not to automatically re-establish flow when a safe situation has been reached. By way of example and not limitation, in certain embodiments, the controller can be configured to allow the user to reposition the suction catheter and manually open the switching valve (typically by actuating a switch that causes the controller to open the switching valve) after repositioning to resume suction treatment. However, in such a case, the controller can immediately return to the "sampling mode" and, if the re-established flow is characterized as unrestricted flow, the controller can close the switching valve again and the user can reposition the suction catheter again to engage a clot and manually resume suction. In certain embodiments, some systems can provide a manual switch to allow the user to manually open the switching valve.

[0017] In certain embodiments, the controller may be configured to control two or more valves. In certain embodiments, the controller may control a first switching valve between the aspiration catheter and a vacuum source and a second switching valve between the aspiration catheter and a pressure source having a pressure at least higher than the pressure of the vacuum source. In certain embodiments, the controller may alternately open the first switching valve and the second switching valve to generate a pressure change within the aspiration catheter and / or the tubing adjacent to such catheter. In certain embodiments, when the first switching valve is open, the controller may sample the flow to determine whether the attached catheter is still positioned within a clot or otherwise occluded. In certain embodiments, if an occlusion or blockage is detected, the controller may keep the first switching valve open. In certain embodiments, if no occlusion or blockage is detected, the controller may keep the second switching valve closed. In certain embodiments, the controller may operate one or more valves to alternately provide a low pressure (such as a vacuum) and a high pressure (such as by introducing a fluid medium) to the aspiration catheter and / or the tubing. In certain embodiments, the controller may operate one or more valves to simultaneously connect the aspiration catheter and / or the tubing to a low pressure source (such as a vacuum) and a high pressure source (such as by introducing a fluid medium). By way of example and not limitation, the simultaneous connection of the high pressure source and the low pressure source may be used to facilitate flushing a fluid medium through the aspiration catheter and / or the tubing.

[0018] In certain embodiments, the vacuum aspiration system includes a base unit that incorporates at least one switching valve and a controller. In certain embodiments, the base unit may be configured to be mounted directly on or near a vacuum pump or console, and / or may include connection cables to receive power from a vacuum console or line and optionally exchange information with the controller and the vacuum console. In certain embodiments, the connecting tubing may have a proximal end configured to connect to a vacuum source and a distal end configured to connect to an aspiration catheter. In such a case, the vacuum aspiration system may further include an external unit configured to be secured to the connecting tubing at a position between the distal end and the proximal end of the connecting tubing. In certain embodiments, an exemplary external unit may include at least a portion of a sensing unit. By way of example and not limitation, in certain embodiments, the sensing unit may include a first pressure sensor in the base unit and a second pressure sensor in the external unit. In certain embodiments, the controller may be configured to determine whether a differential pressure exists based on signals from the first pressure sensor and the second pressure sensor.

[0019] In certain embodiments, a vacuum aspiration method may be provided. In certain embodiments, the vacuum aspiration method may include engaging a distal end of an aspiration catheter against an occlusion in a blood vessel. In certain embodiments, a vacuum may be applied through an aspiration lumen of the aspiration catheter using a vacuum source coupled to a proximal end of the aspiration lumen by a connecting tube. In this manner, portions of a clot and other occlusive material may be drawn into the aspiration lumen through the connecting tube and into a collection container by the vacuum source. In certain embodiments, flow through the connecting tube may be sensed, and a valve may automatically close to stop flow through the connecting tube when the sensed flow exceeds a determined value while the vacuum source remains on. In certain embodiments, flow through the connecting tube may be re-established at a later time by opening the valve, and these steps may be repeated until a desired amount of clot has been aspirated.

[0020] In certain embodiments, a component for generating a pressure differential may be provided that may cause a pressure pulse to perform an extraction cycle. In certain embodiments, the component may include a fluid injection device, a mechanical displacement device, a gravity-induced pressure head, or a combination thereof. In certain embodiments, the fluid injection device may provide a source of relative positive pressure to a catheter that is currently or previously under vacuum aspiration. By way of example and not limitation, the fluid may be at a pressure above the vacuum aspiration system, at a pressure between full vacuum pressure and ambient pressure, at ambient pressure, at a pressure between ambient pressure and systolic pressure, at systolic pressure, or at a pressure above systolic pressure. In certain embodiments, the fluid injection device may utilize an orifice, a valve, a pump, a pressure chamber, or a suitable combination. In certain embodiments, the mechanical displacement device may physically displace the volume of a catheter system to provide a relative increase and decrease in pressure depending on the direction of displacement. In certain embodiments, the mechanical displacement component may assist in vacuum restoration after the pressure in the catheter has increased above the pressure of the vacuum source.

[0021] In certain embodiments, 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. In certain embodiments, unrestricted flow may be high flow, which may be characterized as excessive, and / or may predominantly or entirely comprise healthy blood, clot-free blood, or blood without obstructive vascular clots and / or blood that is not conducive to aspiration. In certain embodiments, restricted flow may include a mixture of healthy blood and clots or other occlusive materials. In certain embodiments, blockage may be caused by a clot or other occlusive material within the aspiration catheter, such as a clot or other occlusive material partially within the aspiration catheter, adjacent to the aspiration catheter, and / or attached to other connecting tubes of the aspiration catheter. By way of example and not limitation, healthy blood may be blood having a low enough proportion of cross-linked fibrin such that it does not integrate sufficiently to cause ischemia or other similar vascular occlusion. In certain embodiments, when the algorithm detects unrestricted flow, it may cause the system to initiate a sampling mode. In certain embodiments, when the algorithm detects restricted flow, it may cause the system to be capable of achieving full vacuum aspiration. In certain embodiments, when the algorithm detects blockage, it may cause the system to generate various pressure pulses during the extraction cycle. In certain embodiments, the algorithm may respond to and adapt to changing circumstances, such as changing to a catheter of a different size during a procedure. In certain embodiments, the algorithm may adjust the sampling mode and the pressure pulse amplitude if the catheter status remains static, changes too quickly, changes too slowly, or improves as expected.

[0022] In certain aspects of the methods disclosed herein, certain embodiments may remove clots and other occlusive materials from a blood vessel including a vein or an artery. In certain embodiments, sensing of flow may include one or more of differential pressure measurement, acoustic flow measurement, optical flow measurement, thermal flow measurement, circumferential expansion measurement of a connecting tube, a rotary aspiration pump torque sensor, and / or other suitable sensing devices and methods.

[0023] In certain aspects of the method, sensing flow may include measuring differential pressure using a first sensor located near the vacuum source and a second sensor located on or adjacent to a connecting tube between the vacuum source and the aspiration catheter.

[0024] In certain embodiments of the method, restoring flow through the connecting tube may include opening a valve for an interval, such as a sub-second interval, detecting when the sensed flow is characterized as acceptable, and automatically restoring flow. In certain embodiments, automatically restoring flow may include automatically detecting when the sensed flow can be characterized as acceptable, and / or the valve remains open as long as the flow is so characterized. In certain embodiments, restoring flow may include manually opening a switch valve.

[0025] In a particular embodiment of the method disclosed herein, a pressure difference is generated by closing the valve of the vacuum pump and / or opening the valve of the pressure source, wherein the pressure of the source is at least higher than the pressure of the vacuum, and then reopening the valve to the vacuum pump. Alternatively, or in combination, in a particular embodiment, the pressure difference is generated by mechanical displacement, wherein the volume of the chamber can be decreased to increase the pressure within the conduit, and / or the volume of the chamber can be increased to decrease the pressure within the conduit, whereby actuation of the mechanically displaced chamber can result in a pressure difference. In a particular embodiment, the pressure difference can be customized to have a specific or dynamic amplitude and frequency to facilitate the removal of clots or other occlusive materials.

[0026] In a particular embodiment of an aspect that may include the above embodiments, with regard to tubing and system flushing, the device may include: a connecting tube configured to serve as a fluid conduit between a suction catheter, a fluid source, and a vacuum source; a first pressure sensor associated with a distal portion of the connecting tube; a second pressure sensor associated with a proximal portion of the connecting tube; a first controllable valve configured to control the vacuum level in the connecting tube provided by the vacuum source; a second controllable valve configured to control the introduction of a fluid medium from the fluid source into the connecting tube; and a controller.

[0027] In a particular embodiment, a third pressure sensor associated with the pressure of the fluid source may be included. In a particular embodiment, a fourth pressure sensor may be used to compare the pressure sensor to a reference atmospheric pressure. In a particular embodiment, a fifth pressure sensor may be included proximate to the first controllable valve and / or in the same static or continuous fluid path as the second sensor.

[0028] In a particular embodiment of an aspect that may include the above embodiments, the controller may be configured to detect, via one or more of the first pressure sensor and the second pressure sensor, one or more pressure levels associated with the connecting tube; and determine whether the connecting tube is occluded based on the detected one or more pressure levels, wherein, based on determining that the connecting tube is occluded, the controller is further configured to determine the location of the occlusion based on the detected one or more pressure levels; and operate one or more of the first valve and the second valve to introduce the fluid medium into the connecting tube during one or more time intervals based on determining the location of the occlusion.

[0029] In a particular embodiment of an aspect that may include the above-described embodiments, prior to detecting the one or more pressure levels, the controller may be configured to operate the first valve to provide fluid communication between the distal portion of the connecting tube and the vacuum source.

[0030] In a particular embodiment of an aspect that may include the above-described embodiments, the controller may be configured to determine whether the connecting tube is occluded based on one or more differences between the one or more pressure levels detected via the first pressure sensor and the second pressure sensor, respectively.

[0031] In a particular embodiment of an aspect that may include the above-described embodiments, the controller may be configured to determine that the connecting tube is occluded between the first pressure sensor and the second sensor based on the one or more differences between the one or more pressure levels detected via the first pressure sensor and the second pressure sensor, respectively.

[0032] In a particular embodiment of an aspect that may include the above-described embodiments, the controller may be configured to operate the first valve and the second valve based on determining that the connecting tube is occluded between the first pressure sensor and the vacuum source to introduce the fluid medium into the connecting tube during a first time interval.

[0033] In a particular embodiment of an aspect that may include the above-described embodiments, the first time interval is a predetermined time interval. In a particular embodiment of an aspect that may include the above-described embodiments, the predetermined time interval is between 200 ms and 800 ms. In a particular embodiment of an aspect that may include the above-described embodiments, the predetermined time interval is between 15 ms and 900 ms.

[0034] In a particular embodiment of an aspect that may include the above-described embodiments, the controller may be configured to determine whether the connecting tube is occluded based on one or more pressure levels detected via the second pressure sensor that exceed a threshold.

[0035] In a particular embodiment of an aspect that may include the above-described embodiments, the controller may be configured to determine that the connecting tube is occluded between the second pressure sensor and the vacuum source based on one or more pressure levels detected via the second pressure sensor that exceed a threshold.

[0036] In certain embodiments that may include aspects of the above-described embodiments, the controller may be configured to operate the first valve and the second valve based on determining that the connecting tube is occluded between the second pressure sensor and the vacuum source to introduce the fluid medium into the connecting tube during a second time interval. In certain embodiments, the second time interval is a predetermined time interval. In certain embodiments, the second time interval is between 70 ms and 300 ms. In certain embodiments, the second time interval is between 150 ms and 200 ms. In certain embodiments, the second time interval is between 15 ms and 800 ms.

[0037] In certain embodiments that may include aspects of the above-described embodiments, the controller may be configured to selectively open or close one or more of the first valve and the second valve during the one or more time intervals.

[0038] In certain embodiments that may include aspects of the above-described embodiments, the controller may be configured to keep the first valve open during at least a portion of the one or more time intervals. In certain embodiments that may include aspects of the above-described embodiments, the controller may be configured to repeatedly open and close the second valve during at least a portion of the one or more time intervals.

[0039] In certain embodiments that may include aspects of the above-described embodiments, the thrombectomy aspiration system may further include a controllable bypass valve, wherein the bypass valve is opened when the first valve is closed, while introducing the fluid medium into the connecting tube and disconnecting the fluid communication between the aspiration catheter and the vacuum source.

[0040] In certain embodiments that may include aspects of the above-described embodiments, the thrombectomy aspiration system may further include a third controllable valve configured to control the introduction of the fluid medium into the aspiration catheter.

[0041] In certain embodiments that may include aspects of the above-described embodiments, the thrombectomy aspiration system may include a fluid medium that includes one or more of air and saline.

[0042] In certain embodiments that may include aspects of the above-described embodiments, the thrombectomy aspiration system may include a third pressure sensor associated with the fluid source. In certain embodiments that may include aspects of the above-described embodiments, the thrombectomy aspiration system may include a fourth pressure sensor configured to compare one or more detected pressure levels with a reference atmospheric pressure level.

[0043] In certain embodiments that may include aspects of the above-described embodiments, the thrombectomy aspiration system may include a fifth pressure sensor disposed proximate to the first controllable valve. In certain embodiments that may include aspects of the above-described embodiments, the controller is configured to determine whether the connecting tube is occluded based on one or more differences between one or more pressure levels detected respectively via the second pressure sensor and the fifth pressure sensor.

[0044] In certain embodiments, the techniques described herein relate to a method for thrombectomy aspiration, comprising: detecting, by a controller via one or more of a first pressure sensor and a second pressure sensor, one or more pressure levels associated with a connecting tube, wherein the connecting tube serves as a fluid conduit between an aspiration catheter, a fluid source, and a vacuum source, wherein the first pressure sensor is associated with a distal portion of the connecting tube, and wherein the second pressure sensor is associated with a proximal portion of the connecting tube; determining whether the connecting tube is occluded based on the detected one or more pressure levels; determining a location of the occlusion based on determining that the connecting tube is occluded and based on the detected one or more pressure levels; and operating one or more of a first controllable valve and a second controllable valve based on determining the location of the occlusion to introduce a fluid medium into the connecting tube during one or more time intervals, wherein the first valve is configured to control a vacuum level provided by the vacuum source in the connecting tube, and the second valve is configured to control introduction of the fluid medium from the fluid source into the connecting tube.

[0045] In certain embodiments, the techniques described herein relate to a method that further comprises, prior to detecting the one or more pressure levels, operating the first valve to enable fluid communication between the distal portion of the connecting tube and the vacuum source.

[0046] The embodiments disclosed herein are merely examples, and the scope of the present disclosure is not limited thereto. A particular embodiment may include all, some, or none of the components, elements, features, functions, operations, or steps of the embodiments disclosed herein. Embodiments according to the present invention are particularly disclosed in the appended claims directed to methods and systems, wherein any feature mentioned in one claim category, such as a method, may also be claimed in another claim category, such as a system. The previous dependencies or references in the appended claims are chosen only for formal reasons. However, any subject matter resulting from a deliberate reference to any previous claim (in particular multiple dependencies) may be claimed, such that any combination of the claims and their features is disclosed and may be claimed, regardless of the dependencies chosen in the appended claims. The subject matter that may be claimed includes not only combinations of the features set forth in the appended claims, but also any other combination of the 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. In addition, any embodiment and feature described or depicted herein may be claimed in a separate claim and / or in any combination with any embodiment or feature described or depicted herein or with any feature of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Shows a vacuum console and a collection canister of an exemplary thrombectomy system according to a particular embodiment.

[0048] Figure 2 Shows a perspective view of a vacuum console and a collection canister of a thrombectomy system according to a particular embodiment.

[0049] Figure 3A Shows a view of a vacuum console according to a particular embodiment with the collection canister removed.

[0050] Figure 3B Shows according to a particular embodiment Figure 3A A detailed view of an on / off switch and a vacuum display area on the top surface of a vacuum console of, which is depicted in a power-off state.

[0051] Figure 3C Shows a schematic diagram of internal components of a vacuum console according to a particular embodiment.

[0052] Figure 4 Shows a collection canister according to a particular embodiment.

[0053] Figure 5 Shows according to a particular embodiment Figure 4An embodiment of a collection tank, depicted as an inverted or "upside-down" view.

[0054] Figure 6 Shows a Figure 4 and Figure 5 exploded view of a vacuum tank according to a particular embodiment.

[0055] Figure 7A and Figure 7B Show a vacuum console and a collection tank according to a particular embodiment, the vacuum console and the collection tank having a vacuum suction control system attached thereto.

[0056] Figure 8A and Figure 8B Show an external unit according to a particular embodiment.

[0057] Figure 9 Show an exemplary base unit according to a particular embodiment, the base unit encapsulating a switching valve and a controller of a type suitable for use in a vacuum suction control system, depicted in cross-section.

[0058] Figure 10 Show an exemplary external unit according to a particular embodiment, depicting internal components including fittings and pressure sensors, depicted in dashed lines.

[0059] Figure 11 Show an angle valve of a type that can be used as a switching valve in a particular embodiment, depicted in cross-section.

[0060] Figure 12 Show an isometric view of an angle valve connected to a coil, the coil having pressure sensors mounted at each of its ends on top of the tank.

[0061] Figure 13 Show an embodiment of an algorithm suitable for use with a pressure differential according to a particular embodiment.

[0062] Figures 14 - 18 Show an exemplary pulsed fluid injection assembly suitable for a particular embodiment.

[0063] Figure 19 Show a mechanical displacement assembly for manipulating pressure in a particular embodiment.

[0064] Figure 20 Show a graphical representation of a particular embodiment of pulsed suction, where the internal pressure of the conduit varies with time.

[0065] Figure 21 Show a schematic diagram of a particular embodiment configured for tube and system flushing.

[0066] Figure 22 Shows a particular implementation of an algorithm suitable for implementing tube and system flushing.

[0067] Figure 23 Shows the detection and flushing of an occlusion in a connecting tube located near a vacuum source according to a particular implementation.

[0068] Figure 24 Shows the detection and flushing of an occlusion in a connecting tube located between a sensor distal to a connecting tube and a vacuum source according to a particular implementation.

[0069] Figure 25 Shows an exemplary process 2500 for determining the flow state of a suction catheter or connecting tube according to a particular implementation.

[0070] Figure 26 Shows an exemplary distal pressure distribution detected over time for a particular implementation, depicting aspects of determining the flow state.

[0071] Figure 27 Shows an exemplary distal pressure distribution in the case of overall open or unrestricted flow for a particular implementation.

[0072] Figure 28 Shows an exemplary distal pressure distribution in the case of partially occluded flow for a particular implementation.

[0073] Figure 29 Shows an exemplary distal pressure distribution indicating the presence of an occlusion for a particular implementation.

[0074] Figure 30 Shows a schematic diagram of a particular implementation configured for tube and system flushing. Detailed implementation

[0075] Aspiration Thrombectomy System

[0076] The following describes a particular implementation. For clarity, not all features of each actual implementation are described in this specification. In the development of an actual device, some modifications may be made, but the modified implementation still falls within the scope of the present disclosure.

[0077] Figure 1 Shows a vacuum console and a collection tank of a thrombectomy system according to a particular implementation. As Figure 1As shown, in a particular embodiment, the aspiration pump 10 may include a base unit 12 enclosing a vacuum pump (not shown) that can operate off-line voltage. The base unit may have an on-off switch 14 and / or a separate knob 16 for adjusting the level of vacuum provided by the pump. The vacuum level can be read on a manometer 18. Blood and clots can be aspirated from a suction tube 22 (shown in dashed lines) into a collection canister 20, and the suction tube can be connected to a reperfusion catheter (not shown) that is introduced into the patient's vasculature to aspirate clots.

[0078] In a particular embodiment, blood and clots can be aspirated into the collection canister by a partial vacuum that can be provided by a vacuum connector 28 on the base unit 12 connected to a vacuum pump (not shown). The vacuum from the vacuum connector 28 can be applied to a vacuum port 24 on a removable lid 25. The vacuum connector 28 can be connected to the vacuum port 24 by an external vacuum tube 30.

[0079] In a particular embodiment, due to the risk of excessive patient blood loss, it may sometimes be necessary to terminate clot aspiration using a mechanical thrombectomy device or other vacuum-assisted thrombectomy system. By way of example and not limitation, when using a large aspiration catheter, the likelihood of terminating clot aspiration due to the risk of excessive blood loss is high. During thrombectomy aspiration, if the catheter tip becomes disengaged from contact with a thrombus or other occlusive material, the tip may be exposed to healthy blood and full flow may occur. In such a situation, the blood loss rate may be too high and, in some cases, may result in premature termination of the procedure. By way of example and not limitation, if the catheter enters healthy blood and full flow occurs during the aspiration procedure, a blood loss rate in the range of 20 - 25 cc per second may occur, such as when using an 8 French size catheter. By way of example and not limitation, assuming a patient's maximum tolerable blood loss is 300 - 1000 mL, the catheter cannot operate in an unrestricted mode for more than approximately 20 to 50 seconds. When the system is manually operated by a physician, the total blood loss may reach an unacceptable level before sufficient clots are removed during the aspiration procedure. In a particular embodiment, it may be an important issue to reliably identify whether the tip of the catheter is in contact with a clot and / or whether healthy, clot-free blood is being undesirably aspirated, and manual control may not be optimal.

[0080] In a particular embodiment, during other surgeries, such as, for example, during a neurovascular surgery for treating an ischemic stroke, the risk of excessive blood removal may be less and the main focus of the surgery can be to maximize the removal of occlusive material. Optimizing both the technique and the aspiration control are very important for the successful removal of occlusive material.

[0081] In certain embodiments, it is desirable to provide improved methods and devices for controlling the aspiration of thrombi and clots using an aspiration catheter in combination with a pumping console. By way of example and not limitation, it may be particularly useful to provide systems and methods for restricting blood loss during such aspiration procedures, such as by automatically stopping aspiration when the aspiration catheter is not in contact with a clot or thrombus. Separately or additionally, in certain embodiments, it is desirable to provide systems and methods for optimizing system performance and procedures for removing occlusive materials. As will be further described herein, certain embodiments are designed to meet these needs and provide corresponding benefits.

[0082] Referring Figures 2 - 6 , specific embodiments of devices and methods for controlled clot aspiration will be described. Figure 2 is a perspective view of a vacuum console and a collection canister according to a specific embodiment. In certain embodiments, the collection canister may be received in an installation area of the vacuum console. By way of example and not limitation, the collection canister may be a blood and / or clot collection canister.

[0083] In certain embodiments, the vacuum system 40 may include a vacuum console 42 and a blood / clot collection canister 44 having a lid 26, which will be discussed below with respect to Figure 7A , Figure 7B and Figure 9 (see also the discussion of lid 80 below with respect to Figures 4 - 6 ). The vacuum console 42 may include a housing having a recess 48, which in certain embodiments may be shaped to removably receive the collection canister 44, which will be described in more detail below.

[0084] Referring Figure 3A , a view of the vacuum console is shown according to a specific embodiment with the collection canister removed. Figure 3B Shows a detailed view of the on / off switch and the vacuum display area on the top surface of the Figure 3A vacuum console according to a specific embodiment, depicted in the power-off state. Figure 3C Shows a schematic diagram of the internal components of the vacuum console according to a specific embodiment.

[0085] In certain embodiments, posts 50 that may form a continuous portion of the outer surface or wall of the housing 46 may be formed within the recess 48 and / or may extend upwardly from a bottom plate 56, which may serve as a support for the collection canister 44 when the collection canister 44 is received within the recess. In certain embodiments, a vacuum connector 52 and a pressure sensing connector 54 may be formed in or on the upper surface of the post 50 and may be positioned such that they may engage with a pressure sensing port 104 and a vacuum port 102 on the vacuum canister 44 (e.g., Figure 5)Alignment. By way of example and not limitation, the lamp 58 may be located on the wall surface of the housing 46 within the recess 48 and may be positioned to illuminate the contents of the collection canister 44 when the system is in use. By way of example and not limitation, another lamp (not visible in Figure 3A ) may be present on the opposite wall of the recess 48. In a particular embodiment, the vacuum console 42 may have an on-off switch 60 on its upper surface. By way of example and not limitation, the on-off switch 60 may be illuminated (such as Figure 2 and Figure 3A shown) when the switch is on and may not be illuminated when the system is off (e.g., Figure 3B ). Separately or additionally, in a particular embodiment, a pressure display 62 may be provided on the upper surface of the housing 46. By way of example and not limitation, as Figure 2 and Figure 3A shown, the display may be a circular lamp, for example, having four segments that may be sequentially illuminated as the vacuum level in the canister increases. By way of example and not limitation, each quarter-circle segment may represent the measured vacuum as a percentage of ambient pressure.

[0086] Figure 3C FIG. shows a schematic view of the internal components of a vacuum console according to a particular embodiment. In a particular embodiment, the main internal components of the vacuum console may include a pressure sensor 64, a pump 68, a power supply 72, and / or a microprocessor controller 74. In a particular embodiment, the pump 68 may have an inlet connected to a vacuum connector 52 on a post 50 of the housing 46. In a particular embodiment, the pressure sensor 64 may be connected to a pressure sensing connector 54 on the post 50. By way of example and not limitation, the pump may be turned on by the switch 60 and may evacuate through the connector 52 and release the removed gas into the interior of the console. In a particular embodiment, the console may be vented through an exhaust port 70 on the bottom surface of the housing 46. In a particular embodiment, a differential or ambient pressure port 66 may be provided to enable the pressure sensor 64 to sample a reference measurement, such as an ambient pressure measurement.

[0087] In certain embodiments, the functions of the pump can be controlled by the microprocessor controller 74. In certain embodiments, the pressure output from the sensor 64 can be controlled and / or processed by the microprocessor controller 74 alone or additionally. In certain embodiments, one or more of the lamp 58, the switch 60, and / or the display 62 can be connected to the microprocessor controller 74, which can be powered by the power supply 72. In certain embodiments, the power supply 72 can be powered through the line current connector 72A. In certain embodiments, the USB connector 72B can be powered by the microprocessor controller 74. By way of example and not limitation, the pump can be plugged into a socket via a power cord supplied with the pump. By way of example and not limitation, the power supply can convert AC current from a wall outlet into DC current, which the microprocessor controller can use to power one or more of the pump, the switch, the lamp, the USB connector, etc.

[0088] In certain embodiments, the pressure sensor 64 can be connected to the microprocessor controller 74 and can measure the vacuum pressure in the tank through the pressure sensing connector 54. In certain embodiments, another pressure sensor (e.g., a second pressure sensor, not shown) can be connected to the microprocessor controller 74 to measure the ambient pressure outside the pump housing through an internal tube that can lead to an exhaust port in the base of the pump. By way of example and not limitation, the microprocessor controller can obtain a vacuum pressure reading from the pressure sensor 64 and divide 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. Now referring Figures 4 - 6 , a particular embodiment of the collection tank 44 can have a body 78. By way of example and not limitation, the body 78 can be formed of a polished transparent plastic material and / or can be molded into the shape shown. Figure 4 A collection tank according to a particular embodiment is shown. Figure 5 A Figure 4 collection tank embodiment according to a particular embodiment is depicted in an inverted or "upside-down" view. Figure 6 A Figure 4 and Figure 5 exploded view of the vacuum tank according to a particular embodiment is shown.

[0089] In certain embodiments, the body 78 can have a bottom 98 and an open upper end 76, which can be covered by a removable transparent plastic cap 80. By way of example and not limitation, the transparent plastic cap 80 can be attached through a bayonet connector 82, and / or a gasket 84 of one form or another can seal the cap to the open end of the body 78.

[0090] In a particular embodiment, a slot 94 may be formed in one side of the body 78. By way of example and not limitation, the slot 94 may be shaped such that it can be placed above a post 50 in a recess 48 of the housing 46 of the vacuum console 42. As Figure 5 shown, in a particular embodiment, the pressure sensing port 104 and the vacuum port 102 may be located at the upper end of the slot 94. By way of example and not limitation, when the canister 44 is in place in the recess 48, they may be positioned to align with and connect to a vacuum connector 52 and a pressure sensing connector 54 on the post 50.

[0091] In a particular embodiment, the pressure sensing port 104 may be connected to a tube or lumen that may extend upwardly in the body 78 of the canister 44 and / or may terminate in an upper opening or aperture 106. In a particular embodiment, the vacuum port 102 may extend upwardly through a much larger lumen or tube and / or may terminate in an opening aperture 108 at its upper end. By way of example and not limitation, the aperture 106 and the aperture 108 may be located near the top inside the body 78, but may be below the bottom of the lid when the lid 80 is in place on the canister 44. Thus, in a particular embodiment, both the aperture 106 and the aperture 108 may be exposed to the interior of the canister 44, but may be kept above the middle section and the bottom of the clot and blood collection area. In a particular embodiment, based on this arrangement, the risk of contamination from blood and clots may be minimized.

[0092] In a particular embodiment, a filter plate 86 (shown herein as a perforated screen, but may also be a woven screen or other separating member) may be held in the middle section inside the body 78 of the canister 44. By way of example and not limitation, a clot or occluding material may be drawn into the interior of the canister through a connector 110 that may be attached to the proximal end of a catheter or other tube. In a particular embodiment, as previously described, the clot and blood may be drawn into the interior of the body 78 by a vacuum drawn by the vacuum console 42 through the vacuum port 102. By way of example and not limitation, since the clot and blood may fall downwardly from the connector 110 into the canister 44, the clot may collect on the upper surface of the filter plate 86, while the blood may flow through the perforations in the plate and collect at the bottom of the canister. Since the plate may be inclined downwardly from the sleeve 88, in a particular embodiment, the sleeve may be mounted on a post 90 inside the canister, and excess blood may flow through an open bypass area 100 ( Figure 4 ), which may be formed on the back side of the plate and / or may allow the blood to flow directly downward to the bottom of the canister.

[0093] In certain embodiments, the filter body 92 may occupy the interior of the column 90 and the aperture 108 and may prevent the extracted material from contaminating the interior of the housing 46. By way of example and not limitation, the filter body 92 may occupy the interior of the column 90 and / or extend into the aperture 108. Thus, in certain embodiments, the filter body may prevent the extracted material from contaminating the interior of the housing 46.

[0094] In certain embodiments, a slot 94 may be formed on one side of the body 78 of the cannister 44 and may be received above the post 50 in the recess 48 of the housing 46 so as to align the vacuum and pressure sensing connectors with the vacuum port. In certain embodiments, a gasket 96 may be disposed at the seal between the vacuum port and the vacuum connector.

[0095] While the particular embodiments of the apparatus and method for controlled clot aspiration for particular embodiments may be used with the vacuum system 40, it will be understood that the particular embodiments described and claimed herein are not limited to use with any particular vacuum console, but rather may be used with any clot or other vascular thrombectomy or aspiration system, such as a thrombectomy or other vascular aspiration catheter in combination with a vacuum pump or other source, where there may be a risk of excessive blood aspiration, blockage, or both.

[0096] Figure 7A and Figure 7B Shown is a vacuum console and a collection cannister according to a particular embodiment, the vacuum console and the collection cannister having a vacuum aspiration control system attached thereto.

[0097] In certain embodiments, an exemplary system 200 for performing controlled clot aspiration may include a base unit 210 and an external unit 204. The proximal end of the connecting tube 206 may be connected to the base unit 210, and the external unit may be secured to or fixed to the connecting tube at a location spaced from the proximal end. By way of example and not limitation, the spacing may be a distance sufficient to draw conclusions about the flow rate. In certain embodiments, the external unit 204 may be configured to be directly connected to the hub of the aspiration catheter and / or other proximal end, or may be configured to be connected intermediate the connecting tubes. In certain embodiments, the connecting tube may be linear and / or flexible along its length in an unconstrained configuration.

[0098] In certain embodiments, the base unit 210 may be configured to be directly on top of the lid 26 on the collection cannister 44 of the vacuum console 40. By way of example and not limitation, a communication cable 208 may extend from the base unit 210 through a portion of the connecting tube 206 to a connection socket on the vacuum console 40 such that the base unit may be powered by the vacuum console and may optionally communicate data with a controller within the vacuum console.

[0099] As Figure 7B shown, in certain embodiments, the external unit 204a may include a switch 204b for initiating treatment using the vacuum console 40 and the controlled clot aspiration system 200. The switch may also shut down the system, thereby providing a manual override of the algorithm, which ensures that the system shuts down in the absence of flow. By way of example and not limitation, when the switch is turned on, the system may immediately enter the algorithm mode, in which it decides to remain open, enter the sampling mode, or initiate an extraction cycle in response to pressure sensor readings. Further details of certain embodiments of the external unit 204a are shown in Figure 8A and Figure 8B which are shown in

[0100] Figure 9 An exemplary base unit according to certain embodiments is shown, which is encapsulated with a switching valve and a controller of a type adapted for use in a vacuum aspiration control system, depicted in cross-section.

[0101] In certain embodiments, the exemplary base unit 200b may include a base unit housing 216 having an open internal cavity 218, which may accommodate a plurality of components. By way of example and not limitation, a controller 220, which may include a microprocessor on a printed circuit board 248, may be mounted within the cavity 218 together with a pressure sensor 224, which is fixed between a proximal end of a tube section 232 and a connecting tube 206 by a pressure fitting 226. By way of example and not limitation, the tube section 232 may be collapsible and is positioned within a pinch valve 228 driven by a solenoid 230. In certain embodiments, 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. In certain embodiments, the base unit 200b may include a connecting fitting 222, which may be configured to removably secure to a vacuum fitting (not shown) on a lid 26 of the canister 44. In certain embodiments, the controller 220 may be configured to open and close the pinch valve 228 to respectively allow and prevent clots and blood from flowing through the tube section 232 from the aspiration catheter into the collection canister. In certain embodiments, the base unit 200b may optionally include buttons (not shown) in electronic communication with the printed circuit board 248 (e.g., the printed circuit board of the controller 220), such as for advanced user control of various parameters of the system. In certain embodiments, the base unit may accommodate a pressure chamber, a fluid source, additional switching valves, and / or combinations thereof or in communication therewith.

[0102] In certain embodiments, a switching valve and a controller of a type suitable for a suction control system can be used to apply a mechanical force on a clot, thrombus, or other occlusive material. In certain embodiments, during an infusion cycle, the mechanical action of the switching valve on the occlusive material can be used to cut, shear, shred, divide, soften, infuse, or otherwise alter the morphology, consistency, and / or deformability of the occlusive material. By way of example and not limitation, altering the morphology or consistency of a clot, thrombus, or other occlusive material by mechanical action can beneficially enable more effective aspiration of the occlusive material through a suction catheter. For example, a large thrombus can be divided into smaller pieces for more effective aspiration. For example, a hard or dense thrombus can be mechanically softened or made more pliable by mechanical action to enable more effective aspiration. In certain embodiments, a pinch valve 228 can be used to apply a mechanical force and action on a clot, thrombus, and / or other occlusive material. In certain embodiments, other types of valves can be used, including but not limited to valves specifically designed to improve the mechanical action on the occlusive material. In certain embodiments, the parameters for selectively operating the valve by the controller, including but not limited to timing, frequency, duty cycle parameters, and / or signal amplitude (which can correspond to parameters related to valve closure, such as force in certain embodiments), can be optimized to provide an improved mechanical action of the valve on the occlusive material.

[0103] Figure 10 An exemplary external unit according to certain embodiments is shown, depicting internal components including a fitting and a pressure sensor, depicted in dashed lines.

[0104] In certain embodiments, the exemplary external unit 204 can include an external unit housing 240 having a flow fitting 242 in its internal cavity. By way of example and not limitation, the flow fitting 242 can be connected to portions 206a and 206b of the connecting tube 206, such as Figure 7B , Figure 8A and Figure 8B shown in certain embodiments. In certain embodiments, a second pressure sensor 246 can be mounted on the printed circuit board 248 and / or within the internal cavity of the housing 240. In certain embodiments, the output of one or more pressure sensors can be conveyed via a connecting cable (not shown) to the controller 220, which 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. In certain embodiments, the connecting cable can have a dual lumen, as Figure 9 shown in certain embodiments. By way of example and not limitation, one of the internal lumens can be used to route a communication cable between the external unit and the base unit, while the other lumen can accommodate a fluid flow. In certain embodiments, the external unit can house a pressure chamber, a fluid source, additional switching valves, or some such combination, or be in communication therewith.

[0105] In certain embodiments, by providing a first pressure sensor 224 in the base unit and a second axially separated pressure sensor 246 in the outer unit housing 240, the material flow rate through the connecting tube can be calculated. By way of example and not limitation, the material flow rate calculation can be based on one or more differential pressures measured by a controller. In certain embodiments, the controller can analyze the pressure differential and flow rate to determine the contents flowing through the aspiration catheter, the connecting tube, or both.

[0106] In certain embodiments, the controller can characterize the state of the catheter contents as unrestricted flow, restricted flow, blocked, and / or a particular intermediate state. In certain embodiments, a high pressure differential between spaced-apart pressure sensors can indicate unrestricted flow. By way of example and not limitation, unrestricted flow can include: primarily healthy, clot-free blood, or blood with an unobstructed vascular clot. In some instances, healthy blood can be blood with a low enough proportion of cross-linked fibrin such that it does not integrate sufficiently to cause ischemia or other similar vascular occlusion. By way of example and not limitation, aspirating such healthy blood in a full aspiration scenario can result in excessive blood loss, which in certain embodiments may require early termination of the aspiration procedure.

[0107] In certain embodiments, a variable and intermediate or low pressure differential can indicate restricted flow. By way of example and not limitation, restricted flow can include clots, occlusive materials, and / or blood. In certain embodiments, restricted flow can benefit from full aspiration. In certain embodiments, a small or near-zero pressure differential can indicate a blockage. In certain embodiments, such flow or lack of flow can benefit from an extraction cycle. It should be understood that the use of differential pressure to detect increased flow and occlusion is provided by way of example and not limitation; other flow measurement and / or material property measurement techniques are fully contemplated and within the scope of the present disclosure.

[0108] Figure 11 An angle valve 260 that can be used as a switching valve in certain embodiments is depicted in cross-section. In certain embodiments, the angle valve 260 can be used in place of the pinch valve 228. In certain embodiments, the angle valve can be provided with a connector 262 for a connector to be fixed to a vacuum tank (not shown), and / or a fitting 266 that can be connected to the connecting tube 206, which in turn can be connected to the aspiration catheter. By way of example and not limitation, there can be a solenoid 268 to open and close the valve stem 270 and the valve seat 272. In certain embodiments, the valve can be opened to permit aspiration and closed to block aspiration. In certain embodiments, the valve can be opened to allow fluid to enter the aspiration tube and / or the aspiration catheter, and / or can be closed to block the fluid.

[0109] Figure 12Shows an isometric view of an angle valve connected to a coiled tube, the coiled tube having pressure sensors mounted at the top of the tank at each of its ends. In a particular embodiment, the pressure sensors can be integrated into a single base unit 276, which can be fixedly attached to the tank lid 278. By way of example and not limitation, Figure 12 The illustration depicts a first pressure sensor 282 and a second pressure sensor 284, which can be attached to opposite ends of the manifold tube 280 so that the differential pressure can be measured. In a particular embodiment, the angle valve 286 can be directly fixed to the outlet of the manifold tube 280 to provide the desired on / off flow control.

[0110] In a particular embodiment, the controller 220 can implement an algorithm that can receive and / or analyze pressure sensor data. By way of example and not limitation, the controller 220 can use this data to open and close one or more valves, such as a switching valve. By way of example and not limitation, the valve can be a pinch valve 228 (e.g., Figure 9 ) and / or an angle valve 286 (e.g., Figure 12 ) or an angle valve 260 (e.g., Figure 11 ). In a particular embodiment, the algorithm can receive and / or analyze pressure data input at a high frequency or repetition rate. By way of example and not limitation, the pressure sensor data can be received and / or analyzed dozens, hundreds, or thousands of times per second. In a particular embodiment, sensor data (which may not be limited to pressure sensor data) can be compiled to determine specific parameters, such as the diameter of an attached conduit, and / or to determine the contents flowing through the conduit and the suction tube, and / or to determine the flow rate.

[0111] In a particular embodiment, the controller 220 can implement an algorithm that can use pressure sensor data to analyze the contents flowing through the suction conduit and characterize it as unrestricted flow, restricted flow, or blocked, and / or a particular intermediate state. By way of example and not limitation, a conduit with unrestricted flow can suction primarily healthy, clot-free blood or blood with unobstructed vascular clots. By way of example and not limitation, a conduit with mixed flow can suction a combination of clots, occlusive material, and blood. By way of example and not limitation, a conduit with little or no flow may be blocked or occluded.

[0112] In certain embodiments, if the algorithm determines that excessive blood may be in the process of being aspirated, such as in the case of a catheter with unrestricted flow, it can limit the aspiration to reduce blood loss. In certain embodiments, if the algorithm determines that the catheter may have restricted flow, it can allow full aspiration. In certain embodiments, if the algorithm determines that the catheter may have little or no flow, it can initiate an extraction cycle to help remove any blockage or occlusion. By way of example and not limitation, as used herein, the term "clot" can be understood to encompass any occlusive material found in the vasculature, such as thrombus, embolus, plaque, occlusive material, vascular obstruction, or any other blocking material. For the sake of brevity, in the specific cases described herein, "clot" can be used to refer to any combination of such occlusive materials.

[0113] Figure 13 An embodiment of an algorithm suitable for use with a pressure differential is shown. By way of example and not limitation, an embodiment 1300 of the algorithm can be suitable for use with a pressure differential ("ΔP") to determine flow rate and / or to control one or more valves, for example, based on the determined flow rate.

[0114] In certain embodiments, a first step 1310 can be to measure maximum and minimum pressure differential windows over a certain evaluation period, and after that evaluation period, obtain the instantaneous pressure differential and compare it to the maximum and minimum pressure differential windows. In certain embodiments, the maximum and / or minimum pressure differential windows can be updated incrementally. In certain embodiments, at step 1320, if it is determined that the instantaneous pressure differential is below the minimum pressure differential of the evaluation period, the algorithm can determine at step 1330 that the system is in a clot, and / or can command at step 1340 the system to continue full aspiration, such as by keeping one or more valves (e.g., switching valves) open until the next sample. On the other hand, according to certain embodiments, if it is determined that the instantaneous pressure differential is above the minimum pressure differential, the algorithm can determine at step 1350 whether the instantaneous pressure differential is above a threshold pressure differential. By way of example and not limitation, the threshold pressure differential can be the product of the maximum pressure differential multiplied by a confidence multiplier 'X'. In certain embodiments, 'X' can individually or additionally correspond to or include a correction factor and / or a safety factor.

[0115] In certain embodiments, if it is determined in step 1350 that the instantaneous pressure differential is not higher than a threshold pressure differential, the algorithm may determine in step 1360 that the system is in a clot, and / or full aspiration may be permitted. In certain embodiments, conversely, if it is determined in step 1350 that the instantaneous pressure differential is higher than the threshold pressure differential, the algorithm may determine in step 1370 an open flow condition, and / or may limit aspiration in step 1380 to limit blood loss, such as entering a sampling state in which aspiration is limited to brief surges to obtain new instantaneous pressure differential readings. In either case, in certain embodiments, whenever aspiration is permitted, the algorithm may continuously take instantaneous pressure differential readings, and / or compare them to the maximum and minimum pressure differentials that may be collected throughout the procedure. In certain embodiments, when unrestricted flow (e.g., open flow) is detected, the algorithm may trigger the sampling state. In certain embodiments, when a clot is detected, the algorithm may initiate full aspiration, or initiate an extraction cycle with pulsed aspiration.

[0116] In certain embodiments, a related algorithm is utilized that determines whether the catheter has unrestricted flow, restricted flow, or, for example, is blocked based on a correlation between flow rate and catheter status. In certain embodiments, a windowing algorithm may be utilized that can analyze discrete portions of the pressure sensor data, such as to establish local minimum and / or local maximum pressure sensor readings. These windowed minimums and maximums may be compared to the global minimum and global maximum on the data set. By way of example and not limitation, for a sudden large change (Δ) in the pressure reading, the system may preferably determine the status of the catheter based on the local minimum and / or local maximum. In certain embodiments, pressure readings below the minimum and above the maximum may indicate a change in the catheter status, e.g., below the minimum may indicate catheter blockage, and / or above the maximum may indicate an unrestricted flow state.

[0117] In certain embodiments, an algorithm may be utilized to emphasize the analysis of the standard deviation on discrete windows of data points. In certain embodiments, the ongoing flow rate signal may be compared to an average flow rate (e.g., a running average). By way of example and not limitation, a small standard deviation may indicate that the catheter is blocked or unrestricted, while a large standard deviation may indicate that the catheter has restricted flow.

[0118] In certain embodiments, a learning algorithm can be used to determine the contents flowing through a suction catheter. By way of example and not limitation, training data can be formed by collecting pressure readings along the length of the catheter in various states (e.g., unrestricted flow, restricted flow, or blocked). For each catheter state, multiple pressure readings can be recorded, and then the algorithm can refer to such a data set to interpret pressure readings never seen before, and / or predict the state of the catheter and / or its flow.

[0119] In certain embodiments, an artificial neural network (ANN) that can employ a multinomial logistic regression algorithm can be utilized. In certain embodiments, the ANN can be trained to predict an answer by considering multiple training data sets. By way of example and not limitation, the training data can include observed data and actual outputs as inputs. In certain embodiments, the inputs can be propagated through the ANN, which can include hierarchical nodes, and each hierarchical node can represent a linear transformation within the solution space. In certain embodiments, the ANN can then "learn" by analyzing the difference between the computed output of the ANN and the actual output (e.g., ground truth). In certain embodiments, the difference can be converted into an error function, and / or can be backpropagated through the ANN, whereby its weights can be modified based on the contribution of each node to the error function. Weighting is a process of mathematical optimization, which can ascertain which nodes can optimally map the input to its correct output.

[0120] In certain embodiments, multiple sets of training data can be iteratively propagated through the ANN until the error function reaches convergence, i.e., an acceptable and / or predetermined tolerance level. In certain embodiments, once the nodes have been appropriately weighted, i.e., the error function has reached convergence, the ANN can accurately predict the output for previously unseen inputs. By way of example and not limitation, this can mean that the trained or learned ANN can take in new pressure sensor data inputs and accurately predict the catheter size, and / or whether the contents of the catheter can be classified as unrestricted, restricted, blocked, and / or a particular intermediate state.

[0121] In certain embodiments, the algorithm can employ semi-supervised and unsupervised learning to continuously update the node weights. In certain embodiments, the algorithm can employ clustering, dimensionality reduction, and / or reinforcement learning to improve the prediction accuracy. In certain embodiments, the algorithm can accurately interpret the pressure fluctuations associated with switching between catheters of different diameters, and / or can filter out the pressure fluctuations generated by the manual movement of a separator within the suction catheter, such as by determining and considering the rhythm of the movement. Certain embodiments can employ one or more algorithms that can use a combination of the above algorithmic flow analysis techniques.

[0122] In certain embodiments, when unrestricted flow is detected, the algorithm may initiate a sampling mode. In certain embodiments, the algorithm may detect changes in flow over a short period of time, such as indicative of unrestricted flow. By way of example and not limitation, such short time intervals may span milliseconds. In certain embodiments of the sampling mode, the algorithm may cyclically stop suction, and / or may open and close a switching valve at a predetermined frequency. In certain embodiments, the sampling state may perform a suction spike when the valve is briefly opened, and / or may evaluate the pressure sensor readings. By way of example and not limitation, based on such a suction spike, the algorithm may determine whether the system should revert to full suction, such as with the switching valve in the open position, or remain in the sampling state. By way of example and not limitation, such a sampling spike may occur on the order of milliseconds, and / or may ensure that full suction only occurs when the system engages a clot, and may thereby minimize blood loss.

[0123] In certain embodiments, upon power-up, the system may have a short delay before the algorithm evaluates the flow in the suction tube. By way of example and not limitation, if the sensor indicates unrestricted flow, an appropriate time delay may be calculated during which one or more valves, such as the switching valve, may remain closed. In certain embodiments, after the short delay, one or more valves, such as the switching valve, may be opened to briefly allow suction, and / or sample the pressure readings in the suction tube. By way of example and not limitation, by doing so, the system may evaluate whether the system still has unrestricted flow, or whether it has been positioned into a clot and / or other occlusive material. In certain embodiments, if the sampling detects unrestricted flow, a new delay may be calculated. In certain embodiments, such a new delay may be determined to be incrementally longer for each successive reading up to a threshold. In certain embodiments, if the sampling detects restricted flow, such as due to a blockage, an appropriate time delay may be calculated during which one or more valves, such as the switching valve, may remain open. In certain embodiments, when open, the system may evaluate the pressure sensor readings, such as at regular intervals, to determine whether the system has been positioned to cause unrestricted flow. In certain embodiments, some, all, or a combination of these processes may be repeated until the program is complete.

[0124] In certain embodiments, an extraction cycle can be used to clear occlusions in a suction catheter and / or facilitate the aspiration of clots that may be too large or difficult to aspirate. In certain embodiments, the extraction cycle can create a pressure differential between the suction catheter and a vacuum source. In certain embodiments, the pressure differential can alternate or cycle over time to create pressure pulses. In certain embodiments, the pressure pulses can employ a variety of mechanisms to facilitate the uptake of thrombus into the suction catheter. By way of example and not limitation, according to one mechanism, the pressure pulses can introduce an acceleration component, which can facilitate the extraction of occlusive material. By way of example and not limitation, according to one mechanism, the pressure pulses can generate force pulses, which can instantaneously break static friction, which in turn can allow for lower dynamic friction to uptake the thrombus. By way of example and not limitation, according to one mechanism, the pressure pulses can move the thrombus away from the distal end of the catheter and / or subsequently rapidly force contact between the thrombus and the catheter, which can macerate the thrombus.

[0125] In certain embodiments, the extraction cycle can alternate between providing vacuum aspiration and relative positive pressure. In certain embodiments, the extraction cycle can be initiated when the suction catheter is already at full vacuum. In certain embodiments, when the extraction cycle is initiated, the vacuum switch valve between the catheter and the suction source can be closed and the pressure in the suction catheter can be increased. By way of example and not limitation, this can cause a positive pressure pulse and create a pressure differential between the vacuum source and the catheter. In certain embodiments, when the switch valve is opened, the contents and the distal end of the suction catheter can experience a pressure differential as a negative pressure pulse. By way of example and not limitation, the negative pressure pulse may have a negative impact on the structural integrity of any occlusion, such as to an extent that static forces can only be achieved with a greater energy supply. In certain embodiments, the amplitude or magnitude of the pressure pulses can be directly related to the pressure differential between the discharge catheter and the pressure source (e.g., for positive pressure pulses) and between the pressurized catheter and the vacuum source (e.g., for negative pressure pulses). In certain embodiments, the frequency or timing at which one or more valves (such as the switch valve) can be opened and / or closed can be predetermined, or responsive to pressure sensor data, or any combination thereof. By way of example and not limitation, the pressure pulses of the extraction cycle can have an amplitude, frequency, and / or other parameters that are optimized to extract thrombus and / or other occlusive material from the vasculature.

[0126] The pressure differential in the catheter can be generated in a variety of ways. By way of example and not limitation, in certain embodiments, the pressure, pressure wave, and / or pressure differential can be generated by closing the catheter's access to the vacuum source. In certain embodiments, the pressure, pressure wave, and / or pressure differential can be generated by introducing a fluid medium into the catheter (e.g., Figures 14 - 17)。By way of example and not limitation, the fluid medium can be introduced at a pressure between full vacuum and ambient pressure, or at ambient pressure, or at the patient's systolic pressure, or above systolic pressure, or at any other pressure suitable for one or more of the purposes disclosed herein. In a particular embodiment, the pressure differential can be generated by mechanical displacement of the pressure chamber (e.g., Figure 18 )。

[0127] In a particular embodiment, when the algorithm of the controller 220 detects a blocked catheter, an occluded catheter, or a catheter located in a clot, the aspiration cycle can be automatically initiated. By way of example and not limitation, the catheter can be identified as being in a blocked state when the pressure differential approaches zero. In a particular embodiment, after the system has detected a blockage that has persisted for longer than a predetermined time interval, the controller can automatically initiate the aspiration cycle. By way of example and not limitation, such as 5 seconds. Alternatively, the aspiration cycle can be initiated and / or terminated according to the user's request. In a particular embodiment, the aspiration cycle can provide pressure pulses for a predetermined period of time. Additionally or alternatively, in a particular embodiment, each time one or more valves (such as switching valves) are opened, the aspiration cycle can evaluate the pressure sensor data to evaluate or sample the flow and / or determine whether the aspiration cycle should continue or end. By way of example and not limitation, if the aspiration cycle is initially unsuccessful in clearing the blockage, it can change the amplitude, frequency, and / or other parameters of the pressure pulse. In a particular embodiment, the algorithm on the controller 220 can consult a library of different pressure pulses and can select one or more pressure pulses or pulse parameters from the contents of the library. In a particular embodiment, if a particular parameter, such as a particular amplitude and / or frequency, begins to clear the blockage, the algorithm can continue to generate pressure pulses of those parameters, such as that frequency and / or amplitude, until the blockage is cleared.

[0128] Figures 14 - 18 An exemplary pulsed fluid injection assembly suitable for a particular embodiment is shown. Figure 14A fluid system is shown that can be used in certain embodiments to generate a pressure differential and thus generate pressure pulses. In certain embodiments, the fluid introduction unit 290 can be attached along the length of the connecting tube 206 having a three-way or three-point junction 292. In certain embodiments, the three-point junction 292 can be positioned between the base unit 210 and the external unit 204, or can be positioned distally to both the base unit 210 and the external unit 204. In certain embodiments, the three-point junction 292 can be positioned in close proximity to the attached aspiration catheter. In certain embodiments, the fluid injection switching valve 296 can control the flow of fluid (liquid or gas) to inject pressure pulses. By way of example and not limitation, introducing such pressure pulses into the flow path of a clot can facilitate the removal, extraction, and / or elimination of the clot or other occlusive material. In certain embodiments, the flow of the fluid medium can be directly introduced into the connecting tube 206. In certain embodiments, the flow of the fluid medium can first pass through the injection tube 294 before entering the connecting tube 206. In certain embodiments, the injection tube 294 can direct the pressure pulse to the catheter, which can optimize the pressure pulse. In certain embodiments, the three-point junction 292 can have a T-joint structure, such as Figure 13 shown by way of example and not limitation. Alternatively, in certain embodiments, the three-point junction can have a Y-joint structure (not shown). By way of example and not limitation, the Y-joint can beneficially direct fluid from the fluid introduction unit to the catheter, which can optimize the pressure pulse in a manner similar to the injection tube of the previous example.

[0129] Figure 15A fluid system in which a pump 398 can be used in a particular embodiment is shown. In a particular embodiment, the pump 398 can be connected between a fluid reservoir 390 and an injection valve 396. In a particular embodiment, the pump 398 can cycle when the injection valve 396 is open. By way of example and not limitation, the pump can provide work (392: three-point junction) by forcefully injecting a fluid medium from the fluid reservoir 390, e.g., through the injection valve 396 (e.g., a switching valve) into the injection tube 394 and / or the connecting tube 306. In a particular embodiment, the magnitude of the positive pressure of the pressure pulse can be directly related to the throughput (e.g., size) of the pump 398. In a particular embodiment, a pressure chamber 397 can be positioned between the pump 398 and the injection valve 396. In a particular embodiment, the pressure chamber 397 can allow the pump 398 to provide work even when the injection valve 396 is closed. By way of example and not limitation, when the injection valve 396 is closed, the pump 398 can forcefully inject a fluid medium from the reservoir 390 into the pressure chamber 397, whereby the pressure chamber 397 can be pressurized. In a particular embodiment, when the injection valve 396 is open, the pressure can be released from the pressure chamber 397 into the injection tube 394 and / or the connecting tube 306. In a particular embodiment, since the pump 398 can accumulate pressure over time, the magnitude of the positive pressure of the pressure pulse can not be directly related to the throughput (e.g., size) of the pump 398, which can allow a smaller pump to be used in some particular embodiments. To provide greater control over the duration or magnitude of the positive pressure pulse, in a particular embodiment, the opening and closing of the injection valve can be throttled or otherwise manipulated to regulate the injection rate. In a particular embodiment, a pressure sensor can be included in the pressure chamber 397 to monitor and control the pressure buildup.

[0130] Figure 16 Another three-point junction 492 attached along the connecting tube 406 according to a particular embodiment is shown. In a particular embodiment, the three-point junction 492 can be positioned between the base unit 210 and the external unit 204. In a particular embodiment, the three-point junction 492 can be positioned distally of both the base unit 210 and the external unit 204. In a particular embodiment, a pressure valve 496 can control the generation of a positive pressure pulse from the fluid chamber 490. By way of example and not limitation, the fluid from the fluid chamber 490 can flow directly into the connecting tube 406, or can first pass through the injection tube 494 before entering the connecting tube 406. In a particular embodiment, a suction valve 499 can control the application of vacuum suction from an attached vacuum source.

[0131] In certain embodiments, the three-point junction 492 may be provided with one or more valves, e.g., to control one or both of the vacuum force and the positive pressure pulse. By way of example and not limitation, such a configuration may allow the three-point junction 492 to alternate between applying vacuum suction and pressure pulses, where the pressure of the pressure pulse may be higher than the pressure of the vacuum source. In certain embodiments, the suction valve 499 and the pressure valve 496 may be opened alternately, simultaneously, with a delay, in some overlapping sequence, or in combination thereof. By way of example and not limitation, in an overlapping sequence, one valve may begin to open when the other valve begins to close, whereby there may be a short period of time when both valves are at least partially open. By way of example and not limitation, in an overlapping sequence, sometimes multiple (e.g., two) valves may be open, and / or multiple (e.g., two) valves may be closed for at least a short period of time.

[0132] In certain embodiments, the suction valve 499 may be positioned between the conduit and the suction source to regulate suction. In certain embodiments, the pressure valve 496 may be positioned between the conduit and the fluid source, e.g., to regulate fluid injection. In certain embodiments, both the suction valve 499 and the pressure valve 496 may be selectively opened and closed, e.g., to create a pressure differential within the conduit and / or the suction tube. By way of example and not limitation, the selective opening and closing of the suction valve 499 and the pressure valve 496 may be customized to provide pressure pulses of a desired amplitude and frequency.

[0133] Figure 17A perspective view of a three-way connector and its connected components according to a particular embodiment is provided. In a particular embodiment, the connecting tube 706 can serve as a common conduit between a vacuum source 700, a pressure source 790, and a suction catheter 750. In a particular embodiment, the connecting tube 706 can have a first end configured to be attached to and / or placed in fluid communication with the vacuum source. In a particular embodiment, the connecting tube 706 can have a second end configured to be attached to the suction catheter or placed in fluid communication with the suction catheter. In a particular embodiment, the second end can be attached to the suction catheter via a rotary hemostatic valve. In a particular embodiment, the three-way connector 792 can be positioned near the second end, e.g., to provide a relatively positive pressure pulse near the suction catheter 750. In a particular embodiment, the three-way connector 792 can be an angled connector or a Y-connector, whereby fluid from the pressure source can be directed to the suction catheter 750. In a particular embodiment, the three-way connector 792 can include an injection tube 794 that can direct fluid from the pressure source to the suction catheter 750. In a particular embodiment, the injection tube 794 can extend from the three-way connector into the suction catheter, whereby fluid can flow from the pressure source into the suction catheter 750. In a particular embodiment, the injection tube 794 can extend from the three-way connector to a location near the distal end of the suction catheter 750, e.g., as depicted in perspective view 751, which shows a schematic enlarged perspective view of the distal end of the suction catheter 750. In a particular embodiment, the pressure source can cause fluid to flow according to direction arrow 761, and the vacuum source can cause fluid to flow according to direction arrow 760. In a particular embodiment, the controller can adjust the vacuum valve 799 and the pressure valve 796, whereby closing the vacuum valve 799 and opening the pressure valve 796 can result in a relatively increased pressure at the distal end of the suction catheter.

[0134] Alternatively, in a particular embodiment, opening the vacuum valve 799 and closing the pressure valve 796 can result in a relatively decreased pressure at the distal end of the suction catheter 750. In a particular embodiment, these pressure changes can be transmitted as pressure pulses along the length of the suction catheter. In a particular embodiment, the controller can close the vacuum valve 799 and open the pressure valve 796 for a short period of time. By way of example and not limitation, this can allow a minimum volume of fluid from the pressure source 790 to be introduced into the proximal end of the suction catheter 750 in order to increase the relative pressure at the distal end of the suction catheter 750 and then return to vacuum by reopening the vacuum valve 799 and closing the pressure valve 796.

[0135] In certain embodiments, the controller can close the vacuum valve 799 and open the pressure valve 796 for a longer period of time, e.g., allowing a greater volume of fluid from the pressure source 790 to be introduced into the aspiration catheter 750. By way of example and not limitation, this can facilitate moving the blocking material away from the distal end of the aspiration catheter and then returning to vacuum by reopening the vacuum valve 799 and closing the pressure valve 796. In certain embodiments, the connecting tube 706 can have a dual lumen along a portion of its length, whereby, for example, one lumen can accommodate fluid while a second lumen can accommodate connecting wiring, which can enable the controller to regulate both the vacuum valve 799 and the pressure valve 796.

[0136] Figure 18 A valve structure for controlling both aspiration force and positive pressure pulses according to certain embodiments is shown. In certain embodiments, a three-way junction 592 can be attached to the connecting tube 506 and the pressure chamber 590. In certain embodiments, a gate valve 550 (illustrated as but not limited to in position 550A or position 550B) can be switched at axis 570 to block aspiration in position 550A and / or to block fluid introduction in position 550B. In certain embodiments, the gate valve 550 can provide pulsed aspiration. By way of example and not limitation, the gate valve 550 can swing back and forth at a predetermined and / or responsive frequency, which can be controlled by an algorithm in the controller 220. In certain embodiments, a three-way gate valve can be provided at the junction between the aspiration source, the pressure source, and the catheter. In certain embodiments, the gate valve 550 can switch between blocking the aspiration source and blocking the pressure source, e.g., to achieve a pressure pulse of desired parameters, such as a pressure pulse of a desired amplitude and / or frequency.

[0137] In certain embodiments, fluid injection may not occur at the three-way junction but may occur at a more distal region closer to the catheter tip. By way of example and not limitation, the location of relative pressure injection can be used to optimize pressure pulse variations to facilitate clot removal. In certain embodiments, the distal region of the aspiration catheter may include a valve that can be opened and closed, such as a distal valve. In certain embodiments, the aspiration valve can be closed and the distal valve can be opened to allow blood to enter the catheter, which can increase the pressure in the catheter and / or amplify the pressure differential between the catheter lumen and the vacuum source. By way of example and not limitation, the distal valve can then be closed and the aspiration valve can be opened, wherein the pressure differential between the vacuum source and the catheter can cause a pressure pulse. In certain embodiments, fluid can be transferred from another adjacent catheter into the aspiration catheter. By way of example and not limitation, an inner catheter can deliver fluid to an outer aspiration catheter. In certain embodiments, an outer catheter can deliver fluid to an inner aspiration catheter through a valve structure. In either case, for example, the fluid medium can be delivered along the length of the aspiration catheter rather than through the proximal end. In certain embodiments, adjacent catheters can provide an alternative or additional connection to the vacuum source.

[0138] Figure 19 A mechanical displacement assembly for manipulating pressure according to certain embodiments is shown. In certain embodiments, a mechanical piston 699 can supplement or replace the injection valves and pressure chambers, pumps, and / or fluid reservoirs previously described herein. By way of example and not limitation, the stroke of the piston 699 or an alternative mechanical device can be controlled to adjust the volume of the catheter, which can result in the generation of negative pressure during one stroke and / or positive pressure during a stroke in the opposite direction. In certain embodiments, the mechanical actuation device can be actuated back and forth, for example, to alternately increase and decrease the overall volume of the system. By way of example and not limitation, when the device can be actuated to increase the volume, the pressure can be reduced, and / or when the device can be actuated to decrease the volume, the pressure can be increased. In certain embodiments, such pressure variations can generate, amplify, and / or assist the pressure pulses of the extraction cycle. In certain embodiments, the piston 699 can be arranged to communicate with the three-way junction 692. By way of example and not limitation, the three-way joint 692 can be attached to the connecting tube 606. By way of example and not limitation, other mechanical equipment for controlling the volume or pressure of the catheter can include linear motors, stepper / servo motors, cam follower actuators, solenoids, audio exciters, voice coil actuators, diaphragms, peristaltic pumps, rotary vanes, gears, screws, syringes, etc., or any combination thereof.

[0139] In certain embodiments, high-frequency pressure pulses can be achieved by mechanical means, such as Figure 19 as shown. By way of example and not limitation, in order to provide high-frequency pressure pulses, the catheter must be rapidly pressurized and / or rapidly evacuated. In certain embodiments, Figures 14 - 18A fluid injection system can readily provide a rapid influx of pressure; however, in certain embodiments, a vacuum source may take a non - insignificant amount of time to reduce the catheter pressure back to full or near - full vacuum. By way of example and not limitation, if a subsequent pressure influx occurs prematurely, the catheter may not have sufficient time to reach full or near - full vacuum. In such a case, in certain embodiments, the pressure differential between the not - fully - evacuated catheter and the pressure source may be low, and the resulting pressure pulse may have a low amplitude. In certain embodiments, a lower pressure differential and / or a lower - amplitude pressure pulse may be sub - optimal in some cases. In certain embodiments, to avoid, for example, low - amplitude pressure pulses caused by high frequencies, a vacuum recovery system may be used. In certain embodiments, the vacuum recovery system can reduce, for example, the time required to return the catheter to full vacuum after a positive - pressure influx. In certain embodiments, with a vacuum recovery system, pressure pulses with high amplitude and high frequency can be achieved.

[0140] Figure 19 A device that can act as a vacuum recovery system by generating a pressure differential is shown, according to certain embodiments. In certain embodiments, the vacuum recovery system can utilize a syringe, a discharge chamber, a second suction pump, or some combination of these or other suitable options. By way of example and not limitation, the syringe can be a piston - actuated device that can be retracted to increase the volume of the system (thereby reducing pressure). By way of example and not limitation, the syringe can be advanced to decrease the volume of the system (thereby increasing pressure). In certain embodiments, a syringe - like device can not only beneficially assist in vacuum recovery but also assist in generating positive - pressure pulses. In certain embodiments, the syringe can be used during an extraction cycle. In such an embodiment, the catheter can start at full or near - full vacuum. By way of example and not limitation, when the vacuum source can be turned off, the syringe can be advanced (e.g., to decrease the system volume), and optionally, a fluid medium can be injected. In certain embodiments, one or more of these measures can facilitate the formation of a positive - pressure pulse. By way of example and not limitation, next, the vacuum source can be turned on, and the syringe can be retracted (e.g., to increase the system volume) to generate a negative - pressure pulse, whereby the syringe can accelerate the return of the catheter to near - full vacuum. In certain embodiments, the suction pump can be configured to selectively enable the discharge chamber that is open to the catheter (alternatively or in addition to the suction pump) after each pressure pulse. In certain embodiments, the suction pump and the discharge chamber together can return the catheter to full vacuum more quickly. By way of example and not limitation, while the suction pump can be closed to the catheter, it can be open to the discharge chamber, for example, to further enable the discharge chamber between pressure pulses. In certain embodiments, a secondary suction pump can assist the primary suction pump, for example, to facilitate vacuum recovery after each pressure pulse.

[0141] Figure 20 A schematic graphical representation of a particular embodiment of pulsatile aspiration is shown, where the pressure inside the catheter can vary over time. In a particular embodiment, the extraction cycle can use a pulsation protocol, for example, to systematically manipulate the amount of pressure within the catheter, and / or to facilitate the extraction of occlusive material.

[0142] The pressure within the catheter can be manipulated by various methods. By way of example and not limitation, vacuum aspiration can be used to reduce the pressure within the catheter. In a particular embodiment, removal of the vacuum suction and / or introduction of fluid can be used to increase the pressure within the catheter. In a particular embodiment, a mechanical actuation device can alternate between increasing and decreasing the pressure within the catheter. In a particular embodiment, such as Figure 20 shown, at time 0, the catheter may not be subject to any suction force. By way of example and not limitation, the catheter can be at atmospheric pressure at time 0. From time 0 to time 1, the catheter may have lost pressure, for example, dropping from atmospheric pressure to near full vacuum (i.e., near -29.9 inHg). From time 1 to time 2, the catheter may have gained pressure, which reduces the vacuum intensity. From time 2 to 3, the catheter may have lost pressure, which may return the catheter to near full vacuum. For example, from time 3 to 4, the catheter may have gained pressure and returned to ambient pressure. From time 4 to 5, the catheter may have lost pressure, again dropping from atmospheric pressure to near full vacuum. From time 5 to 6, the catheter may have gained pressure, which may have caused the pressure to rapidly increase from near full vacuum to above ambient pressure. From time 6 to 7, the catheter may have lost pressure, such as rapidly dropping from a pressurized state above atmospheric pressure to near full vacuum.

[0143] In a particular embodiment, such as Figure 20 the pulsation protocol shown, by way of example and not limitation, can be performed once, or can be repeated a number of times. In a particular embodiment, the pulsation protocol can include one or more time periods with additional pressure variations and / or pressure patterns. In a particular embodiment, the pressure of the system can vary between near vacuum and above mean systolic pressure. In a particular embodiment, the duration of the pulsation protocol can be predetermined, and / or can be adaptive to pressure sensor readings. In a particular embodiment, for example based on pressure sensor readings, the controller can extend or shorten the pulsation protocol. In a particular embodiment, the system can be maintained in a stable pressure state for one or more time periods. By way of example and not limitation, the controller can cause the system to remain in a state of near full vacuum. In a particular embodiment, the dwell time at each pressure state and / or the frequency of transitions of the system between pressure states can be optimized to aspirate, remove, impregnate, and / or remove different clot or occlusive material compositions. Although Figure 20A pulsation protocol is shown having a specific frequency such as a stable and consistent frequency, but in a particular embodiment, the frequency of the pulsation protocol can be variable, and / or some combination of partially stable and partially variable frequencies.

[0144] In a particular embodiment, high amplitude (or high magnitude) pressure pulses can be generated by creating a large pressure differential. By way of example and not limitation, Figure 20 A high amplitude pressure pulse between times 5 and 7 is shown. In a particular embodiment, for example, lower magnitude pressure pulses can be generated by oscillating between less extreme high and low pressures. By way of example and not limitation, the low end of the pressure pulse may not reach near full vacuum, the high end of the pressure pulse may not reach ambient pressure, or both. In a particular embodiment, this reduced pressure range can result in lower magnitude pressure pulses, which may be desirable in some cases. By way of example and not limitation, Figure 20 The time unit can be seconds, milliseconds, microseconds, or different time scales.

[0145] In a particular embodiment, the extraction cycle can use a predetermined series of pressure pulses, for example, using near full vacuum suction before the extraction cycle, between individual pulses of relatively positive pressure, and / or after the extraction cycle. In a particular embodiment, the pressure pulses can be selected from a library of pressure pulses having parameters (such as amplitude and / or frequency) that can facilitate the extraction of clots and / or other occlusive materials. In a particular embodiment, the series of pressure pulses can differ from each other in frequency, amplitude, or both. By way of example and not limitation, the pulsation protocol can use a series of pressure pulses having a trend where one or more pressure parameters, such as amplitude and / or frequency, can increase while the other decreases. By way of example and not limitation, the pulsation protocol can include a series of pressure pulses where both amplitude and frequency increase or decrease, or where one of amplitude or frequency increases or decreases while the other remains constant.

[0146] In certain embodiments, for example, the extraction cycle can provide a specific pressure pulse based on pressure sensor readings. By way of example and not limitation, in response to the extraction cycle, the pressure within the catheter can be measured, and then one or more pressure pulses optimized for the catheter with those pressure readings can be selected. By way of example and not limitation, in another response extraction cycle, the system can cycle through a library of pressure pulses, such as having a period of static or full aspiration and occlusion detection after each individual pressure pulse. In certain embodiments, after the library has been cycled through, the system can repeat the pressure pulse that was measured or otherwise determined to be the most successful. By way of example and not limitation, the success of a particular pressure pulse can be commensurate with the amount of increase in flow rate after the pressure pulse. In certain embodiments, the system can continue to cycle down until only a few pressure pulse protocols remain in the loop. In certain embodiments, if the efficacy of the loop begins to decrease, the system can return to the full library and initiate a new cycle.

[0147] In certain embodiments, the response extraction cycle can have three modes: cycling up, where successive pressure pulses can be stronger in amplitude and / or frequency; cycling down, where successive pressure pulses can be weaker in amplitude and / or frequency; and maintaining the pressure pulse, where the pressure pulse can have a consistent frequency and / or amplitude. In certain embodiments, when the system detects a blocked state, it can enter the cycling up mode. In certain embodiments, when the system detects a restricted flow state, it can enter the maintaining mode. In certain embodiments, when the system detects an unrestricted flow state, it can enter the cycling down mode.

[0148] In certain embodiments, alternative embodiments can be useful in situations where maximizing the removal of occlusive material may be more important than considering blood loss in certain cases, such as in certain cases during neurovascular stroke surgery. In such a context, in certain embodiments, the optimal technique can include positioning the distal end of the catheter within the clot, applying full vacuum, and waiting for a predetermined period of time before proceeding to the next step. In certain embodiments, the goal can be to achieve a complete or near-complete engagement of the catheter tip with a large amount of occlusive material. By way of example and not limitation, such an engagement may substantially block the distal end of the catheter and is sometimes referred to as "plugging the catheter". By way of example and not limitation, if the clinician successfully "plugs the catheter" in a particular case, the catheter system can be removed from the vasculature, thereby removing a large amount of clot or occlusion with it. Alternatively, in certain embodiments, the extraction cycle can be used to aspirate the occlusive material through the catheter lumen and / or to deeply lock or plug the clot within the catheter. In certain embodiments, after the extraction cycle is completed, the clot can be removed or plugged in the attached catheter such that the catheter with the clot can be safely removed from the patient's body.

[0149] In certain embodiments, when a clot or other occlusive material blocks the catheter and plugs it, the aspiration cycle can be stopped automatically and / or manually. By way of example and not limitation, the clot or occlusive material may be too large and / or too hard to pass through the aspiration catheter, but may still be partially entrained within the aspiration catheter. In certain embodiments, the system can transition to full aspiration to allow the user to remove the plugged catheter while pulling out the clot or other occlusive material along with the catheter. In some cases, the clot or occlusive material may still block the catheter once the aspiration cycle is initiated. In certain embodiments, the controller can then revert to full aspiration and / or notify the user of the plugging event, whereby the system can prompt the user to remove the catheter. In certain embodiments, the user can manually turn off the aspiration cycle and / or otherwise return the system to full vacuum and then remove the catheter.

[0150] In certain embodiments, the system can transition to an infusion cycle to allow a valve (such as a pinch valve or a different type of valve) to apply a mechanical force on the clot or other occlusive material. By way of example and not limitation, such mechanical action can be applied to sufficiently modify the morphology and / or consistency of the clot or other occlusive material so that aspiration can be performed more effectively.

[0151] In certain embodiments, to indicate the working state or operation of removing a clot or other occlusive material, visual and / or auditory signals indicating the progress of a given aspiration cycle can be included. In certain embodiments, the start of the aspiration cycle can be signaled by a flashing light, such as a blue flashing light, which can flash until the cycle is complete. In certain embodiments, upon completion, the light can change to a different color to indicate completion, such as green. In certain embodiments, the base unit 200b or the base unit housing 216 can include a light bar. By way of example and not limitation, the light bar can be filled or lit incrementally, whereby the light bar can be gradually "filled" with light in proportion to the progress of the cycle. Additionally or alternatively, the base unit 200b or the base unit housing 216 can include a screen for displaying images. In certain embodiments, a small screen can display an animation indicating loading. By way of example and not limitation, the loading animation can perform a repeating pattern (e.g., a rotating circular object) and / or can perform an extended animation of a single cycle (e.g., slowly filling a circle). In certain embodiments, in combination with or as an alternative to the visual progress indication, the system can use auditory cues in certain embodiments to indicate the start, pulsation phase, and / or completion of the aspiration cycle. By way of example and not limitation, the auditory cues can include tones, beeps, and / or voices. In certain embodiments, the auditory cues can include updates (e.g., "aspirating") and / or suggestions (e.g., "advance / retract the catheter").

[0152] In certain embodiments, the algorithm can also control a lighting mechanism, such as an indicator light, to communicate to the user whether the system is in a full aspiration state, an unrestricted flow state, a restricted flow state, a blocked state, a sampling state, and / or an extraction state. In certain embodiments, a particular light can be illuminated to indicate a bubble and / or to indicate that an override switch has been triggered. In certain embodiments, the algorithm can control an acoustic chip, such as a piezoelectric acoustic chip. By way of example and not limitation, the acoustic chip can communicate an audible message to the physician, such as regarding the status of the effluent and the override switch. In certain embodiments, the piezoelectric acoustic chip can be surface-mounted. By way of example and not limitation, the piezoelectric acoustic chip can selectively generate a 4 kHz tone, e.g., 65 dB at 10 cm. By way of example and not limitation, the signal can include sounds and / or phrases, such as tone / pitch variations, beep patterns, "blocked", "occluded", "clot", "blood", "open flow", etc. Certain embodiments can utilize a dynamic beep rhythm. By way of example and not limitation, the beep pattern can steadily increase as the unrestricted flow state continues to increase. In certain embodiments, the speed of the beeping can indicate the length of time the system has been in a particular state, such as unrestricted flow, and / or can warn the physician of the increasingly problematic nature of the system's positioning or status. In certain embodiments, the system can additionally or alternatively include a multi-position switch or button, e.g., to specifically activate different algorithms, mute audio cues, and / or enable the system with fluid. By way of example and not limitation, such a feature can be activated by inserting a pin into the base unit 210, which can activate the customizable feature.

[0153] In certain embodiments, the system can be manually powered on and aspirated for a predetermined period of time. By way of example and not limitation, if the system detects unrestricted flow, one or more valves (e.g., switching valves) can be closed to stop the flow. The attending physician can then reposition the catheter tip into the clot and / or manually trigger a mechanism (such as a foot pedal or a manual switch) to initiate further aspiration. By way of example and not limitation, such manual triggering can override the algorithm and can allow continued aspiration. In certain embodiments, once the manual trigger is released, the algorithm can again monitor the flow to allow aspiration, e.g., as long as the flow is acceptable and / or within certain parameters. In certain embodiments, if and when the system may again detect unrestricted flow, one or more valves (such as switching valves) can be closed again, e.g., until the physician repositions the aspiration catheter and / or manually overrides the controller. In certain embodiments, such a protocol can be repeated until the physician completes the procedure.

[0154] In certain embodiments, prior to the aspiration catheter being available for removing clots and other occlusive materials, it may need to be primed with an incompressible fluid. In certain embodiments, the catheter may be filled with a suitable fluid, such as a saline fluid, to remove all air from the lumen of the catheter. In certain embodiments, the catheter may be automatically primed, whereby the catheter is filled with a suitable fluid to expel all compressible fluid (e.g., air). In certain embodiments, one or more sensors may monitor the catheter contents during use. By way of example and not limitation, if compressible fluid (e.g., air or bubbles or other gas) is detected, the system may alert the user. In certain embodiments, the system may indicate that the procedure needs to stop, e.g., so that the catheter can be primed again to remove air bubbles.

[0155] Tube and System Flushing

[0156] As previously disclosed herein, during the operation of an aspiration thrombectomy system, occlusive materials may be associated with partial or total blockages related to the operation of the catheter, such as catheter tip blockage, catheter occlusion, or the catheter being positioned within a clot. Separately or additionally, occlusive materials may partially or completely block, coat, deposit, or otherwise impede fluid communication, fluid flow, and / or vacuum transfer between the vacuum source and the catheter tip. By way of example and not limitation, occlusive materials may deposit or accumulate within the lumen and / or along the walls of fluid flow channels in the system. By way of example and not limitation, such fluid flow channels may include the aspiration catheter and connecting tubing that serves as a fluid conduit between the aspiration catheter and the vacuum source, and any other source of fluid medium in the system. Such deposition or accumulation of occlusive materials along the walls of the aspiration catheter and / or connecting tubing, by way of example and not limitation, reduces the available flow area, increases flow channel wall friction, increases the pressure drop, reduces the flow rate, and / or reduces the ability and efficiency to transfer vacuum to the catheter tip.

[0157] In certain embodiments, the aspiration thrombectomy system may be configured to detect, locate, dislodge, and / or operate to displace or remove occlusive materials from the tubing and the system, such as by flushing with a fluid medium. It should be understood that while terms such as "flush" and "flushing" may be used herein for brevity to describe relevant aspects, the present disclosure fully contemplates any and all of the above aspects and / or operations, as well as other related aspects and operations. By way of example and not limitation, the flushing fluid medium may include air and / or saline.

[0158] Figure 21FIG. 2100 is a schematic illustration of a particular embodiment configured for tubing and system flushing. A connecting tubing 2110 is shown which may include paratubing, the proximal end 2112 of which is connected in fluid communication with a vacuum source 2120. The distal end 2114 of the connecting tubing 2110 may be connected in fluid communication with a suction catheter 2130.

[0159] In a particular embodiment, an external unit, such as the units previously described and shown in Figure 8A , Figure 8B and Figure 10 may exist as a connection module between the distal end of the connecting tubing and the proximal end of the suction catheter. In a particular embodiment, the external unit may additionally include a distal pressure sensor.

[0160] In a particular embodiment, the system may be provided with one or more pressure sensors and one or more controllable valves. By way of example and not limitation, as shown in the embodiment of Figure 21 , a vacuum valve 2160 may control the vacuum level in the connecting tubing, such as the vacuum level provided by the vacuum source 2120. In a particular embodiment, a distal pressure sensor 2170 may be associated with the distal end 2114 of the connecting tubing 2110. According to a particular embodiment, singly or additionally, a vacuum sensor 2122 may be associated with the proximal end 2112.

[0161] In a particular embodiment, a fluid source 2162 of a flushing fluid medium may be provided. By way of non-limiting example, the fluid source 2162 may include a saline solution. In a particular embodiment, the fluid source 2162 may be elevated or otherwise pressurized, which may permit the fluid medium to flow into the connecting tubing. In a particular embodiment, the pressure level of the fluid source 2162 may exceed the vacuum pressure level of the vacuum source 2120. In a particular embodiment, the pressure level of the fluid source 2162 may be higher than an external pressure level, such as an ambient or atmospheric pressure level. In a particular embodiment, the pressure level of the fluid source 2162 may be higher than an external pressure level, such as the systolic blood pressure level of a patient. In a particular embodiment, the fluid flow from the fluid source 2162 may be controlled by selectively opening a controllable valve such as a fluid medium valve 2164. In a particular embodiment, the fluid source 2162 may be configured to provide one or more different fluid media other than saline, such as air.

[0162] According to a particular embodiment, a fluid medium tube 2168 can be used to connect a fluid source 2162 to a connection tube 2110, such as at a T-junction or a Y-junction (e.g., T-junction 2174). A fluid medium pressure sensor 2166, such as a saline pressure sensor, can be optionally provided. In a particular embodiment, a fluid medium valve 2164, such as a saline valve, can be used to control the introduction of the fluid medium from the fluid source 2162 into the connection tube 2110.

[0163] In a particular embodiment, the controller 2180 can be configured to detect system quantities of interest, such as one or more pressure levels associated with the connection tube 2110 via one or more of a distal pressure sensor 2170, a vacuum sensor 2122, and / or a fluid medium pressure sensor 2166. As will be discussed further, in a particular embodiment, based on the detected pressure levels, the controller 2180 can be configured to determine whether the connection tube 2110 is occluded. In a particular embodiment, if it is determined that the connection tube 2110 is occluded, the controller 2180 can determine the location of the occlusion. In a particular embodiment, based on determining that the connection tube 2110 is occluded and / or determining the location of the occlusion, the controller 2180 can selectively operate one or more valves, such as a vacuum valve 2160 and / or a fluid medium valve 2164, to selectively introduce the fluid medium from the fluid source 2162 into the connection tube 2110. In a particular embodiment, the controller 2180 can selectively operate one or more valves during one or more time intervals to flush the occlusion material located in the connection tube 2110. In a particular embodiment, the controller 2180 can selectively introduce the fluid medium during one or more time intervals.

[0164] It should be understood that although a particular arrangement, number, location, type, and / or connectivity of sensors and valves are disclosed for purposes of illustration of detection and control methods for tube and system flushing, any suitable arrangement, number, location, type, and / or connectivity of sensors, actuators, and / or valves for proper detection and control are fully contemplated.

[0165] By way of example and not limitation, detection can include, but is not limited to, detecting the presence and / or location of occlusion material in a suction catheter, a connection tube, and / or other relevant parts of a thrombectomy system. By way of example and not limitation, control can include, but is not limited to, controlling the level, degree, and / or location of selectively permitting fluid communication, the corresponding isolation, introduction, alteration, and / or maintenance of vacuum and / or fluid flow of one or more media in a particular part of the tube and system. Based on parameters for operating an actuator or valve, such as the number, sequence, frequency, and / or duty cycle for triggering an open / closed state, multiple operating states for operating one or more actuators or valves can be achieved.

[0166] Figure 22 An exemplary process 2200 for implementing tube and system flushing is shown, such as in the aspiration catheter or connecting tubing of an aspiration thrombectomy system.

[0167] In a first step 2210 of the illustrated algorithm, the controller may detect one or more system quantities associated with the aspiration catheter or connecting tubing via one or more sensors. By way of example and not limitation, one or more of a first pressure sensor and a second pressure sensor associated with the connection may be used for such detection, thereby detecting one or more pressure levels.

[0168] In a second step 2220 of the illustrated algorithm, the controller may determine whether a portion of the system, such as the aspiration catheter or connecting tubing, is occluded based on the detected one or more associated system quantities. By way of example and not limitation, the controller may determine whether the connecting tubing is occluded based on the one or more pressure levels detected via one or more of the first pressure sensor and the second pressure sensor.

[0169] In a third step 2230 of the illustrated algorithm, based on determining that the aspiration catheter or connecting tubing is occluded, the controller may determine the location of the occlusion based on the detected one or more system quantities. By way of example and not limitation, based on the one or more pressure levels detected via one or more of the first pressure sensor and the second pressure sensor, the controller may determine that the connecting tubing is occluded and, further, determine that the occlusion is located between the first pressure sensor and the second pressure sensor.

[0170] In a fourth step 2240 of the illustrated algorithm, the controller may operate one or more actuators or valves of the system to flush a particular portion of the aspiration catheter or connecting tubing. By way of example and not limitation, the controller may operate one or more of a first valve and a second valve based on the determined location of the occlusion to introduce a fluid medium into the connecting tubing during one or more time intervals.

[0171] Figure 23 and Figure 24 Examples 2300 and 2400 of time-varying pressure distributions and valve operations according to particular embodiments are shown as examples of performing tube and system flushing in an aspiration thrombectomy system.

[0172] By way of example and not limitation, these figures include a distal pressure curve 2310 based on the time-varying pressure detected by a distal pressure sensor, such as distal pressure sensor 2170. A vacuum valve curve 2320 indicates the time-varying state of a vacuum valve, such as vacuum valve 2160. The open state of the vacuum valve is indicated herein as a relatively elevated level along the y-axis, such as 2320a, and the closed state of the vacuum valve is indicated herein as a relatively lowered level, such as at 2320b.

[0173] The illustrated pressure curve labeled 2330 is an exemplary vacuum pressure curve 2330 based on the time-varying pressure detected by a pressure sensor (such as vacuum sensor 2122) associated with the proximal portion of the connecting tube. The illustrated pressure curve labeled 2340 is an exemplary saline pressure curve 2340 based on the time-varying pressure detected by a pressure sensor (such as fluid medium pressure sensor 2166) associated with the fluid medium or pressure source.

[0174] The illustrated valve curve labeled 2350 is an exemplary saline valve curve 2350 that indicates the time-varying state of the saline valve as a control valve for the fluid medium (such as fluid medium valve 2164). Similar to the above-described vacuum valve state, in the illustrations herein, the open or closed state of the saline valve curve 2350 can also be indicated by the relative elevation (e.g., 2350a) or depression (e.g., 2350b) level of the respective valve curve along the y-axis.

[0175] Figure 23 An example 2300 of the detection and flushing of an occlusion in the connecting tube located near the vacuum source is shown. Referring Figure 21 , by way of illustration and not limitation, an occlusion located between the vacuum sensor 2122 and the vacuum source 2120 can be considered a representative example among other possible examples.

[0176] In a particular embodiment, as Figure 23 shown, in the absence of an occlusion between the vacuum sensor 2122 and the vacuum source 2120, the vacuum pressure curve 2330 can represent the evolving pressure level associated with the vacuum source 2120. Thus, for example, the pressure values and / or variations of the vacuum pressure curve 2330 can be monitored, such as relative to a particular known or determined reference and / or threshold level. In a particular embodiment, a change in one or more values of the vacuum pressure curve 2330 exceeding a threshold may indicate the presence of an occlusion between the vacuum sensor 2122 and the vacuum source 2120. In a particular embodiment, an occlusion located distal to the vacuum source 2120, at the proximal end 2112 of the connecting tube 2110, and / or near the vacuum source 2120, such as an occlusion between the vacuum sensor 2122 and the vacuum source 2120, can result in a corresponding intermediate pressure increase in the vacuum pressure curve 2330.

[0177] As Figure 23As shown in approximately the first half of the depicted time window, as a non-limiting example, the vacuum pressure curve 2330 generally remains relatively constant and at a low value over time. During this early part of the depicted time window, but not limited thereto, the thrombectomy aspiration system is depicted as being in regulated aspiration, pulsatile aspiration, or any sequence or variation of aspiration, where the vacuum valve curve 2320 and the saline valve curve 2350 operate alternately (i.e., at a given time, one of the two valves is open and the other is closed, and the open / closed states of the two valves periodically reverse) to selectively expose the aspiration catheter to a vacuum source and / or a pressure or fluid medium source. In a particular embodiment, one or more valves (such as the vacuum valve 2160) can be selectively operated to sample the pressure state of the aspiration catheter or the connecting tubing. In a particular embodiment, one or more valves (such as the vacuum valve 2160) and / or a pressure source valve (such as the fluid medium valve 2164) can be selectively operated to generate a pressure change in the aspiration catheter or the connecting tubing.

[0178] Also as shown, by way of example and not limitation, the vacuum valve curve 2320 and the saline valve curve 2350 in the early part of the window (such as before the approximate time point indicated by 23-A) indicate that the respective vacuum valve and saline valve do not remain open simultaneously. Thus, and as previously detailed herein, during this early part of the time window (before 23-A), the saline released or introduced by the fluid medium source can be directed only to the aspiration catheter to provide regulated aspiration and not to the vacuum source.

[0179] In Figure 23After the approximate time point indicated by 23-B as shown, it can be seen that the vacuum pressure curve 2330 increases significantly over time relative to its hitherto lower and approximately stable pressure level. In a particular embodiment, based on the vacuum pressure curve 2330 exceeding one or more thresholds, such as around 23-A, the controller may be configured to determine the presence of an occlusion. In a particular embodiment, the controller may be configured to determine that the connecting tube is occluded between the vacuum sensor 2122 and the vacuum valve 2160 based on one or more pressure levels detected by the vacuum sensor 2122 that exceed one or more thresholds. In a particular embodiment, one or more thresholds may be determined in advance or empirically. In a particular embodiment, one or more thresholds may be invoked based on a particular one-time or ongoing measurement, which may include one or more pressure levels detected via one or more pressure sensors. In a particular embodiment, one or more detected pressure levels may be filtered and / or processed based on suitable criteria. By way of example and not limitation, the detected pressure levels may be processed to filter out transient pressure spikes, such as those caused by clots passing through the connecting tube 2110. By way of example and not limitation, the detected pressure levels may be processed to filter out pressure measurement acquisition artifacts and / or other noise factors.

[0180] Individually or additionally, based on one or more of the respective positions of the corresponding sensors, particular detected pressure distribution characteristics, and / or input from other sensors, the controller may be configured to locate the position of the detected occlusion. By way of example and not limitation, in the Figure 23 example of and following the Figure 21 example configuration, based on the pressure level from the vacuum sensor 2122 exceeding a threshold, it may be determined that the detected occlusion exists between the vacuum sensor 2122 and the vacuum source 2120.

[0181] In a particular embodiment, based on determining the presence and / or location of an occlusion in the connecting tube or the suction catheter, the controller 2180 may be configured to take action to reduce, displace, and / or remove the occlusion. In a particular embodiment, as Figure 23 further shown, between 23-C and 23-D, the controller 2180 may initiate a flushing operation. In a particular embodiment, the flushing operation may include introducing a fluid medium, such as air and / or saline, into the connecting tube and / or the suction catheter. In a particular embodiment, the flushing operation may be provided by the controller 2180 during one or more time intervals.

[0182] In certain embodiments, the fluid medium introduced into the connecting tube and / or the aspiration catheter can provide flushing based on the flow caused by a pressure gradient generated by one or more of a pressure source and / or a vacuum source. In certain embodiments, the pressure source can include a fluid medium source, a pump, and / or a pressurized reservoir. In certain embodiments, one or more of the pressure source and / or the vacuum source can be controllable, such as via a controller that operates one or more controllable valves, actuators, and / or pumps.

[0183] By way of example and not limitation, as shown in the figure, both the vacuum valve and the fluid medium valve can be opened simultaneously, as shown by the corresponding open vacuum valve curve 2320 and saline valve curve 2350, such that the fluid medium (such as saline or air) released or introduced from the fluid medium source can now be directed through the connecting tube or the aspiration catheter towards the vacuum source. In certain embodiments, the occlusive material present in the connecting tube can be flushed or removed based on the introduction of the fluid medium.

[0184] In certain embodiments, other combinations of valve operations can be used instead of keeping both the vacuum valve and the fluid medium valve open simultaneously for flushing. As a non-limiting example, during a flushing operation, one of the valves can be kept open while cycling or oscillating the other valve. By way of example and not limitation, when flushing is in progress, the vacuum valve 2160 can be kept open while oscillating the fluid medium valve 2164, that is, repeatedly opening and closing the fluid medium valve 2164.

[0185] In certain embodiments, the controller can be configured to determine that an occlusion has been cleared based on detecting a pressure level spike. By way of example and not limitation, a pressure level spike can include a rapid increase in the detected pressure, followed by a rapid decrease in the detected pressure, such as Figure 23 shown in 23-E. In certain embodiments, the controller can be configured to interrupt the flushing operation based on detecting a pressure spike, such as by closing the fluid medium valve 2164 and / or the vacuum valve 2160.

[0186] Although this disclosure discusses specific ways of operating or inter-operating valves during the steps of tube and system flushing, it should be understood that any suitable way of operating or inter-operating one or more valves and / or actuators is fully contemplated in this disclosure. The specific examples included herein are only provided to provide a better understanding of the configuration and operating principles. This disclosure is not limited to any particular type, configuration, or number of valves or actuators disclosed herein.

[0187] In certain embodiments, the fluid medium can be introduced or flushed into the connecting tube during one or more time intervals. In certain embodiments, the time interval for introducing the fluid medium into the connecting tube can be a predetermined time interval, such as 200 ms.

[0188] In certain embodiments, the time interval for introducing a fluid medium into the connecting tube can be based on determining that an occlusion has been reduced or eliminated. By way of example and not limitation, the controller 2180 can be configured to determine that the occlusion has cleared, such as based on a decrease in the vacuum pressure curve 2330 (e.g., at 23-F) below a threshold, and accordingly stop flushing the connecting tube with the fluid medium by operating one or more corresponding valves.

[0189] In certain embodiments, the one or more time intervals can be individually or additionally based on determining the location of the occlusion. For example, based on prior knowledge and / or additional relevant parameters determined empirically, such as effective tube length, diameter, type, and number of bends, and / or other geometric and configurational aspects, locating the occlusion orientation can permit operation of the valve or actuator for introducing the fluid medium. Such optimized flushing operations can enable the operation of the thrombectomy aspiration system to be more efficient and / or effective, such as by limiting fluid medium waste, reducing fluid medium make-up cycles, reducing procedure time, and / or system power and size requirements.

[0190] By way of example and not limitation, for an occlusion determined to be present between the vacuum sensor 2122 and the vacuum source 2120, the interval for introducing the fluid medium into the connecting tube can be between 70 and 300 ms. In some embodiments, the interval for introducing the fluid medium into the connecting tube can be between 150 and 200 ms. In some embodiments, the interval for introducing the fluid medium into the connecting tube can be in the range of 15 - 800 ms. In certain embodiments, the interval for introducing the fluid medium into the connecting tube can be determined empirically.

[0191] It should be understood that these aspects of determining the time interval can be predetermined and / or determined or varied based on processing empirical inputs from one or more other sensors (such as pressure sensors). In certain embodiments, the pressure detected by or in combination with other sensors can be used to estimate fluid, occlusion, geometric, and / or other relevant parameters. In certain embodiments, pressure detection can be combined with other known or detected system quantities to establish the operation of one or more valves or actuators to flush the connecting tube, aspiration catheter, or other parts of the system.

[0192] Figure 24 An example 2400 of the detection and flushing of an occlusion in the connecting tube between a sensor distal to the connecting tube and the vacuum source is shown. Referring Figure 21 , by way of illustration and not limitation, an occlusion between the distal sensor 2170 and the vacuum sensor 2122 can be considered herein to be Figure 24 a representative example of the location depicted therein, as well as other possible examples.

[0193] The controller can be configured to determine the presence of an occlusion in the connecting tube. In a particular embodiment, the controller can sample the pressure level in the connecting tube based on one or more available pressure sensors. Separately or additionally, in a particular embodiment, the controller can generate a pressure change in the connecting tube, such as by operating one or more valves, to determine the presence of an occlusion.

[0194] In a particular embodiment, one or more controllable valves can be operated (e.g., opened and / or closed) to enable the controller 2180 to sample the conditions in the connecting tube 2110 and / or the aspiration catheter 2130 based on detecting the pressure level from one or more pressure sensors. By way of example and not limitation, as depicted at time stamp 24-A, the vacuum valve 2160 can be cycled to sample the pressure level and conditions in the connecting tube 2110. Separately or additionally, exposing the aspiration catheter and / or the connecting tube to the vacuum sensor 2122 based on cycling the vacuum valve 2160 can generate a pressure change in the aspiration catheter and / or the connecting tube, and detecting the associated pressure level can permit determination of the presence of an occlusion.

[0195] By way of example and not limitation, the controller can detect and use the following to determine the presence of an occlusion: the pressure values at the start and end of a valve cycle, the peak, minimum, and / or average pressure values within the time window of the valve cycle, and the dynamic aspects of the pressure change and recovery based on the valve cycle. By way of example and not limitation, one or more parameters used in determining the flow state based on the detected pressure profile can be predefined, and / or empirically determined based on operational data, and / or determined based on training and using machine learning algorithms, or any combination thereof. Further details will be discussed herein Figures 25 - 29 Additional details and examples of determining the flow or system state in the connecting tube or the aspiration catheter, such as determining the presence of an occlusion, are disclosed. U.S. Patent Application No. 17 / 991,536, entitled "Aspiration Thrombectomy System and Method for Dynamic System State Detection" and issued as U.S. Patent 11,730,499, further discloses details of systems, devices, and methods for system state detection and is incorporated herein by reference.

[0196] In a particular embodiment, the controller 2180 can determine the presence of an occlusion based on one or more pressure levels detected by the pressure sensor and / or a change in the pressure level. In Figure 24In a non-limiting example shown at the approximate time point indicated by 24-A, the controller 2180 may determine the presence of an occlusion based on the severe attenuation or absence of recovery of the distal pressure curve 2310 to its hitherto higher pressure level after closing the vacuum valve 2160 at the end of 24-A. As discussed above, the vacuum valve curve 2320 is shown to open and close at 24-A corresponding to operating the vacuum valve 2160.

[0197] In certain embodiments, the controller may detect the pressure profile from more than one pressure sensor simultaneously or sequentially to determine the location of the occlusion.

[0198] By way of example and not limitation, the controller 2180 may compute the difference between respective pressure levels corresponding to the distal pressure curve 2310 and the vacuum pressure curve 2330, such as an instantaneous difference or a weighted difference, to locate the occlusion.

[0199] By way of example and not limitation, the controller may locate the occlusion by sequentially checking whether the occlusion is close to a particular sensor or group of sensors. In the depicted non-limiting example, the vacuum pressure curve 2330 remains steadily at a relatively low value throughout the shown time window, such as may be established within a particular limit or threshold. Thus, the controller may, in accordance with the example discussed above Figure 23 determine that there is no occlusion in the proximal portion of the connecting tube, i.e., between the vacuum sensor 2122 and the vacuum source 2120. Subsequently, having determined at 24-A that there is an occlusion between the distal pressure sensor 2170 and the vacuum source 2120, but further determining that there is no blockage in the proximal portion of the connecting tube 2110, the controller 2180 may more specifically determine that the occlusion is located between the distal pressure sensor 2170 and the vacuum sensor 2122.

[0200] In certain embodiments, based on determining that the occlusion is located between the distal pressure sensor 2170 and the vacuum sensor 2122, the controller 2180 may be configured to operate one or more valves, such as the vacuum valve 2160 and / or the fluid medium valve 2164, to introduce a fluid medium into the connecting tube 2110 during one or more time intervals.

[0201] Thus, continuing to follow the Figure 24 non-limiting example, specifically with reference to the time window between 24-B and 24-C, the controller 2180 may initiate a flushing operation, such as by introducing a flushing medium into the connecting tube. By way of example and not limitation, the controller 2180 may initiate the flushing operation based on aspects and factors related to the determined location of the occlusion previously discussed herein (e.g., the length of the tube between the occlusion and a reference location such as the vacuum source 2120). In certain embodiments, the flushing operation may be provided by the controller 2180 during one or more time intervals.

[0202] In certain embodiments, such as those illustrated by way of non-limiting example in Figure 25 , controller 2180 can open both vacuum valve 2160 and fluid medium valve 2164 simultaneously during a predetermined time interval, such as 600 ms. In certain embodiments, the predetermined time interval can be between 200 ms and 800 ms. In some embodiments, the predetermined time interval can be between 15 ms and 900 ms. In certain embodiments, for occluded positions determined to be relatively far from vacuum source 2120, the time interval for the flushing operation can be longer. In certain embodiments, the interval for introducing the fluid medium into the connecting tube can be determined empirically.

[0203] As previously disclosed by way of non-limiting example, the flushing operation can be stopped based on the completion of a pre-determined time interval and / or based on the detection and determination of a change in the occluded state, such as the reduction or elimination of an occlusion detected via one or more pressure sensors and determined based on their respective pressure profiles and / or fluid flow characteristics.

[0204] In certain embodiments, as depicted in 24-D, controller 2180 can be configured to re-sample and / or otherwise determine whether an occlusion still exists. In certain embodiments, controller 2180 can trigger one or more additional flushing operations and / or sequences, each with the same or modified parameters. By way of example and not limitation, controller 2180 can trigger additional or separate actions based on the continuous detection of an occlusion over time, such as a longer flushing sequence, different valve operation modes involving one or more valves (e.g., duration of opening and closing, frequency, staggering, and / or duty cycle), and / or provide warnings and information to the user regarding the occluded state of the system and / or known occlusion parameters.

[0205] In certain embodiments, as depicted by way of non-limiting example, at approximately the time point indicated by 24-E, controller 2180 can determine that the occlusion has cleared, such as by sampling one or more pressure sensors. As previously discussed, and as further detailed by incorporation by reference, the flow state, including non-occluded flow, can be determined by controller 2180 based on the detected pressure profile. Thus, in certain embodiments, the normal operation of the aspiration thrombectomy system can be subsequently reset. In Figure 24 a non-limiting example, after timeline 24-E, it is indicated that controller 2180 can continue to cyclically open vacuum valve 2160 intermittently and sample the relevant pressure changes from one or more detected pressure profiles.

[0206] Figure 25An exemplary process 2500 for determining a system or flow state (such as the presence of an occlusion) in a suction catheter or connecting tube of a thrombectomy system is shown in accordance with a particular embodiment. In a first step 2510 of the illustrated algorithm, by operating a vacuum valve in a first operating mode, such as by selectively opening and closing the vacuum valve, the controller can generate one or more pressure level changes in the connecting tube. In a second step 2520, the controller can detect one or more pressure levels associated with the distal end of the connecting tube via a first pressure sensor. In a third step 2530, the controller can determine one or more system states in the suction catheter and / or connecting tube based on changes in the one or more detected pressure levels. In a fourth step 2540, the controller can operate the vacuum valve in a second operating state based on the one or more determined system states.

[0207] In a particular embodiment or scenario, based on a system state inferred to be present in the suction catheter or connecting tube according to a detected pressure profile, the controller can determine that no additional vacuum valve operation is immediately required. For example, the controller can generate a pressure level change in the connecting tube by opening and then closing the vacuum valve. In a particular embodiment, if the controller subsequently determines that there is unrestricted or open flow in the suction catheter, it can continue to keep the vacuum valve closed until the next action step is required.

[0208] The system state can include a qualitative and / or quantitative description of the flow state within the suction catheter and / or connecting tube. In a particular embodiment, the flow state can be an unrestricted or open flow state, where the distal end or tip of the suction catheter can be in contact with healthy blood and there can be little or no occlusive material in the catheter and / or connecting tube. In a particular embodiment, an occluded flow state may exist in the suction catheter, such as due to a clot and / or other occlusive material. In a particular embodiment, the flow state can also include an "intermediate" state, such as a partially occluded flow.

[0209] Specific embodiments of system status detection may use sensors other than the above-described distal pressure sensor, either alone or additionally. In a specific embodiment, a vacuum pressure sensor that monitors the vacuum level at the canister may be used. In a specific embodiment, a saline pressure sensor that monitors the pressure level of the saline fluid may be used. Additionally, the sensors used in specific embodiments of the method may not be limited to pressure sensors. In a specific embodiment, the data may be sourced from a variety of sensors, including, for example, sensors for detecting pressure, acoustic energy, ultrasonic energy, and flow rate. In a specific embodiment, one or more system scores may be determined to determine the system status, where each system score may independently or in combination with other system scores indicate the likelihood of a specific system status in the aspiration catheter or connecting tubing. In this regard, the system score may serve as a metric for quantifying the corresponding likelihood of a specific system status.

[0210] The system score may be directly or indirectly derived from sensor data (such as the detected pressure profile discussed above). In a specific embodiment, the system score determination may be based on automatically identifying specific features from the detected pressure profile, extracting pressure parameters based on the values and trends derived from those specific features, and calculating one or more system scores based on the pressure parameters of these features. In a specific embodiment, the system score may be determined as the sum of specific parameter metrics (such as pressure parameters). By way of example and not limitation, one or more pressure parameters indicating an open flow system status may return a system score of 1 or 2 or 3, depending, for example, on one or more specific pressure parameters and specific thresholds used in the system combination, application, and / or embodiment, which may be directly summed to calculate a quantitative value of one or more system scores (such as an open flow score). In a specific embodiment, determining the system score may involve further processing. In a specific embodiment, determining the system score based on pressure parameters may further include the appropriate weighting of the parameters and / or the use of correction factors. By way of example and not limitation, the weighting of the pressure parameters may be determined empirically. The maximum and minimum values, thresholds, and other characteristics associated with the system score may be determined and / or adjusted based on a specific system combination and / or application. For example, a specific threshold of the system score may vary based on a specific combination of the catheter and aspiration system. Several examples and specific embodiments having specific features involving the detected pressure profile and the corresponding system scores will be further discussed. It should be understood that deriving the system score from sensor data may vary between embodiments and may be customized for specific configurations and applications.

[0211] In certain embodiments, the system score can be determined based on machine learning. In certain embodiments, intermediate quantities used to determine the system score can be determined based on machine learning. By way of example and not limitation, intermediate quantities of interest can include thresholds and / or weighting factors. In certain embodiments, a training data set can be assembled from detected pressure distribution data obtained in a wide range of scenarios, combined with statistical variations and corresponding to a system state of interest. A trained machine learning model can then be used to predict the system state of new situations. In certain embodiments, 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 certain embodiments, an algorithm using a combination of the above algorithmic flow analysis techniques can be employed.

[0212] It should be noted 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 shown in this document, are exemplary and not restrictive. For example, the Figures 26 - 29 illustrations discussed further below are provided by way of example and not by way of limitation.

[0213] Figure 26 An exemplary distal pressure distribution detected over time for a particular embodiment is shown, depicting aspects of determining a flow state, such as detecting the presence of an occlusion. The distal pressure curve 2310 is based on the time-varying pressure detected by the distal pressure sensor 2170. The corresponding vacuum valve state curve 2320 indicates the time-varying state of the vacuum valve 2160. For example, in Figure 26 the particular embodiment shown and corresponding to a generally unrestricted or open flow situation, when the vacuum valve 2160 is first opened, the distal pressure may experience a significant drop in pressure as the contents of the connecting tube and aspiration catheter may be exposed to the very low absolute pressure level of the vacuum source and accelerate towards the low pressure.

[0214] For example, the value of the distal pressure corresponding to the starting value before the sudden drop in distal pressure can be identified as the starting (or initial) distal pressure, as shown. For example, in certain embodiments, the starting distal pressure can indicate the patient's blood pressure as well as the time history of the system state. Additionally, in certain embodiments, the rate of change of the starting distal pressure can be related to blood viscosity and / or the presence of a clot in the catheter. After the vacuum valve is subsequently closed, the contents of the connecting tube and aspiration catheter may experience a sudden deceleration and eventually return to a new pressure equilibrium in the system that is disconnected from the vacuum source.

[0215] One or more peak pressure levels can be pressure parameters of interest for determining system scores and / or system status. In a particular embodiment, the maximum value of the large overshoot of the recorded distal pressure corresponding to the closing of the vacuum valve in this case can be identified as the maximum absolute rebound pressure, as Figure 26 shown by way of example and not limitation. The maximum absolute rebound pressure may also be related to blood viscosity.

[0216] In a particular embodiment, one or more pressure levels and / or time intervals corresponding to the reset of the pressure level balance after a pressure change generating event (such as a vacuum valve cycle) can be pressure parameters of interest for determining system scores and / or system status. For example, a time window can be established based on the stopped pressure and / or time metric corresponding to the effect of the pressure perturbation associated with the opening and closing sequence of the vacuum valve. In a particular embodiment, as shown in the figure, the distal pressure value at that moment can be identified as the end distal pressure. For example, in a particular embodiment, the end distal pressure can correspond to the distal pressure value at a predetermined time interval (such as 80 ms) after the vacuum valve is closed, or it can also be based on a time interval determined according to other parameters.

[0217] It should be understood that, based on the requirements of specific configurations and applications, the specific definitions and thresholds of sensor parameters can vary between embodiments. The pressure parameters and related features disclosed below are intended to be exemplary and not restrictive.

[0218] In a particular embodiment, the measurement of pressure variance can be further extracted as a pressure parameter. For example, for such extraction, the pressure variance between the moments marking the start and end distal pressures can be considered. In a particular embodiment, as shown in the figure, the mean absolute deviation ("MAD") of the pressure with respect to the median ("Med") pressure can be identified as the measurement of the pressure change between the closing of the vacuum valve and the end distal pressure moment. The mean absolute deviation of the pressure with respect to the median pressure ("MAD / med") can also be related to blood viscosity.

[0219] In a particular embodiment, the differential pressure level can be a pressure parameter of interest for determining system scores and / or system status. In a particular embodiment, for two consecutive vacuum valve cycle sequences, the difference between the second start distal pressure and the first start distal pressure can be identified as the differential pressure level of interest, as Figure 26 shown. Such a start distal pressure difference can be stable across the viscosity range.

[0220] As previously discussed, the system score can be determined based on the detected pressure parameters. In a particular embodiment, the open score can be determined based on the detected pressure parameters. By way of example and not limitation, the value of the open score can vary between 0 and 7 and can indicate the likelihood of at least an open flow state. Similarly, in a particular embodiment, the occlusion score can be determined based on the detected pressure parameters. As another example and not limitation, the value of the occlusion score can vary between 0 and 7 and can indicate the likelihood of at least an occluded flow state. Additionally, in a particular embodiment, various combinations of the open score and the occlusion score can indicate the likelihood of one or more additional system states of interest, such as, for example, a partially occluded flow state.

[0221] In a particular embodiment, thresholds can be established for determining the system state based on the system score. By way of some examples and not limitation, in a particular embodiment, if the occlusion score is equal to or greater than 3 (within the maximum possible score of 7), then it can be determined that the system is in an occluded state. In a particular embodiment, if the open score is equal to or greater than 3 (again, within the maximum possible score of 7), then it can be determined that the system is in an open flow state. In a particular embodiment, if both the open score and the occlusion score are less than 3, then it can be determined that the system is in a partially occluded state. In a particular embodiment, such a partially occluded state may indicate the presence of a clot or thrombus that is flexible or deformable enough to be extracted by continuous aspiration and does not necessarily require pulsed or regulated aspiration.

[0222] Although the present disclosure describes establishing particular thresholds for determining the system state based on particular system scores in a particular manner, the present disclosure contemplates providing any suitable thresholds for determining the system state based on any system score in any suitable manner.

[0223] Figures 27 - 29 A particular embodiment showing the distal pressure distribution for a series of system state scores is presented. In these examples of the particular embodiment, particular portions of the respective detected distributions are highlighted, and the occlusion score and the open score determined based on the detected pressure parameters are indicated as corresponding to the highlighted portions of each detected pressure distribution. These illustrations are exemplary and are provided by way of example and not limitation.

[0224] For example, Figure 27Shows an exemplary distal pressure distribution for a particular embodiment in an overall open or unrestricted flow situation. The detected distribution for the particular embodiment shows a relatively rapid pressure change of the distal pressure curve 2310 in response to a change in the state of the vacuum valve curve 2320. The highlighted area shows a relatively large overshoot or maximum rebound pressure, as well as a high variance in the detected pressure at the immediate flow vacuum valve closure. 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.

[0225] As another example, Figure 28 Shows an exemplary distal pressure distribution for a particular embodiment in a partially occluded flow situation. The distribution shows a relatively attenuated rebound, and the detected pressure level does not reset to the level of its starting distal pressure. 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.

[0226] As another example, Figure 29 Shows an exemplary distal pressure distribution for a particular embodiment indicating the presence of an occlusion. By way of example and not limitation, the distribution shown may correspond to an occlusion fraction of 7 and an open fraction of 0.

[0227] Figure 30 Is a schematic diagram 3000 of another embodiment configured for tube and system flushing. As will be discussed, by way of illustration, relative to Figure 21 the depicted embodiment, Figure 30 the embodiment of Figure 30 incorporates additional valves and / or additional sensors. For clarity of illustration, Figure 21 the controller 2180 is omitted in

[0228] but it can be assumed that the controller is present and communicatively coupled to the additional valves in addition to the original connections shown in Figure 21 or Figure 30 It should be understood that, among other things, the specific aspects and features including

[0229] In certain embodiments, a control valve 3010 may be provided, either alone or additionally, to permit selective isolation of the distal portion of the connecting tube and / or the aspiration catheter 2130 from a vacuum source such as 2120. By way of example and not limitation, flushing the connecting tube 2110 while closing the control valve 3010, such as by opening the vacuum valve 2160 and the fluid medium valve 2164 simultaneously, as an illustrative example and not limitation, can reduce the risk of inadvertently exposing the distal end of the aspiration catheter 2130 to vacuum. By way of example and not limitation, such a control valve 3010 may be beneficial when the catheter tip encounters unoccluded or freely flowing blood.

[0230] In certain embodiments, a bypass valve 3020 may be provided, either alone or additionally, to permit selective isolation of the distal portion of the connecting tube and / or the aspiration catheter 2130 from a vacuum source such as 2120. By way of example and not limitation, the bypass valve 3020 may permit simultaneous introduction of a fluid medium into the connecting tube and disconnection of the aspiration catheter from the vacuum source. For example, closing the vacuum valve 2160 while opening the fluid medium valve 2164 and the bypass valve 3020 can reduce the risk of inadvertently exposing the distal end of the aspiration catheter 2130 to vacuum.

[0231] In certain embodiments, aspects of the present disclosure described in connection with the connecting tube 2110 may extend to include the aspiration catheter 2130. By way of example and not limitation, one or more control valves and / or pressure sensors associated with the aspiration catheter 2130 may be provided. In certain embodiments, a catheter valve 3030 may be provided, either alone or additionally, to permit selective introduction of a fluid medium into the aspiration catheter. By way of example and not limitation, such upstream introduction (relative to the flow towards the vacuum source 2120) may provide the benefit of flushing a greater extent of the aspiration catheter 2130 and / or the connecting tube 2110.

[0232] In certain embodiments, based on the methods discussed in detail previously herein, the controller 2180 may be configured to determine the presence of an occlusion within or proximal to the aspiration catheter 2130, and / or determine the location of the occlusion, and / or provide a flushing operation. By way of example and not limitation, an occlusion may be detected between the distal tip of the aspiration catheter 2130 and a pressure sensor associated with the aspiration catheter 2130. As another non-limiting example, an occlusion may be detected between a pressure sensor associated with the aspiration catheter 2130 and a pressure sensor associated with the connecting tube 2110.

[0233] By way of example and not limitation, the flushing operation may include introducing or releasing a fluid medium into the aspiration catheter 2130, such as by operating the catheter valve 3030, wherein the introduced fluid medium is flushed in a direction away from the distal tip of the aspiration catheter 2130.

[0234] In certain embodiments, one or more of the pressure sensors disclosed herein may be configured to provide differential pressure sensing relative to a reference atmospheric and / or ambient pressure. In certain embodiments, one or more additional or alternative pressure sensors may be provided to compare the pressure sensors to the reference atmospheric and / or ambient pressure.

[0235] In certain embodiments, one or more additional pressure sensors may be provided in the flow path of vacuum sensor 2122. In certain embodiments, a pressure sensor 3040 may be provided near vacuum valve 2160, i.e., in the vicinity of vacuum valve 2160. In certain embodiments, pressure sensor 3040 may be arranged near vacuum valve 2160. In certain embodiments, pressure sensor 3040 may be provided in the same static and / or continuous fluid path as vacuum sensor 2122, which may be provided near vacuum source 2120. By way of example and not limitation, when there is no flow through a portion of connecting tube 2110 that connects pressure sensor 3040 and vacuum sensor 2122, the pressure sensor may sense the same or substantially similar static fluid pressure value as that sensed by the vacuum sensor, such as by closing one or more valves distal to pressure sensor 3040. In certain embodiments, pressure sensor 3040 may be an addition to or an alternative to vacuum sensor 2122.

[0236] In certain embodiments, the use of pressure sensor 3040 may be based on detecting an occlusion present between vacuum valve 2160 and vacuum sensor 2122. Separately or additionally, in certain embodiments, pressure sensor 3040 may be used to detect an occlusion present between vacuum valve 2160 and vacuum source 2120. By way of example and not limitation, pressure sensor 3040 may be used to detect one or more occlusions, such as those described above, without the need to open vacuum valve 2160.

[0237] Miscellaneous

[0238] As used herein, "or" is inclusive and not exclusive, unless expressly indicated otherwise or the context indicates otherwise. Thus, as used herein, "A or B" means "A, B, or both", unless expressly indicated otherwise or the context indicates otherwise. Moreover, "and" is both conjunctive and disjunctive, unless expressly indicated otherwise or the context indicates otherwise. Thus, as used herein, "A and B" refers to "A and B, jointly or separately", unless expressly indicated otherwise or the context indicates otherwise.

[0239] The scope of the present disclosure covers all changes, substitutions, variations, alterations, and modifications to the example embodiments described or illustrated herein that would be understood by a person of ordinary skill in the art. The scope of the present disclosure is not limited to the example embodiments described or shown herein. Moreover, although each of the embodiments of the present disclosure is described and shown herein as including specific components, elements, features, functions, operations, or steps, any one of these embodiments can include any combination or permutation of any of the components, elements, features, functions, operations, or steps described or shown anywhere herein that would be understood by a person of ordinary skill in the art. Additionally, a reference in the appended claims to a device or system, or a component of a device or system, that is adapted to, arranged to, capable of, configured to, enabled to, operable to, or effective in performing a particular function covers that device, system, or component, whether or not that particular function is activated, turned on, or unlocked, so long as the device, system, or component is so adapted, arranged to, capable of, configured to, enabled to, operable to, or effective. Further, although the present disclosure describes or illustrates specific embodiments that provide specific advantages, a particular embodiment may not provide those advantages, may provide some of those advantages, or may provide all of those advantages.

[0240] The drawings provided herein may be illustrative rather than literal or exact; the components and aspects of the drawings may not necessarily be drawn to scale. Moreover, although in many cases, the same reference numerals may denote corresponding parts in different views, the same parts are not always provided with the same reference numerals in each view.

Claims

1. A suction thrombectomy system, comprising: a connecting tube configured to serve as a fluid conduit between the suction catheter, the fluid source, and the vacuum source; a first pressure sensor associated with a distal portion of the connecting tube; a second pressure sensor associated with a proximal portion of the connecting tube; a first controllable valve configured to control a vacuum level in the connecting tube provided by the vacuum source; a second controllable valve configured to control the introduction of a fluid medium from the fluid source into the connecting pipe; and A controller, wherein the controller is configured as: detecting, via one or more of the first pressure sensor and the second pressure sensor, one or more pressure levels associated with the connection tubing; and determining whether the connecting tube is occluded based on the detected one or more pressure levels; Wherein, based on determining that the connecting pipe is blocked, the controller is further configured to: determining a location of the occlusion based on the detected one or more pressure levels; and Based on determining the location of the occlusion, one or more of the first valve and the second valve are operated to introduce the fluid medium into the connecting tube during one or more time intervals.

2. The aspiration thrombectomy system according to claim 1, wherein: Prior to detecting the one or more pressure levels, the controller is configured to operate the first valve to provide fluid communication between the distal portion of the connecting tube and the vacuum source.

3. The aspiration thrombectomy system according to claim 2, wherein: The controller is configured to determine whether the connecting tube is occluded based on one or more differences between the one or more pressure levels detected via the first pressure sensor and the second pressure sensor, respectively.

4. The aspiration thrombectomy system according to claim 3, wherein: The controller is configured to determine that the connection tube is occluded between the first pressure sensor and the second pressure sensor based on the one or more differences between the one or more pressure levels detected via the first pressure sensor and the second pressure sensor, respectively.

5. The aspiration thrombectomy system according to claim 4, wherein: The controller is configured to operate the first valve and the second valve to introduce the fluid medium into the connecting tube during a first time interval based on determining that the connecting tube is occluded between the first pressure sensor and the vacuum source.

6. The aspiration thrombectomy system according to claim 5, wherein: The first time interval is a predetermined time interval.

7. The aspiration thrombectomy system according to claim 6, wherein: The predetermined time interval is between 200 ms and 800 ms.

8. The aspiration thrombectomy system according to claim 6, wherein: The predetermined time interval is between 15 ms and 900 ms.

9. The aspiration thrombectomy system according to claim 1, wherein: The controller is configured to determine whether the connecting tube is occluded based on one or more pressure levels detected via the second pressure sensor that exceed a threshold.

10. The aspiration thrombectomy system according to claim 9, wherein: The controller is configured to determine that the connection tube is occluded between the second pressure sensor and the vacuum source based on one or more pressure levels detected via the second pressure sensor exceeding a threshold.

11. The aspiration thrombectomy system according to claim 10, wherein: The controller is configured to operate the first valve and the second valve to introduce the fluid medium into the connecting tube during a second time interval based on determining that the connecting tube is occluded between the second pressure sensor and the vacuum source.

12. The aspiration thrombectomy system according to claim 11, wherein: The second time interval is a predetermined time interval.

13. The aspiration thrombectomy system according to claim 12, wherein: The second time interval is between 70 ms and 300 ms.

14. The aspiration thrombectomy system according to claim 12, wherein: The second time interval is between 150 ms and 200 ms.

15. The aspiration thrombectomy system according to claim 12, wherein: The second time interval is between 15 ms and 800 ms.

16. The aspiration thrombectomy system according to claim 1, wherein: Based on determining the location of the occlusion, the controller is configured to selectively open or close one or more of the first valve and the second valve during the one or more time intervals.

17. The aspiration thrombectomy system according to claim 16, wherein: The controller is configured to maintain the first valve open during at least a portion of the one or more time intervals.

18. The aspiration thrombectomy system according to claim 16, wherein: The controller is configured to repeatedly open and close the second valve during at least a portion of the one or more time intervals.

19. The aspiration thrombectomy system of claim 1, further comprising a controllable bypass valve, wherein: The bypass valve is opened when the first valve is closed, simultaneously introducing the fluid medium into the connecting tube and disconnecting the fluid communication between the suction conduit and the vacuum source.

20. The aspiration thrombectomy system of claim 1, further comprising a third controllable valve configured to control introduction of the fluid medium into the aspiration catheter.

21. The aspiration thrombectomy system according to claim 1, wherein: The fluid medium includes one or more of air and saline.

22. The aspiration thrombectomy system of claim 1, further comprising a third pressure sensor associated with the fluid source.

23. The aspiration thrombectomy system of claim 1, further comprising a fourth pressure sensor configured to compare one or more detected pressure levels to a reference atmospheric pressure level.

24. The aspiration thrombectomy system of claim 1, further comprising a fifth pressure sensor disposed proximate to the first controllable valve.

25. The aspiration thrombectomy system according to claim 24, wherein: The controller is configured to determine whether the connecting tube is occluded based on one or more differences between one or more pressure levels detected via the second pressure sensor and the fifth pressure sensor, respectively.

26. A method for aspiration thrombectomy, comprising: detecting, by a controller, one or more pressure levels associated with a connection tube via one or more of a first pressure sensor and a second pressure sensor, wherein the connection tube serves as a fluid conduit between an aspiration catheter, a fluid source, and a vacuum source, wherein the first pressure sensor is associated with a distal portion of the connection tube, and wherein the second pressure sensor is associated with a proximal portion of the connection tube; determining whether the connecting tube is occluded based on the detected one or more pressure levels; Based on determining that the connecting tube is occluded and based on the detected one or more pressure levels, determining a location of the occlusion; and Based on determining the location of the occlusion, one or more of the first controllable valve and the second controllable valve are operated to introduce fluid medium into the connecting tube during one or more time intervals, wherein the first valve is configured to control the vacuum level provided by the vacuum source in the connecting tube, and the second valve is configured to control the introduction of the fluid medium from the fluid source into the connecting tube.

27. The method of claim 26, further comprising, prior to detecting the one or more pressure levels, operating the first valve to enable fluid communication between the distal portion of the connecting tube and the vacuum source.

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