Low flow switch for medical suction

Abstract

An example medical device for aspirating a substance from a patient includes a flow switch including an anvil, an actuator, and a surface feature on at least one of the anvil and the actuator. The flow switch is configured to move the actuator away from the anvil to form a flow path for aspiration of the substance, and to move the actuator toward the anvil to reduce the flow path by forming at least one channel defined by the surface feature.

Description

Technical Field

[0001] The present disclosure relates to medical aspiration. Background Art

[0002] In some cases, medical aspiration can be used to remove substances from a patient. For example, medical aspiration can be used to remove a thrombus, such as a clot or other occlusion, from a patient's blood vessel. Summary of the Invention

[0003] The present disclosure describes example devices and systems and related methods configured to reduce the amount of body fluid (e.g., blood) withdrawn from a patient during a medical aspiration procedure. An aspiration catheter can be used to remove a thrombus from a patient's hollow anatomical structure (e.g., a blood vessel). For example, the distal opening of the catheter can be positioned in the hollow anatomical structure near the thrombus, and a suction force can be applied to the lumen of the aspiration catheter to aspirate the thrombus through the catheter lumen and out of the hollow anatomical structure. In some cases, such as in the case of deep vein thrombosis (DVT) and pulmonary embolism (PE) procedures, it may be preferred to use a larger aspiration catheter (e.g., 12 French or larger) to remove a large clot burden from a blood vessel. As the diameter of the aspiration catheter lumen increases, the flow rate through the aspiration catheter increases, shortening the time to reach the maximum blood volume (about 450 ml) that can be withdrawn from the patient, which will be reached faster than in the case of a smaller aspiration catheter, and potentially forcing the procedure to end prematurely.

[0004] In the examples described herein, the aspiration system can be configured to reduce blood loss during the procedure by controlling the flow rate and / or volume of blood through the aspiration catheter, even when using a larger aspiration catheter (e.g., 12 French or larger, or any size catheter). For example, the aspiration system can use a sensor to monitor blood flow and actuate a control valve based on the measured flow rate. When the distal end of the aspiration catheter encounters an obstruction (from a thrombus or potential blood vessel wall), the control valve can allow unrestricted flow through, but if the aspiration catheter is in unobstructed blood flow in the blood vessel, the control valve will regulate (e.g., reduce) the flow rate of the blood. In some examples, the aspiration system can allow a doctor to "search" for a thrombus in a blood vessel using fluoroscopy guidance while essentially only aspirating high blood flow when the catheter tip is blocked.

[0005] In the examples described herein, the aspiration system includes an aspiration catheter fluidly coupled to a flow switch (also referred to herein as a valve) configured to regulate the flow of fluid (e.g., blood) through the lumen of the catheter during a medical procedure to allow a relatively low flow of fluid through the lumen when in a low flow configuration. In the low flow configuration of the flow switch, the flow switch compresses an aspiration conduit, which may include the catheter or other conduits fluidly communicating with the catheter. The low flow configuration may also be referred to herein as a closed configuration, a constricted configuration, or a compressed configuration, but in the examples described herein, there is still some permitted fluid flow when in such a "closed" configuration.

[0006] In some examples, the flow switch includes an actuator and an anvil configured to form a pinch valve operable to constrict the lumen of a flexible tube (e.g., configured to be fluidly in communication with the catheter lumen of the catheter or the catheter itself) when in the low flow configuration. The anvil or the actuator may include surface features configured to keep the channels within the lumen of the flexible tube open when, for example, compressing and / or constricting the lumen of the flexible tube in the low flow configuration.

[0007] The devices, systems, and techniques of the present invention can provide one or more advantages and benefits. For example, allowing some fluid to flow through the catheter lumen when the flow switch is in the low flow configuration can reduce the volume of body fluid withdrawn during an aspiration procedure while reducing blockages in the system compared to when fluid flow through the catheter lumen completely stops. Allowing some fluid to flow through the catheter lumen can help reduce clot formation within the aspiration catheter and / or conduits of the system, as well as maintain an increased pressure within the effluent reservoir, which can reduce boiling and / or foaming of the fluid within the effluent reservoir, e.g., to prevent the fluid from reaching the top and / or lid of the effluent reservoir container.

[0008] Additionally, as described in some examples herein, a flow switch that includes only two positions, open and closed, simplifies the flow switch and can provide better control than a flow switch that can achieve low flow through a catheter lumen only by actuating to an intermediate state between a fully open state and a fully closed state (e.g., to partially close the lumen of a flexible tube). For example, to achieve acceptable low flow repeatability, the tolerances required to partially close the lumen of a flexible tube by such a flow switch may be significantly tighter (e.g., increased tolerances). Additionally, the flexible tube can change over time. For example, the hardness of the material can change with repeated compression and release, or the tube can be replaced with a different tube (e.g., having different dimensions, wall thickness, lumen size, material, or a replacement tube of the same type), which can respond differently to compression and / or release and can even have tight tolerances. Due to the changes in the flexible tube over time and the changes in the response of the flexible tube to compressive forces, the low flow rate of a flow switch configured to partially close the lumen of a flexible tube by actuating to an intermediate state can drift over time. In contrast, and in accordance with the techniques, devices, and systems disclosed herein, in the closed state of the example flow switches described herein, some fluid is allowed to flow through the catheter lumen. For example, the flow switch can be configured to fully contract the lumen of the flexible tube by compressing the flexible tube between an actuator and an anvil, and either or both of the actuator and the anvil include surface features configured to keep the passage within the lumen of the flexible tube open even when the flow switch is in the closed (as opposed to intermediate) state. This can provide improved repeatability and lifespan for achieving a specific low flow rate.

[0009] In one example, the present disclosure describes a medical device for aspirating a substance from a patient, the device including: a flow switch including an anvil; an actuator; and surface features located on at least one of the anvil and the actuator, wherein the flow switch is configured to move the actuator away from the anvil to form a flow path for aspiration of the substance and to move the actuator toward the anvil to reduce the flow path by forming at least one channel defined by the surface features.

[0010] In another example, the present disclosure describes a medical aspiration system including a second aspiration source and an elongate body that defines a lumen fluidly coupled to the second aspiration source of the medical aspiration system and a pinch valve configured to actuate between a high flow configuration and a low flow configuration, wherein in the low flow configuration, the pinch valve is configured to compress the elongate body while still allowing fluid to flow through the lumen.

[0011] In another example, the present disclosure describes a method for aspirating a substance from a patient using a flow switch, an anvil, an actuator, and surface features on at least one of the anvil and the actuator, the method comprising: opening the flow switch by moving the actuator away from the anvil to form a flow path for aspiration of the substance; and closing the flow switch by moving the actuator toward the anvil to reduce the flow path by forming at least one channel defined by the surface features.

[0012] Details of one or more aspects of the present disclosure are set forth in the following drawings and description. Other features, objects, and advantages of the technology described in the present disclosure will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram showing an example aspiration system including a passive flow switch.

[0014] Figure 2A is a schematic side view of an example of an example flow switch in a "high flow" configuration.

[0015] Figure 2B is in a "low flow" configuration Figure 2A of an example of a flow switch.

[0016] Figure 3A is a schematic cross-sectional top view of an example of a flow switch taken along line A-A'. Figure 2A of an example of a flow switch.

[0017] Figure 3B is in a low flow configuration Figure 2B of an example actuator and anvil of a flow switch.

[0018] Figure 4A is a schematic side view of an example flow switch.

[0019] Figure 4B is Figure 4A of an example of a flow switch.

[0020] Figure 4C is Figure 4A of an example of a flow switch.

[0021] Figure 5 is an exploded schematic side view of another example actuator and anvil of another example flow switch in a low flow configuration.

[0022] Figure 6 is in a high flow configuration Figure 1Schematic front view of an example of a flow switch.

[0023] Figure 7 is in a low flow configuration Figure 6 Schematic side view of the deployment of an actuator and an anvil of an example of a flow switch.

[0024] Figure 8 is in a low flow configuration Figure 2A Schematic side view of the deployment of an example flexible tube between the actuator and the anvil of a flow switch. Detailed Description

[0025] The present disclosure describes devices and systems configured to regulate the flow of a body fluid, such as blood, from a patient's body during a medical suction procedure, as well as medical suction systems (e.g., vascular suction systems) including such devices and systems, and corresponding methods. In the examples described herein, the suction system includes a flow switch (also referred to herein as a "valve") configured to control the fluid flow rate through a catheter lumen of a catheter by compressing a flexible tube. The flexible tube can be a catheter or another elongated body (e.g., a suction conduit) that is in fluid communication with the catheter lumen. The flow switch is configured to actuate between an open configuration and a closed configuration (also referred to as an open state and a closed state), wherein the flow switch allows some fluid to flow through the catheter lumen. Relative to substantially the same suction applied in the open state and the closed state, the flow rate through the catheter lumen when the flow switch is in the closed position is greater than zero but less than the flow rate through the catheter lumen when the flow switch is in the open state. For example, the flow rate through the catheter lumen when the flow switch is in the open state is less than or equal to 99%, less than or equal to 50%, less than or equal to 10%, less than or equal to 5%, or less than or equal to 1% of the flow rate through the catheter lumen when the flow switch is in the open state.

[0026] In some examples, the flow switch includes an actuator configured to actuate an actuator (e.g., move the actuator) and an anvil configured to form a "pinch-off" valve that is operable to constrict the lumen of the flexible tube via compression of the flexible tube and has surface features configured to keep the passage within the lumen of the flexible tube open even when the actuator and anvil cannot be moved closer together to define a further closed state of the flexible tube. In some examples, the actuator may include a solenoid, e.g., the actuator includes a solenoid-actuated actuator. In other examples, the actuator may include a pneumatic actuator, a hydraulic actuator, a stepper actuator (e.g., driven by a stepper motor), a servo motor, or any suitable actuator configured to move the actuator. In some examples, the surface features include grooves defined by the surface of one or both of the actuator and the anvil. For example, the grooves may extend inwardly from the surface of the actuator or anvil, e.g., into the actuator or anvil. In some examples, the surface features include protrusions extending from the surface of the actuator and / or from the surface of the anvil. For example, the protrusions may extend outwardly from the surface of the actuator or anvil. In some examples, the surface features include a channel within the anvil or a plurality of biased anvils configured to cause the flexible tube to assume a helical or "kinked" shape when the actuator is in a low flow (e.g., compressed / constricted / closed) configuration.

[0027] Aspects of the present disclosure can be used in thrombectomy procedures for treating vascular occlusions caused by thrombosis in a vascular bed, including, for example, neurovascular, deep vein thrombosis (DVT), peripheral vascular disease, and pulmonary embolism (PE). Some indications, such as DVT and PE, preferably use larger aspiration catheters (12F and above). The larger catheter size can facilitate removal of a large clot burden from the vasculature. The larger inner diameter of the aspiration catheter allows for higher flow rates during aspiration. Due to the higher flow rates, a greater blood volume can be withdrawn from the patient during the procedure. Compared to using smaller aspiration catheters, the recommended limit of the aspirated blood volume (e.g., approximately 450 ml) can be reached more quickly. This results in less time for the physician to complete the thrombectomy procedure before reaching such limits.

[0028] Aspects of the present disclosure can be useful in the context of a Blood Loss Mitigation System (BLoMS) configured to reduce blood loss during a procedure by using a switch to control and reduce the flow of blood through a suction catheter. For example, the BLoMS can use sensors to monitor fluid flow and actuate the switch based on the measured flow. When the distal end of the suction catheter encounters an obstruction (such as from a thrombus or blood vessel wall), the BLoMS switch can be opened to allow unrestricted flow through, while closing to reduce flow if the suction catheter is in a patent blood flow in the blood vessel, thereby reducing blood flow. The operation of the BLoMS will allow the doctor to "search" for thrombi in the blood vessel using fluoroscopic guidance while only aspirating at high flow when the catheter tip is blocked.

[0029] In accordance with certain aspects of the present disclosure, the BLoMS can be configured to allow a small amount of fluid or substance to flow when the switch is in the closed position. Without being limited by theory, using low flow conditions when the BLoMS is actively involved in reducing blood flow can be used to detect when the catheter tip engages a thrombus and when the BLoMS system can be activated. For example, a flow rate sensor can monitor the flow rate at low flow rates and detect when the flow stops or significantly decreases, which can indicate that the catheter tip is blocked by a thrombus.

[0030] Figure 1 is a schematic diagram showing an example medical suction system 100, which includes a suction source 102, an effluent reservoir 104, a catheter 108 (also referred to herein as "suction catheter 108") and a flow switch 110 (e.g., also referred to herein as "pinch valve 110"). The medical suction system 100 can be used to treat various conditions, including thrombosis. Thrombosis occurs when a thrombus (e.g., a blood clot or other material such as plaque or foreign body) forms and blocks the patient's vasculature. For example, the medical suction system 100 can be used to treat pulmonary embolism or deep vein thrombosis, which can occur when a thrombus forms in a patient's deep vein (such as the patient's leg).

[0031] The medical suction system 100 is configured to remove thrombi from a patient. The medical suction system 100 can be configured to remove thrombi via the catheter 108, for example, aspirating thrombi from the patient using a suction force applied to the catheter 108. The material passing through the catheter 108 is deposited into the effluent reservoir 104 by the suction force applied to the catheter 108 (e.g., applied to the inner lumen of the catheter 108) via the suction source 102. The catheter 108 includes an elongate body 112 that defines a catheter lumen ( Figure 1(not shown in the figure) and terminates at the distal opening 114. To treat a patient suffering from thrombosis, a clinician can position the distal opening 114 of the catheter 108 in a patient's blood vessel near a thrombus or other occlusion, and apply a suction force (also referred to herein as aspiration, vacuum force, negative pressure, or suction force) to the catheter 108 (e.g., to one or more lumens of the catheter) to engage the thrombus with the suction force at the distal opening 114 of the catheter 108. For example, the suction source 102 can be configured to create a negative pressure within the inner lumen of the catheter 108 to aspirate material from inside the blood vessel into the catheter lumen via the distal opening 114 of the catheter 108. The negative pressure within the inner lumen can create a pressure differential between the inner lumen and the environment outside at least the distal portion of the catheter 108, and this pressure differential causes substances (e.g., thrombus, fluid (e.g., blood, saline, etc. introduced into the patient's body as part of the aspiration procedure), etc.) to be introduced from the blood vessel into the catheter lumen via the distal opening 114 of the catheter. For example, the fluid can flow from the patient's vasculature into the catheter inner lumen via the distal opening 114 and then into the discharge reservoir 104 through the aspiration conduit 116 (also referred to herein as the "vacuum tube 116").

[0032] Once the distal opening 114 of the aspiration catheter 108 has engaged a thrombus located within the blood vessel, the clinician can remove the aspiration catheter 108 with the thrombus held within the opening 114 or attached to the distal tip of the elongate body 112, or aspirate the thrombus mass (or the entire thrombus) until the thrombus is removed from the patient's blood vessel through the lumen of the aspiration catheter 108 itself and / or through the lumen of an outer catheter in which the aspiration catheter 108 is at least partially positioned. The outer catheter can be, for example, a guiding catheter configured to provide additional structural support to the aspiration catheter. In some cases, aspiration of the thrombus can be performed simultaneously with the use of a thrombectomy device such as a thrombus removal basket to facilitate removal of the thrombus by mechanical thrombectomy as well as by aspiration.

[0033] As used herein, "suction force" is intended to include related concepts such as suction pressure, vacuum force, vacuum pressure, negative pressure, etc. within its scope. The suction force can be generated by a vacuum, for example, by creating a partial vacuum within a sealed volume fluidly connected to the catheter 108, or by directly discharging the liquid in the catheter 108 or the conduit 116 (e.g., by a peristaltic pump or otherwise). Thus, the suction force or suction as specified herein can be measured, estimated, calculated, etc. without directly sensing or measuring the force. The "higher", "more", or "greater" (or "lower", "less", or "smaller") suction force described herein can refer to the absolute value of the negative pressure generated by the suction source on the catheter or another component such as the discharge reservoir 104.

[0034] In some examples, the aspiration source 102 may include a pump (also referred to herein as "pump 102" or "vacuum source 102"). The aspiration source 102 may include one or more of the following: a positive displacement pump (e.g., a peristaltic pump, a rotary pump, a reciprocating pump, or a linear pump), a direct displacement pump (e.g., a peristaltic pump, or a lobe, vane, gear, or piston pump, or other suitable pump of this type), a direct acting pump (which acts directly on the liquid to be displaced or the tube containing the liquid), an indirect acting pump (which acts indirectly on the liquid to be displaced), a centrifugal pump, etc. The indirect acting pump may include a vacuum pump that discharges a compressible fluid (e.g., a gas such as air) from an evacuated volume (e.g., the discharge reservoir 104 which may include a metal canister), thereby creating an aspiration force on the liquid. Thus, the evacuated volume (when present) can be considered part of the aspiration source. In some examples, the aspiration source 102 includes an electric motor driven pump, however in other examples, the aspiration source 102 may include a syringe and mechanical elements such as a linear actuator, a stepper motor, etc. As another example, the aspiration source 102 may include a water aspirating venturi or injector.

[0035] The medical aspiration system 100 includes a control circuit 120 configured to control the aspiration force applied by the aspiration source 102 to the catheter 108. For example, the control circuit 120 may be configured to directly control the operation of the aspiration source 102 to vary the aspiration force applied by the aspiration source 102 to the inner lumen of the catheter 108, e.g., by controlling the motor speed or the stroke length, volume, or frequency or other operating parameters of the aspiration source 102. As another example, the control circuit 120 may be configured to control one or more functions of the flow switch 110. Other techniques for modifying the suction force applied by the aspiration source 102 to the inner lumen of the catheter 108 can be used in other examples.

[0036] The control circuit 120 and other processors, processing circuits, controllers, control circuits, etc. described herein may include any combination of the following: integrated circuits, discrete logic circuits, analog circuits, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), or field programmable gate arrays (FPGAs). In some examples, the control circuit 120 may include multiple components, such as any combination of one or more microprocessors, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete or integrated logic circuits and / or analog circuits. In some examples, in addition to or instead of an electrically based processor, the control circuit 120 may further include one or more controls that operate using fluid motion power (e.g., hydraulic power) in combination with or in addition to electricity. For example, the control circuit 120 can include a fluid circuit that includes a fluid circuit having a plurality of fluid passages and switches, the passages and switches being arranged and configured such that when a fluid (e.g., a liquid or a gas) flows through the passages and interacts with the switches, the fluid circuit performs the functionality of the control circuit 120 described herein.

[0037] The memory 122 may store program instructions, such as software, that may include one or more program modules executable by the control circuit 120. When executed by the control circuit 120, such program instructions may cause the control circuit 120 to provide the functionality attributed to the control circuit 120 herein. The program instructions may be embodied in software and / or firmware. The memory 122 and other memories described herein may include any volatile medium, non-volatile medium, magnetic medium, optical medium, or electrical medium, such as random access memory (RAM), read only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other digital medium. Although the control circuit 120 and the memory 122 are shown in Figure 1 a common housing, in other examples, the control circuit 120 and / or the memory 122 may be physically separated from each other.

[0038] For some other aspiration systems, a certain amount of body fluid may be accidentally aspirated during the aspiration process. For example, when approaching and aspirating a thrombus with the distal opening of a catheter, a clinician may accidentally aspirate and remove a certain volume of the patient's blood, which is not inherently necessary as part of the procedure, for example. The flow switch 110 is configured to reduce the accidental aspiration of the patient's blood during the aspiration procedure by reducing the fluid flow through the catheter lumen of the catheter 108.

[0039] More specifically, the flow switch 110 is configured to control the flow of fluid through the lumen of the catheter between an open state or "high flow" state and a compressed state or "low flow" state, e.g., to control and / or limit the aspiration of body fluid from a patient's body. The medical aspiration system 100 defines a continuous fluid flow path from the distal opening 114 to the effluent reservoir 104, and the flow switch 110 is configured to reduce the flow rate through the continuous fluid flow path by compressing a conduit positioned between the distal opening 114 and the effluent reservoir 104. For example, the flow switch 110 may be positioned to directly compress the elongate body 112 of the catheter 108 or a flexible tube positioned between the proximal end of the catheter 108 and the effluent reservoir 104. Generally, the flow switch 110 is configured to actuate between restricting the continuous fluid flow path to inhibit or interrupt proximal flow of body fluid (such as blood) and allowing proximal flow of body fluid through an unrestricted continuous path, such that thrombus material can be effectively aspirated into the distal catheter opening 114 and proximally through the catheter lumen defined by the elongate body 112 of the catheter 108.

[0040] In some examples, the flow switch 110 includes an anvil and an actuator, wherein at least one of the actuator or the anvil is configured to move toward the other of the anvil or the actuator to compress a flexible tube positioned between the actuator and the anvil, the flexible tube defining at least a portion of the continuous fluid flow path through the medical aspiration system 100. At least one of the anvil or the actuator includes surface features configured to keep the passageway within the lumen of the flexible tube open when the flexible tube is compressed between the anvil and the actuator, e.g., to allow a low flow of fluid when the flow switch is in a compressed, low flow configuration.

[0041] Figure 2A and Figure 2B A schematic side view of an example flow switch 210 is depicted, which is an example of the flow switch 110. In Figure 1 the example. The flow switch 210 is depicted in a "high flow" configuration or "open" configuration, in which the aspirated fluid or material can flow freely proximally (e.g., in the z - direction from the Figure 2A perspective) through the continuous fluid path, which passes through the lumen 220 of the flexible tube 218. The flexible tube 218 is shown in cross - section in Figure 2A and Figure 2A and Figure 2B . In Figure 3B the example, the flow switch 210 is depicted in a "low flow" configuration or "compressed" configuration, in which the continuous passage is blocked to restrict fluid flow and / or limit the fluid flow rate through the lumen 220, e.g., by compressing the flexible tube 218 to reduce the cross - sectional area of the lumen 220.

[0042] AsFigure 2A and Figure 2B As shown, the flow switch 210 includes an actuator 212 and an anvil 214 that are supported and held relative to each other by a housing 224. The flexible tube 218 defines a lumen 220 and is configured to be fluidly coupled to the discharge reservoir 104 and the conduit lumen of the conduit 108. In other examples, the flexible tube 218 includes the conduit 108. When the flow switch 210 is in the open configuration, as Figure 2A shown, the flexible tube 218 is configured to be positioned between the actuator 212 and the anvil 214 without being compressed.

[0043] In some examples, the actuator 212 is configured to be actuated by a solenoid 222, which may also be supported and held by the housing 224. In some examples, the solenoid 222 may be some other type of actuator, e.g., the solenoid 222 may not be a solenoid, but a pneumatic actuator, a hydraulic actuator, a stepper actuator (e.g., driven by a stepper motor), a servo motor, or any suitable actuator configured to move the actuator 212 (and / or the anvil 214). In some examples, the anvil 214 is configured to be actuated (e.g., by the solenoid 222, a motor, etc.), and in some examples, both the actuator 212 and the anvil 214 may be configured to be actuated and move towards or away from each other. The solenoid 222 may be configured to move and / or hold the actuator 212 separated from the anvil 214 (and / or move and / or hold the anvil 214 separated from the actuator 212) in the Figure 2A shown open configuration. The solenoid 222 may also be configured to move and / or hold the actuator 212 towards the anvil 214 (or move the anvil 214 towards the actuator 212, or move both the anvil 214 and the actuator 212 towards each other), e.g., in a compressed configuration ( Figure 2B ). For example, the solenoid 222 may be configured to press the actuator 212 towards the anvil 214 (or the anvil 214 towards the actuator 212, or both the actuator 212 and the anvil 214 towards each other) with at least a threshold amount of force. In some examples, the solenoid 222 is configured to move the actuator 212 (or the anvil 214) to only two positions, e.g., a first position corresponding to the open configuration and a second position corresponding to the closed configuration, where the actuator 212 and the anvil 214 are closer to each other. In other examples, the actuator 212 and / or the anvil 214 are configured to be actuated and / or moved by a motorized valve, an electrostatic actuator, a pneumatic actuator or a hydraulic actuator, or any suitable actuator configured to actuate and / or move the actuator 212 and / or the anvil 214, e.g., as a supplement or alternative to the solenoid 222.

[0044] At least one of the actuator 212 or the anvil 214 includes a surface feature 216 configured to keep the passage within the lumen 220 of the flexible tube 218 open when the flexible tube 218 is compressed between the actuator 212 and the anvil 214, such as in a compressed configuration. Figures 2A to 7 Exemplary surface features 216 - 416 are shown. In FIGS. 2 - Figure 4B In the example shown, the anvil 214 includes a surface feature 216 that is a groove defined by the surface of the anvil 214 facing the actuator 212. Figure 5 The exemplary surface feature 316 is shown as a protrusion defined by the surface of the actuator 312 facing the anvil 314 (or otherwise on the surface), and Figures 6 to 7 the surface feature 416 is shown as including a groove defined by the anvil 414 that extends in a direction along the longitudinal anvil axis, or as having a longitudinal anvil axis and a plurality of generally curved surfaces separated by a gap distance along the longitudinal tube axis. In other examples, one or both of the actuator or the anvil include a surface feature configured to allow fluid to flow within the lumen of the flexible tube when the flow switch is in a compressed configuration and / or a closed configuration. For example, the surface feature can be any one or all of a groove, a protrusion, a surface structure defining a surface profile, etc.

[0045] Figure 3A is a schematic cross - sectional top view of an example of the flow switch 210 along line A - A' shown in Figure 2A and shows the relative orientation of the anvil 214, the flexible tube 218, and the surface feature 216. In the example shown, the surface feature 216 extends in a direction along the longitudinal tube axis of the flexible tube 218, such as along the z - axis shown.

[0046] Figure 3B is a schematic side view of the actuator 212 and the anvil 214 of the flow switch 210 in a compressed configuration or a low - flow configuration, and shows the flexible tube 218 in cross - section. In Figure 3B as well as Figure 5 and Figure 6 other parts of the system, such as the housing 224, are not shown. In Figure 3B the example shown, the surface feature 216 has a triangular cross - sectional shape in the x - y plane (e.g., a plane perpendicular to the longitudinal axis of the flexible tube 218 and substantially in the plane including the longitudinal axis of the anvil 214), but in other examples, the surface feature 216 can have any other suitable cross - sectional shape, such as circular, elliptical, rectangular, or square, etc. In some examples, the surface feature 216 is configured to have blunted, chamfered, or otherwise smoothed edges. For example, while the surface feature 216 inFigure 3B is shown as having sides that terminate at acute angles, but the edges (e.g., at the bottom and apex of the triangular recess), i.e., the edges where the surfaces of the cross-sectional shape of the surface feature 216 intersect, can be curved, angled, or otherwise softened, and the surface feature 216 can be configured to not have sharp edges.

[0047] As Figure 3B shown, in the compressed configuration, a portion of the flexible tube 218 that aligns with the surface feature 216 is subject to a reduced compressive force, e.g., due to material of the anvil 214 being removed at that portion. This portion of the flexible tube 218 can move into (e.g., be compressed and / or forced into) the surface feature 216 and allow a portion of the lumen 220 to remain open. For example, a portion of the flexible tube 218 can expand into the surface feature 216, allowing a portion of the lumen 220 to remain open (e.g., via the elasticity of the flexible tube allowing it to partially or slightly return to its initial uncompressed shape via the surface feature 216) and not be compressed, allowing at least a portion of the lumen 220 to form a fluid passage 230. In other words, the surface feature 216 is configured to keep the passage 230 within the lumen 220 of the flexible tube 218 open when the flexible tube 218 is compressed by the actuator 212 and anvil 214 in a compressed state. In some examples, the flow switch 210 is configured to have two configurations: an open configuration and a compressed configuration, where the flow switch 210 allows some fluid flow, but not an intermediate configuration or state between "open" and "closed". For example, the flow switch 210 is configured such that the compressed configuration of the flow switch 210 effectively "fully closes" (thereby simplifying the complexity of the flow switch 210 relative to a flow switch configured to have three or more configurations or states), while still allowing relatively low fluid flow, e.g., to reduce clot formation within a pipe or conduit and / or boiling and / or foaming within a drain reservoir.

[0048] In some examples, the surface feature 216 extends in a direction along the longitudinal tube axis of the flexible tube 218. In Figures 2A to 6 the example shown, the longitudinal tube axis of the flexible tube 218 extends in the z-axis direction, and the surface feature 216 extends generally in the z-direction (e.g., parallel to the z-axis or within 5 degrees or 10 degrees or less of the z-axis). This allows the passage 230 to extend generally along the longitudinal tube axis of the flexible tube 218 and allows fluid to flow through the flow switch 210 in the compressed configuration via the passage 230 within the lumen 220 of the flexible tube 218. For ease of description, orthogonal x-y-z axes are shown in the figures.

[0049] In some examples, the actuator 212 and / or the anvil 214 can include a generally curved surface. For example, one or both of the surfaces 232 and 234 can be generally curved in at least one dimension, such as a two-dimensional (2D) curved surface (such as a cylindrical surface), a three-dimensional (3D) curved surface, and / or a compound curved surface (such as a spherical surface), a 2D curved surface, or a 3D curved surface, or any suitable curve or shape. In Figures 2A to 7 the example shown, at least a portion of the actuator surface 232 is generally curved in the z-axis direction and generally linear (e.g., straight) in the x-axis direction (e.g., a cylindrical surface having a cylindrical actuator axis that is generally perpendicular to the longitudinal tube axis of the flexible tube 218). In the example shown, at least a portion of the anvil surface 234 is generally curved in the z-axis direction and generally linear (e.g., straight) in the x-axis direction (e.g., a cylindrical surface having a cylindrical actuator axis that is generally perpendicular to the longitudinal tube axis of the flexible tube 218). In some examples, the generally curved surfaces 232, 234 face each other and are configured to provide a contact area to compress the flexible tube 218 substantially without sharp edges or corners, and / or to cause a local stress region in the material of the flexible tube 218 in a compressed configuration.

[0050] In some examples, the flow switch 210 is configured such that the apex (e.g., in the y-axis direction) of the actuator surface 232 is positioned generally opposite the apex (e.g., in the y-axis direction) of the anvil surface 234. For example, the apices of the surfaces 232 and 234 can be generally aligned in the z-axis direction such that the apices of the surfaces 232, 234 are the closest points of the actuator 212 and the anvil 214 along the surfaces 232, 234 in a compressed configuration. For example, in some examples, the flow switch 210 is configured to compress a portion of the length of the flexible tube 218 in the z-axis direction in a compressed configuration without bending and / or moving the longitudinal axis of the flexible tube 218 in the y-direction and / or the x-direction. In other examples, the flow switch 210 can be configured such that the apices of the surfaces 232, 234 do not have to be aligned and do not have to be the closest points along the surfaces 232, 234 in a compressed configuration. For example, the flow switch 210 can be configured to compress a portion of the length of the flexible tube 218 in the z-direction in a compressed configuration while bending and / or moving the longitudinal axis of the flexible tube 218 in the y-direction and / or the x-direction.

[0051] The actuator 212 and the anvil 214 include any material configured to compress the flexible tube 218. For example, the actuator 212 and the anvil 214 can include metal, polymer, rubber, wood, ceramic, or any material capable of compressing the flexible tube 218. The actuator 212 and the anvil 214 can include the same material or can each include a different material from each other.

[0052] Figures 4A to 4C is a schematic view of an exemplary flow switch 260. Figure 4A is a schematic side view of the flow switch 260, Figure 4B is a schematic front view of the flow switch 260, and Figure 4C is a schematic side view of the flow switch 260 of the side opposite to the side shown in Figure 4A . The flow switch 260 may be substantially similar to the above-described flow switch 210 and shows a slot 280 and a tube channel 282 for inserting and holding a flexible tube within the housing.

[0053] In the illustrated example, the flow switch 260 includes an actuator 262 and an anvil 264, which may be substantially similar to the above-described actuator 212 and anvil 214, and which are supported and held relative to each other by a housing 274, which may be substantially similar to the above-described housing 274. In the illustrated example, the anvil 264 includes surface features 266, which may be substantially similar to the above-described surface features 216. In the illustrated example, the housing 274 includes a slot 280 configured to receive a flexible tube from the front of the housing 274 into the tube channel 282, which is configured to hold the flexible tube within the flow switch 260, e.g., centered relative to the actuator 262 and the anvil 264.

[0054] In some examples, the flexible tube 218 may be held centered within the valve 260 by mechanical supports at either side of the valve 260. For example, the mechanical supports may include a narrow opening (e.g., a slot 280 for inserting and / or receiving the flexible tube 218) that opens into a channel 282, which may have a diameter substantially the same as the outer diameter of the flexible tube 218 and may be configured to locate, position, and / or hold the flexible tube 218 within the valve.

[0055] Figure 5 is a schematic side view of the actuator 312 and anvil 314 of a flow switch 310 in a low flow configuration and shows the flexible tube 218 in cross-section. In the illustrated example, the surface features 316 have a circular cross-sectional shape in the x-y plane (e.g., a plane that is substantially perpendicular to the longitudinal axis of the flexible tube 218 and substantially within the plane including the longitudinal axis of the anvil 314), but in other examples, the surface features 316 may have any other suitable cross-sectional shape, e.g., triangular, oval, rectangular, or square, etc. In some examples, similar to the above-described surface features 216, the surface features 316 are configured to have blunted, chamfered, or otherwise smoothed edges.

[0056] AsFigure 5 As shown, in the compressed configuration, a portion of the flexible tube 218 aligned with the surface feature 216 is subjected to increased compressive forces, e.g., due to the surface feature 316 protruding into the portion of the flexible tube 218. The increased compressive forces due to the surface feature 316 can deform and stretch the material of the flexible tube 218, which can open or maintain open one or more channels (e.g., channel 330A and / or channel 330B (collectively referred to as "channels 330")) within the lumen 220. In other words, the surface feature 316 is configured to keep one or more channels 330 within the lumen 220 of the flexible tube 218 open when the flexible tube 218 is compressed by the actuator 312 and the anvil 314 in the compressed configuration. In some examples, the flow switch 31O is configured to have two configurations: an open configuration and a compressed configuration, where the flow switch 310 allows some fluid flow, but not an intermediate configuration or state between "open" and "closed". For example, the flow switch 310 is configured such that the compressed configuration of the flow switch 310 effectively "fully closes" (thereby simplifying the complexity of the flow switch 310 relative to a flow switch configured to have three or more configurations or states), while still allowing relatively low fluid flow, e.g., to reduce clot formation within a pipe or conduit and / or boiling and / or foaming within an effluent reservoir.

[0057] In some examples, when the flexible tube 218 is positioned between the actuator 312 and the anvil 314, the surface feature 316 extends in a direction along the longitudinal tube axis of the flexible tube 218. In Figure 5 the example shown, the longitudinal tube axis of the flexible tube 218 is in the z-axis direction, and the surface feature 316 extends generally in the z-axis direction (e.g., parallel to the z-axis or within 5 degrees or 10 degrees or less of the z-axis). This allows the channel 230 to extend along the longitudinal tube axis of the flexible tube 218 and permits fluid to flow through the flow switch 310 in the compressed configuration via the channels 330 of the lumen 220 within the flexible tube 218.

[0058] As described above, in some examples, the actuator 312 and / or the anvil 314 can each include a generally curved surface 232 and 234, respectively. The actuator 312 and the anvil 314 can include any material configured to compress the flexible tube 218. For example, the actuator 312 and the anvil 314 can include metal, polymer, rubber, wood, ceramic, or any material capable of compressing the flexible tube 218. The actuator 312 and the anvil 314 can include the same material or can each include a different material from one another.

[0059] Figure 6 and Figure 7 depicts a side view of an example flow switch 410, which is Figure 1An example of a flow switch 110 is shown, and the flexible tube 218 is shown in cross-section. In Figure 6 the example, the flow switch 410 is depicted in a "high flow" configuration or an "open" configuration, in which the aspirated fluid or substance can freely flow proximally (e.g., in the z-direction) through the lumen 220 of the flexible tube 218. In Figure 7 the example, the flow switch 410 is depicted in a "low flow" configuration or a "compressed" configuration, in which the continuous passage is blocked to restrict fluid flow and / or limit the fluid flow rate through the lumen 220, e.g., by compressing the flexible tube 218 to reduce the cross-sectional area of the lumen 220 and "kinking" and / or spiraling the flexible tube 218 around the anvil 414, the actuator 412, and / or the surface feature 416.

[0060] As Figure 6 and Figure 7 shown, the flow switch 410 includes an actuator 412 and an anvil 414 that are supported and held relative to each other by a housing 224. The housing 224 can be substantially similar to that described above. In the open configuration, the flexible tube 218 is configured to be positioned between the actuator 412 and the anvil 414 without being compressed. For example, the actuator 412 can be actuated by a solenoid 222, which can also be supported and held by the housing 224. The solenoid 222 can be configured to move and / or hold the actuator 412 in the Figure 6 shown open configuration to be separated from the anvil 414. The solenoid 222 can also be configured to move and / or hold the actuator 412 toward the anvil 414, e.g., in the compressed configuration ( Figure 7 ). For example, the solenoid 222 can be configured to press the actuator 412 toward the anvil 416 with at least a threshold amount of force. In some examples, the solenoid 222 can be configured to move the actuator 412 to only two positions, e.g., a first position corresponding to the open configuration and a second position corresponding to the closed configuration, in which the actuator 412 is closer to the anvil 414. In other examples, the actuator 412 can be actuated and / or moved by a motorized valve, an electrostatic actuator, a pneumatic actuator, or a hydraulic actuator, or any suitable actuator configured to actuate and / or move the actuator 412, e.g., as a supplement or alternative to the solenoid 222.

[0061] At least one of the actuator 412 or the anvil 414 includes a surface feature 416 that is configured to, when the flexible tube 218 is compressed between the actuator 212 and the anvil 214, e.g., in Figure 7The compression configuration shown in FIG. keeps the channels within the lumen 220 of the flexible tube 218 open. The surface features 416 may include surface structures, surface profiles, surface patterns, etc. of one or both of the actuator 412 and the anvil 414. In some examples, the surface structures, surface profiles, surface patterns, etc. may be along the longitudinal tube axis, such as in the z direction.

[0062] In some examples, the surface features 416 are defined by a plurality of anvils having an anvil axis that is substantially perpendicular to the tube axis (e.g., an anvil axis in the x-axis direction as shown in the figure), and for example, they may form an anvil surface profile along the longitudinal tube axis (in the z direction as shown in the figure). For example, the surface features 416 may include a groove defined by the anvil 414 that extends in a direction along the longitudinal anvil axis (e.g., the x-axis direction as shown in the figure). In the example shown, the surface features 416 are channels in the surface of the anvil 414 that define or otherwise include anvil structures 414A and 414B.

[0063] In other examples, the surface features 416 may be defined by a plurality of anvils. For example, the anvil structures 414A and 414B may be physically separate anvils 414A and 414B that include a first generally curved surface 434A having a first longitudinal anvil axis perpendicular to the longitudinal tube axis of the flexible tube and a second generally curved surface 434B having a second longitudinal anvil axis perpendicular to the longitudinal tube axis, and the first generally curved surface 434A and the second generally curved surface 434B are separated from each other by a gap distance along the tube axis (e.g., in the z direction). The actuator 412 may include a curved surface 432, and as Figure 7 shown in FIG., the surface features 416 may be configured to restrict the flow of fluid through the lumen 220 by compressing the lumen 220 and causing the lumen 220 to be spiral and / or curved (e.g., in the y-z plane as shown in the figure) when the flow switch 410 is in the compression configuration or the low flow configuration, while allowing at least one channel (e.g., channel 430) to remain open.

[0064] In the illustrated example, the surface feature 416 includes two anvil structures (or anvils 434A and 434B). In other examples, the surface feature 416 may include multiple structures and / or a surface profile along the tube axis (e.g., in the z-direction), such as a square wave or rectangular wave, triangular wave, sine wave, cylindrical wave, or any surface profile shape. In some examples, the actuator 212 may additionally or alternatively include such a surface profile. For example, the actuator 412 and the anvil 414 may each include multiple anvil structures 434A, 434B (where the anvil structures on the actuator 412 are rotated 180 degrees relative to the illustrated anvil structures 414A and 414B, e.g., having a vertex in the positive y-direction), and the multiple anvil structures may be displaced or offset relative to each other, thereby effectively forming an anvil surface feature and an actuator surface feature that at least partially fit within a gap between the opposing actuator surface feature and anvil surface feature, and causing the lumen 220 to have multiple curves along a greater length of the tube axis and compressing the lumen 220 along a greater length of the tube axis. In some examples, a surface profile having a greater longitudinal compression length and multiple curves of the lumen 220 may have greater repeatability and / or accuracy in achieving a desired fluid flow rate through the flow switch 410 in a compressed configuration, and may provide a greater lifespan of the flexible tube 218. For example, the surface feature 416 may be configured to expand the compression of the flexible tube 218 to a greater surface area of the flexible tube 218 with a smaller compression to achieve a similar flow restriction through the lumen 220, thereby resulting in reduced stress on the material of the flexible tube 218. In other examples, the flow switch 210 and / or 310 may be simpler, easier to manufacture, and less costly, and the flow switch is configured such that the flexible tube 218 is replaceable.

[0065] The flow switches described herein can be formed using any suitable technique and can be used in any suitable medical procedure. Figure 8 is a flow chart of an example technique for using the aspiration systems and flow switches described herein. For illustrative purposes, aspects of the Figure 1 medical aspiration system 100 and Figures 2A to 4B flow switch 210 are described to describe the Figure 8 technique, however, such description is not intended to be limiting. Figure 8 The technique can be used with other aspiration systems and / or flow switches described herein, such as flow switch 310 and / or 410, or Figure 1 the medical aspiration system 100 and / or flow switch 210 can use techniques other than those described with reference to Figure 8 the technique.

[0066] According to Figure 8In the technique shown, the flow switch contracts the lumen of the flexible tube into a compressed configuration such that the flow rate of fluid through the channels within the lumen is less than the flow rate of fluid through the lumen in an open configuration (800). For example, a clinician may fluidly couple a suction conduit including the flexible tube 218 to a suction source 102 and to the inner lumen of a catheter 108. The clinician may mechanically and fluidly connect a vacuum tube 116 to the proximal opening of the flow switch 210. The clinician may also mechanically and fluidly connect the elongate body 112 of the catheter 108 to the distal opening of the flow switch 210 to define a continuous fluid flow path through the inner lumen of the catheter 108, the lumen 220 of the flexible tube 218 of the flow switch 210, and the inner lumen of the vacuum tube 116.

[0067] Before or after coupling the flexible tube 218 to the catheter 108 and the suction source 102, the clinician may introduce the catheter 108 into the vasculature of a patient and navigate the catheter 108 to a target treatment site within the patient. In some examples, the clinician navigates the catheter 108 to the target site with the aid of a guide wire, a guiding catheter, or another guiding member.

[0068] After the distal opening 114 of the catheter 108 is positioned as desired proximate to a thrombus in the vasculature (e.g., as indicated via fluoroscopic imaging), the control circuit 120 controls the suction source 102, either alone or based on input received from a user via a user input device, to create a suction force within the inner cavity of the catheter 108.

[0069] In some cases, the distal opening 114 of the catheter 108 may initially be positioned near the thrombus material but may not be positioned against the thrombus material (e.g., occluded by the thrombus material). In such cases, the suction force from the suction source 102 may begin to draw patient fluid (such as blood) into the catheter 108, for example, via the lumen 229 of the flexible tube 218, creating a proximal fluid flow through the flow switch 210. Automatically (e.g., based on sensed conditions) or in response to a user input, the control circuit 120 controls the solenoid 222 to move the actuator 212 to the compressed configuration, thereby compressing the flexible tube 218 and thus restricting the fluid flow through the flow switch 210, but allowing at least some fluid to flow through the lumen 220 via the channel 230, which the surface features 216 keep open.

[0070] The clinician can continue to manipulate the distal opening 114 of the catheter 108 until the distal opening 114 is positioned against the thrombus material and occluded by the thrombus material. At this time, the fluid flowing into the catheter 108 will be interrupted by the thrombus material at the distal opening 114, and the control circuit 120 can cause the solenoid 222 to move the actuator 212 to open the lumen 220 of the flexible tube 218, such that a high flow rate of fluid is allowed to flow through the lumen 220 (802). With the flow switch 210 in the open configuration, the clinician can continue to aspirate the thrombus and remove the catheter 108 from the patient's vasculature once the procedure is complete.

[0071] The techniques described in this disclosure, including those belonging to the control circuit 120 or various components, can be implemented at least in part in hardware, software, firmware, or any combination thereof. For example, aspects of these techniques can be implemented within one or more processors, which include one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuitry, as well as any combination of such components embodied in a programmer, such as a clinician or patient programmer, a medical device, or other device. For example, the processing circuit, control circuit, and sensing circuit, and other processors and controllers described herein can be implemented at least in part as or include one or more executable applications, application modules, libraries, classes, methods, objects, routines, subroutines, firmware, and / or embedded code. Additionally, one, some, or all of the control circuit 120 can be constructed using analog circuits, components, and circuit elements to replace or supplement some or all of the digital hardware and / or software described herein. Thus, analog or digital hardware, or a combination of both, can be employed. Whether implemented in digital or analog form, or a combination of both, the control circuit 120 system can include timing circuitry.

[0072] In one or more examples, the functions described in this disclosure may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on a computer-readable medium as one or more instructions or code and executed by a hardware-based processing unit. The computer-readable medium may be an article of manufacture that includes a non-transitory computer-readable storage medium encoded with instructions. The instructions embedded or encoded in the article of manufacture that includes the encoded non-transitory computer-readable storage medium may cause one or more programmable processors or other processors to implement one or more of the techniques described herein, such as when the instructions included or encoded in the non-transitory computer-readable storage medium are executed by one or more processors. Exemplary non-transitory computer-readable storage media may include RAM, ROM, programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette tape, magnetic media, optical media, or any other computer-readable storage device or tangible computer-readable medium.

[0073] In some examples, the computer-readable storage medium includes a non-transitory medium. The term "non-transitory" may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. In certain examples, the non-transitory storage medium may store data that can change over time (e.g., in RAM or a cache).

[0074] The functionality described herein may be provided within dedicated hardware and / or software modules. Describing different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Instead, the functions associated with one or more modules or units may be performed by separate hardware or software components, or integrated within common or separate hardware or software components. Additionally, these techniques may be fully implemented in one or more circuits or logic elements.

[0075] The following clauses provide some examples of this disclosure. The examples described herein may be combined in any permutation or combination.

[0076] Example 1: A medical system for aspirating a substance from a patient, the system comprising: a flow switch including: an anvil; an actuator; and surface features located on at least one of the anvil and the actuator, wherein the flow switch is configured to: move the actuator away from the anvil to form a flow path for aspiration of the substance; and move the actuator toward the anvil to reduce the flow path by forming at least one channel defined by the surface features.

[0077] Example 2: The medical system according to Example 1 further includes a flexible tube coupled to the elongate body of the catheter, the catheter being configured to aspirate the substance from the patient, and wherein the substance is a thrombus.

[0078] Example 3: The medical system according to Example 2, wherein the actuator and the anvil are configured to compress the flexible tube from an open configuration to a compressed configuration, wherein when the flexible tube is in the open configuration and fluidly coupled to the elongate body of the catheter, a suction source fluidly coupled to the flexible tube is configured to cause a first flow rate to pass through the lumen of the flexible tube, and wherein the surface feature is configured to keep the channel in the lumen of the flexible tube open when the flexible tube is compressed, such that the channel allows a second flow rate to pass through the lumen, the second flow rate being greater than zero and less than or equal to 5% of the first flow rate.

[0079] Example 4: The medical system according to Example 2 or Example 3, wherein the surface of at least one of the actuator or the anvil defines the surface feature, wherein the surface feature includes at least one of a protrusion extending outward from the surface or a groove extending inward from the surface.

[0080] Example 5: The medical system according to Example 4, wherein the protrusion or the groove extends in a direction along the longitudinal tube axis of the flexible tube to cause the channel to extend along the longitudinal tube axis.

[0081] Example 6: The medical device according to any one of Examples 2 to 5, wherein the anvil includes a generally curved surface having a longitudinal anvil axis perpendicular to the longitudinal tube axis of the flexible tube to cause the channel to extend along the longitudinal tube axis.

[0082] Example 7: The medical system according to Example 6, wherein the surface feature includes a groove defined by the anvil, the groove extending in a direction along the longitudinal anvil axis.

[0083] Example 8: The medical system according to any one of Examples 2 to 7, wherein the anvil includes the surface feature, wherein the surface feature includes a first generally curved surface and a second generally curved surface, the first generally curved surface having a first longitudinal anvil axis perpendicular to the longitudinal tube axis of the flexible tube, the second generally curved surface having a second longitudinal anvil axis perpendicular to the longitudinal tube axis, wherein the first generally curved surface and the second generally curved surface are separated from each other by a gap distance along the tube axis.

[0084] Example 9: The medical system according to any one of Examples 1 to 8 further includes: a suction source; and a catheter fluidly connected to the suction source and designed for use within the peripheral vascular system of the patient.

[0085] Example 10: A medical suction system includes: a suction source; an elongate body defining a lumen fluidly coupled to the suction source; and a pinch valve configured to actuate between a high flow configuration and a low flow configuration, wherein in the low flow configuration, the pinch valve is configured to compress the elongate body while still allowing fluid to flow through the lumen.

[0086] Example 11: The medical suction system according to Example 10, wherein the pinch valve is configured to allow a first flow rate to pass through the lumen in the high flow configuration and a second flow rate to pass through the lumen in the low flow configuration, the second flow rate being less than or equal to 5% of the first flow rate.

[0087] Example 12: The medical suction system according to Example 10 or Example 11, wherein the pinch valve includes: an anvil and an actuator, wherein the elongate body is positioned between the actuator and the anvil, wherein at least one of the actuator or the anvil is configured to move towards the other of the anvil or the actuator to compress the elongate body, wherein at least one of the anvil or the actuator includes surface features configured to keep the channel within the lumen open when the elongate body is compressed between the anvil and the actuator.

[0088] Example 13: The medical suction system according to Example 12, wherein the surface of at least one of the actuator or the anvil defines the surface features, the surface features including at least one of a protrusion extending outward from the surface or a groove extending inward from the surface.

[0089] Example 14: The medical suction system according to Example 13, wherein the protrusion or the groove extends in a direction along the longitudinal body axis of the elongate body such that the channel extends along the longitudinal body axis.

[0090] Example 15: The medical suction system according to any one of Examples 12 to 14, wherein the anvil includes a generally curved surface having a longitudinal anvil axis perpendicular to the longitudinal body axis of the elongate body such that the channel extends along the longitudinal body axis.

[0091] Example 16: The medical aspiration system according to Example 15, wherein the surface feature comprises a groove defined by the anvil, the groove extending in a direction along the longitudinal anvil axis.

[0092] Example 17: The medical aspiration system according to any one of Examples 12 to 16, wherein the anvil comprises the surface feature, and the surface feature comprises a first generally curved surface and a second generally curved surface, the first generally curved surface having a first longitudinal anvil axis perpendicular to the longitudinal body axis of the elongate body, the second generally curved surface having a second longitudinal anvil axis perpendicular to the longitudinal body axis, and wherein the first generally curved surface and the second generally curved surface are separated from each other by a gap distance along the longitudinal body axis.

[0093] Example 18: The medical aspiration system according to any one of Examples 12 to 17, wherein the pinch valve comprises a solenoid configured to actuate the actuator to only the high flow configuration or the low flow configuration.

[0094] Example 19: A method for aspirating a substance from a patient using a flow switch, an anvil, an actuator, and surface features on at least one of the anvil and the actuator, the method comprising: opening the flow switch by moving the actuator away from the anvil to form a flow path for aspiration of the substance; and closing the flow switch by moving the actuator towards the anvil to reduce the flow path by forming at least one channel defined by the surface features.

[0095] Example 20: The method according to Example 19, wherein closing the flow switch comprises: forming the at least one channel within the lumen of a flexible tube, the lumen being defined by at least one of a protrusion extending outward from the surface and a groove extending inward from the surface.

[0096] Example 21: The method according to Example 20, wherein opening and closing the flow switch comprises: using a solenoid to move the actuator only between the compressed configuration or the open configuration.

[0097] Various aspects of the present disclosure have been described. These aspects and other aspects are within the scope of the following claims.

Claims

1. A medical system for aspirating a substance from a patient, the system comprising: A flow switch, the flow switch comprising: An anvil; An actuator; and Surface features located on at least one of the anvil and the actuator, wherein the flow switch is configured to: Move the actuator away from the anvil to form a flow path for the aspiration of the substance; and Move the actuator towards the anvil to reduce the flow path by forming at least one channel defined by the surface features.

2. The medical system according to claim 1, further comprising a flexible tube coupled to an elongate body of a catheter, the catheter being configured to aspirate the substance from the patient, and wherein the substance is a thrombus.

3. The medical system according to claim 2, wherein the actuator and the anvil are configured to compress the flexible tube from an open configuration to a compressed configuration, wherein when the flexible tube is in the open configuration and fluidly coupled to the elongate body of the catheter, a suction source fluidly coupled to the flexible tube is configured to cause a first flow rate to pass through the lumen of the flexible tube, and wherein the surface features are configured to keep the channels in the lumen of the flexible tube open when the flexible tube is compressed, such that the channels allow a second flow rate to pass through the lumen, the second flow rate being greater than zero and less than or equal to 5% of the first flow rate.

4. The medical system according to claim 2 or claim 3, wherein the surface of at least one of the actuator or the anvil defines the surface features, wherein the surface features include at least one of protrusions extending outward from the surface or grooves extending inward from the surface.

5. The medical system according to claim 4, wherein the protrusions or the grooves extend in a direction along the longitudinal tube axis of the flexible tube to cause the channels to extend along the longitudinal tube axis.

6. The medical system according to any one of claims 2 to 5, wherein the anvil includes a generally curved surface having a longitudinal anvil axis perpendicular to the longitudinal tube axis of the flexible tube to cause the channels to extend along the longitudinal tube axis.

7. The medical system according to claim 6, wherein the surface features include a groove defined by the anvil, the groove extending in a direction along the longitudinal anvil axis.

8. The medical system according to any one of claims 2 to 7, wherein the anvil includes the surface features, wherein the surface features include a first generally curved surface and a second generally curved surface, the first generally curved surface having a first longitudinal anvil axis perpendicular to the longitudinal tube axis of the flexible tube, the second generally curved surface having a second longitudinal anvil axis perpendicular to the longitudinal tube axis, wherein the first generally curved surface and the second generally curved surface are separated from each other by a gap distance along the tube axis.

9. The medical system according to any one of claims 1 to 8, further comprising: A suction source; And A catheter fluidly connected to the aspiration source and designed for use within the peripheral vascular system of a patient.

10. A medical aspiration system comprising: An aspiration source; An elongate body defining a lumen fluidly coupled to the aspiration source; And A pinch valve configured to actuate between a high flow configuration and a low flow configuration, wherein in the low flow configuration, the pinch valve is configured to compress the elongate body while still enabling fluid to flow through the lumen.

11. The medical aspiration system according to claim 10, wherein the pinch valve is configured to permit a first flow rate to pass through the lumen in the high flow configuration and a second flow rate to pass through the lumen in the low flow configuration, the second flow rate being less than or equal to 5% of the first flow rate.

12. The medical aspiration system according to claim 10 or claim 11, wherein the pinch valve comprises: An anvil; And An actuator, wherein the elongate body is positioned between the actuator and the anvil, wherein at least one of the actuator or the anvil is configured to move towards the other of the anvil or the actuator to compress the elongate body, wherein at least one of the anvil or the actuator includes surface features configured to keep the channel within the lumen open when the elongate body is compressed between the anvil and the actuator.

13. The medical aspiration system according to claim 12, wherein the surface of at least one of the actuator or the anvil defines the surface features, the surface features including at least one of a protrusion extending outwardly from the surface or a groove extending inwardly from the surface.

14. The medical aspiration system according to claim 13, wherein the protrusion or the groove extends in a direction along the longitudinal body axis of the elongate body to cause the channel to extend along the longitudinal body axis.

15. The medical aspiration system according to any one of claims 12 to 14, wherein the anvil includes a generally curved surface having a longitudinal anvil axis perpendicular to the longitudinal body axis of the elongate body to cause the channel to extend along the longitudinal body axis.

16. The medical aspiration system according to claim 15, wherein the surface features include a groove defined by the anvil, the groove extending in a direction along the longitudinal anvil axis.

17. The medical aspiration system according to any one of claims 12 to 16, wherein the anvil includes the surface features, the surface features including a first generally curved surface and a second generally curved surface, the first generally curved surface having a first longitudinal anvil axis perpendicular to the longitudinal body axis of the elongate body, the second generally curved surface having a second longitudinal anvil axis perpendicular to the longitudinal body axis, wherein the first generally curved surface and the second generally curved surface are separated from each other by a gap distance along the longitudinal body axis.

18. The medical suction system according to any one of claims 12 to 17, wherein the pinch valve includes a solenoid configured to actuate the actuator to only the high flow configuration or the low flow configuration.

19. A method for suctioning a substance from a patient using a flow switch, an anvil, an actuator, and surface features on at least one of the anvil and the actuator, the method comprising: opening the flow switch by moving the actuator away from the anvil to form a flow path for the suction of the substance; and closing the flow switch by moving the actuator towards the anvil to reduce the flow path by forming at least one channel defined by the surface features.

20. The method according to claim 19, wherein closing the flow switch comprises: forming the at least one channel within the lumen of a flexible tube, the lumen being defined by at least one of a protrusion extending outwardly from the surface and a groove extending inwardly from the surface.

21. The method according to claim 20, wherein opening and closing the flow switch comprises: using a solenoid to move the actuator only between the compressed configuration and the open configuration.

Images