Cardiac cycle-based medical aspiration

Abstract

A medical aspiration system (70) is configured to control medical aspiration based on a cardiac cycle of a patient. For example, the medical aspiration system (70) can include: a suction source (19) configured to apply a suction force to a catheter (12) to remove fluid from the catheter (12); and a control circuit (72) configured to control the suction force applied by the suction source (19) to the catheter (12) based on a cardiac cycle of a patient.

Description

Technical Field

[0001] This disclosure relates to a medical aspiration. Background Technology

[0002] In some cases, medical aspiration can be used to remove substances from a patient. For example, medical aspiration can be used to remove blockages from a patient's blood vessels. Summary of the Invention

[0003] This disclosure describes example medical devices and systems configured to control medical aspiration based on a patient's cardiac cycle, and techniques for controlling aspiration based on cardiac cycle. In the examples described herein, the aspiration system is configured to control the amount of suction force applied to the aspiration catheter based on the patient's cardiac cycle.

[0004] Clause 1: In some instances, a medical aspiration system includes: an aspiration source configured to apply a suction force to a catheter to remove fluid from the catheter; and control circuitry configured to control the suction force applied to the catheter by the aspiration source based on the patient's cardiac cycle.

[0005] Clause 2: In some instances of the medical aspiration system of Clause 1, the control circuit is configured to control the suction force applied by the aspiration source based on the cardiac cycle at least by controlling the aspiration source to apply a first suction force during cardiac diastole and controlling the aspiration source to apply a second suction force during cardiac systole, the first suction force being different from the second suction force.

[0006] Clause 3: In some instances of the medical aspiration systems described in Clause 2, the first suction force is greater than the second suction force.

[0007] Clause 4: In some instances of the medical aspiration systems described in Clause 2, the first suction force is less than the second suction force.

[0008] Clause 5: In some instances of the medical aspiration systems described in Clause 2, the second suction force is zero.

[0009] Clause 6: In some instances of the medical aspiration system of any of Clauses 1-5, the control circuit is configured to control the suction force applied by the suction source based on the cardiac cycle by at least the following operation: controlling the suction source to generate a first suction force at the distal opening of the catheter during a first portion of the cardiac cycle, and to generate a second suction force at the distal opening of the catheter during a second portion of the cardiac cycle, different from the first portion, the second suction force being greater than the first suction force.

[0010] Clause 7: In some instances of the medical aspiration systems described in Clause 6, the second part of the cardiac cycle corresponds to diastole.

[0011] Clause 8: In some instances of the medical aspiration systems described in Clause 6, the second part of the cardiac cycle corresponds to cardiac contraction.

[0012] Clause 9: In some instances of the medical aspiration system of any of Clauses 1-8, the system further includes a sensing circuit configured to generate a signal indicative of the patient’s cardiac cycle, wherein a control circuit is configured to receive the signal from the sensing circuit and control the suction force applied to the catheter based on the signal.

[0013] Clause 10: In some instances of the medical aspiration system described in Clause 9, the signal includes at least one of an electrocardiogram, an electrogram, a photoplethysmography, or a blood pressure signal.

[0014] Clause 11: In some instances of the medical aspiration system of Clause 9, the sensing circuitry includes at least one of an electrocardiogram sensor, an electrogram sensor, a blood oxygen saturation sensor, or an arterial blood pressure sensor.

[0015] Clause 12: In some instances of a medical aspiration system of any of Clauses 1-11, the system further includes a catheter fluidly coupled to the aspiration source.

[0016] Clause 13: In some instances of a medical aspiration system of any of Clauses 1-12, the aspiration source includes a evacuation volume fluidly coupled to a pump, wherein the pump is configured to draw fluid from a catheter into the evacuation volume.

[0017] Clause 14: In some instances of the medical aspiration system of Clause 13, the evacuation volume includes a discharge reservoir, the system further comprising: a fluid source reservoir including an incompressible fluid; and a valve movable between a first position and a second position, wherein in the first position, the valve fluidly couples the fluid source reservoir and the catheter but not fluidly couples the aspiration source and the catheter, and wherein in the second position, the valve fluidly couples the aspiration source and the catheter but not fluidly couples the fluid source reservoir and the catheter, wherein control circuitry is configured to control the aspiration force applied to the catheter by the aspiration source based on the cardiac cycle, at least by controlling the movement of the valve between the first and second positions based on the cardiac cycle.

[0018] Clause 15: In some instances of a medical aspiration system of any of Clauses 1-14, the control circuitry is configured to control the suction force applied to the catheter by the aspiration source based on the cardiac cycle, at least by causing the aspiration source to cycle between an on and off phase.

[0019] Clause 16: In some instances of medical aspiration systems of any of Clauses 1-15, the control circuitry is configured to synchronize the application of suction force with the cardiac cycle.

[0020] Clause 17: In some instances of medical aspiration systems of any of Clauses 1-16, the control circuitry is configured to synchronize the application of suction force with a portion of the cardiac cycle.

[0021] Clause 18: In some instances of a medical aspiration system of any of Clauses 1-17, the control circuitry is configured to synchronize the application of suction force with a portion of the cardiac cycle, while applying reduced suction force or not applying suction force with another portion of the cardiac cycle.

[0022] Clause 19: In some instances of the medical aspiration system of any of Clauses 1-18, the control circuitry is configured to synchronize the application of suction force with a portion of the cardiac cycle and to apply reduced suction force or no suction force for the remainder of the cardiac cycle.

[0023] Clause 20: In some instances of a medical aspiration system of any of Clauses 1-19, the aspiration source includes a pulsator, and the control circuitry is configured to control the aspiration force applied by the aspiration source by controlling the pulsator.

[0024] Clause 21: In some instances of the medical aspiration systems described in Clause 20, the pulsator includes a valve.

[0025] Clause 22: In some instances of the medical aspiration systems of Clause 20, the pulsator is configured to fluidly connect and disconnect the aspiration source and the catheter.

[0026] Clause 23: In some instances of medical aspiration systems under any of Clauses 1-22, the aspiration source includes a pump.

[0027] Clause 24: In some instances of medical aspiration systems under any of Clauses 1-23, the aspiration source includes an evacuation volume.

[0028] Clause 25: In some instances of medical aspiration systems described in Clause 24, the evacuation volume includes a tank.

[0029] Clause 26: In some instances of medical aspiration systems of any of Clauses 1-25, the distal end of the catheter is configured to be advanced into a patient’s cerebral artery.

[0030] Clause 27: In some instances, a method includes receiving a signal indicative of a patient’s cardiac cycle in a medical aspiration system; and, based on the signal indicative of the cardiac cycle, controlling a suction force applied by a suction source of the medical aspiration system to a catheter to remove fluid from the catheter.

[0031] Clause 28: In some instances of the method of Clause 27, controlling the suction force applied to the catheter by the suction source includes: controlling the suction source to apply a first suction force during cardiac diastole; and controlling the suction source to apply a second suction force during cardiac systole, the first suction force being different from the second suction force.

[0032] Clause 29: In some instances of the method of Clause 28, the first suction force is greater than the second suction force.

[0033] Clause 30: In some instances of the method of Clause 28, the first suction force is less than the second suction force.

[0034] Clause 31: In some instances of the method of Clause 28, the second suction force is zero.

[0035] Clause 32: In some instances of the method of any one of Clauses 27-31, controlling the suction force applied to the catheter by the suction source includes: controlling the suction source to generate a first suction force at the distal opening of the catheter during a first portion of the cardiac cycle; and controlling the suction source to generate a second suction force at the distal opening of the catheter during a second portion of the cardiac cycle, different from the first portion, the second suction force being greater than the first suction force.

[0036] Clause 33: In some instances of the method of Clause 32, the second part of the cardiac cycle corresponds to cardiac diastole or cardiac contraction.

[0037] Clause 34: In some instances of the methods in any of Clauses 27-33, the signal includes an electrocardiogram signal, a photoplethysmography signal, or a blood pressure signal.

[0038] Clause 35: In some instances of the method of any one of Clauses 27-34, the method further includes: sensing physiological parameters indicating the patient’s cardiac cycle via sensing circuitry; and generating a signal based on the sensed physiological parameters via sensing circuitry.

[0039] Clause 36: In some instances of the method of any one of Clauses 27-35, controlling the suction force generated by the pump on the catheter includes: controlling the movement of a valve between a first position and a second position based on the cardiac cycle, wherein in the first position the valve fluidly couples the catheter and the fluid source reservoir without fluidly couples the suction source and the catheter, and wherein in the second position the valve fluidly couples the suction source and the catheter without fluidly couples the fluid source reservoir and the catheter.

[0040] Clause 37: In some instances of the methods of any of Clauses 27-36, controlling the suction force generated by the suction source on the conduit includes cyclically switching the suction source between an on and off phase.

[0041] Clause 38: In some instances of the methods of any of Clauses 27-37, controlling the suction force includes synchronizing the application of the suction force with the cardiac cycle.

[0042] Clause 39: In some instances of the methods of any of Clauses 27-38, controlling the suction force includes synchronizing the application of the suction force with a portion of the cardiac cycle.

[0043] Clause 40: In some instances of the methods of any of Clauses 27-39, controlling the suction force includes synchronizing the application of the suction force with a portion of the cardiac cycle, while applying a reduced suction force or not applying the suction force with another portion of the cardiac cycle.

[0044] Clause 41: In some instances of the methods of any of Clauses 27-40, controlling the suction force includes synchronizing the application of the suction force with a portion of the cardiac cycle, wherein the method further includes applying a reduced suction force or not applying a suction force for the remainder of the cardiac cycle.

[0045] Clause 42: In some instances of the methods of any of Clauses 27-41, the suction source includes a pulsator, and controlling the suction force applied by the suction source includes controlling the pulsator.

[0046] Clause 43: In some instances of the method of Clause 42, the pulsator includes a valve.

[0047] Clause 44: In some instances of the method of Clause 42, the method further includes fluidly connecting and disconnecting the suction source and the conduit via a pulsator.

[0048] Clause 45: In some instances of the methods of any one of Clauses 27-44, the control is performed by the control circuitry of the medical aspiration system.

[0049] Clause 46: In some instances of the method of Clause 45, the receiving is performed by a control circuit.

[0050] Clause 47: In some instances of the method of any one of Clauses 27-46, the method further includes aspiration from a patient’s blood vessel via a catheter.

[0051] Clause 48: In some instances, a medical aspiration system includes: an aspiration source configured to apply a suction force to a catheter to remove fluid from the catheter; and control circuitry configured to receive a signal from sensing circuitry indicating a patient’s cardiac cycle, determine a current portion of the patient’s cardiac cycle based on the signal, and control the suction force applied to the catheter by the aspiration source based on the determined current portion of the cardiac cycle.

[0052] Clause 49: In some instances of the medical aspiration system of Clause 48, the control circuit is configured to control the suction force applied by the aspiration source by at least the following operations: in response to determining that the current part of the cardiac cycle is diastole, controlling the aspiration source to apply a first suction force, and in response to determining that the current part of the cardiac cycle is contraction, controlling the aspiration source to apply a second suction force during this period, the first suction force being different from the second suction force.

[0053] Clause 50: In some instances of medical aspiration systems described in Clause 49, the first suction force is greater than the second suction force.

[0054] Clause 51: In some instances of medical aspiration systems described in Clause 49, the first suction force is less than the second suction force.

[0055] Clause 52: In some instances of medical aspiration systems described in Clause 49, the second suction force is zero.

[0056] Clause 53: In some instances of a medical aspiration system of any of Clauses 48-52, the control circuitry is configured to control the suction force applied by the aspiration source based on a determined current portion of the cardiac cycle by at least the following operation: controlling the aspiration source to generate a first suction force at the distal opening of the catheter during a first portion of the cardiac cycle, and to generate a second suction force at the distal opening of the catheter during a second portion of the cardiac cycle, different from the first portion, the second suction force being greater than the first suction force.

[0057] Clause 54: In some instances of the medical aspiration systems described in Clause 53, the second part of the cardiac cycle corresponds to diastole.

[0058] Clause 55: In some instances of the medical aspiration systems described in Clause 53, the second part of the cardiac cycle corresponds to a heart contraction.

[0059] Clause 56: In some instances of the medical aspiration system of any of Clauses 48-52, the system further includes sensing circuitry configured to generate a signal indicative of a patient’s cardiac cycle, wherein control circuitry is configured to receive the signal from the sensing circuitry and determine the current portion of the cardiac cycle based on the signal.

[0060] Clause 57: In some instances of the medical aspiration system of Clause 56, the signal includes at least one of an electrocardiogram, an electrogram, a photoplethysmography, or a blood pressure signal.

[0061] Clause 58: In some instances of the medical aspiration system of Clause 56, the sensing circuitry includes at least one of an electrocardiogram sensor, an electrogram sensor, a blood oxygen saturation sensor, or an arterial blood pressure sensor.

[0062] Clause 59: In some instances of a medical aspiration system of any of Clauses 48-58, the system further includes a catheter fluidly coupled to the aspiration source.

[0063] Clause 60: In some instances of a medical aspiration system under any of Clauses 48-59, the aspiration source includes a evacuation volume fluidly coupled to a pump, wherein the pump is configured to draw fluid from a catheter into the evacuation volume.

[0064] Clause 61: In some instances of the medical aspiration system of Clause 60, the evacuation volume includes a discharge reservoir, the system further comprising: a fluid source reservoir including an incompressible fluid; and a valve movable between a first position and a second position, wherein in the first position, the valve fluidly couples the fluid source reservoir and the catheter but not fluidly couples the aspiration source and the catheter, and wherein in the second position, the valve fluidly couples the aspiration source and the catheter but not fluidly couples the fluid source reservoir and the catheter, wherein control circuitry is configured to control the aspiration force applied to the catheter by the aspiration source based on a determined current portion of the cardiac cycle, at least by controlling the movement of the valve between the first and second positions based on the cardiac cycle.

[0065] Clause 62: In some instances of a medical aspiration system of any of Clauses 48-61, the control circuitry is configured to control the suction force applied to the catheter by the aspiration source based on a determined current portion of the cardiac cycle, at least by causing the aspiration source to cycle between an on and off phase.

[0066] Clause 63: In some instances of medical aspiration systems of any of Clauses 48-62, the control circuitry is configured to synchronize the application of suction force with the cardiac cycle.

[0067] Clause 64: In some instances of medical aspiration systems of any of Clauses 48-63, the control circuitry is configured to synchronize the application of suction force with a portion of the cardiac cycle.

[0068] Clause 65: In some instances of a medical aspiration system of any of Clauses 48-64, the control circuitry is configured to synchronize the application of suction force with a portion of the cardiac cycle, while applying reduced suction force or not applying suction force with another portion of the cardiac cycle.

[0069] Clause 66: In some instances of a medical aspiration system of any of Clauses 48-65, the control circuitry is configured to synchronize the application of suction force with a portion of the cardiac cycle and to apply reduced suction force or no suction force for the remainder of the cardiac cycle.

[0070] Clause 67: In some instances of a medical aspiration system of any of Clauses 48-66, the aspiration source includes a pulsator, and the control circuitry is configured to control the aspiration force applied by the aspiration source by controlling the pulsator.

[0071] Clause 68: In some instances of medical aspiration systems described in Clause 67, the pulsator includes a valve.

[0072] Clause 69: In some instances of the medical aspiration systems described in Clause 67, the pulsator is configured to fluidly connect and disconnect the aspiration source and the catheter.

[0073] Clause 70: In some instances of medical aspiration systems under any of Clauses 48-69, the aspiration source includes a pump.

[0074] Clause 71: In some instances of medical aspiration systems under any of Clauses 48-70, the aspiration source includes an evacuation volume.

[0075] Clause 72: In some instances of the medical aspiration systems described in Clause 71, the evacuation volume includes a tank.

[0076] Clause 73: In some instances of medical aspiration systems of any of Clauses 48-72, the distal end of the catheter is configured to be advanced into a patient’s cerebral artery.

[0077] The examples described in this article can be combined in any arrangement or combination.

[0078] Details of one or more aspects of this disclosure are set forth in the following drawings and description. Other features, objects, and advantages of the technology described in this disclosure will become apparent from the specification, drawings, and claims. Attached Figure Description

[0079] Figure 1 This is a schematic diagram illustrating an example aspiration system configured to control medical aspiration based on the patient's cardiac cycle.

[0080] Figure 2 This is a schematic diagram illustrating another instance of aspiration systems configured to control medical aspiration based on the patient's cardiac cycle.

[0081] Figure 3 This is a flowchart illustrating an example technique for controlling the suction force applied to the catheter by a suction source based on the patient's cardiac cycle.

[0082] Figure 4 This is a schematic diagram illustrating another instance of aspiration systems configured to control medical aspiration based on the patient's cardiac cycle.

[0083] Figure 5 This is a schematic diagram illustrating another instance of aspiration systems configured to control medical aspiration based on the patient's cardiac cycle. Detailed Implementation

[0084] This disclosure describes a medical aspiration system configured to control medical aspiration based on a patient's cardiac cycle, and medical devices and methods associated with the aspiration system. The medical aspiration system can be used to treat a variety of conditions, including thrombosis. Thrombosis occurs when a thrombus (e.g., a blood clot or other embolus) forms and obstructs a patient's vascular system. To treat a patient with thrombosis, a clinician may place a medical catheter (also referred to herein as an aspiration catheter) in the patient's blood vessel near the thrombus or other occlusion and apply a suction force (also referred herein as suction, aspiration force, or negative pressure) to the catheter (e.g., one or more lumens of the catheter) to engage the thrombus with the suction force at the catheter tip. Once the tip of the aspiration catheter is engaged with the thrombus, the clinician may remove the aspiration catheter from which the thrombus has adhered or aspirate fragments (or the entire thrombus) of the thrombus until the thrombus is removed from the patient's blood vessel through the lumen of the aspiration catheter itself and / or through the lumen of an external catheter in which at least a portion of the aspiration catheter is located. The external catheter may be, for example, a guiding catheter configured to provide additional structural support to the aspiration catheter. Thrombus aspiration can be part of an aspiration procedure, such as, but not limited to, medical procedures for acute stroke thrombectomy using a Direct Aspiration First Pass Technique (ADAPT), or any other procedure for aspirating thrombi or other material from the neurovascular system or other vessels. Furthermore, thrombectomy devices such as stent thrombectomies can be performed simultaneously with thrombectomy to facilitate removal of the thrombus via both mechanical thrombectomy and aspiration.

[0085] In the examples described herein, the medical aspiration system can be configured to control the amount of suction force applied to the aspiration catheter based on the patient's cardiac cycle. For example, in some instances, the control circuitry of the aspiration system is configured to determine which part of the cardiac cycle the patient's heart is in and control the suction source of the aspiration system to apply a first suction force during a first part of the cardiac cycle, such as diastole, and to apply a second suction force during a second part of the cardiac cycle, such as systole, where the first suction force differs from the second suction force. A part of the cardiac cycle may encompass a portion of the cardiac cycle and does not span multiple cardiac cycles. In some instances, the first suction force is greater than the second suction force, resulting in a greater suction force applied to the aspiration catheter during the first part of the cardiac cycle. In other instances, the first suction force is less than the second suction force, resulting in a greater suction force applied to the aspiration catheter during the second part of the cardiac cycle.

[0086] As used herein, “suction force” is intended to encompass related concepts such as suction pressure, vacuum force, vacuum pressure, negative pressure, and fluid flow rate. Suction force can be generated by a vacuum, for example, by creating a partial vacuum within a sealed volume fluidly connected to a conduit, or by directly discharging liquid from a conduit or pipe via, for example, a peristaltic pump or otherwise. Therefore, suction force or suction power as specified herein can be measured, estimated, calculated, etc., without directly sensing or measuring the force. “Higher,” “more,” or “greater” (or “lower,” “less,” or “smaller”) suction force as used herein can refer to the absolute value of the negative pressure generated by the suction source on the conduit or another component such as a discharge reservoir.

[0087] It is believed that, compared to applying a continuous or steady suction force, the amount of suction force applied to the aspiration catheter based on the patient's cardiac cycle can remove blood clots from the patient's blood vessels more quickly and effectively.

[0088] The cardiac cycle comprises different phases (also referred to as periods in some instances), and in some instances, the control circuitry is configured to change the suction force applied by the suction source to the aspiration system and / or catheter based on the current phase of the patient's cardiac cycle. That is, in some instances, the aspiration system is configured to determine the current phase of the patient's cardiac cycle and apply different amounts of suction force to the aspiration system and / or catheter during the different phases of the cardiac cycle.

[0089] The cardiac cycle comprises diastole and systole. During diastole, the heart muscle relaxes and the chambers fill with blood. During systole, the heart muscle contracts and pumps blood out of the chambers. For example, in a heart-healthy patient, atrial contractions occur during ventricular diastole to actively fill the ventricles during diastole. In some instances, the cardiac cycle may include diastole, atrial contractions, and ventricular contractions. Atrial contractions can be correlated with the P wave of the PQRST complex in cardiac electrical signals, such as on an electrocardiogram (EGM) or electrocardiogram (ECG), and ventricular contractions can be correlated with the Q deflection of the PQRST complex in cardiac electrical signals. The term "contraction" as used herein can refer to either atrial or ventricular contraction. Similarly, the term "diastole" as used herein can refer to either atrial or ventricular diastole.

[0090] As a complement or alternative to these phases, the phases of the cardiac cycle can be described by the fluid flow in the heart. For example, the phases of the cardiac cycle can be referred to as isovolumetric relaxation, ventricular filling, ventricular filling with atrial contraction, isovolumetric contraction, and ejection.

[0091] In some cases, the control circuitry is configured to control the suction force applied by the suction source based on the cardiac cycle at least by: controlling the suction source to generate a minimum (or reduced or relatively small) suction force at the distal end of the catheter during a first portion of the cardiac cycle, and a maximum (or increased or relatively large) suction force at the distal end of the catheter during a second portion of the cardiac cycle, which is different from the first portion. As an example, the second portion may correspond to cardiac diastole, such as, but not limited to, the beginning, midpoint, or end of diastole. As another example, the second portion of the cardiac cycle may correspond to cardiac contraction, such as, but not limited to, the beginning, midpoint, or end of contraction. As yet another example, the second portion of the cardiac cycle may correspond to the maximal ejection phase of the cardiac cycle (e.g., indicated by the M wave of the PQRST complex of the cardiac electrical signal). In other instances, other methods of controlling the suction source based on the patient's cardiac cycle may be used.

[0092] The control circuitry of the aspiration system can use any suitable technique to determine the cardiac cycle (e.g., the current stage of the cardiac cycle). For example, the control circuitry can determine the current stage of the patient's cardiac cycle based on cardiac electrical signals, blood pressure, blood oxygen saturation, or other physiological parameters that vary with the patient's cardiac cycle. In some instances, the aspiration system includes, or is otherwise communicatively coupled to, sensing circuitry configured to generate signals indicative of the patient's physiological parameters indicating the cardiac cycle, and the control circuitry is configured to receive the signals and determine the cardiac cycle (e.g., a specific stage of the cardiac cycle) based on the signals. The signals may include one or more of, for example, ECG, EGM, photoplethysmography (PPG), phonocardiography, or blood pressure signals. The sensing circuitry may include one or more of, for example, an electrocardiogram sensor, an electrocardiogram sensor, a blood oxygen saturation sensor, or an arterial blood pressure sensor.

[0093] In other examples, a device for controlling the suction source, other than the control circuitry, determines the patient's cardiac cycle, and the control circuitry of the suction system receives information indicating the cardiac cycle from this other device. This other device may include, for example, a cardiac monitor, a multi-parameter monitor, etc.

[0094] As further detailed and described herein, the suction source may include a pump. The pump may include a direct-acting pump that acts directly on the liquid to be discharged, or a pipe containing the liquid. A direct-displacement pump may include a peristaltic pump or a vane, impeller, gear, or piston pump, or other suitable pumps of this type. The pump may also include an indirect-acting pump that acts indirectly on the liquid to be discharged. An indirect-acting pump may include a vacuum pump that creates a partial vacuum in a evacuation volume fluidly coupled to the liquid to be discharged. The vacuum pump forces a compressible fluid (e.g., a gas, such as air) out of the evacuation volume (e.g., a discharge reservoir that may include a tank), thereby generating suction on the liquid. Therefore, the evacuation volume (when present) can be considered part of the suction source.

[0095] The aspiration source may also include a pulsator. The pulsator can be used to open, close, vary, oscillate, rhythmically drive, etc., the application of suction force from the aspiration source to the catheter or patient. Therefore, the pulsator can fluidly couple or decouple the catheter from the aspiration source as needed. The pulsator may include valves, clamps, wrenches, fluid switches, etc., which are preferably configured to selectively actuate as needed according to the control of the aspiration system to fluidly couple or decouple the catheter from the aspiration source.

[0096] The control and operation of a suction source may include the control and operation of any one or a combination of the components constituting the suction source. Therefore, when the suction source includes a pump, a evacuation volume, and a pulser, the control of the suction source may include controlling only the pump, only the evacuation volume, only the pulser, or any combination of these components. When the suction source includes only a pump, the control of the suction source includes controlling the pump. Other suction source control may include controlling only the pulser, only the evacuation volume, only the pump, or any combination of the components used in the suction source.

[0097] Figure 1 This is a schematic diagram illustrating an example suction system 10, which includes a conduit 12, a fluid flow switch 14 coupled to the conduit 12 via a suction conduit 16, and a pump 18. The suction system 10 can be used in various medical procedures, such as medical procedures for treating ischemic injuries, which may be caused by occlusion of blood vessels (arteries or veins) leading to hypoxia in brain tissue, heart tissue, or other tissues.

[0098] The aspiration system 10 is configured to remove fluid from the catheter 12 via a suction force applied by a pump 18 to the catheter 12 (e.g., the inner lumen 26 of the catheter 12), for example, drawing fluid from the catheter 12 into a discharge reservoir 24. For example, the pump 18 may be configured to generate a negative pressure within the inner lumen 26 of the catheter 12 to draw fluid, such as blood, aspirated fluid, partially solid material, or a mixture thereof, in the direction indicated by arrow 30, and draw it into the inner lumen 26 via the distal opening 28 of the catheter 12. The negative pressure within the inner lumen 26 can create a pressure differential between the inner lumen 26 and the environment outside at least the distal portion of the catheter 12, allowing fluid and other materials to be introduced into the inner lumen 26 via the distal opening 28. For example, fluid may flow from the patient's vascular system into the inner lumen 26 via the distal opening 28 and subsequently into the discharge reservoir 24 via the aspiration conduit 16, the fluid flow switch 14, and the aspiration conduit 20. Therefore, Figure 1 The suction source of the suction system 10 includes a pump 18, a evacuation volume in the form of a discharge reservoir 24, and a pulsator in the form of a fluid flow switch 14.

[0099] In some instances, the suction system 10 is also configured to transfer fluid from a fluid source (e.g., a fluid reservoir different from the discharge reservoir 24) through the internal lumen 26 of the conduit 12 via the positive pressure applied by the pump 18.

[0100] The conduit 12 and pump 18 can be fluidly coupled using any suitable configuration. Figure 1 In the examples shown, pump 18 is fluidly coupled to catheter 12 via suction conduit 22, discharge reservoir 24, suction conduit 20, fluid flow switch 14, and suction conduit 16. For example, pump 18 may be coupled to discharge reservoir 24 via suction conduit 22, and discharge reservoir 24 may be positioned between pump 18 and catheter 12. In these examples, pump 18 is configured to create a partial vacuum in discharge reservoir 24, which allows fluid (e.g., blood) and partially solid materials (e.g., blood clots) located within the inner lumen 26 of catheter 12 to be drawn into discharge reservoir 24 via conduits 16, 20, and fluid flow switch 14. In other examples, pump 18 may be more directly coupled to catheter 12, or may be further fluidly separated from catheter 12 by means of additional components.

[0101] The suction conduits 16, 20, 22, and other suction conduits described herein are any suitable structures that define fluid paths through which fluid and relatively small fluid particles can flow between the components of the suction system 10. The conduits can be formed of any suitable material, such as, but not limited to, polymers that can be reinforced with adhesive, laminated, or embedded tubular braids, coils, or other reinforcing components.

[0102] Catheter 12 is configured to function as an aspiration catheter to remove thrombi, such as clots, or other materials, such as plaques or foreign bodies, from a patient's vascular system. Catheter 12 defines at least one internal lumen, for example, Figure 1 The lumen 26 shown in the diagram, and at least one distal opening 28 leading to the lumen 26. The distal opening 28 may be located at the distal end of the catheter 12 and / or at another location along the catheter 12, for example in the sidewall of the catheter 12 near the distal end 12B of the catheter 12.

[0103] The catheter 12 includes an elongated body and a hub. The elongated body of the catheter 12 is configured to be advanced through a patient's vascular system via a thrust applied to a proximal portion of the elongated body. The catheter 12 includes any structure suitable for medical aspiration. In some instances, the catheter 12 may include an inner liner, an outer sheath, and a structural support member, such as a coil and / or braid, disposed between at least a portion of the inner liner and at least a portion of the outer sheath. The catheter 12 may include other structures, such as expandable components, configured to expand radially within a patient's blood vessel, for example, to engage clots within the vessel.

[0104] The catheter 12 is configured to travel to any suitable vascular site within the patient. In some instances, the catheter 12 is configured to enter relatively distant locations within the patient, including, for example, the middle cerebral artery (MCA), internal carotid artery (ICA), circle of Willis, and tissue sites even further than the MCA, ICA, and circle of Willis. The MCA and other vascular systems or other relatively distal tissue sites in the brain (e.g., relative to the point of vascular entry) may be relatively difficult to reach with a catheter, at least in part due to the tortuous path (e.g., including relatively sharp twists or turns) through the vascular system to reach these tissue sites. The elongated body of the catheter 12 may be structurally configured to be relatively flexible, maneuverable, and relatively resistant to kinking and bending, such that it does not bend when a driving force is applied to a relatively proximal segment of the catheter 12 to propel the elongated body distally through the vascular system, and that it does not kink when making sharp turns along the vascular system. In some instances, the elongated body is configured to generally conform to the curvature of the vascular system. Furthermore, in some instances, the elongated body possesses column strength and flexibility, allowing at least the distal portion of the elongated body to travel from the femoral artery through the patient's aorta and into the patient's intracranial vascular system, for example, to reach a more distant treatment site. Alternatively, the elongated body may have column strength (and / or be otherwise configured) to allow the distal portion of the elongated body to travel from the radial artery through the patient's aorta via an entry point in the arm (e.g., at or near the wrist) or to the common carotid or vertebral artery, and into the patient's intracranial vascular system, for example, to reach a more distant treatment site.

[0105] Although primarily described as being for reaching relatively distant vascular system sites, catheter 12 can also be configured for other target tissue sites. For example, catheter 12 can be used to access tissue sites throughout the coronary and peripheral vascular system, the gastrointestinal tract, urethra, ureters, fallopian tubes, veins, and other body cavities. The length of catheter 12 may depend on the location of the target tissue site within the patient's body or on the medical procedure in which catheter 12 is used. For example, if catheter 12 is intended for distal entry into the vascular system of the patient's brain from the femoral artery entry point in the groin, the working length of the elongated body of catheter 12 may be from about 115 cm to about 145 cm or greater, such as about 130 cm, but other lengths may also be used (e.g., in the case of radial entry catheters). The length of the distal portion may be from about 5 cm to about 35 cm. The length of the proximal portion may be from about 90 cm to about 130 cm, depending on the length of the distal portion.

[0106] Pump 18 is configured to generate negative pressure (e.g., vacuum or suction) or otherwise induce fluid flow in the internal lumen 26 of conduit 12, for example, drawing fluid through the internal lumen 26 and into the discharge reservoir 24. Therefore, pump 18 is configured to generate a pressure differential that draws fluid from the internal lumen 26 out of the internal lumen 26 and into pump 18, for example, into the discharge reservoir 24. For example, pump 18 may include a port configured to couple to suction conduit 22, such that the negative pressure generated by fluid pump 18 can be applied to the port and through suction conduit 22 to the fluid path between suction conduit 22 and the internal lumen 26 of conduit 12. Figure 1 In the illustrated example, the fluid path further includes a discharge reservoir 24, suction conduits 16 and 20, and a switch 14. In the example operation of pump 18, when the distal opening 28 of conduit 12 is not blocked, pump 18 can draw fluid from the inner cavity 26 of conduit 12 into discharge reservoir 24 via suction conduits 16 and 20 and via switch 14. As another example, when the distal opening 26 is partially or completely blocked, pump 18 can draw fluid from conduit 12 at a reduced flow rate, or in some cases of complete blockage, not draw fluid at all. However, even when the distal opening 26 is blocked, pump 18 can be configured to continue to create a vacuum in the inner cavity 26 of conduit 12, for example, by additionally evacuating air from discharge reservoir 24.

[0107] Pump 18 may also be referred to as a fluid pump and may have any suitable configuration. For example, pump 18 (and pumps commonly found in this disclosure) may comprise one or more of positive displacement pumps (e.g., peristaltic pumps, rotary pumps, reciprocating pumps, or linear pumps), centrifugal pumps, etc. In some instances, pump 18 comprises an electrically driven pump, while in other instances, pump 18 may comprise a syringe configured to be controlled by control circuitry, and mechanical elements such as linear actuators, stepper motors, etc. As other examples, pump 18 may comprise a water-suction venturi or ejector.

[0108] In some instances, pump 18 can be configured for bidirectional operation. For example, pump 18 can be configured to generate a negative pressure that draws fluid from the inner cavity 26 of conduit 12 in a first flow direction and a positive pressure that pumps fluid into conduit 12 and through the inner cavity 26 of conduit 12 in the opposite second flow direction. As an example of this bidirectional operation, the operator of the suction system 10 can operate pump 18 to draw fluid from a fluid reservoir ( Figure 1 (Not shown) Pumping aspiration / fluid, such as saline, to flush and / or infuse catheter 12 (e.g., in an infusion state) and subsequently drawing fluid, such as saline and / or blood, from the distal opening 28 of catheter 12 into discharge reservoir 24.

[0109] In some instances, the aspiration system 10 includes a fluid flow switch 14 (also referred to herein as a fluid switch) to control fluid flow through the aspiration system 10. The fluid switch 14 can be configured to start and stop fluid flow from the conduit 12 toward the pump 18 (or in the opposite direction). For example, the fluid switch 14 can have an "open" position corresponding to fluid flowing through it and a "closed" position corresponding to no fluid flowing through it. The fluid switch 14 can use various switching mechanisms, including but not limited to valves, sliders, clamps, etc. In some instances, the fluid switch 14 can be configured for unassisted operation by a clinician. For example, the mechanism for blocking fluid flow via the fluid switch 14 can be directly operated by mechanical force provided by the clinician. In other instances, the system 10 does not include a fluid switch 14.

[0110] Figure 2 This is a block diagram of an example medical aspiration system 40, which is an example of medical aspiration system 10. Therefore, in some instances, system 40 may be structurally and functionally similar to system 10, except for aspects further discussed herein. Medical aspiration system 40 includes an aspiration source 19 (which may include a pump (e.g., pump 18) and / or other components as disclosed herein), control circuitry 42, memory 44, a user interface 46, and sensing circuitry 48, which includes a sensor 50 configured to sense physiological parameters of a patient 52. Sensor 50 may also be referred to as a physiological parameter sensor. See reference... Figure 1 As discussed, the absorption source 19 is configured to be fluidly coupled to the conduit 12 ( Figure 1 And apply suction force to the inner lumen 26 of catheter 12. Figure 1 Therefore, although not in Figure 2 As shown in the image, but the suction system 40 may include reference components. Figure 1 One or more of the suction pipes 16, 20, 22, fluid switch 14, and discharge reservoir 24.

[0111] The control circuit 42 is configured to control the suction force applied to the conduit 12 by the suction source 19. For example, as shown in the reference... Figure 4 The control circuit 42 can be configured to control a pulsator (e.g., a valve) that modifies the suction force applied by the suction source 19 to the internal lumen 26 of the conduit 12. In these instances, the suction source 19 can apply a substantially continuous suction force (e.g., continuous or nearly continuous to the extent permitted by the hardware) to the discharge reservoir 24, and the amount of this suction force transmitted to the internal lumen 26 can be adjusted by the pulsator (e.g., the position of the valve in such an implementation). As another example, see reference... Figure 5 The control circuit 42 can be configured to more directly control the operation of the pump 92 / 18 to change the suction force applied by the pump 92 / 18 to the internal lumen 26, for example, by controlling the motor speed or stroke length, volume or frequency of the pump 92 / 18 or other operating parameters. In other instances, other techniques for modifying the suction force applied by the suction source 19 to the internal lumen 26 of the conduit 12 can be used.

[0112] The control circuitry 42 described herein, as well as other processors, processing circuits, controllers, and control circuits, 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 instances, the control circuitry system 42 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 circuitry systems and / or analog circuitry systems.

[0113] Memory 44 may store program instructions, such as software, which may contain one or more program modules executable by control circuitry 42. When executed by control circuitry 42, such program instructions cause control circuitry 42 to provide the functionality borne by control circuitry 42 herein. The program instructions may be embodied in software and / or firmware. Memory 202 may include any volatile, non-volatile, magnetic, optical, 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.

[0114] In some, but not all, instances, the aspiration system 40 includes a user interface 46 configured to present information to a user and / or receive user input. For example, the user interface 46 may include a display, input devices, and / or a speaker. In some instances, the user interface 46 may include fewer or additional components. In some instances, the display of the user interface 46 may display information indicating the patient's cardiac cycle, such as EGM or ECG, phonocardiogram, blood pressure signal, or PPG. Furthermore, in some instances, a clinician may interact with the user interface 46 to control the aspiration source 19, such as starting or stopping the aspiration source 19 from applying suction force to the catheter 12. The user interface 46 may include additional controls and displays, such as indication of the canister vacuum level, display and / or control of the maximum vacuum limit, activation and / or deactivation of vacuum pulsation or variations, vacuum amplitude or magnitude (whether variable or constant), faults, and resets.

[0115] Sensing circuit 48 is configured to receive signals indicative of physiological parameters (also referred to herein as physiological signals) from sensor 50 and transmit the physiological signals to control circuit 42. Sensing circuit 48 and sensor 50 may include any sensing hardware configured to sense the patient's physiological parameters, such as, but not limited to, one or more electrodes, optical receivers, pressure sensors, blood pressure cuffs, etc. The sensed physiological signals may include signals indicative of the patient 52's cardiac cycle, such as, but not limited to, electrocardiogram, electrogram, PPG, or blood pressure signals. Therefore, in some instances, sensing circuit 48 and sensor 50 may be configured to include any suitable hardware configured to sense the patient 52's cardiac electrical signals, blood pressure, or blood oxygen saturation (e.g., pulse oximetry). In some instances, sensing circuit 48 may be integrated into control circuit 42, or some or all of its functions may be performed by control circuit 42.

[0116] In some instances, sensing circuit 48 and / or control circuit 42 may include signal processing circuitry configured to perform any suitable analog conditioning of the sensed physiological signal. For example, sensing circuit 48 may transmit an unaltered (e.g., original) signal to control circuit 42. Control circuit 42 may be configured to modify the original signal into a usable signal by, for example, filtering (e.g., low-pass, high-pass, band-pass, notch, or any other suitable filtering), amplification, performing operations on the received signal (e.g., differentiation, averaging), performing any other suitable signal conditioning (e.g., converting a current signal to a voltage signal), or any combination thereof. In some instances, the conditioned analog signal may be processed by an analog-to-digital converter or other component of control circuit 42 to convert the conditioned analog signal into a digital signal. In some instances, control circuit 42 may operate on the analog or digital form of the signal to separate different components of the signal. In some instances, sensing circuit 48 and / or control circuit 42 may perform any suitable digital conditioning on the converted digital signal, such as low-pass, high-pass, band-pass, notch filtering, averaging, or any other suitable filtering, amplification, signal manipulation, or any other suitable digital conditioning or any combination thereof. Additionally or alternatively, sensing circuit 48 may include signal processing circuitry to modify one or more original signals and transmit one or more modified signals to control circuit 42.

[0117] In some instances, sensor 50 includes an ECG sensor containing electrodes, and sensing circuitry 48 can utilize the electrodes to detect cardiac electrical signals indicative of the electrical activity of the heart of patient 52. As a complement or alternative to the ECG sensor, in some instances, sensor 50 includes a blood oxygen saturation sensor, and sensing circuitry 48 can utilize the blood oxygen saturation sensor to sense the blood oxygen saturation level of patient 52 and generate an oxygen saturation signal indicative of blood oxygen saturation in a region of the veins, arteries, and / or capillary systems of patient 52. For example, sensing circuitry 48 and sensor 50 may include a sensor configured to noninvasively generate a PPG signal. One example of this sensor 50 may be one or more blood oxygen measurement sensors (e.g., one or more pulse oximetry sensors) configured to be placed at one or more locations on patient 52, such as the fingertip of patient 52, the earlobe of patient 52, etc.

[0118] As a complement or alternative to the ECG sensor and / or blood oxygen saturation sensor, sensor 50 may include a blood pressure sensor, and sensing circuitry 48 may use the blood pressure sensor to sense the blood pressure of patient 52 and generate a blood pressure signal indicating the sensed blood pressure. For example, the blood pressure sensor may include a continuous noninvasive blood pressure monitor and / or an arterial line configured to invasively (e.g., endovascularly) monitor blood pressure in the arteries of patient 52. In some instances, the blood pressure signal may include at least a portion of the waveform of arterial blood pressure.

[0119] As a complement or alternative to the examples of sensors described above, sensor 50 may include an acoustic sensor configured to sense heart sounds, and control circuitry 42 or other control circuitry may utilize the acoustic sensor to determine the cardiac cycle of patient 52.

[0120] The sensing circuit 48 and the sensor 50 may be part of the device that includes the control circuit 42, or a device separate from the device that includes the control circuit 42, such as another device that is co-located with or located away from the device that includes the control circuit 42.

[0121] In some instances, control circuitry 42 is operatively coupled to sensing circuitry 48 and configured to control the operation of sensing circuitry 48 and sensor 50. For example, control circuitry 42 may be configured to provide timing control signals to coordinate the operation of sensing circuitry 48 and sensor 50. In other instances, control circuitry 42 does not control the operation of sensing circuitry 48.

[0122] The control circuit 42 is configured to receive one or more signals generated by the sensing circuit 48 that indicate the cardiac cycle of the patient 52, and to control the absorption source 19 based on these signals. Figure 3 A flowchart illustrating an example method or technique for controlling the suction force applied to catheter 12 by suction source 19 based on the cardiac cycle of patient 52. Although Figure 3 This is described with reference to systems 10, 40 and control circuitry 42, but in other instances, the technique may be performed by another system alone or in combination with systems 10, 40, such another system comprising... Figure 4 The suction system 70 shown in the image Figure 5 The suction system 90 is shown in the image.

[0123] like Figure 3 As shown, control circuitry 42 receives one or more signals (60) indicating the cardiac cycle of patient 52. In some instances, the signals include physiological signals generated by sensing circuitry 48 and / or sensor 50 and received from sensing circuitry 48. As a supplement to or alternative to the physiological signals, in some instances, the signals include an indication of the current portion (e.g., stage) of the cardiac cycle in which patient 52 is located, and may be received from another device that determines the current portion of the cardiac cycle and transmits the determined portion of the cardiac cycle to control circuitry 42. Thus, although Figure 3Not shown, but in some instances, the suction system 40 includes communication circuitry configured to receive information from another device. This communication circuitry can be used to communicate with an external device via one or more networks by transmitting and / or receiving network signals over those networks. For example, control circuitry 42 can use the communication circuitry to transmit and / or receive radio signals over a radio network, such as a cellular radio network, or over a satellite network. Examples of such communication circuitry include network interface cards (e.g., Ethernet cards), optical transceivers, radio frequency transceivers, or any other type of device capable of transmitting and / or receiving information. Other examples of communication circuitry may include near-field communication (NFC) units, Radio, shortwave radio, cellular data radio, wireless network (e.g., Radio and Universal Serial Bus (USB) controller.

[0124] Control circuit 42 controls the suction source 19 (62) based on the cardiac cycle, which is determined based on one or more received signals. For example, control circuit 42 may be configured to modify (or change) the amount of suction force present at the distal opening 28 of catheter 12 based on the portion of the cardiac cycle currently in which the heart of patient 52 is located, as indicated by one or more signals generated by sensing circuit 48. In some instances, control circuit 42 is configured to control the suction force applied by suction source 19 based on the cardiac cycle by controlling suction source 19 (e.g., via an associated pulsator implemented as a valve, or a fluid switch, or via other techniques for controlling suction source 19 discussed herein) to apply a first suction force to the internal lumen 26 of catheter 12 during a first portion of the cardiac cycle (e.g., diastole) to generate a first suction force at the distal catheter opening 28, and controlling suction source 19 to apply a second suction force to the internal lumen 26 during another portion of the cardiac cycle (e.g., systole) to generate a second suction force at the distal catheter opening 28, the first suction force being different from the second suction force. In some instances, the first suction force is greater than the second suction force. In other instances, the first suction force is less than the second suction force.

[0125] For example, the first or second suction force can be zero, such that the suction source 19 does not actively apply any suction force to the catheter 12 during the corresponding first or second portion of the cardiac cycle. However, in some cases, even if the suction source 19 does not actively apply suction force to the catheter 12, some residual vacuum may exist in the inner lumen 26 of the catheter 12 due to the length of the catheter 12 and the time required to equalize the pressure in the inner lumen 26 with the environment outside the distal opening 28 of the catheter 12. Therefore, even when the suction source 19 is in the closed phase, during which the suction source 19 does not actively apply suction force to the catheter 12, a negative pressure can still be observed in the inner lumen 26. Therefore, the control circuit 42 can be configured to cycle the suction source 19 between the open and closed phases based on the cardiac cycle without making the pressure difference between the inner lumen 26 and the environment outside the distal opening 28 of the catheter 12 zero.

[0126] In some instances, control circuitry 42 is configured to control suction source 19 to apply suction force to catheter 12, the applied suction force having an amount between a first suction force and a second suction force greater than the first suction force. The range of suction force bounded by the first and second suction forces may be referred to as a suction force window. In some instances, the first suction force is 0 mmHg. In some instances, control circuitry 42 controls suction source 19 to apply the maximum suction force within the suction force window to the inner lumen 26 of catheter 12 during cardiac diastole. In these instances, control circuitry 42 may control suction source 19 to apply the minimum suction force within the suction force window to the inner lumen 26 during cardiac systole or during another portion of the cardiac cycle. Aligning the relatively highest (within the suction force window) suction force with cardiac diastole (e.g., between heartbeats) allows aspiration system 40 to apply a relatively maximum suction force to the thrombus when the blood vessels are relaxed and therefore contact with the thrombus may be less.

[0127] In other examples, control circuitry 42 controls suction source 19 to apply the maximum suction force within the suction force window to the inner lumen 26 of catheter 12 during cardiac systole. In these examples, control circuitry 42 may also control suction source 19 to apply the minimum suction force within the suction force window to the inner lumen 26 during cardiac diastole or at another part of the cardiac cycle. Aligning the relatively highest (within the suction force window) suction force with cardiac diastole allows the aspiration system 40 to establish a larger pressure differential between the inner lumen 26 of catheter 12 and the blood vessel, since blood pressure within the blood vessel may be higher during cardiac systole than during cardiac diastole.

[0128] During the cardiac cycle, control circuit 42 can cycle the suction source 19 between the highest and lowest vacuum pressures within the suction force window at frequencies ranging from about 0.5 Hz to about 5 Hz (e.g., differing from these values ​​by no more than 5%, 10%, or 20%), from about 0.5 Hz to about 10 Hz, or about 20 Hz. In an example where the lower limit of the suction force window is 0 mmHg, the suction source 19 can be considered to be in a closed phase when at the lower limit of the suction force window and in an open phase when at the upper limit of the suction force window.

[0129] Control circuit 42 can control the suction force applied to conduit 12 by the suction source 19 by modifying the operation of pump 18 (if present) of suction source 19 (e.g., motor speed or stroke length, volume or frequency) and / or by operating or controlling the state of the pulsator of suction source 19 placed between pump 18 (or discharge reservoir 24, if present) and conduit 12. The latter form of control can be achieved via... Figure 2 fluid switch or Figure 4 Valve 76 is implemented.

[0130] In some instances, control circuitry 42 may be configured to control the suction force applied by suction source 19 based on the cardiac cycle by controlling suction source 19 (e.g., via an associated pump, pulsator, and / or discharge reservoir) to generate minimum suction force at distal opening 28 of catheter 12 during a first portion of the cardiac cycle, and to control suction source 19 to generate maximum suction force at distal opening 28 during a second portion of the cardiac cycle, distinct from the first portion (62). For example, the second portion may correspond to cardiac diastole or cardiac systole. As yet another example, the second portion may correspond to the maximal ejection phase of the cardiac cycle (e.g., indicated by the M wave of the PQRST complex of the cardiac electrical signal).

[0131] As discussed above, in some instances, the control circuitry of the suction system can be configured to control the amount of suction force applied to the catheter by the suction source by controlling a pulsator configured to fluidly couple the suction source and the catheter. Figure 4 This is a schematic diagram of an example of a suction system 70, which is an example of suction systems 10 and 40. Therefore, in some instances, system 70 may be structurally and functionally similar to systems 10 and 40, except for aspects further discussed herein. Suction system 70 includes references... Figure 1 The aforementioned conduit 12, suction pipes 16, 20, and 22 can partially function as the suction source and discharge reservoir 24 of the pump 18. Furthermore, the suction system 70 includes control circuitry 72 and sensing circuitry 74, which serve as a reference. Figure 2 Examples of the control circuit 42 and sensing circuit 48 described above. Therefore, although... Figure 4Not shown, but in some instances, the sensing circuit 74 also includes sensors configured to sense physiological parameters indicating a patient's cardiac cycle. Furthermore, although... Figure 4 Not shown in the diagram, but in some instances, the suction system 70 includes a fluid switch 14. Figure 1 ).

[0132] The suction system 70 may further include a pulser (which may be implemented as a valve 76, or otherwise), a flow restrictor 78, and a fluid source reservoir 80 connected to the valve 76 via a conduit 32, as well as an actuator 82. Figure 4 In the example shown, the discharge reservoir 24 includes a pressure relief valve 84 that controls the flow of gas from the external environment into the discharge reservoir 24. The control circuit 72 or a clinician can adjust the settings of the pressure relief valve 84 to control or limit the amount of vacuum pressure generated within the discharge reservoir 24 and / or passing through the valve 76.

[0133] exist Figure 4 In the example shown, control circuitry 72 is configured to control the amount of suction force applied to the internal lumen 26 of conduit 12 by a suction source (e.g., pump 18) by at least controlling a pulser (e.g., the position of control valve 76). In some embodiments of suction system 70, pump 18 is configured to apply a substantially continuous suction force (e.g., continuous or nearly continuous to the extent permitted by the hardware) to discharge reservoir 24, and the amount of this suction force delivered to the internal lumen 26 of conduit 12 can be adjusted by the position of valve 76. In other embodiments, pump 18 is configured to apply pulsed suction, for example by alternating between “on” and “off” phases (during the “off” phase, no suction force is applied or a reduced suction force is applied to conduit 22) rather than applying a substantially continuous suction force.

[0134] Valve 76 is movable between at least a first position and a second position. For example, valve 76 can be a two-position three-way valve, such as a three-way ball valve, or another suitable valve, such as a pinch valve, lift valve, diaphragm valve, butterfly valve, slide valve, or piston valve. Another suitable valve type is a one-way or two-way valve equipped with a pressure relief vent (in this case, the fluid source reservoir 80 can be omitted along with the flow restrictor 78 and the connection to valve 76). In the first position, valve 76 fluidly couples conduit 12 and fluid source reservoir 80, and conduit 12 and pump 18 are not fluidly coupled. Therefore, in the first position of valve 76, pump 18 does not apply suction force to the inner lumen 26 of conduit 12, and does not draw fluid from the inner lumen 26 into discharge reservoir 24. Fluid source reservoir 80 can store incompressible fluids, such as saline solution; or it can be a compressible fluid source, such as a vent to ambient air via conduit 32. (In some instances, the fluid source reservoir 80 may be omitted along with the flow restrictor 78 and the connection to the valve 76, and the valve may be a conventional two-way valve instead of...) Figure 4 (The three-way valve is depicted in the image.) When present, fluid source reservoir 80 can be discharged to the external environment. When valve 76 is in its first position, fluid source reservoir 80 is fluidly coupled to conduit 12, thereby releasing any negative pressure in conduit 12 or pipe 16, or otherwise allowing conduit 12 and pipe 16 to equalize with ambient pressure or a desired baseline pressure. Furthermore, when valve 76 is in its first position, pump 18 is configured to apply negative pressure to pipe 22, thereby creating and / or maintaining negative pressure in discharge reservoir 24. Control circuitry 72 or a clinician can adjust the setting of flow restrictor 78 (when present) to adjust the fluid flow rate from fluid source reservoir 80 to conduit 12 and / or pipe 16 when valve 76 is in its first position (and intermediate positions, discussed further in detail below).

[0135] In the second position of valve 76, valve 76 fluidly couples pump 18 and conduit 12, while discharge reservoir 24 and fluid source reservoir 80 are not fluidly coupled to each other. Therefore, in the second position of valve 76, pump 18 (via discharge reservoir 24) can apply suction force to the inner lumen 26 of conduit 12 and draw fluid from the inner lumen 26 into discharge reservoir 24.

[0136] In some instances, valve 76 is also configured to take a position between a first and a second position. In such an intermediate position, valve 76 is configured to allow some fluid flow from fluid source reservoir 80 to conduit 12 (the fluid flow is less than the fluid flow observed when valve 76 is in its first position), and simultaneously allow some fluid flow from the inner lumen 26 of conduit 12 to discharge reservoir 24 (the fluid flow is less than the fluid flow observed when valve 76 is in its second position).

[0137] Control circuit 72 is configured to control the position of valve 76 using any suitable technology in order to control the amount of suction force applied by pump 18 to the internal lumen 26 of conduit 12. Figure 4 In the example shown, valve 76 is actuated between a first position and a second position, including any intermediate position, based on the amount of current applied to actuator 82 (and / or the signal transmitted to actuator 82). In some instances, actuator 82 may include a solenoid; in this case, valve 76 may be referred to as a solenoid valve. Actuator 82 may alternatively include a linear or rotary actuator, a servo device, a stepper motor, a piezoelectric element, or any other suitable component, or any combination thereof. Control circuitry 72 can control the amount of current applied to actuator 82 (and / or transmit a signal to actuator 82) to modify the position of valve 76.

[0138] In some instances, control circuitry 72 is configured to receive information from sensing circuitry 74 indicating the patient's cardiac cycle, and to control (and / or actuate or initiate) the suction force applied by pump 18 to the internal lumen 26 of catheter 12 based on the position of cardiac cycle-based control valve 76. For example, control circuitry 72 may control whether valve 76 permits fluid communication (and / or the degree of fluid communication) between pump 18 and catheter 12 based on the portion of the cardiac cycle indicated by the received information. As an example, control circuitry 72 may place valve 76 in a first position to close suction during the first portion of the cardiac cycle in response to detecting that the patient is in a first portion of the cardiac cycle (e.g., diastole or systole), and place valve 76 in a second position to open suction during the second portion of the cardiac cycle in response to detecting that the patient is in a second portion of the cardiac cycle (e.g., the other of diastole or systole).

[0139] In other instances, Figure 4 The pulsator used in system 70 may include one or more pinch valves. For example, a first pinch valve is operatively coupled to pipe 20, and a second pinch valve is operatively coupled to pipe 32. Such pinch valves can be used to open and close pipes 20 and 32 at appropriate times according to the control techniques disclosed herein. In a first position of the pulsator, the first pinch valve is open and the second pinch valve is closed, and in a second position of the pulsator, the first pinch valve is closed and the second pinch valve is open. Pipe 32 may be connected to fluid source reservoir 80 with or without flow restrictor 78, or pipe 32 may terminate at an opening to ambient air. A check valve may be operatively coupled to pipe 32 on the side of the second pinch valve opposite to the connection to pipe 20. The first and second pinch valves may be implemented with a common actuator, thereby forming a double-acting pinch valve that alternately opens and closes the first and second pinch valves.

[0140] Figure 5 This is a schematic block diagram of another example of a suction system 90, which is another example of suction systems 10, 40. Therefore, in some instances, system 90 may be structurally and functionally similar to system 10, except for aspects further discussed herein. Suction system 90 includes a conduit 12, a pump 92, a discharge reservoir 94, control circuitry 98, sensing circuitry 98, and suction conduits 102, 100. Pump 92 is fluidly coupled to suction conduit 102, in… Figure 5 In the example shown, the suction conduit extends from the hub of conduit 12 to the inlet of pump 92. Furthermore, pump 92 is fluidly coupled to discharge reservoir 94 via conduit 100, which extends from the outlet of pump 92 to discharge reservoir 94. Discharge reservoir 94 is similar to the reference... Figure 1 The discharge reservoir 94 is not placed between the pump 18 and the conduit 12 (along the fluid flow path between the pump 18 and the conduit 12); the pump 92 is placed between the discharge reservoir 94 and the conduit 12 (along the fluid flow path between the reservoir 94 and the conduit 12). Figure 5 In the example shown, emission storage device 94 is configured to emit into the external environment.

[0141] Pump 92 is Figure 1 An example of pump 18 is shown. Control circuit 96 and sensing circuit 98 are for reference. Figure 2 Examples of the control circuit 42 and sensing circuit 48 described above. Therefore, although... Figure 4 Not shown, but in some instances, the sensing circuit 98 also includes sensors configured to sense physiological parameters indicating the patient's cardiac cycle. Furthermore, although... Figure 5 Not shown in the diagram, but in some instances, the suction system 90 includes a fluid switch 14. Figure 1 ).

[0142] exist Figure 5 In the examples shown, with Figure 4 Compared to the example suction system 70 shown, the control circuit 96 is configured to supplement or replace the position of the control valve 76 by directly controlling the operation of the pump 92. Figure 4The control circuit 96 controls the suction force applied to the catheter 12 by the pump 92. The pump 92 may comprise, for example, a peristaltic pump or a diaphragm pump. The control circuit 96 may use any suitable technique to control the operation of the pump 92 based on the cardiac cycle. In some instances, the control circuit 96 operates the pump 92 in a repetitive cycle consisting of an “on” phase followed by a “off” phase, in which the pump 92 is configured to apply a preset suction force to the internal lumen 26, and in the “off” phase, the pump 92 does not actively apply the preset suction force to the internal lumen 26. For example, the control circuit 96 may be configured to select whether the pump 92 is in the on or off phase based on the current portion of the patient's cardiac cycle indicated by information received from the sensing circuit 98. As an example, the control circuit 96 may control the timing and / or duration of the on and off phases of the pump 92 such that maximum suction force (e.g., maximum suction force within a predetermined suction window for a particular aspiration procedure) is observed at the distal opening 28 of the catheter 12 during diastole or systole.

[0143] The techniques described in this disclosure may be implemented at least partially in hardware, software, firmware, or any combination thereof, including those techniques belonging to control circuits 42, 72, and 96 and sensing circuits 48, 74, and 98, or various constituent components. For example, aspects of the techniques may be implemented within one or more processors, including one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuits, and any combination of such components embodied in programmers such as clinician or patient programmers, medical devices, or other devices. For example, processing circuitry systems, control circuitry systems, and sensing circuitry systems, as well as other processors and controllers described herein, may be implemented at least partially as or include one or more executable applications, application modules, libraries, classes, methods, objects, routines, subroutines, firmware, and / or embedded code. Furthermore, analog circuitry, components, and circuit elements may be used to construct one, some, or all of the control circuits 42, 72, and 96 and sensing circuits 48, 74, and 98 as an alternative to or supplement to the partial or complete digital hardware and / or software described herein. Therefore, analog or digital hardware, or a combination of both, may be employed. Whether implemented digitally, analogally, or in a combination of both, control circuits 42, 72, and 96 may include timing circuitry configured to command the application of suction force in synchronization with the patient's cardiac cycle (via, for example, a command from a pulsator). This can be achieved by sending a command in response to sensing a desired characteristic of the cardiac cycle (or simply in response to a heartbeat), with appropriate time delays incorporated as needed.

[0144] In one or more instances, the functionality described in this disclosure may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may be an article of manufacture comprising a non-transitory computer-readable storage medium encoded with instructions. Instructions embedded or encoded in an article of manufacture comprising an encoded non-transitory computer-readable storage medium may enable one or more programmable processors or other processors to implement one or more of the techniques described herein, for example, when the instructions included or encoded in the non-transitory computer-readable storage medium are executed by one or more processors. Examples of non-transitory computer-readable storage media may include RAM, ROM, programmable ROM (PROM), erasable programmable ROM (EPROM), electronically erasable programmable ROM (EEPROM), flash memory, hard disk, optical disk ROM (CD-ROM), floppy disk, magnetic tape, magnetic media, optical media, or any other computer-readable storage device or tangible computer-readable medium.

[0145] In some instances, computer-readable storage media include non-transitory media. The term "non-transitory" can indicate that the storage media is not implemented in a carrier wave or propagating signal. In some instances, non-transitory storage media can store data that can change over time (e.g., in RAM or cache).

[0146] The functionality described herein can be housed 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. Rather, the functionality associated with one or more modules or units can be performed by separate hardware or software components, or integrated into shared or separate hardware or software components. Similarly, the technology can be implemented entirely within one or more circuit or logic elements.

[0147] Various examples of this disclosure have been described. Consider any combination of the described systems, operations, or functions. These and other examples are within the scope of the appended claims.

Claims

1. A medical aspiration system, comprising: A suction source configured to apply suction force to a catheter to remove thrombi from a patient’s vascular system using the catheter; and A control circuit configured to control the suction force applied to the catheter by the suction source based on the patient's cardiac cycle, thereby altering the suction force at the distal opening of the catheter to facilitate aspiration of thrombi from the vascular system. The control circuit controls the suction source to apply maximum suction force to the inner lumen of the catheter during cardiac diastole, so that the medical aspiration system applies relatively maximum suction force to the thrombus when the blood vessel is relaxed and therefore has less contact with the thrombus; or the control circuit controls the suction source to apply maximum suction force to the inner lumen of the catheter during cardiac systole, so that the medical aspiration system establishes a large pressure differential between the inner lumen of the catheter and the blood vessel.

2. The medical aspiration system of claim 1, wherein the control circuit is configured to control the suction force applied by the aspiration source based on the cardiac cycle by at least the following operations: controlling the aspiration source to apply a first suction force during cardiac diastole, and controlling the aspiration source to apply a second suction force during cardiac systole, wherein the first suction force is different from the second suction force.

3. The medical aspiration system of claim 1, further comprising a sensing circuit configured to generate a signal indicative of the patient's cardiac cycle, wherein the control circuit is configured to receive the signal from the sensing circuit and control the suction force applied to the catheter based on the signal.

4. The medical aspiration system according to claim 3, wherein the signal includes at least one of electrocardiogram, electrogram, photoplethysmography, or blood pressure signal.

5. The medical aspiration system of claim 1, further comprising the catheter fluidly coupled to the aspiration source.

6. The medical aspiration system of claim 1, wherein the control circuit is configured to control the suction force applied to the catheter by the suction source based on the cardiac cycle, at least by cycling the suction source between an on and off phase.

7. The medical aspiration system of claim 1, wherein the control circuit is configured to synchronize the application of the suction force with the cardiac cycle.

8. The medical aspiration system of claim 1, wherein the control circuit is configured to synchronize the application of suction force with a portion of the cardiac cycle, and to synchronize the application of reduced suction force or no suction force with another portion of the cardiac cycle.

9. The medical aspiration system of claim 1, wherein the control circuit is configured to synchronize the application of suction force with a portion of the cardiac cycle and to apply reduced suction force or no suction force during the remainder of the cardiac cycle.

10. The medical aspiration system of claim 1, wherein the aspiration source includes a pulsator, and the control circuitry is configured to control the aspiration force applied by the aspiration source by controlling the pulsator.

11. The medical aspiration system of claim 10, wherein the pulsator comprises a valve.

12. A medical aspiration system, comprising: A suction source configured to apply suction force to a catheter to remove thrombi from a patient’s vascular system using the catheter; and A control circuit is configured to receive a signal from a sensing circuit indicating a patient's cardiac cycle, determine the current portion of the patient's cardiac cycle based on the signal, and control the suction force applied to the catheter by the suction source based on the determined current portion of the cardiac cycle to change the suction force at the distal opening of the catheter, thereby facilitating the aspiration of thrombi from the vascular system. The control circuit controls the suction source to apply maximum suction force to the inner lumen of the catheter during cardiac diastole, so that the medical aspiration system applies relatively maximum suction force to the thrombus when the blood vessel is relaxed and therefore has less contact with the thrombus; or the control circuit controls the suction source to apply maximum suction force to the inner lumen of the catheter during cardiac systole, so that the medical aspiration system establishes a large pressure differential between the inner lumen of the catheter and the blood vessel.

13. The medical aspiration system of claim 12, wherein the control circuitry is configured to control the suction force applied by the aspiration source by at least the following operations: In response to determining that the current portion of the cardiac cycle is diastole, the suction source is controlled to apply a first suction force, and In response to determining that the current portion of the cardiac cycle is a cardiac contraction, the suction source is controlled to apply a second suction force during this period, the first suction force being different from the second suction force.

14. The medical aspiration system of claim 12, wherein the control circuitry is configured to control the suction force applied by the suction source based on the determined current portion of the cardiac cycle by at least the following operations: controlling the suction source to generate a first suction force at the distal opening of the catheter during a first portion of the cardiac cycle, and generating a second suction force at the distal opening of the catheter during a second portion of the cardiac cycle, different from the first portion, the second suction force being greater than the first suction force.

15. The medical aspiration system of claim 12, wherein the signal includes at least one of electrocardiogram, electrogram, photoplethysmography, or blood pressure signal.

16. The medical aspiration system of claim 12, further comprising the catheter fluidly coupled to the aspiration source.

17. The medical aspiration system of claim 12, wherein the control circuitry is configured to control the suction force applied to the catheter by the suction source based on the determined current portion of the cardiac cycle, at least by cycling the suction source between an on and off phase.

18. The medical aspiration system of claim 12, wherein the control circuit is configured to synchronize the application of the suction force with the cardiac cycle.

19. The medical aspiration system of claim 12, wherein the control circuit is configured to synchronize the application of a suction force with a portion of the cardiac cycle, and to synchronize the application of a reduced suction force or the absence of a suction force with another portion of the cardiac cycle.

20. The medical aspiration system of claim 12, wherein the aspiration source includes a pulsator, and the control circuitry is configured to control the aspiration force applied by the aspiration source by controlling the pulsator.

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