Synchronous aspiration system with a catheter sensor for removal of acute occlusions from blood vessels

Abstract

A suction catheter (102) for assisting in the retrieval of blood clots from a patient's blood vessel, comprising at least one electrode pair (202), a first pressure sensor (204) positioned within the lumen of the suction catheter, and second and third pressure sensors (206, 208) positioned on the outer surface of the suction catheter. The electrode pair and the pressure sensors are in electrical communication with a control console. The control console is configured to adjust a suction vacuum pressure waveform pattern applied through the suction catheter based on electrical and pressure inputs from one or more of the sensors and, optionally, based on the patient's blood pressure waveform pattern.

Description

Technical Field

[0001] The present disclosure generally relates to devices and methods for detecting and removing acute occlusions from blood vessels, and more specifically, to aspiration catheters having sensors for assisting in providing direct feedback while removing acute occlusions from blood vessels.

Background Art

[0002] Acute occlusions can include blood clots, misplaced devices, migrated devices, large emboli, and the like. Thromboembolism occurs when part or all of a blood clot detaches from the vessel wall. The blood clot (herein referred to as an embolus) is then carried in the direction of blood flow. If the blood clot remains within the cerebrovascular system, an ischemic stroke may occur. If the blood clot forms within the venous system or the right side of the heart and becomes lodged within the pulmonary artery or its branches, pulmonary embolism may occur. The blood clot can also develop in the form of an embolus without being released and locally occlude a blood vessel, which mechanism is common in the formation of coronary artery occlusions.

[0003] Blood clot retrieval catheters and devices are often used for mechanical thrombectomy for endovascular intervention when a patient is suffering from acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE). Accessing remote regions such as the neurovascular bed is difficult with conventional techniques when the target blood vessel is small in diameter, distant from the insertion site, and highly convoluted.

[0004] Conventional blood clot retrieval catheters, particularly those for use within neurovasculature, lack direct feedback to medical professionals regarding the extent or quality of blood clot capture at the occlusion site. Thus, medical professionals must rely on indirect feedback from the catheter (e.g., if blood is not flowing through the catheter, whether the blood clot is clogging the end of the catheter, if the blood vessel is collapsed, or if the catheter is adhering to the blood vessel wall). SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0005] The disclosed design aims to provide an improved blood clot retrieval catheter that addresses the above-mentioned deficiencies. MEANS FOR SOLVING THE PROBLEM

[0006] The embodiments presented herein include devices and methods for removing acute occlusions from blood vessels during intravascular medical treatment. More specifically, the present disclosure relates to a blood clot retrieval catheter system having sensors to assist in providing direct feedback during intravascular medical treatment. The examples disclosed herein generally aim to provide direct feedback to medical professionals regarding engagement with the blood clot and the hydrodynamics within and around the catheter during catheter delivery, at the occlusion site, during blood clot aspiration, and / or during catheter removal.

[0007] An example of a system for retrieving an occlusion within a blood vessel may comprise an aspiration catheter having at least one pair of electrodes, a first pressure sensor, a second pressure sensor, and a third pressure sensor. The pair of electrodes can be positioned on a first side of a wall defining the lumen of the aspiration catheter. The lumen can extend proximally along a longitudinal axis between a distal tip and a proximal hub. The first pressure sensor can be positioned in a distal portion proximal to the distal tip and within the lumen of the aspiration catheter. The second pressure sensor can be positioned in a distal portion proximal to the distal tip on an opposite side of the wall defining the outer surface of the aspiration catheter. The third pressure sensor can be positioned on the outer surface in a proximal portion of the aspiration catheter.

[0008] In some examples, at least one pair of electrodes may be configured to transmit an electrical input to a control console. The electrical input may include a change in the conductivity of blood or another fluid flowing inside the lumen of the aspiration catheter. When the distal tip of the aspiration catheter is near a blood clot, at least one pair of electrodes may be configured to detect the blood clot within the blood flowing inside the lumen of the aspiration catheter. When the distal tip of the aspiration catheter is engaged with the blood clot, at least one pair of electrodes may be configured to monitor the blood clot as the aspiration catheter moves around the blood vessel.

[0009] In some examples, the first pressure sensor may be configured to transmit a first pressure input to a control console. The second pressure sensor may be configured to transmit a second pressure input to a control console. The third pressure sensor may be configured to transmit a third pressure input to a control console. The first pressure input, the second pressure input, and the third pressure input may be different.

[0010] In some examples, when the distal tip of the aspiration catheter is near a blood clot, the first pressure input and the second pressure input can be combined to generate a pressure measurement of the antegrade flow around the aspiration catheter in the blood vessel.

[0011] In some examples, the control console may be further configured to adjust suction by applying an oscillating vacuum waveform based on pressure inputs from one or more pressure sensors. The control unit may be further configured to adjust suction with respect to the waveform of the patient's blood pressure by applying an oscillating vacuum waveform that is in phase with the patient's blood pressure waveform. The control unit may be further configured to adjust suction with respect to the waveform of the patient's blood pressure by applying an oscillating vacuum waveform that is out of phase with the patient's blood pressure waveform.

[0012] An example of a system for retrieving an occlusion within a blood vessel may include an outer catheter and an inner catheter. The inner catheter may be disposed within the lumen of the outer catheter. The inner catheter may include at least one pair of electrodes, at least one internal pressure sensor, and at least one external pressure sensor. The pair of electrodes may be positioned on the lumen of the inner catheter. The internal pressure sensor may be positioned on the lumen of the inner catheter. The external pressure sensor may be positioned on the outer surface of the inner catheter.

[0013] In some examples, the system may also include a seal positioned on the outer surface of the inner catheter. The seal may be capable of sealing against the lumen of the outer catheter such that suction applied through the outer catheter can be transmitted to the inner catheter.

[0014] The system may further comprise a control console configured to adjust suction. The control console may be configured to adjust suction by applying a vacuum waveform pattern through the inner catheter based on at least one input from at least one electrode pair, at least one internal pressure sensor, or at least one external pressure sensor. The at least one external pressure sensor may be configured to transmit a pressure input correlated to the patient's blood pressure. The control console may be further configured to adjust suction by applying a vacuum waveform pattern in phase with the patient's blood pressure waveform. The control console may be further configured to adjust suction by applying a vacuum waveform pattern out of phase with the patient's blood pressure waveform.

[0015] An example of a method for manufacturing a suction catheter may include positioning a first pressure sensor on the lumen of the distal portion of the suction catheter. The method may include positioning a second pressure sensor on the outer surface of the distal portion of the suction catheter. The method may also include positioning a third pressure sensor on the outer surface of the proximal portion of the suction catheter.

[0016] In some cases, the method may further include detecting, by the first pressure sensor, a pressure change within the lumen of the suction catheter when the suction catheter is engaged with a blood clot in a blood vessel. The method may include detecting, by the second pressure sensor, a pressure change within the blood vessel outside the suction catheter when the suction catheter is engaged with the blood clot. The method may also include generating a pressure measurement of the flow rate around the suction catheter in the blood vessel.

[0017] In some examples, the method may further include applying a vacuum waveform pattern through the suction catheter based on a pressure change from at least one pressure sensor.

[0018] The method may further include positioning at least one pair of electrodes on the lumen of the distal portion of the aspiration catheter. The method may include detecting a change in conductivity of a fluid flowing inside the aspiration catheter when the aspiration catheter is engaged with a blood clot by at least one pair of electrodes.

[0019] For the achievement of the above and related objects, specific exemplary embodiments will be described herein in connection with the following description and the accompanying drawings. However, these embodiments merely illustrate some of the various ways in which the principles of the subject matter of the claims can be used, and the subject matter of the claims is intended to embrace all such embodiments and their equivalents. Other advantages and novel features may become apparent from the following detailed description when considered in conjunction with the drawings.

Brief Description of the Drawings

[0020] The above and further aspects of the present disclosure will be further considered in conjunction with the following description of the accompanying drawings, and in the various drawings, like numerals indicate like structural elements and features. The drawings are not necessarily to scale, and instead, emphasis is placed on illustrating the principles of the present disclosure. The figures depict one or more implementations of the devices of the invention by way of example and not limitation. Those skilled in the art can envision and combine elements from the multiple figures as better suited to the needs of the user.

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DETAILED DESCRIPTION OF THE INVENTION

[0021] The solutions disclosed herein are directed to devices and systems that can provide direct feedback to medical professionals regarding the degree or quality of blood clot capture within a device. Such devices and systems can also provide hydrodynamic feedback in the catheter and blood vessel at multiple points during the process of retrieving a blood clot, including but not limited to during catheter delivery, at the occlusion site, during blood clot aspiration, or during catheter removal. Additionally, such devices and systems can control a suction pump so as to perform an optimized thrombectomy. Controlling the suction process can be based on hydrodynamic feedback measured along the device at various points during the process, including locally at the occlusion site, systemically at a proximal location within the blood vessel, and within the catheter lumen. The hydrodynamic and blood clot capture feedback can provide substantially greater suction efficiency and reduce the risk of embolus migration. Such advantages can be particularly beneficial in the case of stroke intervention procedures where the blood vessels within the neurovascular bed are particularly small and tortuous, and as a result, a blood clot retrieval catheter having sensors that can provide direct feedback and hydrodynamic can increase suction efficiency through the intricate blood vessels.

[0022] These improvements can lead to safe and more rapid access to complex areas of catheters and other devices in order to remove occlusions and shorten treatment times. This specification is often related to mechanical thrombectomy treatment, but the systems and methods can be similarly adapted to other procedures and other body accesses.

[0023] Accessing various blood vessels within the vascular system involves well-known procedural steps and the use of a number of conventional commercially available accessory products, regardless of whether they are coronary arteries, lungs, or the brain. These products, such as angiographic materials, rotary hemostatic valves, and guidewires, are widely used in examination institutions and medical treatments.

[0024] As used in this specification and the appended claims, it should also be noted that the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. References to a composition containing "a" component are intended to include other components in addition to the specified one. Also, when describing preferred embodiments, technical terms are used for clarity. Each term is intended to have its broadest meaning as understood by those skilled in the art and is intended to include all technical equivalents that act in a similar manner to achieve a similar purpose.

[0025] As used herein, terms such as "having", "has", "including", or "includes" are open-ended and are intended to have the same meaning as terms such as "comprising" or "comprises" and do not exclude the existence of other structures, materials, or acts. Similarly, the use of terms such as "can" or "may" is open-ended and is intended to reflect that a structure, material, or act is not necessary, but the non-use of such terms is not intended to reflect that the structure, material, or act is essential. To the extent that a structure, material, or act is considered essential at the present time, it is so identified.

[0026] Various devices and methods are disclosed for providing an electrically actuated blood clot retrieval catheter, and embodiments of the devices and methods will be described with reference to the accompanying drawings.

[0027] FIG. 1A is a pictorial schematic view of a system 100 having an aspiration catheter 102 with a sensor. In the examples described below, the blood clot retrieval system 100 can be used for diagnostic or therapeutic procedures, such as performing a thrombectomy procedure in a patient's blood vessel. Alternatively, the blood clot retrieval system 100 can be used for other therapeutic and / or diagnostic purposes in the brain, heart, or other internal organs of the body.

[0028] System 100 may include a suction catheter 102 for assisting in the retrieval of blood clots from a patient's blood vessels. As described in the description with reference to FIGS. 2A and 2B below, the suction catheter 102 may include at least one electrode pair 202, a first pressure sensor 204, a second pressure sensor 206, and a third pressure sensor 208. During a medical procedure, a medical professional may insert the suction catheter 102 through the patient's vasculature such that the distal tip 108 of the suction catheter 102 approaches the blood clot. When the distal tip 108 engages the blood clot, the medical professional may initiate suction through the catheter 102 to a syringe (not shown) or pump 400. To initiate the execution of suction of the blood clot, the medical professional may manipulate the vacuum pressure and / or pressure waveform pattern of the suction pump 400 based on inputs from the electrode pair 202 and / or the pressure sensors 204, 206, 208 such that the distal tip 108 of the catheter 102 engages the blood clot.

[0029] In the configuration shown in FIGS. 1A and 1B, the control console 200 is connected, as more clearly shown by FIGS. 2A and 2B, by one or more cables 201 to sensors located above and inside the aspiration catheter 102. The control console 200 includes a processor 46, which, in combination with a tracking module 48, can determine the position coordinates of the distal tip 108 and / or the distal portion 110 of the catheter 102 inside the patient. The position coordinates of the distal portion 110 of the catheter 102 can be determined based on the electromagnetic position sensor output signal provided from the distal portion 108 of the catheter 02 when a generated magnetic field is present. The position coordinates can additionally or alternatively be based on the impedance and / or current measured between an adhesive skin patch positioned on the patient and an electrode pair 202 attached to the catheter 102. In addition to being used as a position sensor during a medical procedure, the electrode pair 202 may perform other tasks such as measuring the electrical impedance and / or composition of an object flowing within the catheter 102. Such determination is typically made after a calibration process that associates impedance or current with a known position of the distal portion 110 has been performed. For example, the electrode pair 202 may be configured to detect a signal when a blood clot enters the distal portion 110 of the catheter 102 via electrical impedance and resistivity measurements. A change in the resistivity of plasma is expected to result from a change in the concentration of clotting factors. Additionally, due to the position of the electrode pair 202 in the distal portion 110 of the catheter 102, the time, size, and position of the blood clot can be characterized by a higher local resistivity as the blood clot approaches and passes through the electrode pair 202. As will be understood by those skilled in the art, an increase in fibrin, a prominent component in a blood clot, causes a change in the resistivity of the blood flowing between the electrode pair 202.

[0030] Processor 46 may include a real-time noise reduction circuit 50 typically configured as a field programmable gate array (FPGA), followed by an analog-to-digital (A / D) signal conversion integrated circuit 52. The processor 46 can be programmed to execute one or more algorithms and uses the features of circuits 50 and 52 and modules such that a medical professional can perform the technique of thrombus removal.

[0031] The control console 200 also includes an input / output (I / O) communication interface 54 that enables the control console 200 to send signals to and / or receive signals from one or more electrode pairs 202 and pressure sensors 204, 206, 208. In an exemplary implementation, the communication interface 54 may provide functionality for rendering video, graphics, images, text, other information, or any combination thereof to a display interface 64. In one example, the communication interface 54 may include a serial port, a parallel port, a general-purpose input and output (GPIO) port, a game port, a universal serial bus (USB), a micro USB port, a high-definition multimedia (HDMI) port, a video port, an audio port, a Bluetooth port, a near-field communication (NFC) port, another similar communication interface, or any combination thereof. In one example, the display interface 64 may be operably coupled to a local display such as a touch screen display associated with a mobile device. In another example, the display interface 64 may be configured to provide video, graphics, images, text, other information, or any combination thereof for an external / remote display that is not necessarily connected to a mobile computing device. In one example, a desktop monitor may be utilized to mirror or extend graphical information presented on a mobile device. In another example, the display interface 64 may wirelessly communicate with an external / remote display via a network connection interface such as, for example, a Wi-Fi transceiver.

[0032] In the configuration shown in FIG. 1B, the control console 200 further includes a blood pressure (BP) tracking module 56 and a switching module 58. The BP tracking module 56 may be configured to measure and monitor the systemic blood pressure from a pressure sensor located on the outer surface 106 of the catheter 102 near the patient's internal carotid artery (ICA), as described in more detail below. In some examples, as provided in FIG. 5, the aspiration catheter 102 may be delivered through an outer catheter or a base catheter. The outlet of the outer catheter may be positioned near the ICA such that the pressure sensor on the aspiration catheter 102 (in this example, a therapeutic catheter supported by the base catheter) is outside the base catheter and near the ICA. This pressure sensor can be used in combination with the BP tracking module 56 to adjust the vacuum pump pressure waveform pattern to match the patient's blood pressure waveform (either in-phase or out-of-phase). Alternatively, or in addition, an adhesive skin patch worn by the patient can be used in combination with the BP tracking module 56 to measure the patient's blood pressure and adjust the vacuum pump blood pressure waveform pattern to be either in-phase or out-of-phase with the blood pressure waveform pattern. The BP tracking module 56 may be configured to generate an aspiration pump pressure waveform pattern (e.g., pulsatile aspiration or continuous aspiration) including a rocking waveform, a rectangular waveform, or a linear waveform. In some examples, a pressure sensor can also be used to evaluate the effect of another device, such as a balloon guide catheter or a stentriever, when reducing the antegrade blood pressure in the distal ICA.

[0033] Based on signals received from one or more electrode pairs 202 and / or pressure sensors 204, 206, 208, processor 46 may be configured to generate procedural data 62 indicative of a procedure, such as an overview of a thrombectomy procedure, e.g., whether a clot is engaged, the length and / or composition of a clot in catheter 102, the hydrodynamics within and around catheter 102, or the pressure at the occlusion site. During the procedure, processor 46 may present procedural data 62 to a medical professional on display interface 64 and store data representative of procedural data 62 in memory 66. Memory 66 may include any suitable volatile and / or non-volatile memory, such as random access memory or a hard disk drive.

[0034] In some examples, a medical professional may use one or more input devices 68 to manipulate procedural data 62. In an alternative example, display interface 64 may include a touch screen configured to accept input from a medical professional in addition to presenting any procedural data 62. It should be understood that the user interface may be accessed on various devices (e.g., laptop computers, tablets, etc.) and implemented in various forms. If desired, an implementation of the disclosed technology may include a computing device having more or fewer components than those shown in FIG. 1. It will be understood that the architecture of control console 200 is provided for illustrative purposes only and does not limit the scope of the various implementations of the systems, methods, and computer-readable media of the present disclosure.

[0035] The aspiration pump 400 may be configured to create a suction force that engages with and aids in removing blood clots during a thrombectomy procedure. The aspiration pump 400 may be a centrifugal pump, a rotary pump, a peristaltic pump, a roller pump, or any other suitable form of pump known in the art. In some cases, as described above, the pump 400 may be controlled by the control console 200 via the I / O communication interface 54. The control console 200 may be operated by a medical professional and may adjust the speed, pressure, waveform pattern, or other attributes of the pump 400 during a medical procedure. The control console 200 may receive input from a medical professional and control the pump 400 via the input device 68, or control a separate aspiration pump input via a dial, touch screen, buttons, or levers for adjusting the pump speed or other pump variables. Alternatively, or in addition, the BP tracking module 56 and the switching module 58 may be configured to adjust the speed, pressure, waveform pattern, or other attributes of the pump 400 to match the patient's blood pressure waveform pattern, as described in more detail below. In some examples, the control console 200 and the pump 400 may be integrated as a single device. The pump 400 may be configured to generate a negative (suction) pressure sufficient to aspirate the patient's blood through the aspiration catheter 102 during use. The pump 400 may be capable of generating a negative pressure of from 0 mmHg to about -400 mmHg (e.g., about 0 mmHg to about -350 mmHg, about 0 mmHg to about -300 mmHg, about 0 mmHg to about -250 mmHg, about 0 mmHg to about -200 mmHg, about 0 mmHg to about -150 mmHg, and about 0 mmHg to about -100 mmHg).

[0036] Figure 2A provides a front view of an aspiration catheter 102 having a sensor for assisting in the retrieval of blood clots from a patient's blood vessel. The aspiration catheter 102 may include at least one electrode pair 202, a first pressure sensor 204, a second pressure sensor 206, and a third pressure sensor 208. As shown in Figure 2B, the electrode pair 202 may be positioned on a first side of a wall defining a lumen 104 that extends in a proximal direction along the longitudinal axis L-L of the aspiration catheter 102. The electrode pair 202 may be positioned between the distal tip 108 and the proximal hub 114 (shown in Figure 1). The first pressure sensor 204 may be positioned within the lumen 104 of the aspiration catheter 102 at a distal portion 110 proximal to the distal tip 108. The second pressure sensor 206 may be positioned on the outer surface 106 of the aspiration catheter 102 at a distal portion 110 on one side of the wall facing the lumen 104. The third pressure sensor 208 may also be positioned on the outer surface 106 of the aspiration catheter 102 at a proximal portion 112 proximal to the position of the second pressure sensor. The electrode pair 202 and the pressure sensors 204, 206, 208 may be in electrical communication with a control console 200 (not shown).

[0037] Figure 2B shows a cross-sectional side view of the distal tip 108 of the aspiration catheter 102. As shown, the catheter 102 may include at least one electrode pair 202, a first pressure sensor 204 positioned within the lumen 104, and second and third pressure sensors 206, 208 positioned on the outer surface 106.

[0038] The suction catheter 102 may include any suitable number of electrode pairs 202, such as, for example, three electrode pairs 202 as shown in FIGS. 2A and 2B. In some examples, each electrode of a pair may be positioned facing another electrode pair. As shown in FIG. 2B, the electrode pairs 202 may be positioned in a linear array within the lumen 104 starting near the distal tip 108 and moving proximally toward the proximal portion 112 of the suction catheter 102. Although not shown, the electrode pairs 202 may be offset from adjacent electrode pairs such that a series of electrode pairs are non-linear within the lumen 104. The electrode pairs 202 may be configured to transmit an electrical input from the distal tip 108 of the suction catheter 102 to the control console 200.

[0039] In addition to the electrical input from the lumen 104 at the distal tip 108, a first pressure sensor 204 can be operated using piezoelectric, piezoresistive, and / or piezo-optic effects to measure the internal pressure within the lumen 104. Similarly, second and third pressure sensors 206, 208 can function the same as or similarly to the first pressure sensor 204 to measure the pressure of fluid, tissue from blood vessels, or other external pressure on the outer surface 106 of the catheter 102. Any of the pressure sensors can measure, detect, or monitor the applied pressure and convert the information into an electrical output signal to the control console 200. The pressure sensor may include an internal analog amplifier with an output where either the voltage changes (i.e., ±10 V) or the current changes (i.e., ±1 - 20 mA). In some examples, the pressure sensor may include a digital or USB pressure sensor amplifier. The differential pressure within the catheter 102 and / or within the blood vessel (outside the catheter) can be determined by measuring the pressure difference between two pressure values or two pressure points within the system. The differential pressure can provide information to a medical professional regarding the blood flow either within the blood vessel or within the catheter.

[0040] As will be understood by those skilled in the art, a combination of electrical sensors and pressure sensors along various points of the aspiration catheter can provide direct feedback to medical professionals regarding the engagement of the aspiration catheter with a blood clot. In addition, the hydrodynamics within and around the aspiration catheter can provide insights into how the catheter is occluding within the blood vessel during catheter delivery, at the occlusion site, during aspiration, and / or during removal of the catheter.

[0041] FIG. 3A is a cross-sectional side view of an example of a suction catheter 102 showing one or more electrode pairs 202 in electrical communication with a control console 200. The arrows indicate the current between the electrode pairs. In some examples, the electrode pairs 202 may function by impedance measurement. The electrical connectors inside the wall of the catheter 102 connect to an amplifier within the control console 200 and can provide a simulation voltage to one of the electrodes 202a in the electrode pair 202, and the return electrical connector can provide a response current from a second one of the electrodes 202b in the electrode pair 202. FIG. 3B provides an example of a waveform of a signal measured when an object (of FIG. 3A) passes between the electrode pairs (202a, 202b, and 202c of FIG. 3A). As a blood clot approaches the distal tip 108 of the catheter 102, the current between each of the electrode pairs 202a, 202b, 202c can change such that the waveform of the measured current signal can be directly related to the dielectric properties of the object approaching or passing through the electrode pairs 202a, 202b, 202c. Such a measured current signal can indicate when a blood clot has entered the distal end 108 of the catheter 102 or whether the blood clot is not yet engaged with the catheter 102. Additionally, a series of electrode pairs 202 extending proximally within the lumen 104 of the catheter 102 can inform a medical professional of how many blood clots have entered the catheter 102 and the composition or mechanical properties of such blood clots. In the case of a blood clot disruptor (represented as a dotted shape in FIG. 3A), impedance measurements from the series of electrode pairs 202 can inform a medical professional that the blood clot disruptor has passed through the catheter. When a blood clot is slowly entering the distal tip 108 of the catheter 102, the progress of the blood clot movement can be measured by the series of electrode pairs 202 and feedback can be provided to the medical professional while the progress is taking place. As will be understood by those skilled in the art, real-time feedback on the composition and / or progress of blood clot aspiration during a procedure can save lives.For example, if no advancement is being made or the blood clot is engaging only minimally with the distal tip 108 of the catheter 102, the physician may choose to attempt deployment of the stentriever in combination with aspiration in a different way, such as to better engage the blood clot or to adjust the vacuum pressure or waveform pattern described herein. In some instances, the measured current signal from the electrode pair 202 in combination with the first pressure sensor 204, the second pressure sensor 206, or the third pressure sensor 208 can establish that the blood vessel has collapsed or that the distal end 108 of the catheter 102 has engaged the blood vessel wall rather than the blood clot, and can inform the physician to adjust the path.

[0042] Figures 4A - 4C show that as the clot approaches the catheter 102, fluid can continue to flow within the lumen 104, the hydrodynamics within and around the clot receiving device (Figure 4A), the catheter 102 begins to engage and begins to restrict the flow within the lumen 104 (Figure 4B), and the catheter 102 fully engages such that the flow stops within the lumen 104 (Figure 4C). The first pressure sensor 204 may be located within the lumen 104 along the distal portion 110, and in some cases, near the distal tip 108 of the aspiration catheter 102. The second pressure sensor 206 may similarly be located along the distal portion 110 and / or near the distal tip 108 of the aspiration catheter 102, but on the outer surface 106. The first pressure sensor 204 can be used to measure the pressure of the fluid within the catheter 102 before the clot engages, while the second pressure sensor 206 can measure the pressure of the fluid flowing within the blood vessel. The dashed lines in Figure 4A indicate signals that the first and second pressure sensors 204, 206 can simultaneously transmit to the control console 200 via an I / O communication interface 54 or the like. Comparing the distal internal pressure to the distal external pressure before clot engagement can be useful for establishing the antegrade flow rate around the catheter 102, which can indicate how the catheter is occluding within the blood vessel. In addition to assisting in the measurement of the antegrade flow rate, the first pressure sensor 204 can be used to measure the pressure within the catheter 102 before, during, and after aspiration. Such measurements can provide useful insights to medical professionals regarding whether the clot engages the distal tip 108 as the catheter 102 advances through the blood vessel. Alternatively, or in addition, in the case of remote aspiration before the distal tip 108 of the catheter 102 engages the clot, the vacuum pressure from the aspiration pump 400 is optionally automatically or manually adjusted in combination with the aspiration waveform 60 managed by the control console 200, based on the reading of the first pressure sensor 204 within the lumen 104 of the catheter 102, to prevent the blood vessel from collapsing due to the pressure difference between the catheter 102 and within the blood vessel. Under such remote aspiration, stable movement of the clot in the retrograde direction towards the distal tip 108 of the catheter 102 can be achieved.

[0043] When the catheter 102 approaches the blood clot, the catheter 102 can almost or completely occlude the blood vessel, as shown in FIGS. 4B and 4C respectively. In a nearly occluded state, the first pressure sensor 204 can indicate a decrease in the fluid flow within the lumen 104 of the catheter 102 as compared to the external pressure measured by the second pressure sensor 206. When the catheter 102 is completely occluded by the blood clot, the pressure difference between the internal pressure sensor and the external pressure sensor prevents the first pressure sensor 204 from providing information regarding the blood pressure in the blood vessel and can optionally be shown to the control console 200 to transmit a signal from the second pressure sensor 206.

[0044] During removal of the catheter 102 with the blood clot fully engaged with the distal tip 108, the blood clot may resist removal and begin to slide off the catheter 102. A combination of signals from the electrode pair 202 and the pressure sensors 204, 206, 208 can indicate the retraction of the blood clot as a change in impedance and / or pressure within the lumen 108 of the catheter 102. The control console 200 may warn the medical professional of such an event before the blood clot disengages from the distal tip 108. The warning may indicate to the medical professional to slow down or stop the removal to avoid losing sight of the blood clot.

[0045] Referring back to FIG. 1, the combination of pressure sensors 206, 208 located on the outer surface 106 of catheter 102 along the distal portion 110 and proximal portion 112 can provide signals to the blood pressure tracking module 56 of the control console 200. A third pressure sensor 208 located on the proximal portion 112 of catheter 102 can signal the control console 200 with information regarding the patient's systemic blood pressure when the third pressure sensor 208 is positioned near the patient's internal carotid artery (ICA). Using the information from this third pressure sensor 208, the suction waveform pattern and vacuum pressure from the suction pump 400 can be automatically or manually adjusted via the control console 200 so that they match the patient's blood pressure waveform pattern. In some examples, the suction waveform pattern can be adjusted to be in phase with the patient's blood pressure or out of phase with the patient's blood pressure.

[0046] FIG. 5 provides an exemplary blood clot receiving system 500 having an outer catheter 502 and an inner suction catheter 102 disposed within the lumen of the outer catheter 502. The inner suction catheter 102 may have electrode pairs 202 and pressure sensors 204, 206, 208. In some examples, the system 500 may further include a seal 116 located on the outer surface 106 of the inner catheter 102. The seal may be configured to seal against the lumen of the outer catheter 502 such that suction applied through the outer catheter 502 is transmitted to the inner catheter 102. Although not shown in FIG. 5, the system 500 may also include a control console 200 connected to the electrode pairs and pressure sensors as described herein. When the third pressure sensor 208 is located on the outer surface 106 within the proximal portion 112 of the inner catheter 102 but outside the outer catheter 502, the third pressure sensor 208 can provide information regarding the effect on the antegrade blood pressure near the ICA when additional devices such as a balloon guide catheter or stentriever are used.

[0047] FIG. 6 is a flowchart illustrating a method 600 of manufacturing a blood clot retrieval system. Method 600 may include positioning a first pressure sensor on the lumen of the distal portion of the aspiration catheter (602). Method 600 may further include positioning a second pressure sensor on the outer surface of the distal portion of the aspiration catheter (604a). Method 600 may include positioning a third pressure sensor on the outer surface of the proximal portion of the aspiration catheter (606). Method 600 may further include positioning at least one pair of electrodes on the lumen of the distal portion of the aspiration catheter, which may be transmitted in step 606 (608).

[0048] As will be appreciated by those skilled in the art, method 600 may include any of the various features of the disclosed techniques described herein and may be varied depending on the particular configuration. In some examples, a method of using a catheter manufactured by method 600 may include positioning the aspiration catheter near a blood clot in a blood vessel, aligning the third pressure sensor of the aspiration catheter with the outlet of the outer catheter, equalizing the third pressure input with the waveform of the patient's blood pressure, and applying an aspiration waveform equal to the waveform of the patient's blood pressure through the aspiration catheter.

[0049] Although the present disclosure has been described in connection with a plurality of exemplary aspects as shown in the various figures and discussed above, it is understood that other similar aspects may be used or modifications and additions may be made to the described aspects without departing from the present disclosure so as to perform the same functions as the present disclosure.

[0050] Some implementations of the disclosed technology have been described above with reference to block diagrams and flow diagrams of systems and methods and / or computer program products according to example implementations of the disclosed technology. It will be understood that one or more blocks of the block diagrams and flow diagrams, as well as combinations of blocks in the block diagrams and flow diagrams respectively, can be implemented by computer-executable program instructions. Similarly, some blocks of the block diagrams and flow diagrams may not necessarily be executed in the order presented, or in some implementations of the disclosed technology, may not necessarily be executed at all.

[0051] These computer-executable program instructions can be loaded onto a general-purpose computer, a special-purpose computer, a processor, or other programmable data processing apparatus to create a machine, and the instructions executed on the computer, processor, or other programmable data processing apparatus create means for implementing one or more functions specified in one or more blocks of the flow diagram. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means for implementing one or more functions specified in one or more flow diagram blocks.

[0052] Embodiments of the disclosed technology can provide a computer program product having a computer-readable program code or a computer-usable medium in which program instructions are embodied, and the computer-readable program code is adapted to be executed to implement one or more functions specified in one or more blocks of the flowchart. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus, and a computer-implemented process may be created by a series of operational elements or steps being executed on the computer or other programmable data processing apparatus, and those instructions executed on the computer or other programmable apparatus provide elements or steps for implementing the functions specified in the blocks of the flowchart.

[0053] Accordingly, it will be understood that the blocks of the block diagrams and the flowchart correspond to combinations of means for performing the specified functions, combinations of elements or steps for performing the specified functions, and means of program instructions for performing the specified functions. It will also be understood that each block of the block diagrams and the flowchart, and combinations of blocks of the block diagrams and the flowchart, can be implemented by a dedicated hardware-based computer system for performing the specified functions, elements or steps, or by a combination of dedicated hardware and computer instructions.

[0054] As described above, specific embodiments of the present invention have been illustrated and described, but it will be apparent from the above description that various changes can be made without departing from the spirit and scope of the present invention. For example, although the embodiments described herein refer to specific features, the present invention includes embodiments having combinations of different features. The present invention also includes embodiments that do not include all of the specific features described. The present invention is not limited to the embodiments that can vary in configuration and details as described hereinabove.

[0055] 〔Embodiments〕 (1) A suction catheter for assisting in the retrieval of blood clots from a patient's blood vessel, wherein the suction catheter comprises: At least one pair of electrodes positioned on a first side of a wall defining the lumen of the suction catheter, the lumen extending proximally along a longitudinal axis between a distal tip and a proximal hub, the at least one pair of electrodes; A first pressure sensor positioned proximal to the distal tip and within the lumen of the suction catheter; A second pressure sensor positioned proximal to the distal tip on an opposite side of the wall defining the outer surface of the suction catheter; And a third pressure sensor positioned on the outer surface at the proximal portion of the suction catheter. (2) The suction catheter according to embodiment 1, wherein the at least one pair of electrodes is configured to transmit an electrical input to a control console, the electrical input including a change in conductivity of a fluid flowing inside the lumen of the suction catheter. (3) The suction catheter according to embodiment 2, wherein when the distal tip of the suction catheter is near the blood clot, the at least one pair of electrodes is configured to detect the blood clot within the fluid flowing inside the lumen of the suction catheter. (4) The suction catheter according to embodiment 1, wherein when the distal tip of the suction catheter is engaged with the blood clot, the at least one pair of electrodes is configured to monitor the blood clot as the suction catheter moves around the blood vessel. (5) The first pressure sensor is configured to transmit a first pressure input to a control console, The second pressure sensor is configured to transmit a second pressure input to the control console, The third pressure sensor is configured to transmit a third pressure input to the control console, and the first pressure input, the second pressure input, and the third pressure input are different. The suction catheter according to embodiment 1.

[0056] (6) When the distal tip of the aspiration catheter is near the blood clot, the first pressure input and the second pressure input are combined to generate a pressure measurement value of the anterograde flow rate around the aspiration catheter in the blood vessel, the aspiration catheter according to embodiment 5. (7) The control console is further configured to adjust aspiration by applying an oscillating vacuum waveform based on pressure inputs from one or more pressure sensors, the aspiration catheter according to embodiment 5. (8) The control console is further configured to adjust aspiration with respect to the waveform of the patient's blood pressure by applying an oscillating vacuum waveform in phase with the patient's blood pressure waveform, the aspiration catheter according to embodiment 5. (9) The control console is further configured to adjust aspiration with respect to the waveform of the patient's blood pressure by applying an oscillating vacuum waveform out of phase with the patient's blood pressure waveform, the aspiration catheter according to embodiment 5. (10) A system for assisting in the retrieval of blood clots from a patient's blood vessel, the system comprising an outer catheter, and an inner catheter disposed within the lumen of the outer catheter, the inner catheter comprising at least one pair of electrodes positioned on the lumen of the inner catheter, and at least one internal pressure sensor positioned on the lumen of the inner catheter, and at least one external pressure sensor positioned on the outer surface of the inner catheter, a system.

[0057] (11) Further comprising a sealing portion positioned on the outer surface of the inner catheter, the sealing portion being capable of sealing against the lumen of the outer catheter such that aspiration applied through the outer catheter is transmitted to the inner catheter, the system according to embodiment 10. The system of embodiment 10, further comprising a control console configured to adjust suction by applying a vacuum waveform pattern through the inner catheter based on at least one input from the at least one electrode pair, the at least one internal pressure sensor, or the at least one external pressure sensor. The system of embodiment 12, wherein the at least one external pressure sensor is configured to transmit a pressure input correlated with the blood pressure of the patient. The system of embodiment 13, wherein the control console is further configured to adjust the suction by applying a vacuum waveform pattern in phase with the blood pressure waveform of the patient. The system of embodiment 13, wherein the control console is further configured to adjust the suction by applying a vacuum waveform pattern out of phase with the blood pressure waveform of the patient.

[0058] A method for manufacturing a suction catheter, the method comprising: positioning a first pressure sensor on the lumen of the distal portion of the suction catheter; positioning a second pressure sensor on the outer surface of the distal portion of the suction catheter; positioning a third pressure sensor on the outer surface of the proximal portion of the suction catheter. The method of embodiment 16, further comprising detecting, by the first pressure sensor, a pressure change within the lumen of the suction catheter when the suction catheter is engaged with a blood clot in a blood vessel; detecting, by the second pressure sensor, a pressure change within the blood vessel outside the suction catheter when the suction catheter is engaged with the blood clot; generating a pressure measurement of a flow rate around the suction catheter in the blood vessel. The method of embodiment 17, further comprising applying a vacuum waveform pattern through the suction catheter based on the pressure change from at least one pressure sensor. The method according to embodiment 16, further comprising positioning at least one electrode pair on the inner lumen of the distal portion of the aspiration catheter. The method according to embodiment 19, further comprising detecting a change in conductivity of a fluid flowing inside the aspiration catheter when the aspiration catheter is engaged with a blood clot by the at least one electrode pair.

Claims

1. A suction catheter for assisting in the retrieval of blood clots from a patient's blood vessel, the suction catheter comprising: at least one pair of electrodes positioned on a first side of a wall defining the lumen of the suction catheter, the lumen extending proximally along a longitudinal axis between a distal tip and a proximal hub, the at least one pair of electrodes; a first pressure sensor positioned proximal to the distal tip and within the lumen of the suction catheter; a second pressure sensor positioned proximal to the distal tip on an opposite side of the wall defining the outer surface of the suction catheter; and a third pressure sensor positioned on the outer surface at the proximal portion of the suction catheter.

2. The suction catheter according to claim 1, wherein the at least one pair of electrodes is configured to transmit an electrical input to a control console, the electrical input including a change in the conductivity of a fluid flowing inside the lumen of the suction catheter.

3. The suction catheter according to claim 2, wherein when the distal tip of the suction catheter is near the blood clot, the at least one pair of electrodes is configured to detect the blood clot in the fluid flowing inside the lumen of the suction catheter.

4. The suction catheter according to claim 1, wherein when the distal tip of the suction catheter is engaged with the blood clot, the at least one pair of electrodes is configured to monitor the blood clot as the suction catheter moves around the blood vessel.

5. The first pressure sensor is configured to transmit a first pressure input to a control console; The second pressure sensor is configured to transmit a second pressure input to the control console; The third pressure sensor is configured to transmit a third pressure input to the control console, and the first pressure input, the second pressure input, and the third pressure input are different. The suction catheter according to claim 1.

6. The suction catheter according to claim 5, wherein when the distal tip of the suction catheter is near the blood clot, the first pressure input and the second pressure input are combined to generate a pressure measurement of the antegrade flow rate around the suction catheter in the blood vessel.

7. The aspiration catheter according to claim 5, wherein the control console is further configured to adjust aspiration by applying an oscillating vacuum waveform based on a pressure input from one or more pressure sensors.

8. The aspiration catheter according to claim 5, wherein the control console is further configured to adjust aspiration with respect to the waveform of the patient's blood pressure by applying an oscillating vacuum waveform in phase with the blood pressure waveform of the patient.

9. The aspiration catheter according to claim 5, wherein the control console is further configured to adjust aspiration with respect to the waveform of the patient's blood pressure by applying an oscillating vacuum waveform out of phase with the blood pressure waveform of the patient.

10. A system for assisting in the retrieval of blood clots from a patient's blood vessel, the system comprising: an outer catheter; an inner catheter disposed within the lumen of the outer catheter, the inner catheter comprising: at least one pair of electrodes positioned on the lumen of the inner catheter; at least one internal pressure sensor positioned on the lumen of the inner catheter; at least one external pressure sensor positioned on the outer surface of the inner catheter.

11. The system according to claim 10, further comprising a sealing portion located on the outer surface of the inner catheter, the sealing portion being capable of sealing against the lumen of the outer catheter such that aspiration applied through the outer catheter is transmitted to the inner catheter.

12. The system according to claim 10, further comprising a control console configured to adjust aspiration by applying a vacuum waveform pattern through the inner catheter based on at least one input from the at least one pair of electrodes, the at least one internal pressure sensor, or the at least one external pressure sensor.

13. The system according to claim 12, wherein the at least one external pressure sensor is configured to transmit a pressure input correlated with the blood pressure of the patient.

14. The system according to claim 13, wherein the control console is further configured to adjust the aspiration by applying a vacuum waveform pattern in phase with the blood pressure waveform of the patient.

15. The system of claim 13, wherein the control console is further configured to adjust the suction by applying a vacuum waveform pattern that is out of phase with the patient's blood pressure waveform. **Claim 16** A method for manufacturing a suction catheter, the method comprising: positioning a first pressure sensor on the lumen of the distal portion of the suction catheter; positioning a second pressure sensor on the outer surface of the distal portion of the suction catheter; positioning a third pressure sensor on the outer surface of the proximal portion of the suction catheter. **Claim 17** detecting, by the first pressure sensor, a pressure change within the lumen of the suction catheter when the suction catheter is engaged with a blood clot in a blood vessel; detecting, by the second pressure sensor, a pressure change within the blood vessel outside the suction catheter when the suction catheter is engaged with the blood clot; generating a pressure measurement of a flow rate around the suction catheter in the blood vessel. The method of claim 16 further comprising. **Claim 18** The method of claim 17, further comprising applying a vacuum waveform pattern through the suction catheter based on the pressure change from at least one pressure sensor. **Claim 19** The method of claim 16, further comprising positioning at least one pair of electrodes on the lumen of the distal portion of the suction catheter. **Claim 20** The method of claim 19, further comprising detecting, by the at least one pair of electrodes, a change in conductivity of a fluid flowing inside the suction catheter when the suction catheter is engaged with a blood clot.

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