Synchronous aspiration system with catheter sensor for removing acute obstructions from blood vessels

Abstract

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

Description

Technical Field

[0001] The present disclosure relates generally to devices and methods for detecting and removing acute obstructions from a blood vessel, and more particularly to an aspiration catheter having a sensor that helps provide direct feedback when removing an acute obstruction from a blood vessel. Background Art

[0002] Acute obstructions may include clots, misplaced devices, migrating devices, large emboli, etc. Thromboembolism occurs when part or all of a thrombus breaks away from the vessel wall. The clot (now called an embolus) is then transported in the direction of blood flow. If the clot is lodged in a cerebral vessel, it may cause an ischemic stroke. If the clot originates from the venous system or the right side of the heart and lodges in the pulmonary artery or its branches, it may cause a pulmonary embolism. The clot may also not be released in the form of an embolism, but instead form locally and block the vessel, a mechanism that is more common in the formation of coronary artery blockages.

[0003] Clot retrieval catheters and devices are frequently used in mechanical thrombectomy for endovascular intervention in patients with acute ischemic stroke (AIS), myocardial infarction (MI), and pulmonary embolism (PE). Accessing distant areas, such as neurovascular beds, is challenging using conventional techniques because the target vessels are small in diameter, distant relative to the insertion site, and highly tortuous.

[0004] Conventional clot retrieval catheters, particularly those used to operate in neurovascular vessels, lack direct feedback to the medical professional regarding the extent or quality of clot entrapment at the occlusion site, so the medical professional must make assumptions based on indirect feedback from the catheter (e.g., if no blood is moving through the catheter, whether the clot is stuck at the end of the catheter, whether the vessel is collapsed, or whether the catheter is attached to the vessel wall).

[0005] The design disclosed in the present invention aims to provide an improved clot retrieval catheter that solves the above-mentioned deficiencies. Summary of the invention

[0006] Examples presented herein include devices and methods for removing acute obstructions from a blood vessel during endovascular medical treatment. More specifically, the present disclosure relates to a clot retrieval catheter system having sensors that help provide direct feedback during endovascular medical treatment. Examples disclosed herein are generally intended to provide medical professionals with direct feedback regarding engagement with a clot during catheter delivery, at the site of an occlusion, during aspiration of a clot, and / or during withdrawal of a catheter, as well as fluid dynamics in and around the catheter.

[0007] An exemplary system for retrieving an obstruction in a blood vessel may include a suction catheter having at least one electrode pair, a first pressure sensor, a second pressure sensor, and a third pressure sensor. The electrode pair may be positioned on a first side of a wall that defines an inner lumen of the suction catheter. The inner lumen may extend proximally between a distal tip and a proximal hub along a longitudinal axis. The first pressure sensor may be positioned at a distal portion near the distal tip and within the inner lumen of the suction catheter. The second pressure sensor may be positioned at a distal portion near the distal tip on an opposite side of the wall that defines an outer surface of the suction catheter. The third pressure sensor may be positioned on the outer surface at a proximal portion of the suction catheter.

[0008] In some examples, at least one electrode pair may be configured to transmit an electrical input to a console. The electrical input may include a change in the conductivity of blood or another fluid flowing within the inner lumen of the aspiration catheter. When the distal tip of the aspiration catheter approaches the clot, at least one electrode pair may be configured to detect the clot within the blood flowing within the inner lumen of the aspiration catheter. When the distal tip of the aspiration catheter engages the clot, at least one electrode pair may be configured to monitor the 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 the console. The second pressure sensor may be configured to transmit a second pressure input to the console. The third pressure sensor may be configured to transmit a third pressure input to the console. The first pressure input, the second pressure input, and the third pressure input may be different.

[0010] In some examples, the first pressure input and the second pressure input may together generate a pressure measurement of antegrade flow rate around the aspiration catheter in the blood vessel as the distal tip of the aspiration catheter approaches a clot.

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

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

[0013] In some examples, the system can further include a seal located on an outer surface of the inner catheter. The seal can be configured to seal against the lumen of the outer catheter so that suction applied through the outer catheter can be transmitted to the inner catheter.

[0014] The system may also include a console configured to regulate suction. The console may regulate suction by applying a vacuum waveform pattern via 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 related to the patient's blood pressure. The console may also be configured to regulate suction by applying a vacuum waveform pattern that is in phase with the patient's blood pressure waveform. The console may also be configured to regulate suction by applying a vacuum waveform pattern that is out of phase with the patient's blood pressure waveform.

[0015] An exemplary method for manufacturing an aspiration catheter may include positioning a first pressure sensor on an internal lumen of a distal portion of the aspiration catheter. The method may include positioning a second pressure sensor on an external surface of the distal portion of the aspiration catheter. The method may also include positioning a third pressure sensor on an external surface of a proximal portion of the aspiration catheter.

[0016] In some cases, the method may further include detecting a pressure change within an interior lumen of the aspiration catheter via a first pressure sensor when the aspiration catheter engages a clot in the blood vessel. The method may include detecting a pressure change within a blood vessel outside of the aspiration catheter via a second pressure sensor when the aspiration catheter engages a clot. The method may further include generating a pressure measurement of a flow rate around the aspiration catheter in the blood vessel.

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

[0018] The method may further include positioning at least one electrode pair on an interior lumen of a distal portion of the aspiration catheter. The method may include detecting a change in conductivity of a fluid flowing within the aspiration catheter by the at least one electrode pair when the aspiration catheter engages the clot.

[0019] To achieve the above and related purposes, certain exemplary aspects are described herein in conjunction with the following description and accompanying drawings. However, these aspects are merely indicative of some of the various ways in which the principles of the claimed subject matter may be employed, and the claimed subject matter is intended to include all such aspects and their equivalents. Other advantages and novel features will become apparent from the following detailed description when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other aspects of the present disclosure will be further discussed through the following description of the accompanying drawings, in which the same numbers indicate the same structural elements and features in the various figures. The accompanying drawings are not necessarily drawn to scale, but the emphasis is placed on illustrating the principles of the present disclosure. The accompanying drawings depict one or more specific implementations of the device of the present invention only by way of example and not by way of limitation. It is expected that those skilled in the art will be able to conceive and combine elements from multiple drawings to better meet the needs of the user.

[0021] Figure 1A is a schematic diagram of an exemplary clot retrieval system having an aspiration catheter with a sensor, a sensor console, and an aspiration pump according to aspects of the present disclosure.

[0022] Figure 1B is a block diagram of an illustrative computer system architecture of an exemplary clot retrieval system 200 in accordance with aspects of the present disclosure.

[0023] Figure 2A An elevation view of the distal tip of an exemplary clot receiving device showing an inner electrode is shown in accordance with aspects of the present disclosure.

[0024] Figure 2B A cross-sectional side view of an exemplary clot retrieval system according to aspects of the present disclosure is shown.

[0025] Figure 3A Cross-sectional side views of exemplary clot-receiving devices according to aspects of the present disclosure are provided.

[0026] Figure 3B According to various aspects of the present disclosure, when an object passes between the electrode pairs, Figure 3A An exemplary waveform of a measurement signal.

[0027] FIG. 4A to FIG. 4C Shown is a side view of an exemplary clot-receiving device and the fluid dynamics in and around the device according to aspects of the present disclosure.

[0028] Figure 5 An exemplary clot receiving system having an outer catheter and an inner aspiration catheter with a sensor is shown in accordance with aspects of the present disclosure.

[0029] Figure 6 is a flow chart illustrating a method of making a clot retrieval system according to aspects of the present disclosure. DETAILED DESCRIPTION

[0030] The solution disclosed herein relates to a device and system that can provide direct feedback to medical professionals about the degree or quality of clot entrapment in the device. Such devices and systems can also provide fluid dynamics feedback at multiple points in the catheter and blood vessels during the process of retrieving the clot, including but not limited to during catheter delivery, at the occlusion site, during the aspiration of the clot, or during the withdrawal of the catheter. Additionally, such devices and systems can control the suction pump so that optimized thrombectomy can be performed. The control of the suction process can be based on fluid dynamics feedback measured along the device at different points during the process, including locally at the occlusion site, systemically at the proximal position in the blood vessel, and in the catheter lumen. Fluid dynamics and clot entrapment feedback can provide significantly higher suction efficiency and reduce the risk of embolus migration. Such advantages are also particularly beneficial in stroke intervention surgery, where the blood vessels in the neurovascular bed are particularly small and tortuous, so the clot retrieval catheter with a sensor can provide direct feedback and fluid dynamics through tortuous blood vessels, thereby improving suction efficiency.

[0031] These improvements can lead to safer and faster access of catheters and other devices to complex areas to remove obstructions and reduce procedure time.While the present description is in many cases in the context of mechanical thrombectomy treatments, the systems and methods may also be applicable to other procedures and other body passages.

[0032] Accessing the various vessels within the vascular system, whether coronary, pulmonary or cerebral, involves well-known surgical procedures and the use of many conventional, commercially available ancillary products. These products, such as angiographic materials, rotary hemostatic valves and guidewires, are widely used in laboratories and medical procedures.

[0033] It should also be noted that the singular forms "a", "an", and "the" used in this specification and the appended claims include plural referents unless the context clearly indicates otherwise. Reference to a composition containing "an" ingredient is intended to include other ingredients in addition to the mentioned ingredient. Moreover, in describing the preferred embodiments, terminology will be employed for the sake of clarity. It is intended that each term contemplate its broadest meaning as understood by those skilled in the art, and includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.

[0034] Here, the use of terms such as "having", "including" is open ended and is intended to have the same meaning as terms such as "comprising" and does not exclude the presence of other structures, materials, or actions. Similarly, although the use of terms such as "may" or "may" is intended to be open ended and reflect that structures, materials, or actions are not required, the failure to use such terms is not intended to reflect that structures, materials, or actions are required. To the extent that structures, materials, or actions are presently considered to be required, they are identified as such.

[0035] Various devices and methods for providing an electrically actuated clot retrieval catheter are disclosed, examples of which will now be described with reference to the accompanying figures.

[0036] Figure 1A 1 is a schematic diagram of a system 100 having an aspiration catheter 102 with a sensor. In the examples described below, the clot retrieval system 100 can be used for diagnostic or therapeutic treatments, such as for performing a thrombectomy procedure in a patient's blood vessel. Alternatively, the clot retrieval system 100 can be used for other therapeutic and / or diagnostic purposes in the brain, heart, or other body organs.

[0037] The system 100 may include an aspiration catheter 102 for assisting in retrieving a clot 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 described below with reference to Figure 2A and Figure 2B During a medical procedure, a medical professional may insert the aspiration catheter 102 through the patient's vascular system so that the distal tip 108 of the aspiration catheter 102 is proximate to a clot. When the distal tip 108 engages with the clot, the medical professional may initiate aspiration through the catheter 102 into a syringe (not shown) or pump 400. To begin aspiration of the clot, the medical professional may manipulate the vacuum pressure and / or pressure waveform pattern of the aspiration pump 400 based on input from the electrode pair 202 and / or pressure sensors 204, 206, 208 so that the distal tip 108 of the catheter 102 engages with the clot.

[0038] exist Figure 1A and Figure 1B In the configuration shown, the console 200 is connected to sensors positioned on and within the suction catheter 102 via one or more cables 201, such as Figure 2A and Figure 2B. The console 200 includes a processor 46 that, in combination with the tracking module 48, can determine the position coordinates of the distal tip 108 and / or the distal portion 110 of the catheter 102 within the patient's body. When there is a generated magnetic field, 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. Additionally or alternatively, the position coordinates can be based on the impedance and / or current measured between the adhesive skin patch positioned on the patient and the electrode pair 202 attached to the catheter 102. In addition to being used as a position sensor during medical surgery, the electrode pair 202 can also perform other tasks, such as electrical impedance measurement and / or composition measurement of objects flowing within the catheter 102. Such determinations are usually performed after a calibration process that associates the impedance or current with a known position of the distal portion 110 has been performed. For example, through electrical impedance and resistivity measurements, the electrode pair 202 can be configured to detect a signal when a clot enters the distal portion 110 of the catheter 102. Due to changes in the concentration of coagulation factors, changes in plasma resistivity are expected. In addition, due to the location of the electrode pair 202 at the distal portion 110 of the catheter 102, the timing, size, and location of the clot can be characterized by a higher local resistivity as the clot approaches and passes through the electrode pair 202. As will be appreciated by those skilled in the art, an increase in fibrin (a major component in a thrombus) will result in a change in the resistivity of the blood flowing between the electrode pair 202.

[0039] Processor 46 may include real-time noise reduction circuitry 50, typically configured as a field programmable gate array (FPGA), and analog-to-digital (A / D) signal conversion integrated circuit 52. Processor 46 may be programmed to execute one or more algorithms and use features of circuitry 50 and 52 and modules to enable a medical professional to perform a thrombectomy procedure.

[0040] The console 200 also includes an input / output (I / O) communication interface 54 that enables the console 200 to transmit signals from and / or to one or more electrode pairs 202 and pressure sensors 204, 206, 208. In an exemplary embodiment, the communication interface 54 may provide functionality for presenting video, graphics, images, text, other information, or any combination thereof on 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 to an external / remote display that is not necessarily connected to a mobile computing device. In one example, a desktop monitor may be used to mirror or extend graphical information that may be presented on a mobile device. In another example, display interface 64 may wirelessly communicate with an external / remote display, for example via a network connection interface such as a Wi-Fi transceiver.

[0041] exist Figure 1B In the configuration shown, the console 200 additionally includes a blood pressure (BP) tracking module 56 and a switching module 58. The BP tracking module 56 can be configured to measure and monitor systemic blood pressure from a pressure sensor positioned on an 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 described in more detail below, Figure 5 As provided in , the suction catheter 102 can be delivered through an outer catheter or a base catheter. The outlet of the outer catheter can be positioned near the ICA so that the pressure sensor on the suction catheter 102 (in this example, a treatment catheter supported by the base catheter) is outside the base catheter and close to the ICA. The pressure sensor can be used in conjunction with the BP tracking module 56 to adjust the vacuum pump pressure waveform pattern so that it matches (in phase or out of phase) the patient's blood pressure waveform. Alternatively, or in addition, an adhesive skin patch worn by the patient can be used in conjunction with the BP tracking module 56 to measure the patient's blood pressure and adjust the vacuum pump pressure waveform pattern to be in phase or out of phase with the blood pressure waveform pattern. The BP tracking module 56 can be configured to generate a suction pump pressure waveform pattern, including an oscillating waveform, a square wave, or a linear waveform (e.g., pulsed suction or continuous suction). In some examples, the pressure sensor can also be used to evaluate the effect of another device (such as a balloon guide catheter or a stent) in reducing the antegrade blood pressure in the distal ICA.

[0042] Based on the signals received from one or more electrode pairs 202 and / or pressure sensors 204, 206, 208, the processor 46 may be configured to generate procedure data 62 indicative of a procedure, such as a summary of the thrombectomy procedure, for example, whether a clot was engaged, the length and / or composition of the clot in the catheter 102, the fluid dynamics in and around the catheter 102, or the pressure at the occlusion site. During the procedure, the processor 46 may present the procedure data 62 to a medical professional on a display interface 64 and store data representing the procedure data 62 in a memory 66. The memory 66 may include any suitable volatile memory and / or non-volatile memory, such as a random access memory or a hard drive.

[0043] In some examples, the medical professional can manipulate the program data 62 using one or more input devices 68. In an alternative example, the display interface 64 may include a touch screen that can be configured to accept input from the medical professional in addition to presenting any program data 62. It should be understood that the user interface can be accessed on a variety of devices (e.g., a laptop computer, a tablet computer, etc.) and embodied in various forms. As desired, embodiments of the disclosed technology may include a computing device having more or less of the components shown in Figure 1. It should be understood that the architecture of the console 200 is provided for exemplary purposes only and does not limit the scope of various embodiments of the systems, methods, and computer-readable media disclosed herein.

[0044] The suction pump 400 may be configured to generate suction to help engage and remove clots during a thrombectomy procedure. The suction pump 400 may be a centrifugal pump, a rotary pump, a peristaltic pump, a roller pump, or other suitable forms of pumps known in the art. In some cases, as described above, the pump 400 may be controlled by the console 200 via the I / O communication interface 54. The console 200 may be operated by a medical professional to adjust the speed, pressure, waveform pattern, or other properties of the pump 400 during a medical procedure. The console 200 may receive input from a medical professional via an input device 68 to control the pump 400, or control the pump based on a separate suction pump input via a dial, touch screen, button, or lever for adjusting the pump speed or another pump variable. 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 properties of the pump 400 to match the speed, pressure, waveform pattern, or other properties of the patient's blood pressure waveform pattern, as will be described in more detail below. In some examples, the console 200 and the pump 400 may be integrated into a single device. The pump 400 may be configured to generate a negative (suction) pressure sufficient to draw a patient's blood during use through the suction conduit 102. The pump 400 may be capable of generating a negative pressure of 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).

[0045] Figure 2A A front view of an aspiration catheter 102 with sensors is provided, the aspiration catheter being used to assist in retrieving a clot 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. Figure 2B As shown, the electrode pair 202 may be positioned on a first side of the wall that defines an inner lumen 104 extending proximally along the longitudinal axis LL of the suction catheter 102. The electrode pair 202 may be positioned between the distal tip 108 and the proximal hub 114 (shown in FIG. 1). The first pressure sensor 204 may be positioned within the inner lumen 104 of the suction catheter 102, at a distal portion 110 near the distal tip 108. The second pressure sensor 206 may be positioned at a distal portion 110 on the outer surface 106 of the suction catheter 102 on the side of the wall opposite to the inner lumen 104. The third pressure sensor 208 may also be positioned on the outer surface 106 of the suction catheter 102, and at a proximal portion 112 near the location of the second pressure sensor. The electrode pair 202 and the pressure sensors 204, 206, 208 may be electrically connected to the console 200 (not shown).

[0046] Figure 2B A cross-sectional side view of the distal tip 108 of the aspiration catheter 102 is shown. As shown, the catheter 102 may include at least one electrode pair 202 and a first pressure sensor 204 positioned within the inner lumen 104 and a second pressure sensor 206 and a third pressure sensor 208 positioned on the exterior surface 106.

[0047] The suction catheter 102 may include any suitable number of electrode pairs 202, such as Figure 2A and Figure 2B Three electrode pairs 202 are depicted. In some examples, each electrode in a pair of electrodes can be positioned facing another electrode pair. Figure 2B As shown, the electrode pairs 202 can be positioned in a linear series within the inner lumen 104, starting near the distal tip 108 and proceeding proximally toward the proximal portion 112 of the aspiration catheter 102. Although not depicted, the electrode pairs 202 can be offset from adjacent electrode pairs so that the series of electrode pairs is non-linear within the inner lumen 104. The electrode pairs 202 can be configured to transmit electrical input from the distal tip 108 of the aspiration catheter 102 to the console 200.

[0048] In addition to the electrical input from the inner lumen 104 of the distal tip 108, the first pressure sensor 204 can operate using piezoelectric, piezoresistive and / or piezo-optical effects to measure the internal pressure within the inner lumen 104. Similarly, the second pressure sensor 206 and the third pressure sensor 208 can play the same or similar role as the first pressure sensor 204 to measure the pressure of the blood vessel based on the fluid, tissue 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 console 200. The pressure sensor may include an internal analog amplifier with a voltage change, i.e., + / -10V, or a current change, i.e., + / -1mA-20mA output. In some examples, the pressure sensor may include a digital or USB pressure sensor amplifier. The pressure difference 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 in the system. The pressure difference can provide information about blood flow within the blood vessel or catheter to medical professionals.

[0049] As will be appreciated by those skilled in the relevant art, a combination of electrical sensors and pressure sensors at various points along the aspiration catheter can provide direct feedback to the medical professional regarding the engagement of the aspiration catheter with the clot. Additionally, the fluid dynamics within and around the aspiration catheter can provide insight into the degree of occlusion of the catheter in the vessel during catheter delivery, at the site of occlusion, during aspiration, and / or during catheter withdrawal.

[0050] Figure 3A 2 is a cross-sectional side view of an exemplary suction catheter 102, showing one or more electrode pairs 202 in electrical communication with a console 200. Arrows indicate current flow between the electrode pairs. In some examples, the electrode pairs 202 can operate by impedance measurement. An electrical connector in the wall of the catheter 102 can be connected to an amplifier in the console 200 and provide an analog voltage to one electrode 202a in the electrode pair 202, and a return electrical connector can provide a response current from a second electrode 202b in the electrode pair 202. Figure 3B Provided when ( Figure 3A The object is in the electrode pair ( Figure 3A 202a, 202b, and 202c). As a clot approaches the distal tip 108 of the catheter 102, the current flow between the various electrode pairs 202a, 202b, 202c may be altered such that the waveform of the measured current signal may be directly related to the dielectric properties of an object approaching or passing through the electrode pairs 202a, 202b, 202c. Such measured current signals may indicate when a clot has entered the distal end 108 of the catheter 102 or whether a clot has not yet engaged the catheter 102. Additionally, a series of electrode pairs 202 extending proximally within the inner lumen 104 of the catheter 102 may inform a medical professional how much clot has entered the catheter 102 and the composition or mechanical properties of such clot. In the event of a clot breakage (at Figure 3A 108 ), impedance measurements from a series of electrode pairs 202 can notify a medical professional that a clot has broken through the catheter. If a clot slowly enters the distal tip 108 of the catheter 102, the progress of the clot movement can be measured by the series of electrode pairs 202, and feedback is provided to the medical professional as progress is ongoing. As will be appreciated by those skilled in the relevant art, real-time feedback on the composition and / or progress of clot aspiration during the procedure can save lives. For example, if there is no progress or the clot is only minimally engaged with the distal tip 108 of the catheter 102, the physician may choose to try different methods in conjunction with aspiration, such as deploying a stent to better engage with the clot or adjusting the vacuum pressure or waveform pattern as described herein. In some cases, the measured current signal from the electrode pair 202 in conjunction with the first pressure sensor 204, the second pressure sensor 206, or the third pressure sensor 208 can determine that the vessel has collapsed or that the distal end 108 of the catheter 102 has engaged with the vessel wall instead of the clot, thereby notifying the physician to adjust the route.

[0051] FIG. 4A to FIG. 4C The fluid dynamics in and around the clot receiving device are shown at the following moments: The clot approaches the catheter 102 ( Figure 4A), allowing the fluid to continue to flow in the inner lumen 104; beginning to engage with the catheter 102 ( Figure 4B ), begins to restrict flow within the inner lumen 104; and fully engages the catheter 102 ( Figure 4C ), so that flow within the inner lumen 104 is stopped. The first pressure sensor 204 can be located within the inner 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 can be similarly positioned 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 is engaged, while the second pressure sensor 206 can measure the pressure of the fluid flowing within the vessel. Figure 4A The dashed lines in indicate signals that the first pressure sensor 204 and the second pressure sensor 206 can transmit to the console 200 simultaneously, such as through the I / O communication interface 54. Comparing the distal internal pressure with the distal external pressure before the clot is engaged can be used to establish the antegrade flow rate around the catheter 102, which can indicate the degree of occlusion of the catheter in the blood vessel. In addition to facilitating antegrade flow rate measurements, the first pressure sensor 204 can also be used to measure the pressure within the catheter 102 before, during, and after suction. As the catheter 102 is advanced through the blood vessel, such measurements can provide medical professionals with valuable insights into whether the clot is engaged with the distal tip 108. Alternatively, or in addition, in the case of remote suction before the distal tip 108 of the catheter 102 is engaged with the clot, the vacuum pressure from the suction pump 400 (optionally combined with the suction waveform 60 given by the console 200) can be automatically or manually adjusted based on the reading of the first pressure sensor 204 within the inner lumen 104 of the catheter 102 to ensure that the blood vessel does not collapse due to the pressure difference between the catheter 102 and the blood vessel. Under such remote suction, steady movement of the clot in a retrograde direction toward the distal tip 108 of the catheter 102 may be achieved.

[0052] As catheter 102 approaches a clot, catheter 102 may become nearly or completely occluded in the vessel, respectively. Figure 4B and Figure 4C As occlusion approaches, the first pressure sensor 204 may indicate a reduction in fluid flow within the inner 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 a clot, the pressure differential between the internal and external pressure sensors may instruct the console 200 to prevent the first pressure sensor 204 from providing information about the blood pressure in the vessel and optionally transmit a signal from the second pressure sensor 206.

[0053] During withdrawal of the catheter 102, with the clot fully engaged at the distal tip 108, the clot may resist removal and begin to slide out of the catheter 102. The combination of signals from the electrode pair 202 and the pressure sensors 204, 206, 208 may indicate the withdrawal of the clot as an impedance change and / or a pressure change within the inner lumen 108 of the catheter 102. The console 200 may alert the medical professional to such an event before the clot breaks free from the distal tip 108. The alert may instruct the medical professional to slow or stop the withdrawal to avoid losing the clot.

[0054] Referring back to FIG. 1 , the combination of pressure sensors 206, 208 located on the outer surface 106 of the catheter 102 along the distal portion 110 and the proximal portion 112 can provide signals to the blood pressure tracking module 56 of the console 200. When the third pressure sensor 208 is located near the patient's internal carotid artery (ICA), the third pressure sensor 208 positioned on the proximal portion 112 of the catheter 102 can signal information about the patient's systemic blood pressure to the console 200. Information from the third pressure sensor 208 can be used to automatically or manually adjust the vacuum pressure by the console 200 so that the aspiration waveform pattern and the vacuum pressure from the aspiration pump 400 match the patient's blood pressure waveform pattern. In some examples, the aspiration 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.

[0055] Figure 5 An exemplary clot receiving system 500 is provided having an outer catheter 502 and an inner suction catheter 102 disposed in a lumen of the outer catheter 502. The inner suction catheter 102 may have an electrode pair 202 and pressure sensors 204, 206, 208. In some examples, the system 500 may also 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 so that suction applied through the outer catheter 502 is transmitted to the inner catheter 102. Although not described herein, the inner suction catheter 102 may be provided with an outer catheter 502 and an inner suction catheter 102 disposed in a lumen of the outer catheter 502. Figure 5 , but the system 500 may also include a console 200 connected to the electrode pair and the pressure sensor, as described herein. When the third pressure sensor 208 is positioned on the outer surface 106 in the proximal portion 112 of the inner catheter 102 but outside the outer catheter 502, the third pressure sensor 208 can provide information about the effect on antegrade blood pressure near the ICA when an additional device (such as a balloon guide catheter or a stent) is used.

[0056] Figure 6is a flow chart illustrating a method 600 of manufacturing a clot retrieval system. The method 600 may include positioning 602 a first pressure sensor on an interior lumen of a distal portion of an aspiration catheter. The method 600 may also include positioning 604 a second pressure sensor on an exterior surface of the distal portion of the aspiration catheter. The method 600 may include positioning 606 a third pressure sensor on an exterior surface of a proximal portion of the aspiration catheter. The method 600 may be sent in step 606 or may further include positioning 608 at least one electrode pair on an interior lumen of a distal portion of the aspiration catheter.

[0057] As will be appreciated by one skilled in the art, method 600 may include any of the various features of the disclosed technology described herein and may vary depending on a particular configuration. In some examples, a method of using a catheter made by method 600 may include positioning an aspiration catheter proximate a clot within a blood vessel, aligning a third pressure sensor of the aspiration catheter with an outlet of an outer catheter, equalizing the third pressure input with a blood pressure waveform of the patient, and applying an aspiration waveform equal to the blood pressure waveform of the patient through the aspiration catheter.

[0058] Although the present disclosure has been described in conjunction with a number of exemplary aspects as shown in the drawings and described above, it should be 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 to perform the same functions of the present disclosure.

[0059] Some embodiments of the disclosed technology are described above with reference to the block diagrams and flow charts of the systems and methods and / or computer program products according to exemplary embodiments of the disclosed technology. It should be understood that one or more blocks in the block diagrams and flow charts and the combination of blocks in the block diagrams and flow charts can be implemented by computer executable program instructions, respectively. Similarly, according to some embodiments of the disclosed technology, some blocks in the block diagrams and flow charts may not necessarily be executed in the order presented, or may not necessarily be executed at all.

[0060] These computer executable program instructions can be loaded onto a general purpose computer, a special purpose computer, a processor or other programmable data processing device to produce a specific machine, so that the instructions executed on the computer, processor or other programmable data processing device create a tool for implementing one or more functions specified in one or more flowchart blocks. These computer program instructions can also be stored in a computer readable memory, which can instruct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce a product including an instruction device that implements one or more functions specified in one or more flowchart blocks.

[0061] Implementations of the disclosed technology may provide a computer program product having a computer usable medium having computer readable program code or program instructions contained therein, the computer readable program code being adapted to be executed to implement one or more functions specified in one or more flowchart blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operating elements or steps are executed on the computer or other programmable device, thereby producing a computer-implemented process, so that the instructions executed on the computer or other programmable device provide elements or steps for implementing the functions specified in one or more flowchart blocks.

[0062] Therefore, the blocks of the block diagrams and flow charts support a combination of devices for performing the specified functions, a combination of elements or steps for performing the specified functions, and a program instruction device for performing the specified functions. It should also be understood that each block in the block diagrams and flow charts, and the combination of blocks in the block diagrams and flow charts can be implemented by a hardware-based special-purpose computer system that performs the specified functions, elements or steps, or a combination of special-purpose hardware and computer instructions.

[0063] It will be apparent from the above description that, although specific embodiments of the present invention have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present invention. For example, although the embodiments described herein relate to specific characteristic structures, the present invention includes embodiments with combinations of different characteristic structures. The present invention also includes embodiments that do not include all the specific characteristic structures described. The present invention is not limited to the embodiments described above, and the configuration and details of these embodiments may vary.

Claims

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

2. The aspiration catheter according to claim 1, wherein: The at least one electrode pair is configured to transmit electrical input to a console, wherein the electrical input comprises a change in electrical conductivity of a fluid flowing within the inner lumen of the aspiration catheter.

3. The aspiration catheter of claim 2, wherein: The at least one electrode pair is configured to detect the clot within the fluid flowing within the inner lumen of the aspiration catheter when the distal tip of the aspiration catheter is proximate the clot.

4. The aspiration catheter of claim 1, wherein: When the distal tip of the aspiration catheter engages the clot, the at least one electrode pair is configured to monitor the clot as the aspiration catheter is moved around the blood vessel.

5. The aspiration catheter of claim 1, wherein: The first pressure sensor is configured to transmit a first pressure input to a console; The second pressure sensor is configured to transmit a second pressure input to the console; and The third pressure sensor is configured to transmit a third pressure input to the console, wherein the first pressure input, the second pressure input, and the third pressure input are different.

6. The aspiration catheter of claim 5, wherein: The first pressure input and the second pressure input together generate a pressure measurement of antegrade flow velocity around the aspiration catheter in the blood vessel as the distal tip of the aspiration catheter approaches the clot.

7. The aspiration catheter of claim 5, wherein: The console is also configured to regulate suction by applying an oscillating vacuum waveform based on pressure input from the one or more pressure sensors.

8. The aspiration catheter of claim 5, wherein: The console is also configured to modulate suction to the patient's blood pressure waveform by applying an oscillating vacuum waveform that is in phase with the patient's blood pressure waveform.

9. The aspiration catheter of claim 5, wherein: The console is also configured to modulate suction to the patient's blood pressure waveform by applying an oscillating vacuum waveform that is out of phase with the patient's blood pressure waveform.

10. A system for assisting in the retrieval of a clot from a patient's blood vessel, the system comprising: External catheter; and An inner catheter, the inner catheter is arranged in the lumen of the outer catheter, and the inner catheter comprises: at least one electrode pair positioned on the inner lumen of the inner catheter; at least one internal pressure sensor positioned on the inner lumen of the inner catheter; and At least one external pressure sensor is positioned on an exterior surface of the inner conduit.

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

12. The system according to claim 10, further comprising: A console is configured to regulate 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.

13. The system of claim 12, wherein: The at least one external pressure sensor is configured to transmit a pressure input related to the patient's blood pressure.

14. The system of claim 13, wherein: The console is also configured to regulate the suction by applying a vacuum waveform pattern that is in phase with the patient's blood pressure waveform.

15. The system of claim 13, wherein: The console is also configured to regulate the suction by applying a vacuum waveform pattern that is out of phase with the patient's blood pressure waveform.

16. A method for manufacturing an aspiration catheter, the method comprising: positioning a first pressure sensor on an interior lumen of a distal portion of the aspiration catheter; positioning a second pressure sensor on an exterior surface of the distal portion of the aspiration catheter; as well as A third pressure sensor is positioned on the exterior surface of the proximal portion of the aspiration catheter.

17. The method according to claim 16, further comprising: When the aspiration catheter engages a clot in a blood vessel, a pressure change within the inner lumen of the aspiration catheter is detected by the first pressure sensor, detecting the pressure change within the blood vessel outside the aspiration catheter by the second pressure sensor when the aspiration catheter engages the clot, and A pressure measurement of the flow rate around the aspiration catheter in the blood vessel is generated.

18. The method according to claim 17, further comprising: A vacuum waveform pattern is applied through the aspiration conduit based on the pressure changes from at least one pressure sensor.

19. The method according to claim 16, further comprising: At least one electrode pair is positioned on the interior lumen of the distal portion of the aspiration catheter.

20. The method according to claim 19, further comprising: When the aspiration catheter engages a clot, a change in conductivity of a fluid flowing within the aspiration catheter is detected by the at least one electrode pair.

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