Thrombus removal system with directional interface modulation function and thrombectomy method

Abstract

The application discloses a thrombus extraction system and a thrombectomy method with a directional interface modulation function, which comprises a stent body that can be delivered through a delivery catheter and expanded in a blood vessel; the stent body is divided into at least two functionally different interface regions in the circumferential direction; a first interface region is used for contacting a thrombus and implementing a local interface modulation effect on the contact interface between the thrombus and the stent body; a second interface region is used for contacting a blood vessel wall and limiting the transmission of the interface modulation effect to the blood vessel wall direction; the first interface region and the second interface region are different in interface energy conduction ability, interface physical properties or interface material configuration, forming a circumferential asymmetric interface structure, and the thrombectomy stability is improved through an interface property modulation mechanism. The mechanism no longer simply depends on structural fitting, but changes the interface mechanical properties through directional local energy effect after the stent body contacts the thrombus, so that the adhesion stability between the thrombus and the stent body is enhanced, and more reliable overall extraction is realized.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a thrombus removal system and method with directional interface modulation function, which can improve the stability of thrombus removal while reducing the risk of vascular injury, thereby solving a key bottleneck problem that has long existed in the clinical application of existing mechanical thrombectomy technology. Background Technology

[0002] The mechanical stability of thrombi is primarily provided by the fibrin network. Fibrin is a fibrous biopolymer formed from fibrinogen under the action of thrombin. Its monomers form protofibrils through specific "bond-cavity" interactions, which then aggregate into thrombi. The physical essence of the thermal anchoring effect is that, at a specific temperature threshold (typically 50°C to 65°C), local denaturation and enhanced cross-linking of fibrin are induced. When the local temperature rises, the secondary and tertiary structures of fibrin fold, exposing hydrophobic groups and reactive sites that promote a tight physical and chemical bond between the scaffold fibers and the thrombus matrix. Studies have shown that under thermally activated conditions, the adhesion of thrombi to specific metal surfaces can be increased by more than two times. This binding force stems not only from increased friction but also from the deep penetration of protein molecules into the nanoscale texture of the scaffold surface.

[0003] Safety is the paramount principle for interventional hyperthermia devices. The sensitivity of the blood vessel wall to thermal damage can be quantified by the cumulative equivalent minutes (CEM43) at 43°C. Studies have shown that as long as the thermal dose received by the blood vessel wall is controlled below 100 CEM43, the tissue can avoid permanent necrosis through self-repair. Because this system uses an asymmetric Parylene insulating coating (180-degree coverage), the instantaneous temperature rise on the contact side of the blood vessel wall is limited to within 4-6°C, corresponding to a CEM43 far below the dangerous threshold of thermal stimulation.

[0004] Furthermore, the blood vessel wall may induce smooth muscle contraction, leading to vasospasm. In the vascular environment, circumferential energy release may have adverse effects on the blood vessel wall. Brain vascular endothelial cells are extremely sensitive to heat; sustained high temperatures can cause endothelial shedding and exposure of the basal layer, and even lead to permanent vascular stenosis or rupture. Traditional monopolar configurations require the current to flow through the body and be recycled to the external patch, posing a significant risk of stray current-induced neural stimulation.

[0005] Current mainstream thrombectomy methods primarily rely on the mechanical intercalation of stents into the thrombus or the grasping effect created by negative pressure suction. Their stability is highly dependent on the characteristics of the thrombus composition and the vascular anatomy. When the thrombus has a high fibrin content or a dense structure, the stent struggles to achieve effective intercalation, leading to decreased grasping ability. During retrieval, the thrombus is prone to slippage, breakage, or distal migration, thus affecting the recanalization success rate. Furthermore, in small-diameter vessels or tortuous vascular regions, relying solely on mechanical action may require increased radial support force, thereby increasing the risk of vessel wall damage.

[0006] On the other hand, there is still room for improvement in the first-time complete recanalization rate (FPE) of existing thrombectomy techniques. The fundamental limitation lies in the uncontrollable stability of the interface between the thrombus and the stent. When there is insufficient interfacial friction or low shear resistance, even if the stent has been successfully embedded in the thrombus, overall slippage may still occur during retrieval. Therefore, how to improve the stability of the thrombus-stent interface without significantly increasing the mechanical load has become the core issue affecting the efficiency and safety of thrombectomy. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a thrombus retrieval system with directional interface modulation function, which enhances thrombus retrieval stability through an interface property modulation mechanism. This mechanism no longer relies solely on structural interlocking; instead, after the stent body contacts the thrombus, it alters the interfacial mechanical properties through directional local energy application, thereby enhancing the adhesion stability between the thrombus and the stent body and achieving more reliable overall retrieval. The system includes: A stent body that can be delivered via a delivery catheter and deployed within a blood vessel; The main body of the support is divided into at least two functionally different interface areas in the circumferential direction, including: The first interface region is used to contact the thrombus and perform local interface modulation on the interface between the thrombus and the stent body; the second interface region is used to contact the blood vessel wall and restrict the transmission of the interface modulation effect towards the blood vessel wall; wherein the first interface region and the second interface region differ in interface energy conduction capability, interface physical properties or interface material configuration, forming a circumferentially asymmetric interface structure.

[0008] Preferably, the first interface region includes at least one of a conductive layer, a micro / nano structure, or a friction-enhancing coating.

[0009] Preferably, the second interface region includes at least one of an insulating coating, a heat insulation layer, or a multilayer composite structure.

[0010] Preferably, the support body includes a partially closed energy circuit, which is a bipolar or multi-bipolar structure; Each of the partially closed energy loops is equipped with an anode and a cathode. The anode and cathode in each partially closed energy loop are connected to wires respectively, and each partially closed energy loop is an independent conductive part.

[0011] Preferably, the partially closed energy loop includes a conductive layer and a wire connected to the conductive layer. The conductive layer is disposed at the outer edge of the inner wall of the support body, and the conductive layer is connected to the energy control unit in the control host through the wire.

[0012] Preferably, the bipolar structure includes an anode contact integrated at the proximal anode of the support body and a cathode contact integrated at the distal anode of the support body, wherein the anode contact and the cathode contact are connected to the conductive layer.

[0013] Preferably, the main body of the stent has an open mesh structure with a diamond-shaped mesh layout; the main body of the stent is made of medical materials with shape memory or superelastic properties.

[0014] Preferably, it also includes a microcatheter that can move radially within the delivery catheter for delivering the stent body. During use, the stent body can be compressed and loaded into the microcatheter, and the microcatheter delivers the stent body to the target vascular segment through the delivery catheter.

[0015] Preferably, it includes: a status detection unit, which is used to identify the status of the medium surrounding the stent and obtain the identification result; The energy control unit selectively triggers interface modulation of the first interface region based on the identification result.

[0016] A thrombectomy method, comprising the above-mentioned thrombectomy system: The main body of the stent is deployed in the segment of the blood vessel where the thrombus is located; Identify the contact state between the stent body and the thrombus; After confirming contact, local interface modulation is applied to the interface between the thrombus and the stent body. The stent was withdrawn to remove the thrombus as a whole.

[0017] The technical effects and advantages of this invention are as follows: 1. This invention provides a thrombus removal system that enhances thrombus removal stability through an interface property modulation mechanism. This mechanism no longer relies solely on structural interlocking; instead, after the stent contacts the thrombus, it alters the interfacial mechanical properties through directional local energy application, thereby enhancing the adhesion stability between the thrombus and the stent body and achieving more reliable overall removal. The system includes a self-expanding stent body that can be delivered via catheter and deployed within the blood vessel. The overall structure of the stent body, after deployment, not only serves to form a mechanical interlocking mechanism but is also constructed to have a circumferentially asymmetric interface function. Specifically, the stent body is circumferentially divided into a first interface region and a second interface region. The first interface region is used to apply local energy to the thrombus, while the second interface region is used to reduce or block energy transmission towards the vessel wall, thus creating a directional effect when the stent body contacts the thrombus. Through this structural design, energy is primarily applied to the thrombus-side interface, thereby avoiding unnecessary impact on the vessel wall.

[0018] 2. In this invention, after the thrombus is embedded in the stent, the mechanical properties of the thrombus interface in the first interface region can be altered through local energy application, including but not limited to increasing the interface friction coefficient, enhancing shear slip resistance, and improving the adhesion stability of the thrombus to the stent. Through interface modulation, the thrombus maintains its integrity during retrieval, reducing the probability of slippage and fragmentation.

[0019] 3. In this invention, the second interface region is used to contact the blood vessel wall. The contact surface between the second interface region and the blood vessel wall has good biocompatibility and protective properties. This circumferential partition design enables the thrombectomy system to capture thrombi while minimizing stimulation or damage to the normal blood vessel wall. The second interface region constitutes a protection zone, which is designed with a low conductivity or low energy transfer capacity structure. It can also form a heat diffusion buffer function through an insulating coating, a heat insulation layer, or a multi-layer composite structure to reduce the exposure of the blood vessel wall and reduce the risk of local intimal damage.

[0020] 4. In this invention, the stent body not only serves as a mechanical capture unit but also constitutes an energy actuation structure. The stent topology participates in the formation of local energy paths, enabling the stent body to achieve interface modulation without the need for additional energy actuators, thereby reducing system complexity and improving device integration.

[0021] 5. The supporting control system provided by this invention includes an energy control unit and a status detection unit. The status detection unit is used to identify the state of the medium surrounding the stent and distinguish whether the environment is in a flowing blood state, a thrombus contact state, or a thrombus encapsulation state. Based on the identification result, the system can trigger local energy action after confirming that the stent has come into contact with a thrombus, thereby avoiding false triggering in the blood flow environment.

[0022] 6. The system may also include safety control mechanisms to limit energy exposure to non-target tissues. For example, controllability of energy action can be achieved through intermittent action modes, adaptive regulation strategies, or passive diffusion-limiting structures. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the energy directional action path of the support body of the present invention in the working state; Figure 2 This is a partially enlarged schematic diagram of the stent body of the present invention after it has been fully deployed in the blood vessel to capture the thrombus; Figure 3 This is a schematic diagram comparing the adhesion mechanism of the thrombus-stent interface in the stent body of the present invention before and after energy application; Figure 4 This is a schematic diagram of the functional zoning of the circumferential cross-section of the support body of the present invention; Figure 5 This is a partially enlarged view of the micro / nano structure of the support body in the first interface region of the present invention; Figure 6 This is an enlarged cross-sectional view of the multi-layer protective structure of the second interface region in this invention; Figure 7 This is a schematic diagram of the overall structure of the thrombus removal system of the present invention; Figure 8 This is a schematic diagram illustrating the principle of the state detection module in this invention, which uses impedance characteristics to identify different tissues. Figure 9 This is a control flowchart of the energy output logic executed by the control system of the present invention; Figure 10 This is a schematic diagram comparing the effectiveness of the thrombectomy method of the present invention with that of the traditional mechanical thrombectomy method in terms of recovery stability.

[0024] In the figure: 1. Support body; 11. First interface area; 111. Friction-enhancing coating; 112. Conductive layer; 113. Micro-nano structure; 12. Second interface area; 121. Insulating coating; 122. Heat insulation layer; 2. Delivery conduit; 3. Microconduit; 4. Control host; 5. Energy control unit; 6. Status detection unit; 7. Wire. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

[0026] Please see Figure 1 As shown, this embodiment provides a thrombus removal system with directional interface modulation function, including: A stent body 1 that can be delivered via catheter and deployed within a blood vessel; the stent body 1 is divided into at least two functionally different interface regions in the circumferential direction, including: a first interface region 11, which is used to contact the thrombus and perform local interface modulation on the interface between the thrombus and the stent body 1; and a second interface region 12, which is used to contact the blood vessel wall and restrict the transmission of interface modulation to the blood vessel wall; wherein the first interface region 11 and the second interface region 12 differ in interface energy conduction capacity, interface physical properties or interface material configuration, thereby forming a circumferentially asymmetric interface structure.

[0027] Based on the above structure, this invention achieves the directional effect of energy and the enhanced interface adhesion mechanism. When the system is working, energy is emitted only from the first interface region 11, such as... Figure 1 As indicated by the thick horizontal arrow, a clear direction of energy action is formed, pointing directly to the thrombus area.

[0028] The second interface region 12 facing the blood vessel wall does not emit energy, which greatly improves safety. This directional effect establishes the key protection point of the invention at the mechanism level.

[0029] The stent body 1 of the present invention is suitable for various types of thrombosis, including fibrin-rich thrombosis, mixed thrombosis or hard thrombosis, and can be used in large blood vessels, medium-diameter blood vessels or tortuous blood vessel environments.

[0030] The stent body 1 of the present invention is suitable for various types of thrombosis, including fibrin-rich thrombosis, mixed thrombosis or hard thrombosis, and can be used in large blood vessels, medium-diameter blood vessels or tortuous blood vessel environments.

[0031] The present invention can also form a complete thrombectomy system, working in conjunction with the catheter delivery assembly and aspiration system to achieve a safe, controllable and stable thrombus removal process.

[0032] In one specific embodiment, the first interface region 11 includes at least one of a conductive layer, a micro / nano structure, or a friction-enhancing coating.

[0033] Specifically, the first interface region 11 is used to contact the thrombus and has an interface modulation effect. The contact surface between the first interface region 11 and the thrombus has special physical and chemical properties to enhance the stability of the adhesion.

[0034] It is understood that the interface modulation effect is not limited to the thermal field as described in this application, but can also be achieved through electric field, mechanical vibration field, sound field or other combinations thereof, which can enhance the stability of thrombus adhesion without significantly increasing radial support force, thereby reducing the risk of thrombus slippage and fragmentation.

[0035] After the thrombus is embedded in the stent, the first interface region 11 can alter the mechanical properties of the thrombus interface through local energy application, including but not limited to increasing the interface friction coefficient, enhancing shear slip resistance, and improving the adhesion stability of the thrombus to the stent body 1. Through interface modulation, the thrombus maintains its integrity during retrieval, reducing the probability of slippage and fragmentation.

[0036] Furthermore, the second interface region 12 includes at least one of an insulating coating, a heat insulation layer, or a multilayer composite structure.

[0037] Specifically, the second interface region 12 constitutes a protection zone, which is designed as a low conductivity or low energy transfer capacity structure, and can form a thermal diffusion buffer function through an insulating coating, a heat insulation layer or a multi-layer composite structure to reduce the exposure of the blood vessel wall capacity and reduce the risk of local intimal damage.

[0038] Furthermore, the support body 1 includes a partially closed energy circuit, which is a bipolar or multi-bipolar structure. Each partially closed energy circuit is equipped with an anode and a cathode. The anode and cathode in each partially closed energy circuit are respectively connected to wires 7, and each partially closed energy circuit is an independent conductive part.

[0039] Furthermore, the interface modulation effect is not limited to the thermal effect described in this application, but can also be achieved through at least one of the following methods: radio frequency energy, low-power electrical stimulation, mechanical vibration, ultrasonic effect, or a combination of multiple methods.

[0040] This invention provides a thrombus removal system comprising a self-expanding stent body 1 that can be delivered via catheter and deployed within a blood vessel. After deployment, the stent body 1 not only forms a mechanical fit but is also configured to have a circumferentially asymmetric interface function. Specifically, the stent body 1 is circumferentially divided into a first interface region 11 and a second interface region 12. The first interface region 11 is used to apply local energy to the thrombus, while the second interface region 12 is used to reduce or block energy transmission towards the vessel wall, thereby creating a directional effect when the stent body 1 contacts the thrombus. Through this structural design, energy is primarily applied to the thrombus-side interface, thus avoiding unnecessary impact on the vessel wall.

[0041] Please see Figure 2 As shown, the stent body 1 in the thrombus removal system has a mesh structure, which can be deployed inside the blood vessel to encapsulate the thrombus inside the mesh.

[0042] Preferably, the stent body 1 is made of medical materials with shape memory or superelastic properties, including but not limited to nickel-titanium alloys, cobalt-chromium alloys, or other biocompatible metallic materials, so that it can provide stable radial support force and has sufficient flexibility to adapt to the tortuous vascular environment after deployment. The deployed stent body 1 simultaneously undertakes the functions of thrombus intercalation and interfacial energy carrier, thus forming a triple functional structure combining mechanical capture and interfacial modulation.

[0043] In one implementation, please refer to Figure 3-4 As shown, the main body 1 of the stent is made of a super-elastic nickel-titanium alloy tube by precision laser cutting. It adopts an open mesh structure with a diamond mesh layout. When it expands, it can generate gradient pressure on the thrombus, guiding the thrombus to bulge into the diamond mesh, providing sufficient contact area for thermal anchoring.

[0044] Specifically, the main body of the support is a circumferentially functionally asymmetrical structure, and the circumferential cross-section of the main body of the support is divided into two regions.

[0045] The first interface region 11 is located on the inner wall of the stent body 1. The first interface region 11 is used to contact the thrombus and has an interface modulation effect. The contact surface between the first interface region 11 and the thrombus has special physical and chemical properties to enhance the stability of adhesion. The interface modulation effect can be achieved through thermal fields, electric fields, mechanical vibration fields, acoustic fields, or a combination of these methods. This can enhance the adhesion stability of the thrombus without significantly increasing the radial support force, thereby reducing the risk of thrombus slippage and fragmentation. Due to the improved interface stability, the overall retrieval probability increases during the recovery process, which helps to improve the potential success rate of first-pass complete recanalization. Simultaneously, due to the reduced mechanical dependence on the vessel wall, the safety of operation in small-diameter or tortuous vessels is also expected to improve.

[0046] The second interface region 12 is located on the outer wall of the stent body 1. The second interface region 12 is used to contact the blood vessel wall. The contact surface between the second interface region 12 and the blood vessel wall has good biocompatibility and protective properties. This circumferential partition design enables the thrombectomy system to capture thrombi while minimizing stimulation or damage to the normal blood vessel wall.

[0047] In this invention, the stent body 1 adopts a circumferential asymmetric structure, the core of which lies in the directional guidance of energy, that is, heat is only released on the contact surface between the stent body 1 and the thrombus, while the side in contact with the blood vessel wall is physically isolated by an insulating barrier.

[0048] Taking the effect of thermal field as an example, Table 1 shows the comparison of physical, electrothermal, and thermal parameters of key tissues and materials under the intervention environment: Table 1 See Figure 5As shown, in one specific embodiment, a friction-enhancing coating 111 is applied to the inner wall of the stent body 1 to enhance the friction between the inner wall of the stent body 1 and the thrombus.

[0049] Specifically, the friction-enhancing coating 111 is a high-friction coefficient coating, which includes, but is not limited to, ceramic-based coatings (such as titanium nitride TiN or alumina microporous structure coatings), biocompatible polymer coatings with micro-nano rough surface morphology (such as modified polyurethane or silicone coatings), and metal-ceramic coatings, etc., which can improve the friction between the stent body 1 and the thrombus.

[0050] See Figure 6 As shown, the second interface area 12 includes an insulating coating 121 and a heat insulation layer 122 disposed from the inside to the outside. The insulating coating 121 covers the outer wall of the support body 1, and the heat insulation layer 122 covers the insulating coating 121.

[0051] The second interface region 12 has a multi-layered structure, forming an effective barrier to prevent energy from being transferred to the blood vessel wall, thus realizing a vascular protection mechanism.

[0052] The second interface region 12 can also be at least one of a single insulating coating 121, a heat insulation layer 122, or a multi-layer composite structure.

[0053] In one specific embodiment, the insulating coating 121 is made of parylene, which has a conformal coating and also has excellent biocompatibility, pinhole-free film formation and extremely high insulation strength. The "semi-circumferential coverage" structure of the insulating coating 121 covering the outer surface of the stent body 1 ensures that the current flows only in the direction of contact between the stent body 1 and the thrombus, while the side facing away from the blood vessel wall maintains a complete high-strength electrical insulation state.

[0054] Furthermore, the heat insulation layer 122 is made of organic polymer materials, including but not limited to PI (polyimide) disclosed in this application.

[0055] The second interface region 12 constitutes a protection zone, designed as a low-conductivity or low-energy-transmission structure. It can also form a thermal diffusion buffer through an insulating coating, heat insulation layer, or multi-layer composite structure to reduce exposure to the vessel wall and lower the risk of local intimal damage. Through the first interface region 11 and the second interface region 12, the stent body 1 forms an axially functionally asymmetric structure, enabling spatial directional control of energy action. Energy diffuses radially from the stent body 1 towards the center of the thrombus, altering the mechanical properties at the contact point between the thrombus surface and the stent body 1. For example, it softens the local fibrin network, increases the interfacial friction coefficient, or enhances shear stability, thereby achieving an adhesion-enhanced thrombectomy mechanism. Simultaneously, the energy diffused to the vessel wall is minimal, and the second interface region 12 does not contact the vessel wall, significantly reducing the risk of local intimal damage.

[0056] Specifically, the multi-layer composite structure is a multi-layer design of insulating coating and heat insulation layer, which can provide better insulation and heat insulation effects.

[0057] See Figure 7 As shown, the present invention provides a thrombus removal system with directional interface modulation function, which also includes an energy control unit 5 and a status detection unit 6; wherein, the status detection unit 6 is used to identify the status of the medium around the stent and obtain the identification result; the energy control unit 5 selectively triggers the interface modulation effect of the first interface region 11 based on the identification result.

[0058] Furthermore, the state detection unit 6 identifies based on at least one of the following parameters: impedance characteristics, phase angle change, capacitance change, current conduction difference, or dielectric property difference.

[0059] Furthermore, the first interface area 11 can be divided into multiple independently activatable local closed energy circuits. Each local closed energy circuit is equipped with an anode and a cathode. The anode and cathode in each local closed energy circuit are connected to wires 7 respectively. Each local closed energy circuit is an independent conductive part. The status detection unit 6 measures the resistance (or impedance) between the two electrodes (i.e., the anode and the cathode) inside each independent local closed energy circuit to determine whether each local area of ​​the stent body 1 is attached to the thrombus.

[0060] In one specific embodiment, the state detection unit 6 uses a current sensor. The mechanical characteristics at the contact point between the thrombus surface and the stent body 1 change, causing a change in impedance characteristics. The current sensor detects the change in current between the two electrodes to determine whether each area of ​​the stent body 1 is in contact with the thrombus.

[0061] In one specific embodiment, the thrombus removal system includes a thrombus removal system, a delivery catheter 2 for delivering the thrombus removal system, and a control host 4, the control host 4 being electrically connected to the thrombus removal system.

[0062] Furthermore, the control host 4 is equipped with an energy control unit 5 and a status detection unit 6. The status detection unit 6 is used to identify the status of the medium around the support, and the energy control unit selectively triggers the interface modulation effect of the first interface area 11 based on the identification result.

[0063] Specifically, the energy control unit 5 is used to generate interface modulation energy, the state detection unit 6 is used to identify the state of the medium around the stent body 1, and the energy generated by the control host 4 is transmitted to the stent body 1 at the distal end via the wire 7. This energy can enhance the stability of the attachment between the stent body 1 and the thrombus.

[0064] Furthermore, the energy control unit 5 adopts a trigger-type control mechanism, which activates the interface modulation function only when the stent body 1 is confirmed to be in a thrombus contact state. The energy control unit adopts at least one of the following control methods: pulse output, duty cycle modulation, adaptive energy regulation, and energy upper limit limitation.

[0065] In one specific embodiment, the energy control unit 5 may employ a drive circuit to drive the ultrasonic transducer to operate.

[0066] Specifically, pulsed output and duty cycle modulation: energy delivery uses a short pulse mode with controlled duty cycle (e.g., 0.5s delivery / 0.3s interval), utilizing the blood flowing in the blood vessels as a natural radiator to remove excess heat.

[0067] Adaptive energy regulation: The energy control unit 5 receives impedance or temperature data from the status detection unit 6 in real time. When it is determined that the highest temperature of the local microenvironment is close to the target anchoring window (e.g., 60°C), the system automatically reduces the output power or reduces the duty cycle to prevent temperature overshoot.

[0068] Energy limit limit: The system sets an absolute safe time limit for a single energy application (e.g., 1 to 10 seconds), or sets a forced stop threshold based on the cumulative equivalent thermal dose (CEM43) (e.g., strictly limiting the CEM43 to the blood vessel wall to below 100). Once either limit is reached, the energy output is forcibly cut off.

[0069] It also includes a microcatheter 3, which can move radially within the delivery catheter 2 to deliver the stent body 1. During use, the stent body 1 can be compressed and loaded into the microcatheter 3. The microcatheter 3 delivers the stent body 1 to the target vascular segment through the delivery catheter 2. After the stent body 1 reaches the area where the thrombus is located, the microcatheter 3 is withdrawn, and the stent body 1 releases and automatically expands to form radial contact with the thrombus.

[0070] Furthermore, the system also includes a direction control structure for adjusting the spatial orientation of the first interface area 11. The direction control structure adjusts the position and rotation of the support body 1.

[0071] The operator can adjust the spatial orientation of the first interface area 11 by pushing and rotating, so that the energy action surface points towards the thrombus body and avoids the blood vessel wall, thereby achieving the effect of directional interface action in eccentric thrombus or tortuous blood vessel environments.

[0072] In an optional embodiment, the direction control structure is a delivery rod (not shown in the figure) fixedly connected to the proximal end of the stent body 1. The stent body 1 is delivered and rotated through the delivery rod. After the delivery catheter 2 reaches the target vascular segment, the microcatheter 3 loaded with the stent body 1 enters the delivery catheter 2 and extends to the outside of the delivery catheter 2. The microcatheter 3 is withdrawn, exposing the stent body 1. The stent body 1 releases and automatically expands to make radial contact with the thrombus.

[0073] The stent body 1 is also provided with a radiopaque marker (not shown in the figure), which is located at the center of the stent body 1 to ensure that the conductive window faces the center of the thrombus.

[0074] Furthermore, in terms of safety control, the system may also include an energy upper limit control mechanism, a single-action time limiting module, and an adaptive feedback adjustment function based on impedance changes to prevent abnormal energy concentration. Simultaneously, the second interface region 12 can serve as a passive protection structure, reducing exposure to non-target tissues through insulation or thermal diffusion design.

[0075] After the energy application is complete, an enhanced attachment interface is formed between the stent body 1 and the thrombus. The thrombus can then be removed by complete retraction or by a combination of retraction and aspiration. Due to the improved interface stability, the risks of thrombus rupture, distal embolism, and repeated procedures are reduced.

[0076] Understandably, the first interface region 11 is defined as the "energy action region," which is mainly oriented towards the thrombus body. This region not only serves as a conductive electrode but also enhances the mechanical interlocking force through surface engineering technology. The micro-nano textures on the surface of the stent body 1 can increase the friction with the thrombus at room temperature. In the thermally activated state, the micro-nano textures act as a "mold" for the penetration of denatured fibrin, forming microscopic anchoring points similar to "Velcro."

[0077] In addition, the high-friction coefficient coating used in the first interface area 11, compared with the traditional thrombec retrieval bracket which pursues extremely low surface friction to facilitate transport, only increases friction in the first interface area 11, thereby maintaining the smoothness of other areas and achieving a balance between transportability and gripping force.

[0078] See Figure 8As shown, in this embodiment, the partially closed energy loop includes a conductive layer 112 and a wire 7 connected to the conductive layer 112. The conductive layer 112 is disposed at the outer edge of the inner wall of the support body 1, and the conductive layer 112 is connected to the energy control unit 5 in the control host 4 through the wire 7.

[0079] Specifically, when the stent body 1 comes into contact with the thrombus, the conductive layer 112, the wire 7, the energy control unit 5, and the control host 4 form a local energy interaction interface, which can further improve the stability of the thrombus contact.

[0080] In this embodiment, the conductive layer 112 is not limited to conductive coatings and conductive ribs, but can also be a conductive layer 112 with conductivity provided at the edge of the first interface region 11 by other structures.

[0081] In other embodiments, the energy may be radio frequency energy, pulsed electric field, low-power electrical stimulation, or other forms of energy suitable for interface modulation. Its purpose is not tissue ablation, but to achieve an adhesion-enhanced thrombectomy mechanism by changing the mechanical properties of the thrombus surface, such as softening the local fibrin network, increasing the interfacial friction coefficient, or enhancing shear stability.

[0082] In a further embodiment, the energy output adopts a trigger-based control mechanism, that is, the energy action is activated only when the status detection unit 6 detects that the stent body 1 is in stable contact with the thrombus and there are no signs of contact with the blood vessel wall.

[0083] Furthermore, the energy output can be pulsed or short-cycle modulated to limit continuous heat accumulation and reduce the risk of potential tissue damage, while maintaining the interface modulation effect.

[0084] In this embodiment, the micro-nano structure 113 is disposed on the inner wall of the support body 1. The micro-nano structure 113 is a micro-nano array with multiple raised micro-nano textures.

[0085] Furthermore, micro-nano textures can be achieved using laser-etched microgrooves or arrayed micropillars.

[0086] The first interface region 11 includes a conductive path, an energy transfer structure, and an interface contact enhancement design. Its surface can be optimized through microstructure textures, high-friction coatings, or conductive layers to improve thrombus contact stability.

[0087] One or more structures in the first interface region 11 together increase the mechanical interlocking force between the stent body 1 and the thrombus. At the same time, electrical or thermal energy is directed to the interface through the energy transmission path, and the local characteristics of the thrombus are changed through physical or chemical means to achieve interface modulation.

[0088] It is understood that the first interface region 11 includes at least one of a friction-enhancing coating 111, a conductive layer 112, and a micro / nano structure 113, which can provide stability for thrombus contact.

[0089] Furthermore, in order to achieve a controlled conductive path, the support body 1 is a bipolar structure or a multi-bipolar structure.

[0090] The bipolar structure is a partially closed energy loop, including an anode contact integrated at the near-end anode of the support body 1 and a cathode contact integrated at the far-end anode of the support body 1. The anode contact and the cathode contact are connected to the conductive layer 112.

[0091] The multi-bipolar structure is a support body 1 that can be equipped with multiple locally closed energy loops. The first interface area 11 is divided into multiple regions. The conductive layer 112 in each region is connected to different wires 7. The different wires 7 are connected to the control body 4. The near end of each region integrates an anode contact, and the far end of each region integrates a cathode contact, thereby forming a multi-bipolar structure.

[0092] Compared with the traditional monopolar configuration, the multi-bipolar structure design strictly restricts the current path within the local space enclosed by the stent body 1, which greatly reduces the risk of nerve stimulation induced by stray current. In addition, the status detection unit 6 measures the resistance (or impedance) between the two electrodes (i.e., anode and cathode) inside each independent local closed energy circuit to determine whether the stent is attached to the thrombus in each local area.

[0093] Through the above embodiments, the present invention forms a thrombectomy path based on interface modulation mechanism, realizing asymmetric energy action and trigger-based safety control, improving thrombus capture stability and reducing the risk of vascular injury without relying on enhanced mechanical interlocking force.

[0094] In practical use, this system can also reduce the risk of spasms through the following design features: Frequency modulation: Radio frequency current above 500kHz is used to reduce direct electrical stimulation of nerve endings by utilizing its Faraday shielding effect. 2. Physical insulation: In addition to electrical insulation, the insulating coating 121 also has certain thermal resistance characteristics, which further slows down the rate of heat conduction to the blood vessel wall.

[0095] Furthermore, the state detection unit 6 identifies the surrounding medium environment based on at least one of the following parameters: impedance characteristics, phase angle changes, capacitance changes, current conduction differences, and dielectric property differences. This identification process can differentiate between free blood flow environments, partial thrombus contact states, and completely thrombus-encapsulated states based on impedance changes, contact capacitance changes, or current conduction property differences. For example, blood typically exhibits a low-impedance environment, while thrombi present medium-impedance characteristics, and the vessel wall has different dielectric properties. The control unit 4 determines whether the stent body 1 has entered an effective thrombus contact state based on the above characteristics and accordingly determines whether to trigger energy action.

[0096] Specifically, the state detection principle is that the conductive layer 112 on the stent body 1 contacts different tissues. Through measurement, the state detection unit 6 can identify three paths with distinctly different impedance characteristics: the blood path (low impedance), the thrombus path (specific complex impedance characteristics), and the vessel wall path (high impedance). Through this impedance analysis, the system can determine in real time whether the first interface area 11 of the stent body 1 is accurately aligned with the thrombus.

[0097] Thrombi and flowing blood have significant differences in electrical properties. Whole blood is rich in electrolytes and has a low resistivity, while thrombi, due to the accumulation of fibrin network and the removal of water, usually have an impedance value several orders of magnitude higher than that of blood.

[0098] The system measures the impedance at both ends of the support in real time by applying a weak, high-frequency (100 kHz) sensing current. Based on different impedance magnitude and phase angle characteristics, the system can automatically determine the following three states: 1. Free state: The impedance reference is low, indicating that the stent is in the blood circulation and has not come into contact with the thrombus.

[0099] 2. Contact status: Characteristic fluctuations in impedance and a phase angle shift towards capacitive behavior indicate that the stent has begun to embed in the thrombus.

[0100] 3. Complete Encapsulation State: The impedance reaches a peak value (e.g., >0.1 M ohms), indicating that the thrombus has completely filled the mesh of the stent body 1.

[0101] See Figure 9 As shown, the invention provides a thrombectomy method to improve the stability of thrombus adhesion, comprising: The stent body 1 is deployed in the blood vessel segment where the thrombus is located; Identify the contact state between the stent body 1 and the thrombus; After confirming contact, local interface modulation is applied to the contact interface between the thrombus and the stent body 1. The stent was withdrawn to remove the thrombus as a whole.

[0102] Furthermore, the interface modulation effect is directionally selective, and the interface modulation effect automatically stops after reaching a preset threshold.

[0103] The preset threshold includes at least one of the following parameters: 1. Time threshold: This refers to the continuous duration of a single interface modulation energy to reach a preset safe duration, such as a specific value set within the range of 1 to 10 seconds.

[0104] 2. Temperature threshold: Detect or estimate the local temperature at the interface between the thrombus and the stent to reach the target range for inducing fibrin denaturation (e.g., 50°C to 65°C).

[0105] 3. Electrical characteristic threshold (based on result judgment): Due to the local dehydration and solidification of the thrombus matrix caused by interface modulation, the contact impedance will increase characteristically. When the state detection unit 6 detects that the impedance of the local closed loop reaches the peak plateau period, or the impedance change rate (ΔZ / Δt) is lower than a certain set value, it determines that the interface has formed a stable physical anchorage, thereby triggering automatic stop.

[0106] Furthermore, when identifying the contact state between the stent body 1 and the thrombus, the identification steps are based on impedance characteristic analysis.

[0107] Furthermore, when withdrawing the stent, the withdrawal step is performed simultaneously with negative pressure suction.

[0108] Please see Figure 10 As shown, the interface states before and after action are compared. Before action (left figure), the stent body 1 is in contact with a loose thrombus. Through the energy action of the first interface region 11, the thrombus undergoes local physical or chemical changes at the interface (such as local coagulation or dehydration condensation), forming an adhesion enhancement region at the interface after action (right figure). This interface modulation capability significantly enhances the adhesion of the thrombus to the mesh structure of the stent body 1, rather than a simple mechanical mesh.

[0109] The advantages of this invention compared to traditional technologies are significant. Traditional thrombectomy stents (left figure) rely solely on mechanical mesh during retrieval, making it easy for thrombi to slip out of the mesh (thrombus slippage), leading to thrombectomy failure or distal embolism. In contrast, the stent body 1 of this invention (right figure) utilizes an enhanced interfacial adhesion mechanism, resulting in stable adhesion between the thrombus and the stent body 1. This prevents slippage during overall retrieval, significantly improving the success rate and safety of thrombectomy.

[0110] Furthermore, impedance data is acquired through the status detection unit 6; the control host determines whether the stent body is aligned with the thrombus. If so, the energy control unit 5 is activated; otherwise, if the stent body 1 is detected to be deviated from the thrombus or thrombectomy is completed, the termination control is executed.

[0111] In the above-mentioned thrombectomy methods, trigger-based control ensures the safety and effectiveness of the treatment.

[0112] Specifically, in the aforementioned thrombectomy method, the thermal dose adaptive modulation logic works as follows: when the impedance data confirms that the stent body 1 has been stably embedded in the thrombus, the control unit 4 will initiate the thermal anchoring program. To prevent temperature overshoot, the system employs adaptive pulse width modulation (PMM) technology. Energy delivery uses a duty cycle-controlled short pulse mode (e.g., 0.5s delivery / 0.3s interval), utilizing the natural blood flow within the blood vessel as a radiator to remove excess heat and ensure that the local maximum temperature is maintained within the "anchoring window" of 60°C.

[0113] Specifically, thrombectomy systems with asymmetric thermal anchoring function follow refined neurointerventional protocols in actual operation: Phase 1: Precise Navigation and Transthrombus Deployment. The physician, using a standard femoral artery approach and guided by a microguidewire, advances microcatheter 3 to the distal end of the thrombus. Subsequently, the thermally anchored stent body 1 is advanced to the target site, and microcatheter 3 is withdrawn to release the stent. After release, stent body 1 remains in place for approximately 3 to 5 minutes, utilizing its own radial force to fully cut and embed itself within the thrombus. At this point, due to the asymmetrical window design on the surface of stent body 1, the physician can rotate the delivery rod and use contrast markers to ensure the conductive window faces the center of the thrombus.

[0114] Phase Two: After confirming the stable position of the stent body 1, the radiofrequency control unit within the control unit 4 is activated, and thermal anchoring energy is delivered. The system first performs an impedance self-check to rule out the possibility of accidental contact with the vessel wall. Subsequently, a set of modulated radiofrequency energy is delivered. Within 1-10 seconds, the microenvironment temperature at the interface between the stent body 1 and the thrombus rapidly increases. Fibrin molecules unfold and physically anchor themselves to the micron-sized pores on the surface of the stent body 1. At this point, the originally fluid thrombus matrix undergoes localized "solidification" at the interface, significantly increasing slippage resistance.

[0115] Phase 3: After the synchronous retrieval and thrombus removal anchoring procedure is completed, the physician, with the assistance of proximal negative pressure aspiration, pulls back the stent body 1 at a constant speed. Because thermal anchoring provides additional mechanical coupling, the stent body 1 can firmly grasp the thrombus like a "gripper," effectively preventing the thrombus from escaping due to lateral force compression, even when passing through extremely curved anatomical structures such as the internal carotid siphon.

[0116] The stent body 1 described in this invention is applicable to various types of vascular occlusion scenarios, including but not limited to large vessel occlusion, mid-to-distal vessel thrombosis, and thrombus removal requirements with different compositions. Even in complex vascular anatomy environments, this invention can still achieve stable capture through interface modulation mechanisms, thereby expanding the applicability of thrombectomy technology.

[0117] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention, unless otherwise specified or limited, shall be implemented according to conventional means in the art.

Claims

1. A thrombus removal system with directional interface modulation function, characterized in that, include: A stent body that can be delivered via a delivery catheter and deployed within a blood vessel; The main body of the support is divided into at least two functionally different interface areas in the circumferential direction, including: The first interface region is used to contact the thrombus and to perform local interface modulation on the interface between the thrombus and the stent body. The second interface region is used to contact the blood vessel wall and restrict the transmission of the interface modulation effect towards the blood vessel wall; wherein the first interface region and the second interface region differ in interface energy conduction capability, interface physical properties or interface material configuration, forming a circumferentially asymmetric interface structure.

2. The thrombus removal system according to claim 1, characterized in that, The first interface region includes at least one of a conductive layer, a micro / nano structure, or a friction-enhancing coating.

3. The thrombus removal system according to claim 1, characterized in that, The second interface region includes at least one of an insulating coating, a heat insulation layer, or a multilayer composite structure.

4. The thrombus removal system according to claim 1, characterized in that, The support body includes a partially closed energy circuit, which is a bipolar or multi-bipolar structure. Each of the partially closed energy loops is equipped with an anode and a cathode. The anode and cathode in each partially closed energy loop are connected to wires respectively, and each partially closed energy loop is an independent conductive part.

5. A thrombus removal system according to claim 4, characterized in that, The partially closed energy loop includes a conductive layer and a wire connected to the conductive layer. The conductive layer is located at the outer edge of the inner wall of the support body and is connected to the energy control unit in the control host through the wire.

6. A thrombus removal system according to claim 5, characterized in that, The bipolar structure includes an anode contact integrated at the proximal anode of the support body and a cathode contact integrated at the distal anode of the support body, with the anode and cathode contacts connected to the conductive layer.

7. A thrombus removal system according to claim 1, characterized in that, The main body of the support structure is an open mesh structure with a diamond-shaped mesh layout; The main body of the stent is made of medical materials with shape memory or superelasticity properties.

8. A thrombus removal system according to claim 1, characterized in that, It also includes a microcatheter, which can move radially along the delivery catheter to deliver the stent body. During use, the stent body can be compressed and loaded into the microcatheter, which then delivers the stent body to the target vascular segment through the delivery catheter.

9. The thrombus removal system according to any one of claims 1-8, characterized in that, include: The status detection unit is used to identify the status of the medium surrounding the stent and obtain the identification result. The energy control unit selectively triggers interface modulation of the first interface region based on the identification result.

10. A thrombectomy method, using the thrombectomy system according to any one of claims 1-9, characterized in that, include: The main body of the stent is deployed in the segment of the blood vessel where the thrombus is located; Identify the contact state between the stent body and the thrombus; After confirming contact, local interface modulation is applied to the interface between the thrombus and the stent body. The stent was withdrawn to remove the thrombus as a whole.

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