Pressure guide wire and blood pressure monitoring equipment

Abstract

The invention relates to the technical field of medical instruments, and provides a pressure guide wire and blood pressure monitoring equipment. The pressure guide wire comprises a guide wire main body, a contact head and an ion electron layer; the guide wire main body comprises a catheter and a core wire arranged in the catheter; the contact head is arranged at the far end of the catheter; one end of the contact head towards the core wire is provided with a contact surface; the ion conducting layer has flexibility and is arranged between the core wire and the contact head; the ion conducting layer is provided with a first electrode end and a second electrode end; the core wire is connected to the first electrode end; the contact head has conductivity, and the contact surface is connected to the second electrode end; when the pressure guide wire is inserted into a human body, the contact head can deform under the action of in-vivo pressure so as to extrude the ion conducting layer, so that the capacitance of the ion conducting layer is changed. The ion conduction characteristic and flexibility of the ion conducting layer are utilized, other transmission wires do not need to be arranged in the catheter, the hardness of the guide wire body and the torque transmission influence from the near end to the far end are reduced, and the operability of the guide wire body is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a pressure guidewire and a blood pressure monitoring device having the pressure guidewire. Background Technology

[0002] Coronary artery disease (CAD) is a condition in which the coronary arteries become narrowed or blocked due to the accumulation of atherosclerotic plaques, leading to myocardial ischemia, angina pectoris, and even myocardial infarction. Fractional flow reserve (FFR) is a core physiological and functional indicator used to assess the impact of coronary artery stenosis on blood flow. It measures the pressure at different locations within the coronary arteries—specifically, the ratio of the pressure distal to the stenosis at the point of maximum myocardial congestion to the mean pressure in the aorta proximal to the stenosis—to determine whether the stenosis caused by plaque is severe enough to require intervention. This assessment technique has become the gold standard for diagnosing coronary artery disease in clinical practice. Currently, FFR values ​​are primarily obtained by clinicians through interventional measurement of the coronary arteries using a pressure guidewire.

[0003] Existing pressure guidewires typically include an electrical (piezoresistive or piezoelectric) or optical sensor located distally, transmitting pressure signals via conductive wires or optical fibers embedded within the guidewire. For example, traditional piezoelectric guidewires require two conductive wires: one for signal transmission and the other as ground. Some piezoresistive sensors even use Wheatstone bridge circuits, requiring four conductive wires for voltage supply and signal transmission. However, incorporating multiple wires within the guidewire reduces its stiffness, resulting in reduced torque transmission from proximal to distal, a significant decrease in the torsion ratio, and severely impacting the guidewire's maneuverability in stenotic and tortuous coronary arteries, especially at stenosis sites in a dynamically beating heart. Similarly, optical pressure guidewires use embedded optical fibers to transmit pressure signals, but their inherent fragility limits guidewire flexibility, increasing the risk of kinking and complicating what should be smooth navigation through stenotic coronary arteries. The complex internal structure of the aforementioned guidewire increases its cost due to the manufacturing process; furthermore, the reduced operability requires more repeated advance and withdrawal operations during guidewire operation, and the excessive and repeated contact force between the guidewire tip and the blood vessel can lead to complications such as dissection or perforation of fragile arteries. Summary of the Invention

[0004] The purpose of this invention is to provide a pressure guidewire that addresses the problems of complex internal structure and insufficient operability of existing guidewires.

[0005] In a first aspect, embodiments of this application provide a pressure guidewire, comprising:

[0006] A guidewire body, the guidewire body comprising a catheter and a core wire disposed within the catheter;

[0007] A contact head is located at the distal end of the conduit; the end of the contact head facing the core wire has a contact surface;

[0008] An ion-conducting layer, which is flexible, is disposed between the core wire and the contact head; the ion-conducting layer has a first electrode and a second electrode; the core wire is connected to the first electrode; the contact head is conductive, and the contact surface is connected to the second electrode; when the pressure guide wire is inserted into the human body, the contact head can deform under the pressure in the body to squeeze the ion-conducting layer, thereby changing the capacitance of the ion-conducting layer.

[0009] In some embodiments, the pressure guide wire further includes a connecting sleeve; both ends of the connecting sleeve are respectively sleeved on the core wire and the contact head; a receiving cavity is formed inside the connecting sleeve, and the ion-conducting layer is disposed in the receiving cavity.

[0010] By adopting the above technical solution, the connecting sleeve enables the core wire and the contact head to make conductive contact with the ion-conducting layer, making the connection convenient and quick.

[0011] In some embodiments, the pressure guidewire further includes a flexible sealing structure; the distal end of the core wire protrudes outward from the distal end of the catheter and extends into the connecting sleeve, a predetermined interval is formed between the end of the connecting sleeve near the catheter and the distal end of the catheter, and the sealing structure includes a first sealing connection portion disposed at the predetermined interval, and the first sealing connection portion is flexibly connected to the connecting sleeve and the catheter.

[0012] By adopting the above technical solution, the connecting sleeve and the conduit are flexibly connected through the first sealing connection part, so the connecting sleeve can move relative to the conduit in the axial direction of the conduit; then when the contact head is subjected to external force, the contact head drives the connecting sleeve to move toward the conduit, so that the contact head has a moving stroke to compress the ion conductive layer.

[0013] In some embodiments, the sealing structure further includes a second sealing connection portion, through which the contact head is connected to the connecting sleeve.

[0014] In some embodiments, the first sealing connection portion and the second sealing connection portion are an integral structure.

[0015] In some embodiments, the first sealing connection portion is separated from the second sealing connection portion.

[0016] By adopting the above technical solution, the connecting sleeve is sealed to the conduit and the contact head respectively, and the sealing structure can be an integrated structure or a separate structure.

[0017] In some embodiments, the ion-conducting layer is an ion-conducting soft material.

[0018] By adopting the above technical solutions, the ion-conducting layer can be an ion gel, an ion-conducting elastomer, a hydrogel, an organic gel, etc.

[0019] In some embodiments, the surface of the ion-conducting soft material has a microstructure;

[0020] In some embodiments, the mass ratio of the polymer to the ionic liquid in the ion-conducting soft material is 1:4.

[0021] By adopting the above technical solution, a high proportion of ionic liquid (80wt%) ensures high conductivity, while the polymer maintains the structural stability of the material.

[0022] In some embodiments, the contact head includes a column and a ball head disposed on the column; the column is used to engage with the connecting sleeve.

[0023] By adopting the above technical solution, the contact head is designed to combine a cylindrical column with a spherical ball head. The column matches the connecting sleeve so that the two can be fitted together. The smooth curved surface design of the ball head can avoid endothelial damage or vascular spasm during measurement.

[0024] In some embodiments, the outer surface of the ball head is provided with an isolation layer.

[0025] By adopting the above technical solution, the isolation layer is a dense inert metal layer, which is used to enhance the wear resistance, corrosion resistance, biocompatibility and optimize the electrical performance of the ball head.

[0026] In some embodiments, the diameter of the ion-conducting layer ranges from 400 μm to 430 μm;

[0027] In some embodiments, the length of the ion-conducting layer in the axial direction ranges from 80 μm to 120 μm.

[0028] In some embodiments, the inner diameter of the connecting sleeve ranges from 430μm to 460μm;

[0029] In some embodiments, the length of the connecting sleeve in the axial direction ranges from 0.8 mm to 1.2 mm.

[0030] In some embodiments, the connecting sleeve is made of resin.

[0031] By adopting the above technical solution, the resin material exhibits good biocompatibility and is suitable for the medical field. Furthermore, the connecting sleeve is manufactured using 3D printing, enabling rapid production according to set dimensions.

[0032] Secondly, embodiments of this application provide a blood pressure monitoring device, including a pressure guidewire, a power supply assembly, and an external contact electrode; the power supply assembly includes a first electrode and a second electrode; the first electrode is connected to the proximal end of the guidewire; the second electrode is connected to the external contact electrode, and the external contact electrode is used to be attached to the human body.

[0033] The beneficial effects of this application are as follows: When the pressure guidewire of this application is inserted into the human body for blood pressure measurement, the contact head applies pressure to the ion-conducting layer under the action of internal pressure. The ion-conducting layer is correspondingly compressed, resulting in structural deformation and a change in the capacitance parameter of the ion-conducting layer. This change is then converted into an electrical signal corresponding to the pressure via a conversion circuit (capacitance-voltage), enabling real-time and sensitive monitoring of the blood pressure signal. The pressure guidewire utilizes the ion conduction characteristics and flexibility of the ion-conducting layer itself; consequently, there is no need to install other transmission wires inside the catheter, reducing the impact on the rigidity of the guidewire body and the torque transmission from proximal to distal end, effectively improving the operability of the guidewire body and avoiding operational risks. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 A three-dimensional structural schematic diagram of a pressure guidewire provided in an embodiment of the present invention;

[0036] Figure 2 This is a schematic cross-sectional view of the distal end of a pressure guidewire provided in an embodiment of the present invention.

[0037] Figure 3 This is a schematic diagram of the distal end of a pressure guidewire according to an embodiment of the present invention; wherein, the pressure guidewire has not yet been provided with a sealing structure;

[0038] Figure 4 A cross-sectional view of a contact head provided in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the surface microstructure of an ion gel provided in an embodiment of the present invention;

[0040] Figure 6 The maneuverability test was performed on the pressure guidewire provided in one embodiment of the present invention and the existing sensor guidewire, and the resulting curves of torsion ratio versus torsion angle were obtained.

[0041] Figure 7A graph showing the change in capacitance with pressure value during a pressure guide wire sensitivity test according to an embodiment of the present invention;

[0042] Figure 8 A graph showing the change in capacitance with contact force during the insertion of a pressure guidewire into a living body during a biopsy, according to an embodiment of the present invention.

[0043] Figure 9 The graph shows the capacitance change over time during a live in vivo test using a pressure guidewire provided in an embodiment of the present invention.

[0044] The following are the labeling elements in the figure:

[0045] 1. Guidewire body; 110. Catheter; 120. Core wire;

[0046] 2. Contact head; 201. Contact surface; 210. Column; 220. Ball head;

[0047] 3. Ion-conducting layer; 310. First electrode; 320. Second electrode;

[0048] 4. Connecting sleeve; 401. Receiving cavity;

[0049] 5. Sealed structure;

[0050] 510. First sealing connection part; 520. Second sealing circuit part; 530. Third sealing connection part;

[0051] 6. Isolation layer. Detailed Implementation

[0052] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0053] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0055] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0056] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Currently, fractional flow reserve (FFR) is primarily obtained by clinicians through intervention with pressure guidewires in the coronary arteries. Existing pressure guidewires typically include an electrical (piezoresistive or piezoelectric) or optical sensor located distally, transmitting pressure signals via multiple conductive wires or optical fibers within the guidewire. However, incorporating multiple wires within the guidewire reduces its stiffness, leading to decreased torque transmission from proximal to distal end and a significant drop in the torsion ratio. This severely impacts the guidewire's maneuverability in stenotic and tortuous coronary arteries, particularly at narrow points in a dynamically beating heart. Furthermore, the complex internal structure of these guidewires increases their manufacturing cost.

[0058] To address these issues, this application presents a pressure guidewire. When the guidewire is inserted into the human body for blood pressure measurement, the contact head applies pressure to the ion-conducting layer under internal pressure. This compression causes structural deformation of the ion-conducting layer, resulting in a change in its capacitance parameters. A conversion circuit (capacitance-voltage) outputs an electrical signal corresponding to the pressure, enabling real-time and sensitive monitoring of blood pressure. The pressure guidewire utilizes the ion conduction characteristics of the ion-conducting layer itself; consequently, no other transmission wires are needed within the catheter, reducing the impact on the guidewire's rigidity and torque transmission from proximal to distal ends, effectively improving the guidewire's operability and mitigating operational risks.

[0059] In the field of interventional medical device technology, the direction closer to the operator is generally defined as proximal, and the direction farther from the operator is defined as distal. The direction of the central axis of objects such as cylinders and tubes is defined as axial. Radial refers to the direction passing through the central axis in the radial plane, for example, a straight line along a diameter or radius, or a straight line perpendicular to the central axis.

[0060] Please refer to Figure 1 , Figure 2 , Figure 3 The pressure guidewire provided in the first aspect of this application includes a guidewire body 1 and a contact head 2, i.e., an ion-conducting layer 3. The guidewire body 1 includes a conduit 110 and a core wire 120 disposed within the conduit 110. The contact head 2 is disposed at the distal end of the conduit 110, and the end of the contact head 2 facing the core wire 120 has a contact surface 201. The ion-conducting layer 3 is disposed between the core wire 120 and the contact head 2, and the ion-conducting layer 3 has a first electrode 310 and a second electrode 320. The core wire 120 is connected to the first electrode 310. The contact head 2 is conductive, and the contact surface 201 is connected to the second electrode 320. When the pressure guidewire is inserted into the human body, the contact head 2 can deform under the action of internal pressure to squeeze the ion-conducting layer 3, thereby changing the capacitance of the ion-conducting layer 3.

[0061] Specifically, refer to Figure 1 The pressure guidewire of this application is specifically used to measure human blood pressure. It is inserted into a narrowed coronary artery via the contact head 2. To conform to the tortuous vascular structure, the catheter 110 has a slender and flexible tube body. Inside the body, the contact head 2 is subjected to blood flow pressure or contact force from the vessel wall. The contact surface 201 of the contact head 2 will exert pressure on the ion-conducting layer 3, and the capacitance of the ion-conducting layer 3 will change under the pressure of the contact head 2.

[0062] It should be noted that the ion-conducting layer 3 comprises an ion-conducting material. By combining with an external power source, the ion-conducting material (such as a solid electrolyte, ionic liquid, or aqueous electrolyte) exhibits ion conductivity. Under the influence of an applied electric field, positive and negative ions migrate in opposite directions, forming charge separation within the material or at the electrode interface, thereby storing electrical energy. In this application, the capacitance change of the ion-conducting layer 3 is utilized to achieve highly sensitive mechanical detection. The ion-conducting layer 3 also possesses flexibility. When the contact head 2 squeezes the ion-conducting layer 3, it can deform the structure of the ion-conducting layer 3, affecting the ion mobility and changing the distance between the first electrode end 310 and the second electrode end 320. The capacitance (C) and resistance (R) of the ion-conducting layer 3 will change due to variations in the material's microstructure.

[0063] In some embodiments, according to the capacitance formula: C = ∈0∈ r (A / d);

[0064] in:

[0065] ∈0: vacuum permittivity; ∈ r : The relative permittivity of the ion-conducting layer 3 material;

[0066] A: Effective overlap area between plates; d: Electrode spacing.

[0067] Specifically, the ion-conducting layer 3 forms two opposing plates at the end face of the first electrode 310 and the end face of the second electrode 320. When the ion-conducting layer 3 is compressed by the pressure of the contact head 2, the distance d between the two plates decreases, and the capacitance C increases accordingly. Furthermore, the end face of the core wire 120 contacts the ion-conducting layer 3 more tightly, and the contact surface 201 of the contact head 2 contacts the ion-conducting layer 3 more tightly, thus expanding the electrode contact area A (e.g., lateral adhesion of micropillars). Ions in the ion-conducting layer 3 are redistributed, resulting in local ∈ r The increase in capacitance C results in an increase in capacitance C.

[0068] In the actual testing process of the pressure guidewire in this application, by combining it with electronic devices, the ion-conducting layer 3 forms a capacitance detection circuit under the action of an external electric field, obtaining the calibration curve (Δ)P=f(ΔC) of pressure and capacitance; then, based on the obtained real-time capacitance, the capacitance change is calculated, and the pressure signal value is output according to the calibration curve (Δ)P=f(ΔC), thereby accurately measuring the current pressure value. Therefore, the essence of the principle of this application is external force → deformation of the structure / material of the ion-conducting layer 3 → capacitance parameters (d / A / ∈) of the ion-conducting layer 3. r The change is converted into an electrical signal, enabling high-precision real-time detection of pressure.

[0069] Understandably, the ion-conducting layer 3 is also elastic. The ion-conducting layer 3 deforms under external force and can return to its original shape after the external force is removed; thus, the pressure guide wire can be used repeatedly.

[0070] When the pressure guidewire of this application is inserted into the human body for blood pressure measurement, the contact head 2 applies pressure to the ion-conducting layer 3 under the action of internal pressure. The ion-conducting layer 3 is compressed accordingly, causing structural deformation and changing its capacitance parameters. The corresponding voltage signal is output through a conversion circuit (capacitance-voltage) to obtain the required pressure for measurement, thereby achieving real-time and sensitive monitoring of blood pressure signals. The pressure guidewire utilizes the ion conduction characteristics and flexibility of the ion-conducting layer 3 itself, eliminating the need for multiple signal transmission wires in traditional guidewires. This reduces the impact on the rigidity of the guidewire body 1 and the torque transmission from proximal to distal end, effectively improving the operability of the guidewire body 1 and avoiding operational risks.

[0071] In some embodiments, the pressure guide wire further includes a connecting sleeve 4; the two ends of the connecting sleeve 4 are respectively sleeved on the core wire 120 and the contact head 2; a receiving cavity 401 is formed inside the connecting sleeve 4, and the ion-conducting layer 3 is disposed in the receiving cavity 401.

[0072] Specifically, the ion-conducting layer 3 is disposed in the receiving cavity 401 of the connecting sleeve 4. One end of the connecting sleeve 4 is sleeved outside the core wire 120, so that the core wire 120 contacts the first electrode 310 of the ion-conducting layer 3; the other end of the connecting sleeve 4 is sleeved outside the contact head 2, so that the second electrode 320 of the ion-conducting layer 3 contacts the contact surface 201 of the contact head 2; then the connecting sleeve 4 makes the core wire 120 and the contact head 2 make conductive contact with the ion-conducting layer 3 respectively, making the connection convenient and quick.

[0073] Both the core wire 120 and the contact head 2 are conductive, and the ion-conducting layer 3 is ion-conducting. Thus, the core wire 120, the ion-conducting layer 3, and the contact head 2 can form a conductive circuit. It can be understood that by combining the pressure guide wire of this application with an external power supply device, the ion-conducting layer 3 can form charge separation under the action of an external electric field.

[0074] In some embodiments, the pressure guide wire of this application is combined with an external power supply device to subject the ion-conducting layer 3 to an external electric field; an LCR meter is set in the circuit, which is an electronic instrument used to measure the parameters of passive devices such as inductance (L), capacitance (C) and resistance (R), thereby forming a capacitance-to-voltage (CV) conversion circuit to convert the capacitance change of the ion-conducting layer 3 into a measurable voltage signal, and obtain the corresponding pressure to be detected based on the voltage signal.

[0075] In some embodiments, the connecting sleeve 4 is made of resin material; resin material has good biocompatibility and is suitable for the medical field. Furthermore, the connecting sleeve 4 is manufactured using 3D printing, enabling rapid fabrication according to set dimensions.

[0076] refer to Figure 2 and Figure 3 In some embodiments, the pressure guidewire further includes a flexible sealing structure 5; the distal end of the core wire 120 protrudes outward from the distal end of the conduit 110 and extends into the connecting sleeve 4, and the end of the connecting sleeve 4 near the conduit 110 has a preset interval with the distal end of the conduit 110; the sealing structure 5 includes a first sealing connection portion 510 disposed at the preset interval; the connecting sleeve 4 can move relative to the conduit 110 in a first direction X through the first sealing connection portion 510.

[0077] Specifically, before installing the connecting sleeve 4 to the guidewire body 1, a portion of the distal end of the catheter 110 is removed to expose part of the core wire 120, and the connecting sleeve 4 is fitted over the exposed core wire 120. In some embodiments, the catheter 110 is a polymer coating covering the core wire 120, which serves as insulation protection; the core wire 120 is a nickel-titanium alloy guidewire, a shape-memory metal widely used in the field of medical devices.

[0078] It should be noted that the catheter 110 of this application has only a core wire 120 inside, and no other wire structure is required inside; while realizing the ability to detect the contact pressure between the contact head 2 and the blood vessel wall, the guide wire body 1 has good maneuverability and low manufacturing cost.

[0079] Understandably, the end face of the core wire 120 that is in contact with the ion-conducting layer 3 is ground smooth to make the end face of the core wire 120 in contact with the ion-conducting layer 3 smooth and able to fit tightly in contact with the ion-conducting layer 3.

[0080] refer to Figure 3 The connecting sleeve 4 is sleeved with the core wire 120, and there is a preset distance between the end of the connecting sleeve 4 near the conduit 110 and the far end of the conduit 110, that is, the connecting sleeve 4 and the conduit 110 do not contact each other; a first sealing connection part 510 is provided at the preset distance, and the first sealing connection part 510 is used to seal the connection between the connecting sleeve 4 and the conduit 110.

[0081] Specifically, the first sealing connection part 510 is made of silicone. The first sealing connection part 510 is formed at a predetermined interval using a silicone encapsulation process, and achieves a flexible bonding effect between the connecting sleeve 4 and the conduit 110. Silicone also has good biocompatibility; (Reference) Figure 2During the encapsulation process, silicone material is filled around the preset interval through injection molding, casting, or other methods, and then connected to the connecting sleeve 4 and the conduit 110 respectively. Subsequently, the first sealing connection part 510 can form a dense protective layer at the preset interval, achieving a better sealing and insulation protection effect.

[0082] Understandably, a preset gap is reserved between the connecting sleeve 4 and the distal end of the conduit 110. The first sealing connection part 510 is located at the preset gap, and the connecting sleeve 4 and the conduit 110 are flexibly connected through the first sealing connection part 510. Therefore, the connecting sleeve 4 can move relative to the conduit 110 in the axial direction of the conduit 110. Then, when the contact head 2 is subjected to external force, the contact head 2 drives the connecting sleeve 4 to move toward the conduit 110, so that the contact head 2 has a moving stroke to compress the ion-conductive layer 3.

[0083] refer to Figure 2 In some embodiments, the pressure guide wire further includes a second sealing connection 520, through which the contact head 2 is connected to the connecting sleeve 4.

[0084] Understandably, the second sealing connection 520 is sealed between the contact head 2 and the connecting sleeve 4, forming a good sealing effect at the connection between the two, and effectively providing insulation protection for the internal ion-conducting layer 3.

[0085] In one specific embodiment of this example, the first sealing connection part 510 and the second sealing connection part 520 are an integrated structure.

[0086] Specifically, after the connecting sleeve 4 is fitted with the core wire 120 and the contact head 2 respectively, silicone material is filled between the conduit 110 and the contact head 2 through injection molding, casting, or other methods. After the silicone cures, an integrated sealing structure is formed. (Refer to...) Figure 2 The sealing structure covers the connecting sleeve 4, and the sealing structure includes at least a first sealing connection 510 that is sealed between the connecting sleeve 4 and the conduit 110, and a second sealing connection 520 that is sealed between the contact head 2 and the connecting sleeve 4.

[0087] In another specific embodiment of this example, the first sealing connection portion 510 and the second sealing connection portion 520 are separated.

[0088] Specifically, after the connecting sleeve 4 is sleeved with the core wire 120 and the contact head 2 respectively, a first sealing connection part 510 is formed between the connecting sleeve 4 and the conduit 110 through a silicone encapsulation process; a second sealing connection part 520 is formed between the contact head 2 and the connecting sleeve 4 through a silicone encapsulation process; and the first sealing connection part 510 and the second sealing connection part 520 are separated.

[0089] Preferably, the sealing structure 5 is an integrated structure, and the sealing structure 5 includes a third sealing connection 530 connected between the first sealing connection 510 and the second sealing connection 520, and the third sealing connection 530 covers the connecting sleeve 4.

[0090] Specifically, the thickness of the third sealing connection 530 is in the range of 30μm-60μm; the thickness of the sealing structure 5 can be any value among 30μm, 40μm, 50μm, and 60μm; preferably, the thickness of the third sealing connection 530 is 50μm, and the silicone thickness of the encapsulation structure is set within a reasonable range to form a good sealing protection effect while reducing the impact on operational sensitivity.

[0091] In some embodiments, the ion-conducting layer 3 is an ion-conducting soft material.

[0092] The ion-conducting layer 3 is an ion-conducting soft material that achieves conductivity through ion migration. Under the action of an external electric field, positive and negative ions migrate in opposite directions within the ion-conducting layer 3, forming charge separation within the material or at the electrode interface. Furthermore, the ion-conducting layer 3 is flexible and can be compressed under the pressure of the contact head 2.

[0093] For example, the ion-conducting layer 3 can specifically be: ion gel, ion elastomer, hydrogel, organic gel, etc.

[0094] Preferably, the ion-conducting layer 3 is an ion gel.

[0095] Ionic gels are composed of cross-linked polymer networks (such as polyacrylates, polyvinyl alcohol, etc.) and ionic liquids (or salt solutions), possessing both high dielectric constant and deformability. Free ions in the gel migrate under the influence of an electric field, forming conductive pathways; furthermore, the elasticity of the polymer network allows the gel to deform under external forces and return to its original shape.

[0096] Specifically, ionogels have the following advantages: 1. High sensitivity; ionogels are designed with porous or microstructures, enabling them to sense minute pressures and achieve highly sensitive detection. 2. Excellent flexibility and stretchability; the elastic modulus of ionogels is close to that of biological tissue (~10). 4 -10 6It can be bent, folded, or stretched (strain up to 300% or more), making it suitable for bonding to complex surfaces; and the polymer network of the ionogel can withstand repeated deformation without breaking, exhibiting excellent mechanical fatigue resistance. 3. Stable electrochemical performance; the ion liquid-based gel can withstand high voltage (>3V), suitable for long-term operation; in addition, the ion liquid retains ionic conductivity at low temperatures (below -20℃). 4. Strong environmental adaptability; the ion liquid is difficult to volatilize and has strong resistance to dehydration, effectively avoiding drying problems (good long-term stability). 5. Easy to process and low cost; ion gels can be prepared in large areas through coating, 3D printing, or injection molding; and the performance can be flexibly optimized by changing the polymer / ion liquid ratio or additives (such as nanoparticles).

[0097] refer to Figure 5 In some embodiments, the surface of the ionogel has a microstructure.

[0098] Understandably, constructing micro- and nano-structures (such as columnar, porous, wrinkled, and wavy structures) on the surface of ionogels increases the specific surface area and enhances sensitivity to external stimuli (pressure, strain, humidity). Furthermore, by combining microstructure design with the properties of ionogels to form self-filling microstructures, the autonomous flow, redistribution, or dynamic filling of the ionogel in response to external stimuli (pressure) can be achieved.

[0099] Preferably, this application introduces a sandpaper template during the ion gel preparation process to control the microstructure of the ion gel surface; the rough surface of the sandpaper is imprinted or transferred onto the ion gel surface to form a multi-level uneven structure. Specifically, during the ion gel fabrication process, the cross-section is polished successively with low-mesh and high-mesh sandpaper, with the highest mesh size of the sandpaper template being 10,000 mesh, which can form a dense and uniform micron-level uneven structure on the surface of the ion gel.

[0100] In some embodiments, the mass ratio of the polymer to the ionic liquid in the ionic gel ranges from 1:1 to 1:4.

[0101] Specifically, the polymer used in the ion gel of this application is polyvinylidene fluoride-hexafluoropropylene copolymer (P(VdF-HFP)), and the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ([EMIM][TFSI]). P(VdF-HFP) and ([EMIM][TFSI]) in the ion gel can be blended in any mass ratio of 1:1, 1:2, 1:3, or 1:4.

[0102] In one embodiment, P(VdF-HFP) and ([EMIM][TFSI]) are blended at a mass ratio of 1:4; the high proportion of ionic liquid (80 wt%) ensures high conductivity, while P(VdF-HFP) maintains the stability of the gel structure.

[0103] refer to Figures 1 to 3 In some embodiments, the contact head 2 includes a column 210 and a ball head 220 disposed on the column 210; the column 210 is used to engage with the connecting sleeve 4.

[0104] Specifically, the contact head 2 is designed with a cylindrical column 210 combined with a spherical ball head 220. The column 210 matches the connecting sleeve 4 for easy engagement. The ball head 220 is used for point contact with the blood vessel wall, which can accurately capture weak blood pressure fluctuations and improve sensitivity. Furthermore, the smooth curved surface design of the ball head 220 reduces local pressure on the blood vessel wall or soft tissue, reduces mechanical friction during measurement, and avoids endothelial damage or vasospasm during measurement.

[0105] The contact head 2 can be made of metals such as copper, aluminum, stainless steel, titanium alloy, and tungsten-cobalt alloy, and has electrical conductivity.

[0106] refer to Figure 4 In some embodiments, the outer surface of the ball head 220 is provided with an isolation layer 6.

[0107] Specifically, the isolation layer 6 is a dense inert metal layer, which is a chemically stable and low-activity metal coating formed on the surface of the ball head 220 through special processes (such as electroplating, vapor deposition, thermal spraying, etc.). It is used to enhance wear resistance, corrosion resistance, biocompatibility and optimize electrical performance. The isolation layer 6 can protect the ball head 220 body from chronic corrosion by ionic solutions and improve its service life.

[0108] In some embodiments, the diameter of the ion-conducting layer 3 is in the range of 400 μm to 430 μm. Specifically, the diameter of the ion-conducting layer 3 can be any value among 400 μm, 405 μm, 410 μm, 415 μm, 420 μm, 425 μm, and 430 μm.

[0109] In some embodiments, the length of the ion-conducting layer 3 in the axial direction ranges from 80 μm to 120 μm. The axial direction of the ion-conducting layer 3 is parallel to the axial direction of the connecting sleeve 4, and the length of the ion-conducting layer 3 in the axial direction can be any value among 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, and 120 μm.

[0110] In some embodiments, the inner diameter of the connecting sleeve 4 is in the range of 430μm-460μm. Specifically, the inner diameter of the connecting sleeve 4 can be any value among 430μm, 435μm, 440μm, 445μm, 450μm, 455μm, and 460μm, so as to ensure that the ion-conducting layer 3 can be placed inside the connecting sleeve 4.

[0111] In some embodiments, the length of the connecting sleeve 4 in the axial direction ranges from 0.8mm to 1.2mm. Specifically, the length of the connecting sleeve 4 in the axial direction can be any value among 0.8mm, 0.9mm, 1.0mm, 1.1mm, and 1.2mm.

[0112] In a preferred embodiment of this application, the parameters of the guidewire body 1, the contact head 2, and the ion-conducting layer 3 are as follows:

[0113] The diameter of the core wire 120 is 415 μm.

[0114] The diameter of the ion-conducting layer 3 is 420 μm, and the length of the ion-conducting layer 3 in the axial direction is 100 μm.

[0115] The inner diameter of the connecting sleeve 4 is 450μm, and the length of the connecting sleeve 4 in the axial direction is 1.0mm;

[0116] The wall thickness of the connecting sleeve 4 is 100μm.

[0117] The diameter of the cylinder 210 of the contact head 2 is 435 μm, and the length of the cylinder 210 is 180 μm;

[0118] The diameter of the ball head 220 of the contact head 2 is 700 μm; the thickness of the isolation layer 6 on the surface of the ball head 220 is 3 μm.

[0119] In some embodiments, this application also provides a blood pressure monitoring device, including a pressure guidewire, a power supply assembly, and an external contact electrode; the power supply assembly includes a first electrode and a second electrode; the first electrode is connected to the proximal end of the core wire 110; the second electrode is connected to the external contact electrode, and the external contact electrode is used to contact the body surface.

[0120] Understandably, the pressure guide wire is combined with the power supply component to form a signal conversion circuit, thereby applying an electric field to the ion-conducting layer 3; the contact head 2 is subjected to pressure and squeezes the ion-conducting layer 3, and the ion-conducting layer 3 is compressed to change the capacitance parameter; for example, an LCR meter is connected in series in the circuit. An LCR meter is an electronic instrument used to measure the parameters of passive devices such as inductance (L), capacitance (C) and resistance (R), thereby forming a capacitance-to-voltage (CV) conversion circuit, which converts the capacitance change of the ion-conducting layer 3 into a measurable voltage signal, and obtains the corresponding pressure based on the voltage signal, thereby realizing real-time and sensitive monitoring of the blood pressure signal.

[0121] In some examples, torsion simulations were performed on the pressure guidewire of this application and the guidewire with an internally installed sensor in the prior art, and linear graphs of the corresponding torsion ratio and proximal torsion angle were generated based on the simulation data (see reference). Figure 6 );

[0122] According to the comparison of the charts: Since the conduit 110 of the pressure guidewire in this application only has a core wire 120 inside, there is no need to set other wire structures inside. The guidewire body 1 has better maneuverability. In actual maneuverability simulation, the torsion ratio (torsion angle at the distal end / torsion angle applied at the proximal end) of the guidewire body 1 is close to 1. In contrast, the existing technology uses guidewires with electrical (piezoresistive or piezoelectric) or optical sensors. Due to the multiple circuit transmission lines set inside the guidewire, the torque transmission from the proximal end to the distal end of the guidewire is reduced, and the torsion ratio drops significantly, with the torsion ratio approaching 0.4. Therefore, the pressure guidewire of this application undoubtedly has excellent maneuverability.

[0123] In some embodiments, reference Figure 7 In a simulated aquatic environment, the pressure guide wire of this application was combined with a power supply component to form a signal conversion circuit. The relationship between the capacitance signal and pressure was tested, and the test was repeated to obtain three sets of test samples. The test results are as follows: Figure 7 As shown, the capacitance change-pressure change curve of the pressure guidewire is linear. The sensitivity was calculated accordingly, where sensitivity represents the change in capacitance signal per millimeter of mercury pressure. The measured sensitivity is 0.39 pF / mmHg. -1 Furthermore, the data curves in the repeated test samples basically overlap, indicating that the pressure guidewire of this application has good stability.

[0124] refer to Figure 8 In some embodiments, this application also provides a curve showing the effect of inserting a pressure guidewire into a living organism (e.g., a rabbit) and changing the contact force between the contact head 2 and the living organism by controlling the pressure guidewire, and the capacitance signal changing with the contact force; according to Figure 8 Demonstration: Within 0-4 seconds, when contact head 2 is not in contact with the blood vessel wall, it outputs a normal capacitive pulsating signal; within 4-7 seconds, when contact head 2 contacts the blood vessel wall, the capacitive pulsating signal will increase significantly, clearly different from the normal signal. This can alert the operator of the risk of blood vessel wall dissection or puncture, allowing the operator to make timely adjustments, thereby improving the safety in actual surgery; within 8-10 seconds, contact head 2 detaches from the blood vessel wall, and the capacitive signal returns to normal.

[0125] refer to Figure 9 In some embodiments, this application also provides a curve showing the change of capacitance signal over time when a pressure guidewire is inserted into a living organism (e.g., the coronary artery of a pig) for an extended period of time. As shown in the figure, after 5 seconds, the pressure guidewire is inserted into the coronary artery of the pig and the blood flow in the coronary artery is detected for an extended period of time. During the detection process, the capacitance signal remains stable for a long time and can sensitively capture small pressure fluctuations in the blood flow, indicating that the pressure guidewire of this application has the advantages of high sensitivity and fast response.

[0126] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pressure guidewire, characterized in that: include: A guidewire body, the guidewire body comprising a catheter and a core wire disposed within the catheter; A contact head is located at the distal end of the conduit; the end of the contact head facing the core wire has a contact surface; An ion-conducting layer, which is flexible, is disposed between the core wire and the contact head; the ion-conducting layer has a first electrode and a second electrode; the core wire is connected to the first electrode; the contact head is conductive, and the contact surface is connected to the second electrode; when the pressure guide wire is inserted into the human body, the contact head can deform under the pressure in the body to squeeze the ion-conducting layer, thereby changing the capacitance of the ion-conducting layer.

2. The pressure guidewire according to claim 1, characterized in that: The pressure guide wire also includes a connecting sleeve; the two ends of the connecting sleeve are respectively sleeved on the core wire and the contact head; a receiving cavity is formed inside the connecting sleeve, and the ion-conducting layer is disposed in the receiving cavity.

3. The pressure guidewire according to claim 2, characterized in that: The pressure guidewire also includes a flexible sealing structure; the distal end of the core wire protrudes outward from the distal end of the catheter and extends into the connecting sleeve, a preset interval is formed between the end of the connecting sleeve near the catheter and the distal end of the catheter, and the sealing structure includes a first sealing connection part disposed at the preset interval, and the first sealing connection part is flexibly connected to the connecting sleeve and the catheter.

4. The pressure guidewire according to claim 3, characterized in that: The sealing structure further includes a second sealing connection portion, through which the contact head is connected to the connecting sleeve; wherein... The first sealing connection and the second sealing connection are an integral structure; or, The first sealing connection portion is separated from the second sealing connection portion.

5. The pressure guidewire according to any one of claims 1-4, characterized in that: The ion-conducting layer is an ion-conducting soft material.

6. The pressure guidewire according to claim 5, characterized in that: The surface of the ion-conducting soft material has a microstructure; and / or, The mass ratio of the polymer to the ionic liquid in the ion-conductive soft material ranges from 1:1 to 1:

4.

7. The pressure guidewire according to any one of claims 2-4, characterized in that: The contact head includes a column and a ball head disposed on the column; the column is used to engage with the connecting sleeve.

8. The pressure guidewire according to claim 7, characterized in that: The outer surface of the ball head is provided with an isolation layer.

9. The pressure guidewire according to claim 2, characterized in that: The diameter range of the ion-conducting layer is 400μm-430μm; and / or, The ionic conductive layer has a length range of 80μm-120μm in the axial direction.

10. The pressure guidewire according to claim 9, characterized in that: The inner diameter of the connecting sleeve is in the range of 430μm-460μm; and / or, The length of the connecting sleeve in the axial direction ranges from 0.8mm to 1.2mm.

11. The pressure guidewire according to claim 2, characterized in that: The connecting sleeve is made of resin.

12. A blood pressure monitoring device, characterized in that, It includes a pressure guidewire, a power supply assembly, and an external contact electrode as described in any one of claims 1-11; the power supply assembly includes a first electrode and a second electrode; the first electrode is connected to the proximal end of the guidewire; the second electrode is connected to the external contact electrode, and the external contact electrode is used to contact the body surface.

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