Pressure microcatheter

Abstract

The present invention provides a pressure microcatheter, which is characterized by comprising: a catheter and an assembled mandrel disposed in the catheter. The assembled mandrel includes multiple core wires, a fixed base for connecting the multiple core wires, and a pressure sensor fixed to the fixed base. The multiple core wires include a first core wire, a second core wire, and a third core wire arranged in sequence. The first core wire is a variable-diameter core wire, the second core wire is an equal-diameter core wire and the front end of the second core wire has an inclined cut, the third core wire is a variable-diameter core wire, and the outer diameter of the rear end portion thereof gradually decreases to the outer diameter of the front end portion, and the front end of the third core wire has an inclined cut. In the present invention, the first sensor fixed to the fixed base measures the pressure at the distal end of the lesion stenosis in the coronary artery, and the second pressure sensor fixed to the fixed base measures the pressure at the proximal end of the lesion stenosis in the coronary artery. Thus, a measurement system externally connected to the pressure microcatheter can calculate the fractional flow reserve of the patient.

Description

Technical Field

[0001] The present invention relates to a microcatheter for intravascular pressure measurement, and particularly to a pressure microcatheter. Background Art

[0002] Coronary artery disease is one of the main causes of death worldwide. The ability to better diagnose, monitor, and treat coronary artery disease can save lives. Coronary angiography is a technique commonly used to evaluate coronary artery stenosis lesions. However, coronary angiography cannot reflect the true situation of coronary artery function. Therefore, it is basically impossible to determine whether the stenotic coronary artery is related to the myocardial ischemia symptoms of the patient. Currently, the main method used clinically to judge coronary artery stenosis lesions is the fractional flow reserve (FFR) technique obtained by using a pressure wire examination.

[0003] FFR is defined as the ratio of the maximum blood flow in a stenotic artery to the normal maximum blood flow. To calculate the FFR for a given stenosis in a blood vessel (i.e., a site where a vascular stent may be placed), blood pressure readings need to be measured and collected separately at the distal side of the stenosis (e.g., downstream of the stenosis, away from the aorta) and the proximal side of the stenosis (e.g., upstream of the stenosis, close to the aorta). Clinical studies have shown that the higher the degree of stenosis, the lower the FFR value. Whether the FFR value is less than an evaluation value (e.g., 0.75) can be used as a useful judgment criterion. Based on this criterion, a doctor can decide whether to perform interventional treatment on such a patient. As a method for measuring intravascular blood pressure to measure the FFR value of vascular stenosis, currently, FFR measurement uses an invasive pressure sensor measurement catheter. The measurement catheter has a pressure sensor and a pressure wire. The pressure wire transmits the pressure sensor through a guiding catheter to the distal part of the coronary artery stenosis for pressure measurement Pd. Then, the pressure wire retracts and pulls the pressure sensor to the proximal part of the coronary artery stenosis for pressure measurement Pa. During the measurement of Pa, the pressure difference between the pressure of the aortic pressure sensor and the pressure of the pressure wire should be less than + / -9 mmHgm. If the pressure difference exceeds + / -9 mmHgm, the position of the pressure sensor needs to be readjusted, the guiding catheter needs to be flushed. During the measurement of Pd, the distal end of the wire needs to be zeroed outside the body. During the movement of the wire in the catheter, it may pass through blood vessels with complex and variable shapes, such as the coronary arteries of the heart, and the wire needs to be exchanged back and forth, increasing the operation time and consuming the physical strength of the operator, increasing the operation cost and operation risk of the patient. Summary of the Invention

[0004] The present invention is completed in view of the above-mentioned prior art situation, and its purpose is to provide a pressure measurement catheter that can effectively improve the measurement accuracy and at the same time reduce the use steps and operation time of the FFR catheter.

[0005] To this end, the present invention provides a pressure microcatheter, comprising: a catheter and an assembly mandrel disposed in the catheter. The catheter is of a rapid exchange structure and includes a front-end catheter and a rear-end catheter connected to each other. The front-end catheter has a guide wire port, and the rear-end catheter has a cavity. The assembly mandrel is disposed in the rear-end catheter. The assembly mandrel includes multiple segments of core wires, a fixed base for connecting the multiple segments of core wires, and a pressure sensor fixed to the fixed base. Each of the multiple segments of core wires has a front end close to the guide wire port and a rear end far from the guide wire port. The multiple segments of core wires include a first core wire, a second core wire, and a third core wire arranged in sequence. The fixed base includes a first fixed base connecting the first core wire and the second core wire and a second fixed base connecting the second core wire and the third core wire. The pressure sensor includes a first pressure sensor and a second pressure sensor; the first pressure sensor is disposed in the first fixed base, and the second pressure sensor is disposed in the second fixed base. Thus, the first pressure sensor and the second pressure sensor can be fixed to the fixed base, and the multi-segment core wires can support and fix the mandrel.

[0006] In the present invention, the first core wire is a variable-diameter core wire, the second core wire is an equal-diameter core wire and the front end of the second core wire has an inclined cut, and the third core wire is a variable-diameter core wire and the front end of the third core wire has an inclined cut; the first fixed base is connected to the inclined cut at the front end of the second core wire, and the second fixed base is connected to the inclined cut at the front end of the third core wire. In this case, the first core wire, the second core wire, and the third core wire can be respectively connected and fixed to the first fixed base and the second fixed base.

[0007] In the present invention, the first pressure sensor and the second pressure sensor are arranged at intervals along the axial direction of the assembly mandrel so that the first pressure sensor measures the pressure at the distal end of the lesion stenosis in the coronary artery, and the second pressure sensor measures the pressure at the proximal end of the lesion stenosis in the coronary artery. In this case, the pressure Pd measured by the first pressure sensor at the distal end of the lesion stenosis in the coronary artery and the pressure Pa measured by the second pressure sensor at the proximal end of the lesion stenosis in the coronary artery can be used to calculate the fractional flow reserve (FFR) within a short time through ratio calculation.

[0008] In the present invention, the first pressure sensor and the second pressure sensor are located on the same axial side within the catheter. In this case, the first pressure sensor and the second pressure sensor are in one plane, which can facilitate the smooth passage of the rear-end catheter through the lesion site.

[0009] In the present invention, the distance between the first pressure sensor and the second pressure sensor is 5 cm to 20 cm. Thus, the first pressure sensor can measure the distal pressure at the stenotic lesion in the coronary artery, and the second pressure sensor can measure the proximal pressure at the stenotic lesion in the coronary artery.

[0010] In the present invention, the fixed base has a front end close to the guide wire port and a rear end away from the guide wire port. The front end of the fixed base has a circular tube structure, and the rear end of the fixed base has a slot. The rear end of the first core wire is inserted into the circular tube structure of the first fixed base and welded to the circular tube structure of the first fixed base. The front end of the second core wire is inserted into the slot of the first fixed base and welded to the slot of the first fixed base. The rear end of the second core wire is inserted into the circular tube structure of the second fixed base and welded to the circular tube structure of the second fixed base. The front end of the third core wire is inserted into the slot of the second fixed base and welded to the slot of the second fixed base. In this case, the first core wire can be fixed to the first fixed base, the second core wire can be fixed to the first fixed base and the second fixed base, and the third core wire can be fixed to the second fixed base.

[0011] In the present invention, a first groove is provided between the circular tube structure of the first fixed base and the slot of the first fixed base. The first pressure sensor is disposed in the first groove. A second groove is provided between the circular tube structure of the second fixed base and the slot of the second fixed base. The second pressure sensor is disposed in the second groove. Thus, the first pressure sensor can be fixed to the first groove, and the second pressure sensor can be fixed to the second groove.

[0012] In the present invention, the cross-section of the rear end of the first core wire is circular and the outer diameter of the cross-section of the rear end of the first core wire matches the inner diameter of the circular tube structure of the first fixed base. The cross-section of the front end of the second core wire is bow-shaped, and the cross-section of the front end of the second core wire matches the cross-section of the slot of the first fixed base. The cross-section of the rear end of the second core wire is circular and the outer diameter of the cross-section of the rear end of the second core wire matches the inner diameter of the circular tube structure of the second fixed base. The cross-section of the front end of the third core wire is bow-shaped, and the cross-section of the front end of the third core wire matches the cross-section of the slot of the second fixed base. In this case, the first core wire, the second core wire and the third core wire can be well fixed to the fixed base, and thus can be placed in the rear catheter and can well support the movement of the rear catheter in the blood vessel.

[0013] In the present invention, the fixed base has a front end close to the guide wire port and a rear end far from the guide wire port. The rear end of the first core wire is welded and fixed to the front end of the first fixed base, the front end of the second core wire is welded and fixed to the rear end of the first fixed base, the rear end of the second core wire is welded and fixed to the front end of the second fixed base, and the front end of the third core wire is welded and fixed to the rear end of the second fixed base. In this case, the first core wire, the second core wire, and the third core wire can be well fixed to the fixed base, and thus can be placed in the rear catheter, and can well support the movement of the rear catheter in the blood vessel.

[0014] In the present invention, a first groove is provided between the front end and the rear end of the first fixed base, the first pressure sensor is disposed in the first groove, a second groove is provided between the front end and the rear end of the second fixed base, and the second pressure sensor is disposed in the second groove. Thus, the first pressure sensor can be fixed in the first groove of the first fixed base, and the second pressure sensor can be fixed in the second groove of the second fixed base, which is beneficial for the pressure sensor to accurately measure blood pressure.

[0015] According to the present invention, a pressure microcatheter can be provided to measure the distal pressure value Pd and the proximal pressure value Pa of a coronary artery lesion stenosis. A measurement system connected to the pressure microcatheter calculates the ratio of Pd to Pa to obtain the fractional flow reserve (FFR) in a short time. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. shows a schematic diagram of an application scenario of the pressure microcatheter involved in the present disclosure.

[0017] Figure 2 FIG. shows a plan view of the pressure microcatheter involved in the present disclosure.

[0018] Figure 3 FIG. shows a top view schematic diagram of a first embodiment of the assembled mandrel involved in the present disclosure.

[0019] Figure 4 FIG. shows a plan view schematic diagram of a first embodiment of the assembled mandrel involved in the present disclosure.

[0020] Figure 5 FIG. shows a cross-sectional schematic diagram of a longitudinal section of a first embodiment of the pressure microcatheter involved in the present disclosure.

[0021] Figure 6 FIG. shows the Figure 5 enlarged schematic diagram of area A in.

[0022] Figure 7A cross-sectional schematic diagram of a longitudinal section of a first embodiment of a fixed base of a pressure microcatheter according to the present disclosure is shown.

[0023] Figure 8 A top view schematic diagram of a second embodiment of an assembly mandrel according to the present disclosure is shown.

[0024] Figure 9 A plan view schematic diagram of a second embodiment of an assembly mandrel according to the present disclosure is shown.

[0025] Figure 10 A cross-sectional schematic diagram of a longitudinal section of a second embodiment of a pressure microcatheter according to the present disclosure is shown.

[0026] Figure 11 Shown is what the present disclosure relates to Figure 10 An enlarged schematic diagram of region B in

[0027] Figure 12 A cross-sectional schematic diagram of a longitudinal section of a second embodiment of a fixed base of a pressure microcatheter according to the present disclosure is shown.

[0028] Figure 13 Shown is the fixed base of the present disclosure at Figure 12 A cross-sectional schematic diagram of position C in Detailed Description of the Invention

[0029] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. In the following description, the same reference numerals are given to the same components, and repeated descriptions are omitted. In addition, the drawings are only schematic diagrams, and the dimensional ratios between components or the shapes of components may be different from the actual ones.

[0030] In addition, the subheadings and the like involved in the following description of the present invention are not intended to limit the content or scope of the present invention, and they only serve as a reading prompt. Such subheadings should neither be understood as being used to divide the content of the article, nor should the content under the subheadings be limited only to the scope of the subheadings.

[0031] The pressure microcatheter according to the present invention, which may also be referred to as a pressure microcatheter with dual pressure sensors, can directly measure the pressure value at the lesion in the patient's blood vessel by the pressure sensor in the pressure microcatheter, obtain the fractional flow reserve, and be able to judge the stenosis condition of the patient's blood vessel lesion. The distal part involved in the present disclosure may be the distal end relative to the operator during the operation.

[0032] The proximal part involved in the present disclosure may be the proximal end relative to the operator during the operation.

[0033] Figure 1 A schematic diagram of an application scenario of the pressure microcatheter 1 according to the present disclosure is shown. Figure 2A schematic plan view of the pressure microcatheter 1 involved in the present disclosure is shown.

[0034] Referring to Figure 1 , in some examples, the pressure microcatheter 1 may include a front-end catheter 10 and a rear-end catheter 11. The front-end catheter 10 may have a guide wire port 102 (which may also be referred to as the Rx port). The guide wire 20 may enter the front-end catheter 10 through the guide wire port 102 and exit from the other end of the front-end catheter 10. In some examples, one end of the guide wire 20 that pre-enters the guide wire port 102 may be referred to as the front end of the guide wire 20, and the other end opposite to the front end may be referred to as the rear end of the guide wire 20. The rear end of the guide wire 20 is disposed on the surface of the rear-end catheter 11.

[0035] In some examples, the guide wire 20 may be coated in the front-end catheter. In other words, the guide wire may be a solid structure and is disposed inside the front-end catheter so that the combined structure of the front-end catheter and the guide wire is a similar solid structure. The guide wire 20 may guide the front-end catheter 10 to move within the patient's blood vessel. The front-end catheter 10 and the rear-end catheter 11 may be integrally connected. The front-end catheter 10 may move within the patient's blood vessel. In this case, the rear-end catheter 11 can move together with the front-end catheter 10 and can move to the position of the diseased and stenotic part within the patient's blood vessel.

[0036] Referring to Figure 2 , in some examples, the assembly mandrel 12 may be disposed in the rear-end catheter 11. The assembly mandrel 12 may include multiple segments of core wires, a fixing base for connecting the multiple segments of core wires, and a pressure sensor fixed to the fixing base.

[0037] Figure 3 A schematic top view of the first embodiment of the assembly mandrel 12 involved in the present disclosure is shown. Figure 4 A schematic plan view of the first embodiment of the assembly mandrel 12 involved in the present disclosure is shown.

[0038] Referring to Figure 3 and Figure 4 , the multiple segments of core wires in the assembly mandrel 12 may include a first core wire 121, a second core wire 122, and a third core wire 123 arranged in sequence. In some examples, the fixing base for connecting the multiple segments of core wires may include a first fixing base 124 and a second fixing base 125. Each segment of the core wires in the multiple segments of core wires has a front end close to the guide wire port 102 and a rear end far from the guide wire port 102. The proximal part and the distal part involved in the present disclosure may also be relative positions with respect to the operator during the operation.

[0039] Referring to Figure 2 , in some examples, there may be two sensors fixed to the fixing base, for example, a first sensor 126 and a second sensor 127.

[0040] AsFigure 1 As shown, in some examples, the rear catheter 11 can be moved to the position of the stenotic lesion in the patient's blood vessel. The first pressure sensor 126 can be located distal to the stenotic lesion in the blood vessel, and the second pressure sensor 127 is located proximal to the stenotic lesion in the blood vessel. The first pressure sensor 126 can measure the pressure distal to the stenotic lesion in the blood vessel and generate pressure data, and the second pressure sensor 127 can measure the pressure proximal to the stenotic lesion in the blood vessel and generate pressure data.

[0041] Example 1

[0042] In some examples, the first core wire 121 can be a variable-diameter core wire. The first core wire 121 can have a front end near the guide wire port 102 and a rear end far from the guide wire port 102. In some examples, the outer diameter of the rear end portion of the first core wire 121 to the outer diameter of the front end portion of the first core wire 121 can gradually decrease. The front end portion of the first core wire 121 can be the end near the guide wire port 102, and the rear end portion of the first core wire 121 can be the end far from the guide wire port 102. In this case, the front end portion of the first core wire 121 can be conveniently assembled into the rear catheter 11, and the front end portion of the rear catheter 11 has a smaller diameter, whereby the rear catheter 11 can conveniently cross the stenotic lesion.

[0043] In some examples, the second core wire 122 can be an equal-diameter core wire. In some examples, the front end portion of the second core wire 122 can be the end near the guide wire port 102, and the rear end portion of the second core wire 122 can be the end far from the guide wire port 102. In some examples, the front end portion of the second core wire 122 can have an oblique cut.

[0044] In some examples, the third core wire 123 can be a variable-diameter core wire, and the front end portion of the third core wire 123 can have an oblique cut. In some examples, the front end portion of the third core wire 123 can be the end near the guide wire port 102, and the rear end portion of the third core wire 123 can be the end far from the guide wire port 102. The outer diameter of the rear end portion of the third core wire 123 to the outer diameter of the front end portion of the third core wire 123 can gradually decrease.

[0045] In addition, the front end portion of the first core wire 121 can also be referred to as the distal end of the first core wire 121, the rear end portion of the first core wire 121 can also be referred to as the proximal end of the first core wire 121, the front end portion of the second core wire 122 can also be referred to as the distal end of the second core wire 122, the rear end portion of the second core wire 122 can also be referred to as the proximal end of the second core wire 122, the front end portion of the third core wire 123 can also be referred to as the distal end of the third core wire 123, and the rear end portion of the third core wire 123 can also be referred to as the proximal end of the third core wire 123.

[0046] In addition, the first pressure sensor 126 and the second pressure sensor 127 may have a sensing part and a lead wire part. The sensing part may have a sensing area for sensing pressure, and the lead wire transmits the pressure signal of the sensing part to an externally connected data processing device.

[0047] In some examples, the rear end of the first core wire 121 may be welded and fixed to the front end of the first fixed base 124a. The front end of the second core wire 122 may be welded and fixed to the rear end of the first fixed base 124a. In some examples, the front end portion of the second core wire 122 may have an inclined cut. In this case, the first pressure sensor 126 can be well fitted into the first groove 1241a (described later) of the first fixed base, and the first pressure sensor 126 can be better welded to the lead wire.

[0048] In some examples, the rear end of the second core wire 122 may be welded and fixed to the front end of the second fixed base 125a, and the second core wire 122 may be a wire with a constant diameter. This can be beneficial to the passing performance of the pressure microcatheter 1. There is no need to open a guide wire cavity to use a guide wire to increase its passing performance. Thus, after the second core wire 122 is welded to the second fixed base 125a, it can maintain a small outer diameter, making the outer diameter size of the pressure microcatheter 1 close to that of a 0.014-inch guide wire.

[0049] In some examples, the front end of the third core wire 123 may be welded and fixed to the rear end of the second fixed base 125a, and the front end portion of the third core wire 123 has an inclined cut. In this case, the second pressure sensor 127 can be well fitted into the second groove 1251a (described later) of the second fixed base, and the second pressure sensor 127 can be better welded to the lead wire.

[0050] In addition, the third core wire 123 may be a wire with a variable diameter. The outer diameter of the rear end portion of the third core wire 123 to the outer diameter of the front end portion of the third core wire 123 may gradually decrease. In this case, the front end portion of the third core wire 123 can be disposed in the rear end catheter 11. The front end portion of the third core wire 123 is disposed in the rear end catheter 11, and the front end portion of the third core wire 123 has a smaller outer diameter. In this case, the size of the rear end catheter 11 disposed outside the front end portion of the third core wire 123 can be kept close to 0.014 inches and can smoothly pass through the diseased stenosis.

[0051] Furthermore, the size of the rear end portion of the third core wire 123 may be larger than that of the front end portion. Thus, the weight of the rear end portion of the third core wire 123 increases, which can facilitate the operator to more easily push the catheter.

[0052] In some examples, the materials of the first core wire 121, the second core wire 122, and the third core wire 123 can be composed of one of the materials such as stainless steel 304 material, stainless steel 316 material, nickel-chromium alloy, or nickel-titanium alloy.

[0053] In some examples, the first core wire 121, the second core wire 122, and the third core wire 123 can be solid core wires.

[0054] In some examples, the surfaces of the first core wire 121, the second core wire 122, and the third core wire 123 can be coated with a biocompatible coating to form a protective film.

[0055] Figure 5 The cross-sectional schematic diagram of the longitudinal section of the first embodiment of the pressure microcatheter involved in the present disclosure is shown.

[0056] Figure 6 The one involved in the present disclosure is shown Figure 5 The enlarged schematic diagram of area A in. Figure 7 The cross-sectional schematic diagram of the longitudinal section of the first embodiment of the fixed base of the pressure microcatheter involved in the present disclosure is shown. Figure 8 The top view schematic diagram of the second embodiment of the assembled mandrel involved in the present disclosure is shown.

[0057] See Figure 7 , in some examples, a first groove 1241a can be provided between the front end and the rear end of the first fixed base 124a. The first pressure sensor 126 can be disposed in the first groove 1241a. In some examples, a second groove 1251a can be provided between the front end and the rear end of the second fixed base 125a, and the second pressure sensor 127 can be disposed in the second groove 1251a.

[0058] See Figure 8 , in some examples, the front end of the second core wire 122 can be fixed in the slot 1242a of the first fixed base. The front end of the third core wire 123 can be fixed in the slot 1252a of the second fixed base. The second core wire 122 can be fixed in the slot 1242a of the first fixed base by laser welding or ultrasonic welding, and the third core wire 123 can be fixed in the slot 1252a of the second fixed base by laser welding or ultrasonic welding.

[0059] In some examples, the partial enlarged view of the second fixed base 125a can be as Figure 6As shown, the second pressure sensor 127 can be fixed in the second fixed base 125a. The front end of the third core wire 123 can be fixed to the rear end of the second base 125a. In some examples, there can be a gap between the sensing part of the second pressure sensor 127 and the second fixed base 125a. In this case, the pressure signal generated by the pressure deformation of the second pressure sensor 127 can be transmitted to an external connected data processing device or measurement system through the lead wire.

[0060] In addition, the front end of the first fixed base 124a can also be referred to as the distal end of the first fixed base 124a, and the rear end of the first fixed base 124a can also be referred to as the proximal end of the first fixed base 124a; the front end of the second fixed base 125a can also be referred to as the distal end of the second fixed base 125a, and the rear end of the second fixed base 125a can also be referred to as the proximal end of the second fixed base 125a.

[0061] In some examples, the first pressure sensor 126 can be fixed to the first fixed base 124a, and there is a gap between the sensing part of the first pressure sensor 126 and the first fixed base 124a. In this case, the pressure signal generated by the pressure deformation of the first pressure sensor 126 can be transmitted to the measurement system connected to the pressure microcatheter through the lead wire.

[0062] In some examples, the first fixed base 124a and the second fixed base 125a can be fixed bases of the same shape, the same material, and the same structure. In some examples, the first fixed base 124a can have the same structure, material, and shape as the second fixed base 125a, and the first groove 1241a of the first fixed base can have the same structure, material, and shape as the second groove 1251a of the second fixed base.

[0063] In some examples, the second pressure sensor 127 can be disposed in the second groove 1251a in the second fixed base 125a, and there can be a gap between the sensing part of the second pressure sensor 127 and the base of the second fixed base 125a. In some examples, the first pressure sensor 126 can be disposed in the first groove 1241a in the first fixed base 124a, and there can be a gap between the sensing part of the first pressure sensor 126 and the base of the second fixed base 124. In this case, even when the intravascular pressure microcatheter enters a blood vessel with a highly variable shape, it is possible to suppress the contact between the pressure sensor, especially the sensing part of the pressure sensor, and the main body of the pressure microcatheter. Thus, it is possible to effectively suppress the influence of, for example, the bending deformation of the pressure microcatheter (especially the front catheter 10) on the pressure measurement result of the pressure sensor, and improve the measurement accuracy of the intravascular pressure measurement catheter.

[0064] In some examples, the first pressure sensor 126 and the second pressure sensor 127 may be arranged at an axial interval along the assembled mandrel such that the first pressure sensor 126 measures the pressure distal to the stenotic lesion in the coronary artery, and the second pressure sensor 127 measures the pressure proximal to the stenotic lesion in the coronary artery. The first pressure sensor 126 and the second pressure sensor 127 may measure multiple intravascular pressure values within one cardiac cycle or multiple cardiac cycles of the patient. The measurement system externally connected to the pressure microcatheter will calculate, analyze, and process the multiple intravascular pressure values measured by the first pressure sensor 126 and the second pressure sensor 127, and can directly calculate the fractional flow reserve of the patient within a relatively short time.

[0065] In some examples, the first pressure sensor 126 and the second pressure sensor 127 may be located on the same axial side. In this case, it is possible to better reduce the diameter of the rear end catheter 11 to facilitate the movement of the rear end catheter 11 in the blood vessel and smoothly pass through the stenotic lesion.

[0066] In addition, the axial distance between the first pressure sensor 126 and the second pressure sensor 1 may be 5 to 20 cm. Preferably, the axial distance between the first pressure sensor 126 and the second pressure sensor 127 may be 10 cm. [[ID=??]]

[0067] In some examples, the first pressure sensor 126 may be fixed to the first fixed base 124a by laser welding, bonding, or ultrasonic welding. The second pressure sensor 127 may be fixed to the second fixed base 125a by laser welding, bonding, or ultrasonic welding.

[0068] In addition, the first pressure sensor 126 may also be fixed to the first fixed base 124a by snap connection, and the second pressure sensor 127 may also be fixed to the second fixed base 125a by snap connection.

[0069] In some examples, the core wire may be fixed to the fixed base by laser welding or ultrasonic welding. Thus, the first core wire 121, the second core wire 122, and the third core wire 123 may be respectively fixed to the first fixed base 124a and the second fixed base 125a by laser welding or ultrasonic welding.

[0070] In some examples, the core wire may also be fixed to the fixed base by brazing welding. Thus, the first core wire 121, the second core wire 122, and the third core wire 123 can be respectively fixed to the first fixed base 124a and the second fixed base 125a by brazing welding.

[0071] Note: There seems to be a mistake in where it says "the second pressure sensor 1" instead of "the second pressure sensor 127". This has been translated as best as possible while keeping the error.In some examples, the rear catheter 11 can be a single-layer structure, and the constituent material can be composed of one of nylon elastomer PEBAX material or polyethylene terephthalate PET material. In some examples, the rear catheter 11 can also be a double-layer structure, and its structure can be a composite structure composed of polyimide PI and polytetrafluoroethylene PTFE. The inner layer can be a polyimide inner tube, and the outer layer can be a polytetrafluoroethylene outer tube. It can also be that the inner layer is a polytetrafluoroethylene inner tube and the outer layer is a polyimide outer tube.

[0072] In addition, the rear catheter 11 can also be a three-layer structure, and the three-layer structure can be a composite structure composed of high-density polyethylene HDPE, linear low-density polyethylene LLDPE, and nylon Nylon11. The inner, middle, and outer layer materials can be arranged in combinations. Preferably, the composite structure can be a high-density polyethylene HDPE inner layer, a linear low-density polyethylene LLDPE middle layer, and a nylon Nylon11 outer layer.

[0073] Example 2

[0074] Figure 9 Fig. shows a schematic plan view of a second embodiment of an assembled mandrel according to the present disclosure.

[0075] In some examples, the fixed base has a front end that can be close to the guide wire port 102 and a rear end that is far from the guide wire port 102. The front end of the fixed base can have a circular tube structure, and the rear end of the fixed base can have a slot.

[0076] In some examples, the first core wire 121 is a variable-diameter core wire, and the outer diameter of the rear end portion of the first core wire 121 gradually decreases to the outer diameter of the front end portion of the first core wire 121. The rear end of the first core wire 121 is inserted into the circular tube structure at the front end of the first fixed base 124b and welded to the circular tube structure of the first fixed base 124b. In this case, the first core wire 121 can be well fixed to the first fixed base 124b.

[0077] In some examples, the second core wire 122 is an equal-diameter core wire, and the front end of the second core wire 122 has an inclined cut. The front end of the second core wire 122 is inserted into the slot 1242b of the first fixed base and welded to the slot 1242b of the first fixed base. In addition, the rear end of the second core wire 122 is inserted into the circular tube structure of the second fixed base 125 and welded to the circular tube structure of the second fixed base 125. In this case, the second core wire 122 can be fixed to the first fixed base 124b and the second fixed base 125.

[0078] In some examples, the third core wire 123 can be a stepped core wire with an inclined cut at the front end. The outer diameter of the rear end portion of the third core wire 123 gradually decreases to the outer diameter of the front end portion of the third core wire 123. The front end of the third core wire 123 is inserted into the slot 1252b of the second fixed base and welded to the slot 1252b of the second fixed base. Thus, the front end of the third core wire 123 can be fixed in the second fixed base 125b.

[0079] In some examples, the front end of the first core wire 121 can also be referred to as the distal end of the first core wire 121, the rear end of the first core wire 121 can also be referred to as the proximal end of the first core wire 121, the front end of the second core wire 122 can also be referred to as the distal end of the second core wire 122, the rear end of the second core wire 122 can also be referred to as the proximal end of the second core wire 122, the front end of the third core wire 123 can also be referred to as the distal end of the third core wire 123, and the rear end of the third core wire 123 can also be referred to as the proximal end of the third core wire 123.

[0080] In addition, the front end of the first fixed base 124b can also be referred to as the distal end of the first fixed base 124b, and the rear end of the first fixed base 124b can also be referred to as the proximal end of the first fixed base 124b; the front end of the second fixed base 125b can also be referred to as the distal end of the second fixed base 125b, and the rear end of the second fixed base 125b can also be referred to as the proximal end of the second fixed base 125b.

[0081] In some examples, the materials of the first core wire 121, the second core wire 122, and the third core wire 123 can be composed of one of the materials such as stainless steel 304 material, stainless steel 316 material, nickel-chromium alloy, or nickel-titanium alloy.

[0082] Preferably, the first core wire 121 can be a nickel-titanium alloy, and the second core wire 122 and the third core wire 123 can be stainless steel 304. Dividing into three core wires is relatively conducive to convenient processing. When the first core wire 121 is a nickel-titanium alloy and the second core wire 122 and the third core wire 123 are stainless steel 304 catheters, they can have relatively good pushing performance.

[0083] In some examples, the first core wire 121, the second core wire 122, and the third core wire 123 can be solid core wires. This can effectively increase the weight of the core wire and facilitate the operator of the surgery to control the pressure microcatheter.

[0084] In this embodiment, the cross-section of the rear end of the first core wire 121 is circular and the outer diameter of the cross-section of the rear end of the first core wire 121 matches the inner diameter of the circular tube structure of the first fixed base 124b. Thus, the first core wire 121 can be well welded in the circular tube structure of the first fixed base 124b.

[0085] In this embodiment, the cross-section of the front end of the second core wire 122 is bow-shaped, and the cross-section of the front end of the second core wire 122 matches the cross-section of the slot 1242b of the first fixed base (see Figure 13 ). The cross-section of the rear end of the second core wire 122 is circular, and the outer diameter of the cross-section of the rear end of the second core wire 122 matches the inner diameter of the circular tube structure of the second fixed base 125b. In this case, the second core wire 122 can be well fixed to the first fixed base 124b and the second fixed base 125b.

[0086] In this embodiment, the cross-section of the front end of the third core wire 123 matches the cross-section of the slot 1252b of the second fixed base (see Figure 13 ). In this case, the front end of the third core wire 123 can be well welded in the slot 1252b of the second fixed base.

[0087] In some examples, a first groove 1241b is provided between the front end of the first fixed base 124b having a circular tube structure and the first slot 1242b at the rear end of the first fixed base 124b, and the first pressure sensor 126 is disposed in the first groove 1241b. A second groove 1251b is provided between the front end of the second fixed base 125b having a circular tube structure and the second slot 1252b at the rear end of the second fixed base 125b, and the second pressure sensor 127 is disposed in the second groove 1251b. Thus, the first pressure sensor 126 and the second pressure sensor 127 can be well fixed in the grooves of the fixed base.

[0088] In some examples, the first pressure sensor 126 and the second pressure sensor 127 are located on the same axial side, so that the diameter of the rear catheter 11 can be well reduced, which is beneficial for the rear catheter 11 to move in the blood vessel and smoothly pass through the diseased stenosis.

[0089] In addition, the axial distance between the first pressure sensor 126 and the second pressure sensor 127 is 5 cm to 20 cm. Preferably, the axial distance between the first pressure sensor 126 and the second pressure sensor 127 is 10 cm.

[0090] In some examples, the first pressure sensor 126 is fixed to the first fixed base 124b by laser welding, bonding or ultrasonic welding, and the second pressure sensor 127 is fixed to the second fixed base 125b by laser welding, bonding or ultrasonic welding.

[0091] In addition, the first pressure sensor 126 can also be fixed to the first fixed base 124b by snap connection, and the second pressure sensor 127 can also be fixed to the second fixed base 125b by snap connection.

[0092] In some examples, the core wires are fixed to the fixed base by laser welding or ultrasonic welding. Thus, the first core wire 121, the second core wire 122, and the third core wire 123 can be respectively fixed to the first fixed base 124b and the second fixed base 125b by laser welding or ultrasonic welding.

[0093] In some examples, the core wires can also be fixed to the fixed base by brazing. Thus, the first core wire 121, the second core wire 122, and the third core wire 123 can be respectively fixed to the first fixed base 124b and the second fixed base 125b by brazing.

[0094] In some examples, the first fixed base 124b and the second fixed base 125b can be composed of stainless steel, metal alloy, or hard engineering plastic. Among them, the metal alloy can be cobalt-chromium alloy, nickel-chromium alloy, nickel-titanium alloy, molybdenum alloy, or an alloy of stainless steel doped with any of the above materials, or a composite material of any of the above alloys. In addition, the hard engineering plastic can be ABS, PMMA, PET, PBT, PEEK, PTFE, etc.

[0095] In addition, the size of the rear end portion of the third core wire 123 is larger than that of the front end portion. Thus, the weight of the rear end portion of the third core wire 123 increases, which can facilitate the operator during the operation to push the pressure microcatheter more easily.

[0096] In some examples, the first pressure sensor 126 is fixed in the first groove 1241b of the first fixed base 124b, and the front end portion of the second core wire 122 has an oblique cut. Thus, the lead wire of the first pressure sensor 126 can be conveniently welded to the first pressure sensor 126.

[0097] In some examples, the second pressure sensor 127 is fixed in the second groove 1251b of the second fixed base 125b, and the front end portion of the third core wire 123 has an oblique cut. Thus, the lead wire of the second pressure sensor 127 has sufficient space and can be conveniently welded to the second pressure sensor 127.

[0098] Figure 10 The schematic cross-sectional view of the longitudinal section of the second embodiment of the pressure microcatheter involved in the present disclosure is shown.

[0099] In some examples, the first core wire 121, the first fixed base 124b, the first pressure sensor 126, the second core wire 122, the second fixed base 125b, the second pressure sensor 127, and the third core wire 123 form an assembled mandrel 12, and the assembled mandrel 12 is arranged in the rear catheter 11 of the pressure microcatheter 1.

[0100] In some examples, the guide wire 20 is coated in the front catheter 10, and the front catheter 10 and the rear catheter 11 are integrally connected (seeFigure 1 ) The guide wire 20 guides the front-end catheter 10 to move in the patient's blood vessel. In this case, the rear-end catheter 11 can move along with the front-end catheter 10, and the rear-end catheter 11 can move to the position of the diseased and stenotic part in the patient's coronary artery. Thus, the assembly mandrel 12 disposed in the rear-end catheter 11 can move along with the rear-end catheter 11.

[0101] In some examples, the first pressure sensor 126 and the second pressure sensor 127 can move along with the assembly mandrel 12 to the position of the diseased and stenotic part in the patient's coronary artery.

[0102] In addition, the first pressure sensor 126 and the second pressure sensor 127 are arranged at intervals along the axial direction of the assembly mandrel so that the first pressure sensor 126 measures the pressure at the distal end of the diseased and stenotic part in the coronary artery, and the second pressure sensor 127 measures the pressure at the proximal end of the diseased and stenotic part in the coronary artery. The first pressure sensor 126 and the second pressure sensor 127 can measure multiple pressure values in the blood vessel within one or multiple cardiac cycles of the patient. The externally connected data processing device will calculate, analyze, and process the multiple pressure values in the blood vessel measured by the first pressure sensor 126 and the second pressure sensor 127, and can calculate the fractional flow reserve of the patient in a relatively short time.

[0103] Figure 11 shows the Figure 10 enlarged schematic diagram of region B involved in the present disclosure.

[0104] In some examples, the second pressure sensor 127 is disposed in the second groove 1251b of the second fixed base 125b, and there is a gap between the sensing part of the second pressure sensor 127 and the base of the second fixed base 125b; similarly, the first pressure sensor 126 is disposed in the first groove 1241b of the first fixed base 124b, and there is a gap between the sensing part of the first pressure sensor 126 and the base of the second fixed base 124. In this case, even when the pressure microcatheter 1 in the blood vessel enters the blood vessel with various shape changes, it can inhibit the contact between the pressure sensor, especially the sensing part of the pressure sensor, and the main body of the pressure microcatheter 1. Thus, it can effectively inhibit the influence of the bending deformation of the pressure microcatheter 1 (especially the front-end catheter 10) on the pressure measurement result of the pressure sensor, thereby improving the measurement accuracy of the pressure microcatheter 1 in the blood vessel.

[0105] Figure 12 shows a schematic cross-sectional view of a longitudinal section of a second embodiment of the fixed base of the pressure microcatheter 1.

[0106] In some examples, the cross-section of the rear end of the first core wire 121 is circular, and the outer diameter of the cross-section of the rear end of the first core wire 121 matches the inner diameter of the circular tube structure of the first fixing base 124b. Thus, the first core wire 121 can be well welded in the circular tube structure of the first fixing base 124b.

[0107] Figure 13 The cross-sectional schematic diagram of the fixing base of the present disclosure at Figure 12 the C position is shown.

[0108] In some examples, the cross-section of the front end of the second core wire 122 is bow-shaped, and the cross-section of the front end of the second core wire 122 matches the cross-section of the slot 1242b of the first fixing base (see Figure 13 ). The cross-section of the rear end of the second core wire 122 is circular, and the outer diameter of the cross-section of the rear end of the second core wire 122 matches the inner diameter of the circular tube structure of the second fixing base 125b. In this case, the second core wire 122 can be well fixed to the first fixing base 121 and the second fixing base 122.

[0109] In some examples, the cross-section of the front end of the third core wire 123 matches the cross-section of the slot 1252b of the second fixing base (see Figure 13 ). In this case, the front end of the third core wire 123 can be well welded in the slot 1252b of the second fixing base.

[0110] In the present embodiment, the first fixing base 124b and the second fixing base 125b can be fixing bases of the same shape, the same material, and the same structure. Figure 12 The schematic diagram of the first fixing base 124b and the slot 1242b of the first fixing base is shown. The second fixing base 125b can have the same structure, material, shape, and size as the first fixing base 124b, and the slot 1252b of the second fixing base can have the same structure, material, shape, and size as the slot 1242b of the first fixing base.

[0111] Although the present invention has been specifically described above in conjunction with the drawings and embodiments, it is not intended to limit the present invention. It should be understood that those skilled in the art can make deformations and changes to the present invention without departing from the essence and scope of the present invention, and these deformations and changes all fall within the scope protected by the claims of the present invention.

Claims

1. A pressure microcatheter, comprising: A catheter and an assembly mandrel disposed in the catheter The catheter has a rapid exchange structure and includes a front-end catheter and a rear-end catheter connected to each other. The front-end catheter has a guide wire port, and the rear-end catheter has a cavity. The assembly mandrel is disposed in the rear-end catheter The assembly mandrel includes multiple segments of core wires, a fixing base for connecting the multiple segments of core wires, and a pressure sensor fixed to the fixing base Each of the multiple segments of core wires has a front end close to the guide wire port and a rear end far from the guide wire port. The multiple segments of core wires include a first core wire, a second core wire, and a third core wire arranged in sequence The fixing base includes a first fixing base connecting and fixing the first core wire and the second core wire and a second fixing base connecting and fixing the second core wire and the third core wire. The pressure sensor includes a first pressure sensor and a second pressure sensor; the first pressure sensor is fixedly disposed in the first fixing base, and the second pressure sensor is fixedly disposed in the second fixing base The fixing base has a front end close to the guide wire port and a rear end far from the guide wire port. The front end of the fixing base has a round tube structure, and the rear end of the fixing base has a slot The rear end of the first core wire is inserted into the round tube structure of the first fixing base and welded to the round tube structure of the first fixing base. The front end of the second core wire is inserted into the slot of the first fixing base and welded to the slot of the first fixing base. The front end of the second core wire has an inclined cut, and the first fixing base is connected to the inclined cut at the front end of the second core wire. A first groove is provided between the round tube structure and the slot of the first fixing base, and the first pressure sensor is disposed in the first groove The rear end of the second core wire is inserted into the round tube structure of the second fixing base and welded to the round tube structure of the second fixing base. The front end of the third core wire is inserted into the slot of the second fixing base and welded to the slot of the second fixing base. The front end of the third core wire has an inclined cut, and the second fixing base is connected to the inclined cut at the front end of the third core wire. A second groove is provided between the round tube structure and the slot of the second fixing base, and the second pressure sensor is disposed in the second groove The rear-end catheter is moved to the position of the stenotic lesion in the patient's blood vessel. The first pressure sensor is located distal to the stenotic lesion in the blood vessel, and the second pressure sensor is located proximal to the stenotic lesion in the blood vessel 2. The pressure microcatheter according to claim 1, wherein The first core wire is a variable-diameter core wire, the second core wire is a constant-diameter core wire, and the third core wire is a variable-diameter core wire 3. The pressure microcatheter according to claim 1, wherein The first pressure sensor and the second pressure sensor are arranged at intervals along the axial direction of the assembly mandrel so that the first pressure sensor measures the pressure distal to the stenotic lesion in the coronary artery, and the second pressure sensor measures the pressure proximal to the stenotic lesion in the coronary artery 4. The pressure microcatheter according to claim 1, wherein The first pressure sensor and the second pressure sensor are located on the same axial side within the catheter.

5. The pressure microcatheter according to any one of claims 1-4, characterized in that The distance between the first pressure sensor and the second pressure sensor is 5 cm to 20 cm.

6. The pressure microcatheter according to claim 1, characterized in that The cross-section of the rear end of the first core wire is circular and the outer diameter of the cross-section of the rear end of the first core wire matches the inner diameter of the circular tube structure of the first fixed base. The cross-section of the front end of the second core wire is bow-shaped, and the cross-section of the front end of the second core wire matches the cross-section of the slot of the first fixed base; The cross-section of the rear end of the second core wire is circular and the outer diameter of the cross-section of the rear end of the second core wire matches the inner diameter of the circular tube structure of the second fixed base. The cross-section of the front end of the third core wire is bow-shaped, and the cross-section of the front end of the third core wire matches the cross-section of the slot of the second fixed base.

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