Pressure microcatheter and assembling mandrel thereof

Abstract

The invention provides a pressure microcatheter and an assembly mandrel thereof, the assembly mandrel comprises multiple sections of core wires, a fixed base and a pressure sensor, and the multiple sections of core wires comprise a first core wire, a second core wire and a third core wire which are arranged in sequence; the fixed base comprises a first fixed base connected with the first core wire and the second core wire and a second fixed base connected with the second core wire and the third core wire, and the pressure sensors comprise a first pressure sensor fixed in the first fixed base and a second pressure sensor fixed in the second fixed base; a first groove is formed between the front end of the first fixing base and the rear end of the first fixing base, the first pressure sensor is arranged in the first groove, a second groove is formed between the front end of the second fixing base and the rear end of the second fixing base, and the second pressure sensor is arranged in the second groove. According to the invention, the measurement accuracy of the pressure measurement catheter can be effectively improved, and meanwhile, the use steps and the operation time of the FFR catheter are reduced.

Description

[0001] This application is a divisional application of the patent application with application date of March 31, 2022, application number 2022103356968, and invention name as pressure microcatheter. Technical Field

[0002] The present invention relates to a microcatheter for measuring intravascular pressure, in particular to a pressure microcatheter and an assembly core shaft thereof. Background Art

[0003] Coronary artery disease is one of the leading causes of death worldwide. Better diagnosis, monitoring, and treatment of coronary artery disease can save lives. Coronary angiography is routinely used to assess coronary artery stenosis. However, it fails to reflect the true state of coronary artery function, making it difficult to definitively determine whether coronary artery stenosis is associated with a patient's myocardial ischemia. Currently, the primary clinical method for assessing coronary artery stenosis is the Fractional Flow Reserve (FFR) technique, derived from pressure wire imaging.

[0004] FFR is defined as the ratio of the maximum blood flow in a narrowed artery to the normal maximum blood flow. In order to calculate the FFR for a given stenosis in a blood vessel (i.e., the site where a vascular stent may be placed), it is necessary to measure and collect blood pressure readings on 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 the estimated value (e.g., 0.75) can serve as a useful judgment criterion, based on which doctors can decide whether to perform interventional treatment on such patients. As a method for measuring intravascular blood pressure to measure the FFR value of vascular stenosis, FFR measurement currently uses an invasive pressure sensor measurement catheter. The measurement catheter contains a pressure sensor and a pressure guidewire. The pressure guidewire transmits the pressure sensor through the guide catheter to the distal part of the coronary artery stenosis to measure the pressure Pd. The pressure guidewire is then withdrawn and pulls the pressure sensor to the proximal part of the coronary artery stenosis to measure the pressure Pa. During the measurement of Pa, the pressure difference between the aortic pressure sensor and the pressure guidewire should be less than + / -9 mmHgm. If the pressure difference exceeds + / -9 mmHgm, the pressure sensor position needs to be readjusted and the guide catheter needs to be flushed. During the measurement of Pd, the distal end of the guidewire needs to be zeroed in vitro. During the movement of the catheter, the guidewire may pass through complex and changing blood vessels, such as the coronary arteries of the heart, necessitating the exchange of guidewires back and forth, which increases the time of the operation and consumes the physical strength of the surgeon, increasing the cost and risk of the patient's surgery. Summary of the Invention

[0005] The present invention is made in view of the above-mentioned prior art conditions, and its purpose is to provide a device that can effectively improve the measurement accuracy of a pressure measuring catheter while reducing the use steps and operation time of an FFR catheter.

[0006] To this end, the present invention provides a pressure microcatheter, comprising: a catheter and an assembly mandrel disposed in the catheter, the catheter being a quick-exchange structure and comprising a front-end catheter and a rear-end catheter connected to each other, the front-end catheter having a guidewire port, the rear-end catheter having a cavity, the assembly mandrel disposed in the rear-end catheter, the assembly mandrel comprising a plurality of core wire segments, a fixed base for connecting the plurality of core wire segments, and a pressure sensor fixed to the fixed base, each of the plurality of core wire segments having a front end proximal to the guidewire port and a rear end distal to the guidewire port, the plurality of core wire segments comprising a first core wire, a second core wire, and a third core wire disposed sequentially, the fixed base comprising 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 comprising a first pressure sensor and a second pressure sensor; the first pressure sensor being disposed in the first fixed base, and the second pressure sensor being disposed in the second fixed base. Thus, the first and second pressure sensors can be fixed to the fixed base, and the plurality of core wire segments can support the fixed mandrel.

[0007] In the present invention, the first core wire is a variable diameter core wire, the second core wire is a constant diameter core wire with an oblique cut at its front end, and the third core wire is a variable diameter core wire with an oblique cut at its front end; the first fixing base is connected to the oblique cut at the front end of the second core wire, and the second fixing base is connected to the oblique 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 connected and fixed to the first fixing base and the second fixing base, respectively.

[0008] In the present invention, the first and second pressure sensors are spaced apart along the axial direction of the assembly mandrel, such that the first pressure sensor measures the pressure distal to the coronary artery lesion stenosis, and the second pressure sensor measures the pressure proximal to the coronary artery lesion stenosis. In this case, the first pressure sensor measures the pressure Pd distal to the coronary artery lesion stenosis, and the second pressure sensor measures the pressure Pa proximal to the coronary artery lesion stenosis. By calculating the ratio of these values, FFR (Fractional Flow Reserve) can be obtained in a relatively short time.

[0009] In the present invention, the first pressure sensor and the second pressure sensor are located on the same axial side of the catheter. In this case, the first pressure sensor and the second pressure sensor are in the same plane, which can facilitate the rear end catheter to pass through the lesion smoothly.

[0010] 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 of the coronary artery lesion stenosis, and the second pressure sensor can measure the proximal pressure of the coronary artery lesion stenosis.

[0011] 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, 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, and 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.

[0012] 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, and the first pressure sensor is provided 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, and the second pressure sensor is provided in the second groove. Thus, the first pressure sensor can be fixed in the first groove, and the second pressure sensor can be fixed in the second groove.

[0013] 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 arched, 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 arched, 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, thereby being able to be placed in the rear end catheter, and can well support the rear end catheter to move in the blood vessel.

[0014] In the present invention, the fixed base has a front end close to the guidewire port and a rear end away from the guidewire 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, second, and third core wires can be well fixed to the fixed base, thereby being able to be placed in the rear end catheter and well supporting the rear end catheter to move in the blood vessel.

[0015] In the present invention, a first groove is provided between the front end and the rear end of the first fixing base, in which the first pressure sensor is disposed. A second groove is provided between the front end and the rear end of the second fixing base, in which the second pressure sensor is disposed. This allows the first pressure sensor to be fixed in the first groove of the first fixing base, and the second pressure sensor to be fixed in the second groove of the second fixing base, thereby facilitating accurate blood pressure measurement by the pressure sensors.

[0016] 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 the coronary artery lesion stenosis. The measurement system connected to the pressure microcatheter calculates the ratio of Pd to Pa to obtain the FFR blood flow reserve fraction in a relatively short time. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of an application scenario of the pressure microcatheter involved in the present disclosure is shown.

[0018] Figure 2 A schematic plan view of the pressure microcatheter according to the present disclosure is shown.

[0019] Figure 3 A schematic top view of a first embodiment of an assembly mandrel according to the present disclosure is shown.

[0020] Figure 4 A schematic plan view of a first embodiment of an assembly mandrel according to the present disclosure is shown.

[0021] Figure 5 A schematic cross-sectional view showing a longitudinal section of a first embodiment of the pressure microcatheter according to the present disclosure.

[0022] Figure 6 Shows the present disclosure Figure 5 A magnified schematic diagram of area A in the middle.

[0023] Figure 7A schematic cross-sectional view showing a longitudinal section of a first embodiment of a fixing base of a pressure microcatheter according to the present disclosure.

[0024] Figure 8 A schematic top view of a second embodiment of an assembly mandrel according to the present disclosure is shown.

[0025] Figure 9 A schematic plan view of a second embodiment of an assembly mandrel according to the present disclosure is shown.

[0026] Figure 10 A schematic cross-sectional view showing a longitudinal section of a second embodiment of the pressure microcatheter according to the present disclosure.

[0027] Figure 11 Shows the present disclosure Figure 10 Schematic diagram of the enlarged area B.

[0028] Figure 12 A schematic cross-sectional view showing a longitudinal section of a second embodiment of a fixing base of a pressure microcatheter according to the present disclosure is shown.

[0029] Figure 13 The fixed base of the present disclosure is shown in Figure 12 Schematic diagram of the cross-section of the C position. DETAILED DESCRIPTION

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, identical components will be assigned identical reference numerals, and duplicate descriptions will be omitted. Furthermore, the accompanying drawings are merely schematic, and the proportions of the dimensions of the components and the shapes of the components may differ from the actual ones.

[0031] In addition, the subheadings and the like in the following description of the present invention are not intended to limit the content or scope of the present invention, but are merely provided as a guide for reading. Such subheadings should not be understood as dividing the content of the article, nor should the content under the subheadings be limited to the scope of the subheadings.

[0032] The pressure microcatheter of the present invention, also known as a dual-pressure-chip pressure microcatheter, has a pressure sensor that can directly measure pressure at the site of a patient's vascular lesion, thereby obtaining the fractional flow reserve (FFR) and assessing the stenosis of the patient's vascular lesion. The distal portion referred to in this disclosure may be distal to the operator.

[0033] The proximal portion referred to in the present disclosure may be the proximal end relative to the operator.

[0034] Figure 1 A schematic diagram of an application scenario of the pressure microcatheter 1 involved in the present disclosure is shown. Figure 2FIG. 1 shows a schematic plan view of the pressure microcatheter 1 according to the present disclosure.

[0035] See also Figure 1 In some examples, the pressure microcatheter 1 may include a front catheter 10 and a rear catheter 11. The front catheter 10 may have a guidewire port 102 (also referred to as an Rx port), through which a guidewire 20 may enter the front catheter 10 and exit from the other end of the front catheter 10. In some examples, the end of the guidewire 20 that pre-enters the guidewire port 102 may be referred to as the front end of the guidewire 20, and the other end opposite the front end may be referred to as the rear end of the guidewire 20. The rear end of the guidewire 20 is disposed on the surface of the rear catheter 11.

[0036] In some examples, the guidewire 20 can be covered in the front end catheter. In other words, the guidewire can be a solid structure and the guidewire is arranged in the front end catheter so that the structure after the front end catheter and the guidewire are combined is similar to a solid structure. The guidewire 20 can guide the front end catheter 10 to move in the patient's blood vessel. The front end catheter 10 and the rear end catheter 11 can be connected as one, and the front end catheter 10 can move in the patient's blood vessel. In this case, the rear end catheter 11 can move with the front end catheter 10 and can move to the location of the stenosis of the lesion in the patient's blood vessel.

[0037] See also 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 core wire segments, a fixed base for connecting the multiple core wire segments, and a pressure sensor fixed to the fixed base.

[0038] Figure 3 A schematic top view of a first embodiment of an assembly mandrel 12 according to the present disclosure is shown. Figure 4 A schematic plan view of a first embodiment of an assembly mandrel 12 according to the present disclosure is shown.

[0039] See also Figure 3 and Figure 4 , the multiple 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 core wires may include a first fixing base 124 and a second fixing base 125. Each core wire in the multiple core wires has a front end close to the guide wire port 102 and a rear end away from the guide wire port 102. The proximal end portion and the distal end portion involved in the present disclosure may also be relative positions relative to the operator.

[0040] See also Figure 2 In some examples, there may be two sensors fixed to the fixed base, for example, a first sensor 126 and a second sensor 127 .

[0041] like Figure 1 As shown, in some examples, the rear end catheter 11 can be moved to the location of the stenosis of the patient's vascular lesion, the first pressure sensor 126 can be located distal to the stenosis of the vascular lesion, and the second pressure sensor 127 can be located proximal to the stenosis of the vascular lesion. The first pressure sensor 126 can measure the pressure distal to the stenosis of the vascular lesion and generate pressure data, while the second pressure sensor 127 can measure the pressure proximal to the stenosis of the vascular lesion and generate pressure data.

[0042] Example 1

[0043] 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 close to the guidewire port 102 and a rear end away from the guidewire port 102. In some examples, the outer diameter of the rear end portion of the first core wire 121 can gradually decrease to the outer diameter of the front end portion of the first core wire 121. The front end portion of the first core wire 121 can be the end close to the guidewire port 102, and the rear end portion of the first core wire 121 can be the end away from the guidewire port 102. In this case, the front end portion of the first core wire 121 can be easily assembled into the rear end catheter 11, and the front end portion of the rear end catheter 11 has a smaller diameter, so that the rear end catheter 11 can easily cross the stenosis of the lesion.

[0044] In some examples, the second core wire 122 may be a core wire of equal diameter. In some examples, the front end portion of the second core wire 122 may be an end close to the guide wire port 102, and the rear end portion of the second core wire 122 may be an end away from the guide wire port 102. In some examples, the front end portion of the second core wire 122 may have an oblique cut.

[0045] In some examples, the third core wire 123 may be a reduced diameter core wire, and the front end portion of the third core wire 123 may have an oblique cut. In some examples, the front end portion of the third core wire 123 may be an end close to the guide wire port 102, and the rear end portion of the third core wire 123 may be an end away from the guide wire port 102. The outer diameter of the rear end portion of the third core wire 123 may gradually decrease to the outer diameter of the front end portion of the third core wire 123.

[0046] 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.

[0047] In addition, the first pressure sensor 126 and the second pressure sensor 127 can have a sensing portion and a lead wire portion. The sensing portion can have a sensing area that senses pressure, and the lead wire transmits a pressure signal of the sensing portion to an externally connected data processing device.

[0048] In some examples, the rear end of the first core wire 121 can be welded to the front end of the first fixed base 124a. The front end of the second core wire 122 can be welded to the rear end of the first fixed base 124a. In some examples, the front end portion of the second core wire 122 can have a bevel cut, in which case the first pressure sensor 126 can be well fitted into the first groove 1241a of the first fixed base (described later), and the first pressure sensor 126 can be better welded to the lead wire.

[0049] In some examples, the rear end of the second core wire 122 can be welded to the front end of the second fixed base 125a, and the second core wire 122 can be a constant diameter core wire. This can be advantageous for the passage performance of the pressure microcatheter 1, and there is no need to open a guide wire lumen and use a guide wire to increase the passage performance, whereby the second core wire 122 can maintain a small outer diameter after being welded to the second fixed base 125a, so that the outer diameter size of the pressure microcatheter 1 is close to that of a 0.014 inch guide wire.

[0050] In some examples, the front end of the third core wire 123 can be welded to the rear end of the second fixed base 125a, and the front end portion of the third core wire 123 has a bevel cut. In this case, the second pressure sensor 127 can be well fitted into the second groove 1251a of the second fixed base (described later), and the second pressure sensor 127 can be better welded to the lead wire.

[0051] In addition, the third core wire 123 can be a variable diameter core wire. The outer diameter of the rear end portion of the third core wire 123 can gradually decrease to the outer diameter of the front end portion of the third core wire 123. 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 small outer diameter, in which case the size of the rear end catheter 11 disposed outside the front end portion of the third core wire 123 can be maintained close to 0.014 inches, and can smoothly pass through a lesion stenosis.

[0052] In addition, the rear end portion of the third core wire 123 can be larger in size than the front end portion. Thus, the weight of the rear end portion of the third core wire 123 is increased, which can facilitate the surgeon to more easily push the catheter.

[0053] In some examples, the material of the first core wire 121 , the second core wire 122 , and the third core wire 123 may be made of one of stainless steel 304, stainless steel 316, nickel-chromium alloy, or nickel-titanium alloy.

[0054] In some examples, the first core wire 121 , the second core wire 122 , and the third core wire 123 may be solid core wires.

[0055] In some examples, the surfaces of the first core wire 121 , the second core wire 122 , and the third core wire 123 may be coated with a biocompatible coating to form a protective film.

[0056] Figure 5 A schematic cross-sectional view showing a longitudinal section of a first embodiment of the pressure microcatheter according to the present disclosure.

[0057] Figure 6 Shows the present disclosure Figure 5 A magnified schematic diagram of area A in the middle. Figure 7 A schematic cross-sectional view showing a longitudinal section of a first embodiment of a fixing base of a pressure microcatheter according to the present disclosure. Figure 8 A schematic top view of a second embodiment of an assembly mandrel according to the present disclosure is shown.

[0058] See also Figure 7 In some examples, a first groove 1241a may be provided between the front end and the rear end of the first fixing base 124a. The first pressure sensor 126 may be provided in the first groove 1241a. In some examples, a second groove 1251a may be provided between the front end and the rear end of the second fixing base 125a. The second pressure sensor 127 may be provided in the second groove 1251a.

[0059] See also Figure 8 In some examples, the front end of the second core wire 122 can be fixed in the slot 1242a of the first fixing base. The front end of the third core wire 123 can be fixed in the slot 1252a of the second fixing base. The second core wire 122 can be fixed in the slot 1242a of the first fixing base by laser welding or ultrasonic welding, and the third core wire 123 can be fixed in the slot 1252a of the second fixing base by laser welding or ultrasonic welding.

[0060] In some examples, a partial enlarged view of the second fixed base 125a can be as follows: Figure 6As shown, the second pressure sensor 127 can be fixed to 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, a gap can exist between the sensing portion 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 externally connected data processing device or measurement system via a lead wire.

[0061] 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.

[0062] In some examples, the first pressure sensor 126 can be fixed to the first fixed base 124a, with a gap between the sensing portion 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 a measurement system connected to the pressure microcatheter via a lead wire.

[0063] In some examples, the first fixing base 124a and the second fixing base 125a can be fixing bases of the same shape, material, and structure. In some examples, the first fixing base 124a can be the same structure, material, and shape as the second fixing base 125a, and the first groove 1241a of the first fixing base can be the same structure, material, and shape as the second groove 1251a of the second fixing base.

[0064] In some examples, the second pressure sensor 127 can be disposed in the second groove 1251a of the second fixed base 125a, with a gap between the sensing portion 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 of the first fixed base 124a, with a gap between the sensing portion 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 wide variety of shapes, contact between the pressure sensor, particularly the sensing portion of the pressure sensor, and the main body of the pressure microcatheter can be prevented. This effectively reduces the impact of bending deformation of the pressure microcatheter (particularly the front end catheter 10) on the pressure sensor's pressure measurement results, thereby improving the measurement accuracy of the intravascular pressure measurement catheter.

[0065] In some examples, first pressure sensor 126 and second pressure sensor 127 may be spaced apart along the axial direction of the assembly mandrel, such that first pressure sensor 126 measures pressure distal to the coronary artery lesion and second pressure sensor 127 measures pressure proximal to the coronary artery lesion. First pressure sensor 126 and second pressure sensor 127 can measure multiple intravascular pressure values ​​within a patient's cardiac cycle or over multiple cardiac cycles. A measurement system externally connected to the pressure microcatheter calculates, analyzes, and processes the multiple intravascular pressure values ​​measured by first pressure sensor 126 and second pressure sensor 127, enabling direct calculation of the patient's fractional flow reserve in a relatively short period of time.

[0066] 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, the diameter of the rear end catheter 11 can be better reduced, so as to facilitate the rear end catheter 11 to move in the blood vessel and pass smoothly through the lesion stenosis.

[0067] In addition, the axial distance between the first pressure sensor 126 and the second pressure sensor 127 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.

[0068] In some examples, the first pressure sensor 126 may be fixed to the first fixing base 124a by laser welding, bonding, or ultrasonic welding. The second pressure sensor 127 may be fixed to the second fixing base 125a by laser welding, bonding, or ultrasonic welding.

[0069] In addition, the first pressure sensor 126 may be fixed to the first fixing base 124 a by a snap-fitting manner, and the second pressure sensor 127 may be fixed to the second fixing base 125 a by a snap-fitting manner.

[0070] In some examples, the core wires can be fixed to the fixing 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 fixed to the first fixing base 124a and the second fixing base 125a by laser welding or ultrasonic welding, respectively.

[0071] In some examples, the core wires may be fixed to the fixing base by brazing. Thus, the first core wire 121, the second core wire 122, and the third core wire 123 may be fixed to the first fixing base 124a and the second fixing base 125a, respectively, by brazing.

[0072] In some examples, the rear-end catheter 11 can be a one-layer structure, and the constituent material thereof can be one of a nylon elastomer PEBAX material or a polyethylene terephthalate PET material. In some examples, the rear-end catheter 11 can also be a double-layer structure, and the structure thereof can be a composite structure composed of a polyimide PI inner tube and a polytetrafluoroethylene PTFE outer tube, or a polytetrafluoroethylene inner tube and a polyimide outer tube.

[0073] In addition, the rear-end 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 Nylon 11, and the inner layer, the middle layer, and the outer layer materials can be arranged in combination. Preferably, the composite structure can be a high-density polyethylene HDPE inner layer, a linear low-density polyethylene LLDPE middle layer, and a nylon Nylon 11 outer layer.

[0074] Embodiment 2

[0075] Figure 9 A plan view of a second embodiment of an assembly mandrel is shown.

[0076] In some examples, the fixed base has a front end close to the guide wire port 102 and a rear end away 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.

[0077] 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 of the front end of the first fixed base 124b and welded with 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.

[0078] In some examples, the second core wire 122 is a constant-diameter core wire, and the front end of the second core wire 122 has a bevel. The front end of the second core wire 122 is inserted into the slot 1242b of the first fixed base and welded with 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 with 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.

[0079] In some examples, the third core wire 123 may be a reduced-diameter core wire having an oblique cut at the front end, wherein the outer diameter of the rear end portion of the third core wire 123 gradually decreases toward the front end portion of the third core wire 123. The front end of the third core wire 123 is inserted into and welded to the slot 1252b of the second fixing base. Thus, the front end of the third core wire 123 can be fixed to the second fixing base 125b.

[0080] 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.

[0081] 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.

[0082] In some examples, the material of the first core wire 121 , the second core wire 122 , and the third core wire 123 may be made of one of stainless steel 304, stainless steel 316, nickel-chromium alloy, or nickel-titanium alloy.

[0083] 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 it into three core wires can be more convenient for processing. 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. The catheter can have relatively good pushing performance.

[0084] In some examples, the first core wire 121 , the second core wire 122 , and the third core wire 123 may be solid core wires, which can effectively increase the weight of the core wires and facilitate the operator to manipulate the pressure microcatheter.

[0085] 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, so that the first core wire 121 can be well welded in the circular tube structure of the first fixed base 124b.

[0086] In this embodiment, the cross section of the front end of the second core wire 122 is arched, and the cross section of the front end of the second core wire 122 is the same as the cross section of the slot 1242b of the first fixed base (see FIG. 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.

[0087] In this embodiment, the cross section of the front end of the third core wire 123 is similar to 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 fixed base.

[0088] 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 groove 1242b at the rear end of the first fixed base 124b. The first pressure sensor 126 is provided 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 groove 1252b at the rear end of the second fixed base 125b. The second pressure sensor 127 is provided 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 bases.

[0089] In some examples, the first pressure sensor 126 and the second pressure sensor 127 are located on the same axial side, which can effectively reduce the diameter of the rear end catheter 11, thereby facilitating the rear end catheter 11 to move in the blood vessel and pass smoothly through the stenosis.

[0090] 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.

[0091] In some examples, the first pressure sensor 126 is fixed to the first fixing base 124b by laser welding, bonding, or ultrasonic welding, and the second pressure sensor 127 is fixed to the second fixing base 125b by laser welding, bonding, or ultrasonic welding.

[0092] In addition, the first pressure sensor 126 may be fixed to the first fixing base 124b by a snap-fitting manner, and the second pressure sensor 127 may be fixed to the second fixing base 125b by a snap-fitting manner.

[0093] In some examples, the core wires are fixed to the fixed base by laser welding or ultrasonic welding, so that the first core wire 121 , the second core wire 122 and the third core wire 123 can be fixed to the first fixed base 124 b and the second fixed base 125 b by laser welding or ultrasonic welding, respectively.

[0094] In some examples, the core wires may be fixed to the fixing bases by brazing, so that the first core wire 121 , the second core wire 122 , and the third core wire 123 may be fixed to the first fixing base 124 b and the second fixing base 125 b , respectively, by brazing.

[0095] In some examples, the first fixed base 124b and the second fixed base 125b can be made of stainless steel, a metal alloy, or a hard engineering plastic. The metal alloy can be a cobalt-chromium alloy, a nickel-chromium alloy, a nickel-titanium alloy, a 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. Furthermore, the hard engineering plastic can be ABS, PMMA, PET, PBT, PEEK, PTFE, or the like.

[0096] In addition, the rear end portion of the third core wire 123 is larger than the front end portion. Thus, the weight of the rear end portion of the third core wire 123 is increased, which can facilitate the surgeon to push the pressure microcatheter more easily.

[0097] In some examples, the first pressure sensor 126 is fixed in the first groove 1241b of the first fixing base 124b, and the front end portion of the second core wire 122 has an oblique cut, so that the lead wire of the first pressure sensor 126 can be easily welded to the first pressure sensor 126.

[0098] 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, so that the lead-out wire of the second pressure sensor 127 has sufficient space and can be easily welded to the second pressure sensor 127.

[0099] Figure 10 A schematic cross-sectional view showing a longitudinal section of a second embodiment of the pressure microcatheter according to the present disclosure.

[0100] In some examples, the first core wire 121 , the first fixed base 124 b , the first pressure sensor 126 , the second core wire 122 , the second fixed base 125 b , the second pressure sensor 127 and the third core wire 123 constitute an assembly core shaft 12 , which is disposed in the rear end catheter 11 of the pressure microcatheter 1 .

[0101] In some examples, the guide wire 20 is wrapped in the front end catheter 10, and the front end catheter 10 and the rear end catheter 11 are connected as a whole (see Figure 1 ), the guidewire 20 guides the front catheter 10 to move within the patient's blood vessel. In this case, the rear catheter 11 can move along with the front catheter 10, and the rear catheter 11 can be moved to the location of the stenosis in the patient's coronary artery. As a result, the assembly core shaft 12 disposed in the rear catheter 11 can move along with the rear catheter 11.

[0102] In some examples, the first pressure sensor 126 and the second pressure sensor 127 can be moved along with the assembly mandrel 12 to the location of the stenosis in the patient's coronary artery.

[0103] Furthermore, first and second pressure sensors 126, 127 are spaced apart along the axial direction of the assembly mandrel, such that first pressure sensor 126 measures pressure distal to the coronary artery lesion and second pressure sensor 127 measures pressure proximal to the coronary artery lesion. First and second pressure sensors 126, 127 can measure multiple intravascular pressure values ​​within a patient's cardiac cycle or over multiple cardiac cycles. An externally connected data processing device calculates, analyzes, and processes the multiple intravascular pressure values ​​measured by first and second pressure sensors 126, 127, enabling calculation of the patient's fractional flow reserve in a relatively short period of time.

[0104] Figure 11 Shows the present disclosure Figure 10 Schematic diagram of the enlarged area B.

[0105] In some examples, the second pressure sensor 127 is disposed in the second groove 1251b of the second fixed base 125b, with a gap between the sensing portion 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, with a gap between the sensing portion of the first pressure sensor 126 and the base of the second fixed base 124. In this case, even when the intravascular pressure microcatheter 1 enters a blood vessel with a wide variety of shapes, contact between the pressure sensor, particularly the sensing portion of the pressure sensor, and the main body of the pressure microcatheter 1 can be suppressed. This effectively suppresses the influence of bending deformation of the pressure microcatheter 1 (particularly the front end catheter 10) on the pressure measurement results of the pressure sensor, thereby improving the measurement accuracy of the intravascular pressure microcatheter 1.

[0106] Figure 12 A schematic cross-sectional view of a longitudinal section of a second embodiment of a fixing base of a pressure microcatheter 1 is shown.

[0107] 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 fixed base 124b, so that the first core wire 121 can be well welded in the circular tube structure of the first fixed base 124b.

[0108] Figure 13 The fixed base of the present disclosure is shown in Figure 12 Schematic diagram of the cross-section of the C position.

[0109] In some examples, the cross-section of the front end of the second core wire 122 is arched, and the cross-section of the front end of the second core wire 122 is the same as 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 fixed base 125b. In this case, the second core wire 122 can be well fixed to the first fixed base 121 and the second fixed base 122.

[0110] In some examples, the cross section of the front end of the third core wire 123 is similar to 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 fixed base.

[0111] In this embodiment, the first fixing base 124b and the second fixing base 125b may be fixing bases of the same shape, the same material, and the same structure. Figure 12 What is shown is a schematic diagram of the first fixed base 124b and the slot 1242b of the first fixed base. The second fixed base 125b can have the same structure, material, shape and size as the first fixed base 124b, and the slot 1252b of the second fixed base can have the same structure, material, shape and size as the slot 1242b of the first fixed base.

[0112] Although the present invention has been specifically described above with reference to the accompanying drawings and embodiments, it is not intended to limit the present invention. It should be understood that those skilled in the art can modify and change the present invention without departing from the essence and scope of the present invention, and these modifications and changes fall within the scope of protection of the claims of the present invention.

Claims

1. An assembly mandrel for a pressure microcatheter, characterized in that: It 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 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 fixed in the first fixed base, and a second pressure sensor fixed in the second fixed base; a first groove is provided between the front end of the first fixed base and the rear end of the first fixed base, the first pressure sensor is provided in the first groove, a second groove is provided between the front end of the second fixed base and the rear end of the second fixed base, the second pressure sensor is provided in the second groove.

2. The assembly mandrel of the pressure microcatheter according to claim 1, characterized in that: The first core wire, the second core wire, and the third core wire are made of one of stainless steel 304, stainless steel 316, nickel-chromium alloy, and nickel-titanium alloy.

3. The assembly mandrel of the pressure microcatheter according to claim 1, characterized in that: The front end of the second core wire has an oblique cut, and the first fixing base is connected to the oblique cut of the front end of the second core wire. The front end of the third core wire has an oblique cut, and the second fixing base is connected to the oblique cut of the front end of the third core wire.

4. The assembly mandrel of the pressure microcatheter according to claim 1, characterized in that: The first core wire is a reduced diameter core wire, the second core wire is a constant diameter core wire, and the third core wire is a reduced diameter core wire.

5. The assembly mandrel of the pressure microcatheter according to claim 1, characterized in that: 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, and 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; and / or 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, and 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.

6. The assembly mandrel of the pressure microcatheter according to claim 5, characterized in that: The multiple core wire segments are fixed to the fixed base by laser welding, ultrasonic welding or brazing welding.

7. The assembly mandrel of 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; and / or 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.

8. The assembly mandrel of the pressure microcatheter according to claim 1, characterized in that: The first pressure sensor is fixed to the first fixed base by laser welding, bonding, ultrasonic welding or clamping; and / or the second pressure sensor is fixed to the second fixed base by laser welding, bonding, ultrasonic welding or clamping.

9. The assembly mandrel of the pressure microcatheter according to claim 1, characterized in that: There is a gap between the sensing part of the first pressure sensor and the first fixed base; and / or there is a gap between the sensing part of the second pressure sensor and the second fixed base.

10. A pressure microcatheter, characterized in that: An assembly mandrel comprising a catheter and the pressure microcatheter according to any one of claims 1 to 9.

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