A thermal flow rate chip, a blood vessel detection component, a catheter, and a detection method thereof.

Abstract

This invention discloses a thermal flow velocity chip, a blood vessel detection component, a catheter, and a detection method thereof, belonging to the field of medical device technology. The thermal flow velocity chip includes a flexible substrate material, a thermistor, and solder joints. The thermistor includes a first thermistor unit and a second thermistor unit. The first thermistor unit forms a heat source region, and the second thermistor unit detects the temperature change signal after the blood carries away heat. The blood vessel detection component includes a flexible flow sensing chip module, a matching circuit, data processing software, and a display module. The flexible flow sensing chip module is attached to the distal outer wall of the catheter and enters the blood vessel with the catheter. The data processing software obtains blood flow velocity information based on the temperature change signal and determines the location and degree of vascular stenosis. This invention can directly detect changes in blood flow velocity, improving the real-time performance of vascular stenosis assessment and localization.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a thermal flow rate chip, a blood vessel detection component, a catheter, and a detection method thereof. Background Technology

[0002] Vascular stenosis is a crucial pathological basis for coronary heart disease, peripheral vascular disease, and cerebrovascular disease. As the lumen diameter decreases, local hemodynamics changes, which can lead to tissue ischemia, organ dysfunction, and even death in severe cases. Therefore, accurately determining the location and degree of vascular stenosis is of great significance for clinical diagnosis, interventional treatment planning, and postoperative efficacy evaluation.

[0003] Currently, clinical techniques used for diagnosing vascular stenosis mainly include angiography, computed tomography angiography (CTA), magnetic resonance angiography (MRA), intravascular ultrasound (IVUS), and pressure guidewire testing. Angiography, CTA, and MRA primarily observe changes in vascular morphology through imaging to determine the degree of stenosis. Pressure guidewire technology, on the other hand, measures blood pressure parameters proximal and distal to the stenosis site using pressure sensors placed at the tip of a guidewire or catheter, and indirectly assesses the degree of stenosis based on indicators such as fractional flow reserve (FFR). Existing pressure guidewire products generally use piezoresistive pressure sensors, which utilize the piezoresistive effect of semiconductor materials to convert pressure changes into resistance changes, and then calculate blood pressure parameters based on the electrical signal.

[0004] However, the aforementioned existing technologies still have certain limitations. On the one hand, imaging detection equipment is large in size and expensive, and some detection methods require the use of contrast agents, which poses certain invasiveness and usage limitations. On the other hand, pressure guidewire technology mainly acquires intravascular pressure information and indirectly infers blood flow status through pressure parameters, but cannot directly acquire local blood flow velocity information within the blood vessel. When vascular stenosis occurs, blood flow velocity and flow distribution usually change significantly, making it difficult to directly characterize hemodynamic features relying solely on pressure parameters. Furthermore, existing pressure measurement methods typically only acquire single-point pressure information, limiting their ability to continuously locate the position of vascular stenosis and making it difficult to simultaneously identify the location and degree of stenosis.

[0005] Therefore, there is an urgent need to provide an intravascular detection component and its measurement method that can directly detect changes in blood flow velocity within blood vessels, locate the position of vascular stenosis, and determine the degree of stenosis, so as to improve the real-time performance, accuracy, and clinical application value of the detection. Summary of the Invention

[0006] To address the shortcomings of existing methods for detecting vascular stenosis, which primarily rely on imaging or pressure parameters and struggle to directly capture changes in local blood flow velocity within the vessel, resulting in insufficient real-time accuracy and precision in stenosis location and severity assessment, this application provides a thermal flow velocity chip, a vascular detection component, a catheter, and a detection method thereof. The technical solution is as follows: On the one hand, a thermal flow rate chip is provided, comprising: Flexible substrate material (7); Thermistor (8) is disposed on the substrate flexible material (7); Solder joint (9) is electrically connected to the thermistor (8); The thermistor (8) includes a first thermistor unit and a second thermistor unit, which are spaced apart along the blood flow direction. The first thermistor is used to form a heat source area higher than the blood temperature after being energized, and the second thermistor is used to detect the temperature change signal generated after the blood flows through the first thermistor, so as to obtain blood flow velocity information based on the temperature change signal.

[0007] Optionally, there are multiple thermistors (8), which are arranged at intervals along the axial direction of the catheter microcatheter segment (2) to form a sensing array for detecting blood flow velocity information at different axial positions.

[0008] Optionally, the base flexible material (7) is used to attach to the outer wall of the catheter microcatheter segment (2), and the base flexible material (7) can enter the blood vessel interior (1) along with the catheter microcatheter segment (2).

[0009] Optionally, the substrate flexible material (7) includes polyimide, polydimethylsiloxane, thermoplastic polyurethane elastomer, SU8 or epoxy resin; The thermistor (8) includes nickel, chromium, tantalum, copper, aluminum, gold, titanium, platinum, silicon, or carbon nanomaterials.

[0010] Optionally, the thermal flow rate chip further includes a protective layer covering the thermistor (8) to isolate the thermistor (8) from the blood.

[0011] On the other hand, a blood vessel detection component is provided, including: Flexible flow sensing chip module (5); Matching circuit; Data processing software; Display module; The flexible flow sensing chip module (5) includes the thermal flow velocity chip described above. The flexible flow sensing chip module (5) is disposed on the outer wall of the catheter microcatheter segment (2) and can enter the blood vessel interior (1) along with the catheter microcatheter segment (2). The matching circuit is electrically connected to the flexible flow sensing chip module (5). The matching circuit is used to provide a heating electrical signal to the first thermistor and to collect the temperature change signal output by the second thermistor. The data processing software is used to obtain blood flow velocity information based on the temperature change signal, and to determine the location and degree of vascular stenosis based on the blood flow velocity information; The display module is used to display the location and degree of stenosis of the blood vessel.

[0012] Optionally, the matching circuit includes an excitation module, a data acquisition module, and a signal conditioning module; the excitation module is used to provide a heating electrical signal to the first thermistor; the data acquisition module is used to acquire the temperature change signal output by the second thermistor; and the signal conditioning module is used to amplify, filter, and perform analog-to-digital conversion on the temperature change signal. The data processing software includes a blood flow velocity conversion module, a normalization module, and a stenosis analysis module; the blood flow velocity conversion module is used to obtain blood flow velocity information based on the temperature change signal; the normalization module is used to normalize the blood flow velocity information corresponding to multiple thermistors (8); the stenosis analysis module is used to determine the location and degree of vascular stenosis based on the normalized blood flow velocity information.

[0013] On the other hand, a vascular detection catheter is provided, comprising: The entire conduit conductor (15); The aforementioned vascular detection component; The catheter conductor (15) includes a catheter seat (11), a stress relief tube (13), a radiopaque ring (10), and a hydrophilic coating (14). The flexible flow sensing chip module (5) is disposed on the distal outer wall of the conduit conductor (15) and adjacent to the imaging ring (10); The flexible flow sensing chip module (5) is electrically connected to the matching circuit (24) via a metal wire (23). The matching circuit (24) is located at the conduit seat (11) and is connected to the communication module (25). The stress relief tube (13) is disposed between the conduit seat (11) and the conduit conductor (15).

[0014] Optionally, the metal wire (23) is embedded between the inner and outer walls of the conduit conductor (15) and extends along the conduit axis to form a signal transmission path, so as to realize the electrical connection between the flexible flow sensing chip module (5) and the matching circuit (24).

[0015] On the other hand, a blood vessel detection method is provided, employing the blood vessel detection component described above, the method comprising: The flexible flow sensing chip module (5) is inserted into the blood vessel along with the catheter microcatheter segment (2) (1). A heating electrical signal is provided to the first thermistor unit, causing the first thermistor unit to form a heat source area higher than the blood temperature; The second thermistor unit acquires the temperature change signal generated after the blood flows through the first thermistor unit; Blood flow velocity information is obtained based on the temperature change signal; The location and degree of vascular stenosis are determined based on the blood flow velocity information corresponding to different detection locations.

[0016] Compared with the prior art, the present invention has the following significant advantages.

[0017] This invention acquires blood flow velocity information by placing a thermistor on a flexible substrate and using a first thermistor unit to heat the blood and a second thermistor unit to detect temperature changes. Compared to existing pressure detection methods, this directly reflects local blood flow velocity changes within the blood vessel. The flexible flow sensing chip module is attached to the distal outer wall of the catheter and enters the blood vessel with the catheter, eliminating the need for additional large-volume detection structures and reducing interference with blood flow. Multiple thermistor flow velocity chips form a sensing array along the catheter axis, allowing for comparison and normalization of blood flow velocity information at different locations. This enables the localization of vascular stenosis and assessment of its degree, improving the real-time performance and accuracy of detection. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0019] Figure 1 This is a schematic diagram of the overall device of the present invention for locating vascular stenosis and determining the degree of stenosis in blood vessels; Figure 2 This is a schematic diagram of the installation and test of the flexible flow sensing chip of the present invention; Figure 3 This is a schematic diagram of the flexible flow sensing chip of the present invention; Figure 4 This is a flowchart of the method for locating and determining the degree of vascular stenosis according to the present invention; Figure 5 This is a schematic diagram of the signal data displayed after data processing according to the present invention. Figure 1 ; Figure 6 This is a schematic diagram of the signal data displayed after data processing according to the present invention. Figure 2 ; Figure 7 Schematic diagram of the renal artery blood flow pressure detection catheter of the present invention Figure 1 ; Figure 8 Schematic diagram of the renal artery blood flow pressure detection catheter of the present invention Figure 2 ; Figure 9 This is a rendered schematic diagram of the finished vascular detection catheter of the present invention.

[0020] Figures 1 to 3 The corresponding numbers in the text are: 1-Inside the blood vessel; 2-Microcatheter segment; 3-Intermediate catheter segment; 4-Outer wall of the blood vessel; 5-Flexible flow sensor chip module; 6-Movable parts of the catheter; 7-Flexible substrate material; 8-Thermistor; 9-Solder joint; Figures 7 to 8 The corresponding numbers in the text are: 10-Illuminating ring; 11-Catheter seat; 13-Stress relief tube; 14-Hydrophilic coating; 15-Entire catheter conductor; 23-Metallic wire; 24-Matching circuit; 25-Communication module. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0022] In this article, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0023] Example 1

[0024] This embodiment provides a thermal flow velocity chip, which can be used as the core detection unit of the flexible flow sensing chip module 5 to detect changes in blood flow velocity inside the blood vessel 1.

[0025] like Figure 3As shown, the thermal flow rate chip includes a flexible substrate material 7, a thermistor 8, and solder joints 9. The thermistor 8 is disposed on the flexible substrate material 7, and the solder joints 9 are electrically connected to the thermistor 8 to lead out the electrical signal generated by the thermistor 8. The flexible substrate material 7 is used to support the thermistor 8 and the solder joints 9, and to enable the thermal flow rate chip to conform to the shape of the outer wall of the microcatheter segment 2 of the catheter for attachment.

[0026] The thermistor 8 includes a first thermistor unit and a second thermistor unit. The first and second thermistor units are spaced apart along the direction of blood flow. The first thermistor unit forms a heat source area higher than the blood temperature after being energized, and the second thermistor unit detects the temperature change signal generated after the blood flows through the first thermistor unit. When the blood flows through the first thermistor unit, it carries away heat from the area surrounding the first thermistor unit, and when it flows through the second thermistor unit, it generates a detectable temperature change. Based on this temperature change signal, the blood flow velocity information at the corresponding detection location can be obtained.

[0027] Optionally, the first and second thermistor units can both be formed from different regions of the thermistor 8, or they can be formed from two independent thermistors 8. The first and second thermistor units can be spaced apart along the length of the thermistor flow chip, or their relative positions can be adjusted according to the actual blood flow direction after the chip is attached, as long as the blood flows through the first thermistor unit first and then through the second thermistor unit.

[0028] Optionally, the flexible substrate material 7 may include PI, PDMS, TPU, SU8, or epoxy resin. The material of the thermistor 8 may include nickel, chromium, tantalum, copper, aluminum, gold, titanium, platinum, silicon, or carbon nanomaterials. The thermistor 8 may have a rectangular, serpentine, or spiral structure. A serpentine or spiral structure can increase the effective length of the thermistor 8 within a limited chip area, which is beneficial for improving the sensitivity of temperature change detection.

[0029] Optionally, the thermistor flow rate chip also includes a protective layer. The protective layer covers the thermistor 8 and serves to isolate the thermistor 8 from the blood. The protective layer material may include PI, parylene, polytetrafluoroethylene, silicon oxide, or silicon nitride. The protective layer reduces the risk of thermistor 8 being corroded, contaminated, or oxidized by blood, without affecting the thermistor 8's ability to sense temperature changes.

[0030] In this embodiment, the thermal flow velocity chip forms a heat source region through a first thermal unit and detects the temperature change caused by the blood carrying away heat through a second thermal unit, thereby transforming blood flow velocity detection from pressure measurement to heat transfer measurement. Because the flexible substrate material 7 can conform to the outer wall of the catheter and the thermistor 8 can be formed using a thin-film structure, the overall thickness of the thermal flow velocity chip is small, making it less likely to significantly alter the original blood flow state inside the blood vessel 1, which is beneficial for improving the accuracy and sensitivity of blood flow velocity detection.

[0031] Example 2

[0032] This embodiment, based on embodiment 1, provides an installation structure for a flexible flow sensing chip module 5.

[0033] like Figure 2 As shown, a microcatheter segment 2 is disposed within the lining of the blood vessel 1, and the microcatheter segment 2 is connected to the intermediate catheter segment 3. The outer side of the lining of the blood vessel 1 is the outer wall of the blood vessel 4. A flexible flow sensing chip module 5 is disposed on the outer wall surface of the microcatheter segment 2 and can enter the lining of the blood vessel 1 along with the microcatheter segment 2. A movable part 6 of the catheter is located near the microcatheter segment 2 and is used to assist the movement or positioning of the catheter within the lining of the blood vessel 1.

[0034] The flexible flow sensing chip module 5 includes at least one thermal flow rate chip as described in Embodiment 1. The flexible flow sensing chip module 5 can be attached to the outer wall of the microcatheter segment 2 of the catheter using PDMS, polyimide tape, or other adhesive biocompatible materials. During attachment, the surface of the adhesive material is kept flat, ensuring that the surface of the flexible flow sensing chip module 5 is free of wrinkles, warping, or significant protrusions after attachment.

[0035] In one embodiment, the flexible flow sensing chip module 5 includes multiple thermal flow velocity chips, which are arranged at intervals along the axial direction of the catheter microcatheter segment 2 to form a sensing array. The multiple thermal flow velocity chips can be arranged sequentially from distal to proximal along the catheter microcatheter segment 2, or the spacing can be set according to the diameter of the blood vessel to be detected, the length of the target detection area, and the accessibility of the catheter. Each thermal flow velocity chip can obtain blood flow velocity information at its corresponding axial position.

[0036] In one specific embodiment, the flexible flow sensing chip module 5 includes five thermal flow velocity chips. These five thermal flow velocity chips are attached parallel to each other along the axial direction of the microcatheter segment 2 and are sequentially labeled a, b, c, d, and e from the distal to the proximal end of the catheter. Thus, after the microcatheter segment 2 enters the blood vessel interior 1, the five thermal flow velocity chips can respectively collect blood flow velocity information at different axial positions. When stenosis exists at different locations in the blood vessel, the blood flow velocity information collected by different thermal flow velocity chips will differ, which can then be used to determine the location of the stenosis.

[0037] The flexible flow sensing chip module 5 is electrically connected to the matching circuit via wires. The wires can be attached to or wound around the outer wall of the microcatheter segment 2 and the intermediate catheter segment 3 of the catheter, and arranged along the extension direction of the catheter to the proximal end of the catheter. The wires are used to transmit the electrical signals generated by the flexible flow sensing chip module 5 to the matching circuit, and can also be used to transmit the heating electrical signals provided by the matching circuit to the first thermistor unit.

[0038] In this embodiment, the flexible flow sensing chip module 5 is attached to the outer wall of the catheter microcatheter segment 2, and can directly enter the target detection area inside the blood vessel 1 along with the catheter microcatheter segment 2. Because the flexible flow sensing chip module 5 uses a flexible attachment method, it eliminates the need for a large independent measuring device at the catheter tip, thus reducing the obstruction of the blood flow channel. Multiple thermal flow velocity chips form a sensing array along the catheter axis, enabling the detection results to reflect not only single-point blood flow velocity changes but also blood flow velocity distribution at different axial positions, thereby providing a structural basis for stenosis localization.

[0039] Example 3

[0040] This embodiment provides a vascular detection component, which is used to detect changes in blood flow velocity inside a blood vessel 1, and to determine the location and degree of vascular stenosis based on the detection results.

[0041] like Figure 1 As shown, the vascular detection component includes a flexible flow sensing chip module 5, a matching circuit, data processing software, and a display module. The flexible flow sensing chip module 5 is disposed on the outer wall of the catheter microcatheter segment 2, which is located within the vascular interior 1, with the vascular interior 1 surrounded by the vascular outer wall 4. The flexible flow sensing chip module 5 is electrically connected to the matching circuit, the matching circuit is communicatively connected to the data processing software, and the data processing software is communicatively connected to the display module.

[0042] The matching circuit provides an operating electrical signal to the flexible flow sensing chip module 5 and acquires the temperature change signal output by the flexible flow sensing chip module 5. Specifically, the matching circuit may include an excitation module, an acquisition module, and a signal conditioning module. The excitation module provides a heating electrical signal to the first thermistor unit, enabling the first thermistor unit to operate within a temperature range higher than blood temperature but harmless to the measured object. The acquisition module acquires the temperature change signal output by the second thermistor unit. The signal conditioning module amplifies, filters, and performs analog-to-digital conversion on the temperature change signal.

[0043] In one embodiment, the matching circuit may further include an input power protection circuit, a linear regulator circuit, a constant temperature control circuit, a constant current temperature measurement circuit, and a signal acquisition circuit. The input power protection circuit is used to reduce the impact of external power supply anomalies on the flexible flow sensing chip module 5. The linear regulator circuit is used to provide a stable voltage for the excitation module and the acquisition module. The constant temperature control circuit is used to control the heating state of the first thermistor unit. The constant current temperature measurement circuit is used to reduce the impact of current fluctuations on the temperature detection results during temperature measurement. The signal acquisition circuit is used to acquire the electrical signal output by the thermistor 8.

[0044] The data processing software receives the signal output from the matching circuit and analyzes the blood flow status of that signal. The software may include a blood flow velocity conversion module, a normalization module, and a stenosis analysis module. The blood flow velocity conversion module obtains blood flow velocity information based on temperature change signals and can further obtain blood flow rate and blood flow temperature information. The normalization module normalizes the blood flow velocity information corresponding to multiple thermistor flow velocity chips to reduce the impact of differences in initial resistance, sensitivity, or installation location between different thermistor flow velocity chips on the detection results. The stenosis analysis module determines the location and degree of vascular stenosis based on the normalized blood flow velocity information.

[0045] In one implementation, the data processing software may further include an effective data analysis model. The effective data analysis model is used to select stable segments as valid data from continuously acquired data, filter out significant abnormal fluctuations, and perform relative blood flow change analysis, vascular stenosis assessment, and thrombus localization analysis on the valid data.

[0046] The display module shows the location and degree of vascular stenosis. It can also display blood flow velocity, blood volume, blood temperature, normalized curve, and information indicating the location or degree of stenosis, allowing the operator to make subsequent judgments based on the displayed results.

[0047] In this embodiment, the flexible flow sensing chip module 5 is responsible for acquiring the temperature change signal of blood flowing through the thermal flow velocity chip. The matching circuit is responsible for providing stable heating and signal conditioning. The data processing software is responsible for converting the temperature change signal into blood flow velocity information and performing normalization and stenosis analysis. The display module is responsible for outputting the judgment result. The above structures are arranged in sequence according to the signal flow, enabling the vascular detection component to obtain the blood flow velocity distribution from the temperature change caused by blood flow, and further realize the judgment of the location and degree of vascular stenosis.

[0048] Example 4

[0049] This embodiment provides a vascular detection catheter, which carries the vascular detection component of Embodiment 3 and delivers the flexible flow sensing chip module 5 into the target blood vessel for blood flow velocity detection.

[0050] like Figures 7 to 9 As shown, the vascular detection catheter includes a complete catheter conductor 15 and a vascular detection assembly disposed on the entire catheter conductor 15. The entire catheter conductor 15 includes a catheter seat 11, a stress relief tube 13, a radiopaque ring 10, and a hydrophilic coating 14.

[0051] The flexible flow sensing chip module 5 is disposed on the distal outer wall of the entire catheter conductor 15, adjacent to the imaging ring 10. The imaging ring 10 is used to display the distal position of the catheter under X-ray fluoroscopy or other medical imaging equipment, to assist the operator in determining the detection location of the flexible flow sensing chip module 5. By placing the flexible flow sensing chip module 5 near the imaging ring 10, the operator can determine whether the flexible flow sensing chip module 5 has reached the target blood vessel area based on the imaging position of the imaging ring 10.

[0052] The entire outer surface of the catheter conductor 15 is provided with a hydrophilic coating 14. The hydrophilic coating 14 can reduce the frictional resistance between the catheter and the blood vessel wall, improve the catheter's passage performance in tortuous blood vessels, and reduce the irritation and damage to the blood vessel tissue during catheter advancement.

[0053] The catheter hub 11 is located at the proximal end of the entire catheter conductor 15 for the operator to hold and for connection to external equipment. The stress relief tube 13 is located between the catheter hub 11 and the entire catheter conductor 15 to reduce stress concentration in the proximal connection area of ​​the catheter, reduce the risk of damage or breakage of the catheter during repeated advancement, retraction and bending, and improve the overall structural reliability of the catheter.

[0054] like Figure 1 , Figure 7 and Figure 8 As shown, the flexible flow sensing chip module 5 is electrically connected to the matching circuit 24 via metal wire 23. Among them, Figure 7 and Figure 8 The matching circuit 24 in this example is the same as the matching circuit in Embodiment 3 and the blood vessel detection component. Matching circuit 24 provides a heating electrical signal to the first thermistor in the flexible flow sensing chip module 5 and receives the temperature change signal output by the second thermistor. Matching circuit 24 is connected to communication module 25, which transmits the detection signal processed by matching circuit 24 to external data processing software and a display module, thereby enabling the acquisition, analysis, and display of blood flow velocity information.

[0055] Specifically, the flexible flow sensor chip module 5 collects temperature change signals generated when blood flows through the detection area and transmits them to the matching circuit 24 via the metal wire 23. The matching circuit 24 performs excitation control, signal acquisition, and conditioning processing on the temperature change signals, and then sends them to the data processing software via the communication module 25 for blood flow velocity calculation, normalization analysis, and determination of the location and degree of vascular stenosis. The display module outputs the detection results. This forms a signal transmission link between the flexible flow sensor chip module 5, the metal wire 23, the matching circuit 24, the communication module 25, the data processing software, and the display module.

[0056] In one implementation, such as Figure 8 As shown, the metal wire 23 is embedded between the inner and outer walls of the entire catheter conductor 15 and extends along the axial direction of the entire catheter conductor 15 to form a signal transmission path. One end of the metal wire 23 is connected to the flexible flow sensing chip module 5, and the other end is connected to the matching circuit 24. The embedded wiring structure avoids the wire being exposed on the outer surface of the catheter, thereby reducing the risk of wire detachment, wear, or friction damage to the blood vessel wall. It also maintains the smoothness of the outer surface of the catheter, improving the catheter's propulsion performance and detection stability within the blood vessel.

[0057] like Figure 9 The schematic diagram of the finished catheter shown depicts a slender, flexible tubular structure for vascular detection. A catheter hub 11 is located at the proximal end for connection to external equipment and for the operator to hold and manipulate the device. The distal end is the detection section that enters the blood vessel, where the flexible flow sensor chip module 5 and the imaging ring 10 are positioned. The entire catheter conductor 15 exhibits excellent flexibility and bending adaptability, enabling it to be advanced along the curved path of the blood vessel to the target detection area. Figure 9 The bending state shown demonstrates the catheter's compliance with complex vascular environments, which is beneficial for improving catheter accessibility and detection stability.

[0058] In this embodiment, by integrating the flexible flow sensing chip module 5, metal wire 23, matching circuit 24, and communication module 25 onto the entire catheter conductor 15, and combining this with the structural design of the imaging ring 10, hydrophilic coating 14, and stress relief tube 13, the vascular detection catheter can not only complete intravascular positioning and advancement, but also acquire blood flow velocity information in real time and detect the location and degree of vascular stenosis, thereby improving the real-time performance and accuracy of the detection. Furthermore, combined with... Figure 9 The overall flexible catheter structure shown allows the catheter to adapt to complex vascular anatomy while ensuring blood flow detection functionality, thereby improving catheter delivery performance and clinical reliability.

[0059] Example 5

[0060] This embodiment provides a vascular detection method, which can be implemented using the vascular detection component of Embodiment 3 or the vascular detection catheter of Embodiment 4.

[0061] like Figure 4 As shown, the vascular detection method may include the following process.

[0062] First, the temperature coefficient of resistance (TCR) of the thermistor units in the flexible flow sensing chip module 5 is calibrated to obtain the TCR of each thermistor unit. Calibration methods can include oven calibration, water bath calibration, or other constant temperature environment calibration methods. The TCR can be obtained according to the following relationship: ; Where α is the temperature coefficient of resistance, R is the resistance value of thermistor 8 at temperature T, and R0 is the resistance value of thermistor 8 at the initial temperature T0. After calibration, multiple thermistor units can be adjusted to the same or similar initial states through a matching circuit to reduce the initial differences between the multiple thermistor units.

[0063] Then, the flexible flow sensing chip module 5 is fixed to the outer wall of the catheter microcatheter segment 2, and the flexible flow sensing chip module 5 is allowed to enter the blood vessel interior 1 along with the catheter microcatheter segment 2. During the process of entering the blood vessel interior 1, the catheter microcatheter segment 2 moves along the blood vessel path, and the flexible flow sensing chip module 5 remains attached to the outer wall of the catheter microcatheter segment 2, so that the flexible flow sensing chip module 5 can contact or approach the blood flow area.

[0064] Next, the measuring resistance and operating voltage are set through a matching circuit, enabling the first thermistor to operate within a temperature range above blood temperature that is harmless to the measured object. In one embodiment, the first thermistor can operate between 38°C and 42°C. In another embodiment, the first thermistor can be controlled to be approximately 2°C above blood temperature. When the first thermistor is energized, it forms a heat source area. When blood flows through the first thermistor, it carries away heat from the area surrounding the first thermistor, creating a temperature change as it flows through the second thermistor. The second thermistor detects this temperature change and outputs a temperature change signal.

[0065] Subsequently, the matching circuit acquires the temperature change signal and performs amplification, filtering, and analog-to-digital conversion on it. The data processing software receives the processed temperature change signal and obtains blood flow velocity information based on it. If needed, the software can further obtain blood flow rate and blood flow temperature information.

[0066] Subsequently, the data processing software normalizes the acquired blood flow parameter data. Normalization reduces the impact of initial sensitivity differences, installation location differences, or circuit differences between different thermal flow rate chips on the judgment results. The data processing software can select stable segments from continuously acquired data as valid data and perform normalization based on this valid data.

[0067] In one specific embodiment, taking the detection of arterial blood vessel status in the renal region as an example, five flexible flow sensing chips are selected, and the temperature coefficient of resistance of each flexible flow sensing chip is calibrated. After calibration, the five flexible flow sensing chips are attached parallel and spaced apart to the outer wall of the catheter microcatheter segment 2, and are sequentially labeled a, b, c, d, and e along the direction from the distal to the proximal end of the catheter. During detection, the catheter microcatheter segment 2 enters the blood vessel interior 1, and the blood flow direction is opposite to or approximately opposite to the direction of catheter movement. The five flexible flow sensing chips respectively collect blood flow velocity information at their corresponding locations.

[0068] like Figure 5 As shown, blood flow velocity or blood flow rate information acquired by a single flexible flow sensor chip can be presented as a pulse-like signal that varies over time. This pulse-like signal is related to heartbeats and can reflect changes in blood flow over a certain period of time. Data processing software can extract features such as peak value, trough value, period, phase, or amplitude from this pulse-like signal for subsequent analysis.

[0069] like Figure 6 As shown, when five flexible flow sensing chips (a, b, c, d, and e) form a sensing array, blood flow signals from five detection locations can be combined and compared. When the blood vessel is relatively normal, the peak values ​​of the normalized blood flow signals at each detection location are similar; when local stenosis occurs in the blood vessel, the blood flow signals at the detection locations before and after the stenosis will differ. If the relative blood flow peak value at some detection locations drops to, for example, 0.6, it indicates that the patency area of ​​the blood vessel near that location is relatively reduced, thus suggesting the presence of stenosis. The data processing software can determine the location of the stenosis based on the location of the peak value drop and assess the degree of stenosis based on the degree of change in the relative peak value.

[0070] Finally, the display module shows blood flow velocity information, normalization results, location and degree of vascular stenosis. The operator can then determine whether to extend the testing time, adjust the catheter position, or perform further procedures based on the displayed results.

[0071] In this embodiment, the detection method first reduces individual differences between thermistor units through calibration, then obtains temperature change signals by heating with the first thermistor unit and measuring the temperature with the second thermistor unit, and converts the temperature change signals into blood flow velocity information. By forming a sensor array along the catheter axis using multiple flexible flow sensor chips, the blood flow velocity distribution at different axial positions can be obtained. By normalizing and comparing the data at each detection position, the location and degree of stenosis can be determined based on changes in blood flow velocity, thereby improving the real-time performance and accuracy of intravascular stenosis detection and localization.

[0072] The sequence numbers of the embodiments in this application are for description only and do not represent the superiority or inferiority of the embodiments.

[0073] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware, or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk. The above are merely optional embodiments of this application and are not intended to limit the application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A thermal flow rate chip, characterized in that, include: Flexible substrate material (7); Thermistor (8) is disposed on the substrate flexible material (7); Solder joint (9) is electrically connected to the thermistor (8); The thermistor (8) includes a first thermistor unit and a second thermistor unit, which are spaced apart along the blood flow direction. The first thermistor is used to form a heat source area higher than the blood temperature after being powered on, and the second thermistor is used to detect the temperature change signal generated after the blood flows through the first thermistor, so as to obtain blood flow velocity information based on the temperature change signal. The thermistors (8) are multiple, and the multiple thermistors (8) are arranged at intervals along the axial direction of the catheter microcatheter segment (2) to form a sensing array for detecting blood flow velocity information at different axial positions; The base flexible material (7) is used to attach to the outer wall of the catheter microcatheter segment (2), and the base flexible material (7) can enter the blood vessel interior (1) along with the catheter microcatheter segment (2). The thermal flow rate chip also includes a protective layer that covers the thermistor (8) and is used to isolate the thermistor (8) from the blood.

2. The thermal flow rate chip according to claim 1, characterized in that, The substrate flexible material (7) includes polyimide, polydimethylsiloxane, thermoplastic polyurethane elastomer, SU8 or epoxy resin; The thermistor (8) includes nickel, chromium, tantalum, copper, aluminum, gold, titanium, platinum, silicon, or carbon nanomaterials.

3. A blood vessel detection component, characterized in that, include: Flexible flow sensing chip module (5); Matching circuit; Data processing software; Display module; The flexible flow sensing chip module (5) includes the thermal flow rate chip according to any one of claims 1 to 2; The flexible flow sensing chip module (5) is disposed on the outer wall of the catheter microcatheter segment (2) and can enter the blood vessel interior (1) along with the catheter microcatheter segment (2). The matching circuit is electrically connected to the flexible flow sensing chip module (5). The matching circuit is used to provide a heating electrical signal to the first thermistor and to collect the temperature change signal output by the second thermistor. The data processing software is used to obtain blood flow velocity information based on the temperature change signal, and to determine the location and degree of vascular stenosis based on the blood flow velocity information; The display module is used to display the location and degree of stenosis of the blood vessel.

4. The blood vessel detection component according to claim 3, characterized in that, The matching circuit includes an excitation module, a data acquisition module, and a signal conditioning module; the excitation module is used to provide a heating electrical signal to the first thermistor; the data acquisition module is used to acquire the temperature change signal output by the second thermistor; and the signal conditioning module is used to amplify, filter, and perform analog-to-digital conversion on the temperature change signal. The data processing software includes a blood flow velocity conversion module, a normalization module, and a stenosis analysis module; the blood flow velocity conversion module is used to obtain blood flow velocity information based on the temperature change signal; the normalization module is used to normalize the blood flow velocity information corresponding to multiple thermistors (8); the stenosis analysis module is used to determine the location and degree of vascular stenosis based on the normalized blood flow velocity information.

5. A vascular detection catheter, characterized in that, include: The entire conduit conductor (15); The blood vessel detection component according to any one of claims 3 to 4; The catheter conductor (15) includes a catheter seat (11), a stress relief tube (13), a radiopaque ring (10), and a hydrophilic coating (14). The flexible flow sensing chip module (5) is disposed on the distal outer wall of the conduit conductor (15) and adjacent to the imaging ring (10); The flexible flow sensing chip module (5) is electrically connected to the matching circuit (24) via a metal wire (23). The matching circuit (24) is located at the conduit seat (11) and is connected to the communication module (25). The stress relief tube (13) is disposed between the conduit seat (11) and the conduit conductor (15).

6. The vascular detection catheter according to claim 5, characterized in that, The metal wire (23) is embedded between the inner and outer walls of the conduit conductor (15) and extends along the conduit axis to form a signal transmission path, so as to realize the electrical connection between the flexible flow sensing chip module (5) and the matching circuit (24).

7. A method for detecting blood vessels, characterized in that, The method, using the vascular detection component according to any one of claims 3 to 4, comprises: The flexible flow sensing chip module (5) is inserted into the blood vessel along with the catheter microcatheter segment (2) (1). A heating electrical signal is provided to the first thermistor unit, causing the first thermistor unit to form a heat source area higher than the blood temperature; The second thermistor unit acquires the temperature change signal generated after the blood flows through the first thermistor unit; Blood flow velocity information is obtained based on the temperature change signal; The location and degree of vascular stenosis are determined based on the blood flow velocity information corresponding to different detection locations.

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