CN101347360A - Blood flow characteristics test device designed for vascular stent structure - Google Patents

Abstract

A blood flow characteristic test device designed for vascular stent structure, including a liquid storage tank and a centrifugal pump connected to the liquid storage tank, the outlet of the centrifugal pump is connected to a proportional valve, a flow meter and a vascular stent test model in sequence through pipelines, The outlet of the vascular stent test model is connected with the liquid storage tank through the pipeline, and the said proportional valve and the flow meter are respectively connected with the single-chip microcomputer, and the single-chip microcomputer is also connected with the computer, and a light source is arranged on one side of the vascular stent test model , the other side of the vascular stent test model is provided with a high-speed camera connected with a computer. The present invention adopts the proportional valve to regulate the flow in real time to simulate the blood physiological pulsation flow in the human body. On the one hand, the single-chip microcomputer controls the proportional valve, and on the other hand, it collects the data of the flow meter and compares it with the previously scheduled input flow data to ensure the accuracy of the required flow. Compared with other pulsating driving sources, it has the advantages of high adjustment accuracy and fast response speed.

Description

Blood flow characteristics test device designed for vascular stent structure

technical field

The invention belongs to the field of design and manufacturing technology and measurement, and in particular relates to a blood flow characteristic testing device designed for vascular stent structures.

Background technique

Vascular stenting is an interventional therapy for the clinical treatment of arterial stenosis. It mainly sends the stent to the vascular lesion through the balloon catheter, expands it and restores the stenosis of the blood vessel to its normal size, and keeps the vascular lumen unobstructed. However, many studies have shown that restenosis after stent placement is a key issue affecting the long-term use of stents. At present, it is generally believed that intimal hyperplasia is the main cause of in-stent restenosis.

In recent years, most of the solutions to this problem have been in-depth research on stent coating technology, especially drug eluting (active coating technology). However, the latest medical research data show that compared with bare metal stents (BMS), using Eluting stents (DES) have no significant effect on inhibiting the re-thrombosis in patients, so it is particularly necessary to consider solving this problem from another angle. Some studies in recent years have found that after stent implantation, the local flow laminar flow in the blood vessel will form irregular and unsteady flow, even turbulent flow, and may also form blood stasis areas and stent rods at the proximal and distal ends of the stent rod. The eddy current at the distal end, and the corresponding shear stress will change. In addition, the implantation of the stent will cause a compliance mismatch between the segment of the vessel and the adjacent natural vessel segment without the stent, so that the shearing effect between the laminar flow of the flowing blood will be significantly enhanced, that is, the local shear stress will be abnormally increased. It is generally believed that hemodynamic factors such as low wall shear stress, high particle residence time, and non-laminar flow are more likely to cause intimal hyperplasia. Therefore, an ideal stent should have good hydrodynamic compatibility to a certain extent, and this property has a lot to do with the structure of the stent.

Contents of the invention

The object of the present invention is to provide an experimental device with simple structure, low cost and capable of testing the internal blood flow characteristics of the designed stent after it is implanted in the blood vessel.

In order to achieve the above object, the technical scheme adopted by the present invention is: comprising a liquid storage tank and a centrifugal pump connected to the liquid storage tank, the outlet of the centrifugal pump is connected with a proportional valve, a flow meter and a vascular stent test model in turn through a pipeline, and the blood vessel The outlet of the support test model is connected with the liquid storage tank through pipelines, and the said proportional valve and flow meter are also connected with the single-chip microcomputer respectively, and the single-chip microcomputer is also connected with the computer. The blood flow is similar to the liquid pulsation source, and a light source is set on one side of the vascular stent test model, and a high-speed camera connected to a computer is set on the other side of the vascular stent test model.

In the present invention, a gate valve is also provided on the pipeline between the liquid storage tank and the centrifugal pump; a buffer tank is also provided on the pipeline between the centrifugal pump and the proportional valve, and the buffer tank adopts an arrangement of bottom inlet and top outlet.

The present invention uses a centrifugal pump to transport the fluid in the liquid storage tank into the experimental pipeline, and adjusts the flow of the fluid in the pipeline by a proportional valve. The flow is measured by a high-precision flowmeter, and both the proportional valve and the flowmeter are controlled by a single-chip computer program. . Afterwards, the fluid enters the test model of the vascular stent, and the flow characteristics of the internal fluid are photographed by a high-speed camera, and the high-speed camera is also controlled by a computer to complete storage and processing. The fluid flowing out of the test model is sent back to the liquid storage tank through the pipeline, thus forming a circulating flow system. The present invention uses a centrifugal pump, a proportional valve and a single-chip microcomputer to form a liquid pulsation source that is similar to the blood flow of the human body. The input flow data is compared to form a closed-loop control system to ensure the accuracy of the required flow. Compared with other pulsating driving sources (such as diaphragm pumps or cam mechanisms), this solution has the advantages of high adjustment accuracy and fast response speed.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the device of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

Referring to Fig. 1, the present invention includes a liquid storage tank 1 and a centrifugal pump 2 connected to the liquid storage tank 1, and a gate valve 3 is also arranged on the pipeline between the liquid storage tank 1 and the centrifugal pump 2, and the outlet of the centrifugal pump 2 passes through The pipeline is connected with the buffer tank 4, the proportional valve 5, the flow meter 6 and the vascular stent test model 8 in sequence. The outlet of the vascular stent test model 8 is connected with the liquid storage tank 1 through the pipeline. The layout of the outlet, the proportional valve 5 and the flowmeter 6 are also connected with the single-chip microcomputer 7 respectively, and the single-chip microcomputer 7 is also connected with the computer 11, and a light source 9 is arranged on one side of the vascular stent test model 8, and the vascular stent test model 8 The other side is provided with an adjustment camera 10 connected to a computer 11 .

The liquid storage tank 1 is a mixture of glycerin (35%) and water (65%), and the solution viscosity after the two are mixed is close to that of human blood, so as to achieve a real simulated environment. The centrifugal pump 2 is used to transport the mixed solution to the experimental pipeline. Considering that the required flow rate of the main pipeline is small, a gate valve 3 is set in the return pipeline of the centrifugal pump to adjust the flow rate into the main pipeline. In order to eliminate the high-frequency pulsation of the fluid caused by the centrifugal pump, a buffer tank 4 is installed behind it, and the arrangement of the bottom inlet and the top outlet is adopted, which can eliminate the air bubbles in the pipeline during the experiment. Then the proportional valve 5 is connected and the real-time flow required by the experiment is accurately controlled through its opening. The input signal of the proportional valve 5 is a 4-20mA current signal, and different current signals correspond to different opening degrees. According to the flow characteristic curve required by the experiment, the current signal of the proportional valve 5 at different times is given by the single-chip microcomputer 7, and the current signal is converted into the opening of the valve by the characteristic curve of the proportional valve 5 to control the flow. The response time of the proportional valve 5 is extremely fast, and it can quickly respond to the control program of the single-chip microcomputer 7 to generate a waveform similar to the physiological pulsation of blood flow. A flow meter 6 is connected after the proportional valve 5 to actually measure the flow in the pipeline to verify the correctness of the control. The real-time flow rate is also collected and converted by the single-chip microcomputer 7, and then input into the computer 11 for display and storage, and compared with the previously predetermined input flow value in real time to form a closed-loop control system to ensure the pulsating flow waveform required for the experiment. After passing through the flowmeter 6, the fluid enters the test model 8, and the light source 9 is used to provide test light behind the test model 8, and a high-speed camera 10 is set on the front for real-time flow field shooting, which is controlled and recorded by a computer 11 in real time.

Claims (3)

1, a kind of blood flowing characteristic test set towards the intravascular stent structural design, comprise fluid reservoir (1) and the centrifugal pump (2) that links to each other with fluid reservoir (1), it is characterized in that: the outlet of centrifugal pump (2) by pipeline successively with proportioning valve (5), effusion meter (6) and intravascular stent test model (8) are connected, the outlet of intravascular stent test model (8) is connected with fluid reservoir (1) by pipeline, said proportioning valve (5) and effusion meter (6) also are connected with single-chip microcomputer (7) respectively, single-chip microcomputer (7) also links to each other with computer machine (11), centrifugal pump (2), proportioning valve (5) and single-chip microcomputer (7) have constituted and can produce and liquid pulsation source like the blood of human body mobile phase, and the side at intravascular stent test model (8) is provided with light source (9), and the opposite side of intravascular stent test model (8) is provided with the high-speed camera (10) that is connected with computer (11).

2, the blood flowing characteristic test set towards the intravascular stent structural design according to claim 1 is characterized in that: also be provided with gate valve (3) on the pipeline between said fluid reservoir (1) and the centrifugal pump (2).

3, the blood flowing characteristic test set towards the intravascular stent structural design according to claim 1, it is characterized in that: also be provided with surge tank (4) on the pipeline between said centrifugal pump (2) and the proportioning valve (5), surge tank (4) adopts the arrangement of bottom inlet, top exit.