Hemodynamics system for guiding formulation of pulse pneumatic hand pump implementation scheme

Abstract

The invention discloses a hemodynamic system for guiding formulating of a pulse air pressure hand pump implementation scheme, and belongs to the technical field of hemodynamic experimental devices for internal arteriovenous fistula health and rehabilitation. The system comprises a feedback control system, a fluid loading system, a multi-channel optical imaging system, a bionic internal fistula blood vessel model and a detection system. According to the system, WSS distribution characteristics corresponding to the endothelial surface of the AVF anastomosis position under different hand pump intervention conditions can be reproduced at the bionic vascular anastomosis position; the distribution characteristic of the WSS at the anastomosis position of the bionic blood vessel is always kept consistent with the distribution characteristic of the WSS on the endothelial surface at the AVF anastomosis position of the patient. The system can accurately and comprehensively reproduce the distribution characteristics of the WSS on the endothelial surface at the AVF anastomosis position under the condition of hand pump intervention with different intensities and frequencies, can simply and intelligently carry out a hemodynamic experiment, and provides a basis for obtaining a rule of regulating and controlling the WSS distribution characteristics on the endothelial surface at the AVF anastomosis position through hand pump intervention. And a miniaturized, objective, standardized, quantitative and automatic experiment platform is provided.

Description

Technical Field

[0001] This invention belongs to the technical field of hemodynamic experimental devices for arteriovenous fistula (AVF) health and rehabilitation. It is a hemodynamic system developed based on hemodynamic principles, 3D printing, and detection technology. The system consists of five modules: a feedback control system, a fluid loading system, a multi-channel optical imaging system, a biomimetic AVF vascular model, and a detection system. Hemodynamic experiments are conducted based on this system, and the experimental results guide the development of pulsed pneumatic hand pump implementation plans, thereby reducing the occurrence of AVF stenosis through hand pump intervention. Background Technology

[0002] End-stage renal disease (ESRD) has become a serious threat to human life. Currently, the primary treatment for ESRD is to create an arteriovenous fistula (AVF) by connecting the arteries and veins in the forearm via anastomosis surgery for hemodialysis. However, the maturation rate of AVFs is only about 40%, meaning that an AVF requires a 4-8 week period of vascular wall reconstruction before it can be used, known as the maturation period. During this time, approximately 60% of AVFs experience failure due to vascular stenosis or occlusion. Furthermore, even after maturation, the failure rate of AVFs during dialysis is as high as 50%. AVF failure directly affects the patient's hemodialysis treatment progress, thus exacerbating the patient's condition and even endangering their life.

[0003] Intimal hyperplasia at the AVF anastomosis site is the primary factor leading to AVF failure. Following anastomosis, venous blood flow in the AVF surges, causing venous dilation and blood flow separation near the anastomosis, creating a region of low-velocity turbulent flow. Under the stimulation of wall shear stress (WSS) generated by this low-velocity turbulent flow, endothelial cells activate inflammatory signaling pathways such as nuclear factor-κB, promoting the production of intracellular inflammatory factors such as interleukin-6 and increasing the secretion of intracellular intercellular adhesion molecule-1. This series of adverse events leads to endothelial dysfunction, ultimately resulting in intimal hyperplasia at the AVF anastomosis site. Therefore, effectively regulating the distribution characteristics of WSS on the endothelial surface at the AVF anastomosis site can reduce or even inhibit the abnormal expression of intracellular inflammatory factors and adhesion molecules in this region, thereby reducing the incidence of intimal hyperplasia at the anastomosis site while maintaining or improving endothelial function, thus improving the maturation rate and long-term patency of the AVF.

[0004] To regulate the distribution characteristics of vascular sclerosis surface syndrome (WSS) at the AVF anastomosis site, previous researchers have conducted active hand movement training exercises for ESRD patients, such as wall pushing and ball gripping. These interventions aim to increase blood reflux in the palm, thereby reducing the generation of low-velocity turbulent flow at the anastomosis site. However, the precise control of the force applied during these hand movements makes it difficult to effectively regulate the distribution characteristics of WSS at the AVF anastomosis site, and ESRD patients often struggle with effective exercise training. Clinicians can address the limitations of active movement interventions by using post-AVF vascular rehabilitation equipment, such as pulsed pneumatic hand pumps, to passively compress the patient's palm. This approach enhances blood reflux in the distal AVF arteries, thereby reducing the formation of undesirable WSS at the anastomosis site.

[0005] However, as the arterial flow factor (AVF) matures and is put into use, the continuous reconstruction of its geometry leads to dynamic changes in the blood flow distribution ratio among its branches, resulting in temporal heterogeneity in the distribution characteristics of the endothelial surface sclerotherapy (WSS) at the AVF anastomosis site. Therefore, to optimize the constantly changing WSS distribution characteristics at the anastomosis site before and after AVF maturation, the intensity and frequency of manual pump intervention need to be dynamically adjusted according to different developmental stages of the AVF, thereby achieving the goal of improving the WSS distribution characteristics at different stages. However, how to set the intervention intensity and frequency at each stage to effectively regulate the WSS distribution characteristics at the anastomosis site still requires further research. In summary, a hemodynamic system can be developed to study the laws governing the regulation of WSS distribution characteristics at the AVF anastomosis site by manual pump intervention, thereby guiding the development of implementation plans for preventing AVF failure using pulsed pneumatic manual pumps. However, no related invention patents have been applied for to date. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a hemodynamic system for guiding the development of a pulsed pneumatic hand pump implementation plan. Based on three-dimensional vascular images of the arteries and veins in the patient's forearm, a biomimetic AVF (arterial vein fragment) vascular model is fabricated using 3D printing technology. The biomimetic vascular model is integrated with its peripheral systems to construct the hemodynamic system corresponding to this patent. This system comprises five modules: a feedback control system, a fluid loading system, a multi-channel optical imaging system, the biomimetic AVF vascular model, and a detection system. The feedback control system operates the fluid loading system and the imaging system, receiving and recording flow data from these systems. The fluid loading system injects the experimental solution into the biomimetic AVF vascular model and adjusts the resistance of the afterloading element, which can change its compression force on the catheter based on the input flow rate. The imaging system measures the flow field characteristics on the surface of the lumen at the anastomosis site of the biomimetic AVF vascular model. The detection system measures the flow data at each port.

[0007] Before and after the patient's AVF matured, manual pump interventions of varying intensities and frequencies were performed. Color Doppler ultrasound was used to measure the axial velocity and flow waveforms of blood flow at the anastomosis site and distal arteriovenous branches. Based on a control system, fluid loading system, multi-channel optical imaging system, and detection system, the pulsating fluid waveforms input and output at each port of the biomimetic vascular model were adjusted accordingly to ensure that the axial velocity waveform characteristics at the biomimetic vascular model anastomosis site were consistent with the axial velocity waveform of the patient's AVF anastomosis site. The axial velocity and WSS distribution characteristics at the biomimetic vascular anastomosis site were acquired using the imaging system and particle image velocimetry (PIV) technology. Based on the fluid data acquired by the imaging system at the biomimetic vascular anastomosis site, the changing trends of the WSS distribution characteristics at the patient's anastomosis site under different intervention intensities and frequencies were analyzed, thereby revealing the pattern of WSS distribution characteristics on the endothelial surface at the AVF anastomosis site regulated by manual pump intervention. Integrating the above, a hemodynamic system was developed that can reproduce in vitro the distribution characteristics of WSS on the endothelial surface of the AVF anastomosis under different intensities and frequencies of hand pump intervention. Based on the fluid experiment results obtained by this system, an implementation plan for preventing AVF failure using a pulsed pneumatic hand pump was formulated.

[0008] The technical solution of the present invention: a hemodynamic system for guiding the formulation of a pulse pneumatic hand pump implementation scheme, the system comprising a feedback control system, a fluid loading system, a multi-channel optical imaging system, a biomimetic AVF vascular model, and a detection system;

[0009] The biomimetic AVF blood vessel model is a Y-shaped blood vessel structure, with a proximal arterial port, a distal arterial port, and a proximal venous port; the feedback control system is connected to the corresponding ports of the biomimetic AVF blood vessel model through the proximal arterial unit, the distal arterial unit, and the proximal venous unit, respectively.

[0010] In the proximal artery unit, the microprocessor controls the proximal artery servo motor to drive the proximal artery electric cylinder to act on the proximal artery syringe-type reservoir. The outlet pipe of the proximal artery syringe-type reservoir passes through the proximal artery one-way valve and the proximal artery flow sensor in sequence before being connected to the proximal artery port.

[0011] In the distal artery unit, the microprocessor controls the distal artery servo motor to drive the distal artery electric cylinder to act on the distal artery syringe-type reservoir. The outlet pipe of the distal artery syringe-type reservoir passes through the distal artery one-way valve and the distal artery flow sensor in sequence before being connected to the distal artery port.

[0012] In the proximal vein unit, a microprocessor controls a proximal vein servo motor to drive a proximal vein electric cylinder to act on a proximal vein syringe-type reservoir. The outlet tube of the proximal vein syringe-type reservoir is connected to the chamber inlet of the afterload element via a proximal vein one-way valve. The catheter at the proximal vein port passes sequentially through a proximal vein outlet one-way valve and a proximal vein flow sensor before connecting to the catheter insertion port of the afterload element. The catheter exiting the afterload element is connected to the waste liquid tank. An elastic membrane is provided between the chamber inlet and the catheter inserted into the catheter insertion port.

[0013] Under the synergistic action of the feedback control system and the proximal arterial unit, distal arterial unit and proximal venous unit, pulsating fluids with different characteristics are generated at the three ports of the biomimetic AVF vascular model. The corresponding pulsating characteristics are referenced from the blood flow axial velocity fluctuation characteristics collected at the three ports distal to the AVF anastomosis of the patient.

[0014] Furthermore, the multi-channel optical imaging system in this system includes a first high-speed camera, a second high-speed camera, and a third high-speed camera.

[0015] Furthermore, the biomimetic AVF vascular model is fabricated based on three-dimensional vascular images of arteries and veins in the patient's forearm and 3D printing technology; the feedback control system is used to control the fluid loading system and imaging system, and to receive and record flow data from the imaging system and detection system.

[0016] The fluid loading system injects the experimental solution into the biomimetic AVF vascular model and adjusts the resistance of the afterloading element, which can change its squeezing force on the catheter based on the input flow rate. The imaging system measures the flow field characteristics on the lumen surface at the anastomosis site of the biomimetic AVF vascular model. The detection system measures the flow data at each port.

[0017] Furthermore, before and after the patient's AVF matured, hand pump interventions of different intensities and frequencies were performed. Color Doppler ultrasound was used to measure the axial velocity and flow waveform of blood flow at the anastomosis site and at each branch artery and vein distal to the anastomosis.

[0018] Based on the corresponding regulation of the pulsating fluid waveforms at each port of the biomimetic blood vessel model by the fluid dynamics system, the axial velocity waveform characteristics at the anastomosis of the biomimetic blood vessel model tend to be consistent with the axial velocity waveform of the acquisition area at the anastomosis of the patient's AVF.

[0019] Furthermore, based on the fluid data of the biomimetic AVF vascular model anastomosis acquired by the multi-channel imaging system, the changing trends of WSS distribution characteristics at the anastomosis site under different intervention intensities and frequencies were analyzed, thereby obtaining the pattern of WSS distribution characteristics on the endothelial surface of the AVF anastomosis site regulated by hand pump intervention.

[0020] The system comprises a feedback control system, a fluid loading system, a multi-channel optical imaging system, a biomimetic arteriovenous fistula (AVF) vascular model, and a detection system. Based on three-dimensional images of the arteries and veins in the patient's forearm, a biomimetic AVF vascular model is fabricated using 3D printing technology. The fluid loading system, combined with the feedback control system, can reproduce the WSS (water surface saturation) distribution characteristics of the endothelial surface at the AVF anastomosis under different hand pump intervention conditions at the biomimetic vascular anastomosis. The multi-channel optical imaging and detection system can observe and record the flow field characteristics at the biomimetic vascular anastomosis and each port in real time, feeding back the images and detection data to the control system. This dynamically adjusts the fluid loading system to ensure that the WSS distribution characteristics at the biomimetic vascular anastomosis remain consistent with the WSS distribution characteristics of the endothelial surface at the patient's AVF anastomosis.

[0021] The beneficial effects of this invention are:

[0022] (1) The hemodynamic system described in this patent can reproduce the WSS distribution characteristics on the surface of endothelial cells at the AVF anastomosis site under different intensities and frequencies of hand pump intervention in vitro. Based on this system, hemodynamic experiments can be carried out to replace animal experiments and clinical experiments to study the law of hand pump intervention regulating the WSS distribution characteristics on the endothelial surface at the AVF anastomosis site. This overcomes the problems of difficulty, high risk, high cost, long cycle and ethical controversy in in vivo hemodynamic signal monitoring.

[0023] (2) Using the hemodynamic system described in this patent to conduct fluid experiments, revealing the pattern of WSS distribution characteristics on the endothelial surface of the AVF anastomosis site by hand pump intervention, will provide a theoretical basis for further clarifying the potential mechanobiological mechanism of AVF anastomosis site endometrial proliferation, and for guiding the formulation of implementation plans for personalized prevention or treatment of AVF failure by hand pump intervention at different stages before and after AVF maturation.

[0024] (3) Previous studies analyzing the distribution characteristics of WSS on the endothelial surface of the AVF based on CFD simulation and imaging techniques have not discussed the influence of blood reflux from the distal artery of the AVF on the flow field characteristics at the anastomosis. Moreover, although CFD simulation results can comprehensively describe the flow field distribution characteristics at the AVF anastomosis, their accuracy still needs to be verified through in vivo data or fluid experiment results. Currently, there are no reports on hemodynamic systems used to study blood reflux from the distal artery of the AVF, i.e., manual pump intervention, to regulate the distribution characteristics of WSS on the endothelial surface of the AVF anastomosis. The hemodynamic system involved in this patent can be used to reveal the above-mentioned patterns, and on this basis, to obtain an implementation scheme for preventing AVF failure using a pulsed pneumatic manual pump. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a hemodynamic system used to guide the development of an implementation scheme for a pulse pneumatic hand pump, as described in this invention.

[0026] Figure 2 This is a schematic diagram of the load-bearing element.

[0027] In the diagram: 1. Feedback control system; 1-1. Industrial computer; 2. Fluid loading system; 2-1. Microprocessor; 2-2. Proximal artery servo motor; 2-3. Distal artery servo motor; 2-4. Proximal vein servo motor; 2-5. Proximal artery electric cylinder; 2-6. Distal artery electric cylinder; 2-7. Proximal vein electric cylinder; 2-8. Proximal artery syringe-type reservoir; 2-9. Distal artery syringe-type reservoir; 2-10. Proximal vein syringe-type reservoir; 2-11. Proximal artery one-way valve; 2-12. Distal artery one-way valve; 2-13. Proximal vein one-way valve; 2-14. 3. Multi-channel optical imaging system, 3-1. First high-speed camera, 3-2. Second high-speed camera, 3-3. Third high-speed camera, 3-4. Laser, 4. Bionic AVF blood vessel model, 4-1. Proximal arterial port, 4-2. Distal arterial port, 4-3. Proximal venous port, 5. Detection system, 5-1. Proximal arterial flow sensor, 5-2. Distal arterial flow sensor, 5-3. Proximal venous flow sensor, 6. Afterload element, 6-1. Slot, 6-2. Elastic membrane, 6-3. Chamber inlet, 6-4. Catheter insertion port, 7. Waste liquid pool. Detailed Implementation

[0028] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0029] A hemodynamic system for guiding the development of a pulsed pneumatic hand pump implementation scheme, the system comprising five modules: a feedback control system, a fluid loading system, a multi-channel optical imaging system, a biomimetic AVF vascular model and detection system, and an afterload system.

[0030] The feedback control system consists of a computer, a microprocessor for the fluid loading device, and sensors. It is used to control the fluid loading system, the imaging system, and the strength of the vascular afterload resistance, and to receive and record flow field characteristic data acquired from the imaging system and the detection system.

[0031] The fluid loading system consists of three injection pump systems, each composed of a servo motor, an electric cylinder, and a syringe-type reservoir, used to regulate the flow characteristics of the fluid at each port of the bionic AVF blood vessel model. The first and second pump systems are connected to the proximal and distal arterial ports of the bionic AVF blood vessel model, responsible for injecting the experimental solution into the model. The third pump system is connected to the afterload element at the proximal venous port of the bionic blood vessel outlet, used to regulate the resistance of the afterload element, thereby altering the pulsating fluid characteristics at the outlet of the bionic blood vessel.

[0032] The multi-channel optical imaging system consists of devices such as lasers and high-speed cameras. It uses particle image velocimetry (PIV) technology to measure the axial flow velocity at the anastomosis site of the biomimetic AVF blood vessel model and the distribution characteristics of WSS on the lumen surface.

[0033] The biomimetic AVF vascular model is manufactured using 3D printing technology, and its dimensions are obtained from three-dimensional vascular images of the arteries and veins in the patient's forearm.

[0034] The afterloading element is a self-made slot with an elastic membrane. Fluid output from the injection pump system controls the deformation of the membrane within the slot, thereby changing the diameter of the catheter within the slot and thus adjusting the strength of the afterloading resistance in the vascular model. Under the action of the injection pump system, this afterloading system can automatically adjust the magnitude of the afterloading resistance in real time based on the axial flow velocity pulsation characteristics of the blood at the distal vein of the AVF under different conditions of manual pump intervention. Combined with the combined action of other modules of the hemodynamic system, it can relatively accurately and intelligently reproduce the WSS distribution characteristics of the endothelial surface at the anastomosis site of the biomimetic AVF vascular model under different intervention conditions.

[0035] Specifically:

[0036] Figure 1 The diagram shows a hemodynamic system for guiding the development of a pulse pneumatic hand pump implementation scheme, as described in this invention. It includes five modules: a feedback control system 1, a fluid loading system 2, a multi-channel optical imaging system 3, a biomimetic AVF vascular model 4, and a detection system 5.

[0037] like Figure 1As shown, the fluid loading system 2 described in this invention consists of a microprocessor 2-1, a proximal artery servo motor 2-2, a distal artery servo motor 2-3, a proximal vein servo motor 2-3, a proximal artery electric cylinder 2-5, a distal artery electric cylinder 2-6, a proximal vein electric cylinder 2-7, a proximal artery syringe-type reservoir 2-8, a distal artery syringe-type reservoir 2-9, a proximal vein syringe-type reservoir 2-10, a proximal artery one-way valve 2-11, a distal artery one-way valve 2-12, a proximal vein one-way valve 2-13, and a proximal vein outlet one-way valve 2-14. The microprocessor 2-1 controls the proximal artery servo motor 2-2, the distal artery servo motor 2-3, and the proximal vein servo motor 2-4 respectively. The proximal artery servo motor 2-2, the distal artery servo motor 2-3, and the proximal vein servo motor 2-4 are connected to the proximal artery electric cylinder 2-5, the distal artery electric cylinder 2-6, and the proximal vein electric cylinder 2-7 respectively, so that their piston rods can move in extension and retraction. Then, through the piston rods of the electric cylinders, the piston heads in the proximal artery syringe-type reservoir 2-8, the distal artery syringe-type reservoir 2-9, and the proximal vein syringe-type reservoir 2-10 are pushed to reciprocate.

[0038] The proximal arterial syringe-type reservoir 2-8 and the distal arterial syringe-type reservoir 2-9 are connected to the proximal arterial port 4-1 and the distal arterial port 4-2 of the biomimetic AVF vascular model 4, respectively. The proximal venous port 4-3 is connected to the catheter insertion port 6-4 of the afterload element 6, thereby generating physiological pulsating fluids at the ports of the biomimetic AVF vascular model 4, simulating the blood flow characteristics at the proximal and distal arterial and venous ends of the AVF. The flow direction of the three fluids is controlled by one-way valves. Finally, at the anastomosis site of the biomimetic AVF vascular model, the WSS distribution characteristics corresponding to the endothelial surface of the AVF anastomosis site of patients under different intervention conditions are reproduced.

[0039] like Figure 2 As shown, the afterload element 6 of this invention includes a slot 6-1 and an elastic membrane 6-2. Fluid input through the proximal intravenous syringe-type reservoir 2-9 regulates the deformation of the elastic membrane 6-2, thereby changing the diameter of the tube within the slot and thus controlling the strength of the biomimetic blood vessel's afterload resistance.

[0040] The principles of this invention are explained in detail below:

[0041] Based on the "Y-shaped" vascular structure of the arteriovenous fistula (AVF), the distribution characteristics of the endothelial surface vascular smoothing (WSS) at the anastomosis site are jointly influenced by the blood flow characteristics of three vascular pathways: the proximal artery and vein, and the distal artery. To address this characteristic, this invention utilizes 3D printing technology to fabricate a biomimetic AVF vascular model based on a three-dimensional vascular image of the AVF in the patient's forearm. Building upon this, a biomimetic vascular peripheral feedback control system, a fluid loading system, a multi-channel optical imaging system, and a detection system are constructed, integrating the biomimetic vascular system and external systems to develop the hemodynamic system described in this patent.

[0042] Under the synergistic action of the feedback control system and the fluid loading system, pulsating fluids with different characteristics are generated at the three ports of the biomimetic AVF vascular model. The corresponding pulsation characteristics are referenced from the blood flow axial velocity fluctuation characteristics collected at the three ports distal to the AVF anastomosis in the patient. Through the feedback control system, fluid loading system, imaging system, and detection system, the fluid characteristics at each port of the biomimetic vascular model are adjusted in real time, thereby ensuring that the distribution characteristics of WSS on the surface of the biomimetic vascular anastomosis lumen are always consistent with the WSS distribution characteristics on the endothelial surface of the AVF anastomosis.

[0043] Based on fluid data acquired by the imaging system at the biomimetic vascular anastomosis site, the changing trends of WSS distribution characteristics at the anastomosis site under different intervention intensities and frequencies are analyzed. This reveals the pattern of WSS distribution characteristics on the endothelial surface of the AVF anastomosis site regulated by hand pump intervention. Based on this, an implementation plan for preventing AVF failure using a pulsed pneumatic hand pump is obtained. Based on these principles, a hemodynamic system can be developed to guide the formulation of pulsed pneumatic hand pump implementation plans.

[0044] The specific working process of the hemodynamic system described in this invention is as follows:

[0045] The proximal artery servo motor 2-2, distal artery servo motor 2-3, and proximal vein servo motor 2-4 in the fluid loading system 2 are connected to the microprocessor 2-1 and the industrial computer 1-1 of the feedback control system 1, respectively. The industrial computer 1-1 and microprocessor 2-1 set the rotation speed and direction of the proximal artery servo motor 2-2, distal artery servo motor 2-3, and proximal vein servo motor 2-4. The proximal artery servo motor 2-2, distal artery servo motor 2-3, and proximal vein servo motor 2-4 are connected to the proximal artery electric cylinder 2-5, distal artery electric cylinder 2-6, and proximal vein electric cylinder 2-7, respectively, causing their piston rods to extend and retract. These piston rods then drive the piston heads in the proximal artery syringe-type reservoir 2-8, distal artery syringe-type reservoir 2-9, and proximal vein syringe-type reservoir 2-10, respectively, to reciprocate. The extension and retraction speed and stroke of the piston rods within the electric cylinders are adjusted. The piston rod of the electric cylinder drives the piston head in the syringe-type reservoir to reciprocate, thereby reproducing the physiological pulsating fluid at the four ports of the biomimetic AVF blood vessel model, which reproduces the blood flow characteristics of the proximal and distal arteries of the AVF. The flow direction of the two fluids is controlled by a one-way valve.

[0046] The proximal venous port 4-3 of the bionic AVF vascular model 4 is connected to a catheter, which is then placed into the slot 6-1 of the afterload element 6. Subsequently, the proximal venous syringe-type reservoir 2-10 is connected to the inlet 6-3 of the elastic membrane 6-2 chamber of the afterload element 6. By adjusting the output flow rate of the proximal venous syringe-type reservoir 2-10, the deformation of the elastic membrane 6-2 is adjusted, thereby changing the diameter of the catheter in the slot 6-1 in real time. This achieves intelligent and automatic control of the afterload resistance of the bionic AVF vascular model 4, ensuring that the pulsating waveform generated at the proximal venous port 4-3 of the bionic AVF vascular model 4 matches the axial velocity waveform of the blood flow collected at the proximal venous end of the AVF. The output end of the catheter placed in the slot 6-1 of the afterload element 6 is connected to the waste liquid pool 7, and the flow direction of the fluid is controlled by the proximal venous one-way valve control 2-13.

[0047] Using the proximal arterial flow sensor 5-1, distal arterial flow sensor 5-2, and proximal venous flow sensor 5-3 corresponding to the detection system 5, flow data at the proximal arterial port 4-1, distal arterial port 4-2, and proximal venous port 4-3 of the biomimetic AVF blood vessel model 4 are acquired in real time. Based on the first high-speed camera 3-1, second high-speed camera 3-2, third high-speed camera 3-3, and laser 3-4 involved in the multi-channel optical imaging system 3, PIV fluid experiments are conducted to collect and analyze the WSS distribution characteristics of the flow field at the anastomosis channel surface of the biomimetic AVF blood vessel model 4. An experimental solution is prepared by mixing distilled water with glycerol and polystyrene fluorescent particles (Thermo Fisher). The radius and volume concentration of the fluorescent particles in this solution are set according to the geometric characteristics of the biomimetic blood vessel model 4.

[0048] Data and images collected by sensors and imaging systems are fed back to the industrial control computer 1-1 as reference data for adjusting the fluid flow characteristics at different ports of the bionic AVF vascular model 4. This ensures that the WSS distribution characteristics of the flow field at the anastomosis surface of the bionic AVF vascular model 4 are consistent with the WSS distribution characteristics of the endothelial surface of the AVF anastomosis in patients under different intervention conditions. Different intervention conditions refer to hand pump intervention conditions with different intensities and frequencies. Based on the changes in the average WSS time, relative residence time, oscillatory shear index, and Reynolds number corresponding to the flow field at the anastomosis surface of the bionic AVF vascular model 4, the influence and potential patterns of the changes in distal arterial regurgitation flow caused by hand pump intervention of different intensities on the WSS distribution characteristics of the anastomosis endothelial surface are determined. On this basis, the implementation plan for the prevention and treatment of AVF failure using pulsed pneumatic hand pumps is summarized.

[0049] The above embodiments are only used to illustrate the present invention. Any equivalent transformations and improvements made on the basis of the technical solutions of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A hemodynamic system for guiding the development of implementation plans for pulse pneumatic hand pumps, characterized in that, The system includes a feedback control system (1), a fluid loading system (2), a multi-channel optical imaging system (3), a biomimetic AVF blood vessel model (4), and a detection system (5); The biomimetic AVF blood vessel model (4) is a Y-shaped blood vessel structure, with a proximal arterial port (4-1), a distal arterial port (4-2), and a proximal venous port (4-3); the feedback control system (1) is connected to the corresponding ports of the biomimetic AVF blood vessel model (4) through the proximal arterial unit, the distal arterial unit, and the proximal venous unit, respectively. In the proximal artery unit, the microprocessor (2-1) controls the proximal artery servo motor (2-2) to drive the proximal artery electric cylinder (2-5) to act on the proximal artery syringe-type reservoir (2-8). The outlet pipe of the proximal artery syringe-type reservoir (2-8) passes through the proximal artery one-way valve (2-11) and the proximal artery flow sensor (5-1) in sequence before being connected to the proximal artery port (4-1). In the distal artery unit, the microprocessor (2-1) controls the distal artery servo motor (2-3) to drive the distal artery electric cylinder (2-6) to act on the distal artery syringe-type reservoir (2-9). The outlet pipe of the distal artery syringe-type reservoir (2-9) passes through the distal artery one-way valve (2-12) and the distal artery flow sensor (5-2) in sequence before being connected to the distal artery port (4-2). In the proximal vein unit, the microprocessor (2-1) controls the proximal vein servo motor (2-4) to drive the proximal vein electric cylinder (2-7) to act on the proximal vein syringe-type reservoir (2-10). The outlet tube of the proximal vein syringe-type reservoir (2-8) is connected to the chamber inlet (6-3) of the afterload element (6) through the proximal vein one-way valve (2-13). The catheter of the proximal vein port (4-3) passes through the proximal vein outlet one-way valve (2-14) and the proximal vein flow sensor (5-3) in sequence and is connected to the catheter insertion port (6-4) of the afterload element (6). The catheter that passes through the afterload element (6) is connected to the waste liquid pool (7). An elastic membrane (6-2) is provided between the chamber inlet (6-3) and the catheter inserted into the catheter insertion port (6-4). Under the synergistic action of the feedback control system and the proximal arterial unit, distal arterial unit and proximal venous unit, pulsating fluids with different characteristics are generated at the three ports of the biomimetic AVF vascular model. The corresponding pulsating characteristics are referenced from the blood flow axial velocity fluctuation characteristics collected at the three ports distal to the AVF anastomosis of the patient.

2. The hemodynamic system for guiding the development of a pulse pneumatic hand pump implementation scheme according to claim 1, characterized in that: The multi-channel optical imaging system (3) in this system includes a first high-speed camera (3-1), a second high-speed camera (3-2), and a third high-speed camera (3-3).

3. A hemodynamic system for guiding the development of a pulse pneumatic hand pump implementation scheme according to claim 1, characterized in that: The biomimetic AVF vascular model (4) is fabricated based on the three-dimensional vascular image of the arteries and veins in the patient's forearm and 3D printing technology; the feedback control system is used to control the fluid loading system and the imaging system, and to receive and record flow data from the imaging system and the detection system. The fluid loading system injects the experimental solution into the biomimetic AVF vascular model and adjusts the resistance of the afterloading element, which can change its squeezing force on the catheter based on the input flow rate. The imaging system measures the flow field characteristics on the lumen surface at the anastomosis site of the biomimetic AVF vascular model. The detection system measures the flow data at each port.

4. A hemodynamic system for guiding the development of a pulse pneumatic hand pump implementation scheme according to claim 1, characterized in that: Before and after the patient's AVF matured, hand pump interventions of different intensities and frequencies were performed. Color Doppler ultrasound was used to measure the axial velocity and flow waveform of blood flow at the anastomosis site and at each branch artery and vein distal to the anastomosis. Based on the corresponding regulation of the pulsating fluid waveforms at each port of the biomimetic blood vessel model by the fluid dynamics system, the axial velocity waveform characteristics at the anastomosis of the biomimetic blood vessel model tend to be consistent with the axial velocity waveform of the acquisition area at the anastomosis of the patient's AVF.

5. A hemodynamic system for guiding the development of a pulse pneumatic hand pump implementation scheme according to claim 1, characterized in that: Based on fluid data from the anastomosis site of the biomimetic AVF vascular model acquired by a multi-channel imaging system, the changing trends of WSS distribution characteristics at the anastomosis site under different intervention intensities and frequencies were analyzed, thereby obtaining the pattern of WSS distribution characteristics on the endothelial surface of the AVF anastomosis site regulated by hand pump intervention.

Images