Improvement On An In Vitro Simulating Vascular Prostheses' Compliance Testing Instrument And Analysis Of Influencing Factors Of Compliance

Compliance refers to the deformation responsiveness to the inter-duct stress of artificial blood vessel. When inferior artificial vessel was transplanted with vessel with normal compliance, would lead to hemodynamics to fluctuate. Viscoelasticity is the very characteristic of human artery, which functions fundamentally in the cardiovascular function. The systole would cause turgor vitalis, subsequently the vascular wall would expand. The expansion is essential for the stability of the blood flow. If hemodynamics fluctuate, due to the distinct pressure wave transmission rate created by different duct-wall elasticity, the reflex of the waves would be generated, and subsequently lead to the present of vortex, which is the cause of coagulation and vascular intra-wall hyperplasia.In addition, for the reason of distinct diameter expansion rate of the artificial vessel and host vessel, redundant stress would be generated at the suture, which lead to sutural fatigue, shearing force produced by host vessel and fibrous tissue at the suture. To obtain benign stress conduction and avoid reflex effect, identical duct should be shared by host vessel and transplanted artificial vessel. Therefore, compliance match may present as a essential issue in artificial biodynamics. Aiming this issue, after summarizing the characteristics and insufficiency of several domestic and foreign vessel compliance testing machine, developed artificial vessel compliance emulation testing machine.This artificial vessel compliance emulation testing machine work with scientific testing protocol, advanced testing software, especially is able to emulate the acture in vivo environment, and could generate several kinds of impulse wave, which make it the leading position in this area domestically. However, this machine may encounter some issues, such as the absence of delicate control of preliminary stress at the sample holding part, the overwhelming thickness of the intra silica gel duct wall of the artificial vessel sample, the instability of the intra spandex tube, the scarcity of diameter gauge, incapability of suffice the experience demand, absence of experimental justification of the quantitative relationship between the sample material, structure, testing parameter setting and compliance and instability of the temperature of the flow circuit, et al.Therefore, to settle problem above, this paper is targeted on the improvement of the vitro simulating vascular prostheses'compliance testing instrument and influencing factors of compliance:firstly, install pre-tension device on the test sample-holding device, improve precision and reproduction quality of analysis;secondly, improve manufacturing technology of spandex pipe, prepare spandex pipe in small thickness,high elastic properties,good compliance to improve sample transfer characteristics of lumenal pressure;thirdly, according to the different structure of the artificial vascular sample compliance testing, analyze the material and structure factors of artificial vascular sample compliance;lastly, Install the system-fluid heating device and encapsulate the vitro simulating vascular prostheses'compliance testing instrument, making the test environment better model body real environment.In brief, based on the former vitro simulating vascular prostheses'compliance testing instrument,this paper is successful on test sample-holding device,lining tubing and experimental temperature,improve the overall performance of the instrument and the precision and reproduction quality of analysis. Moreover, through analysis of the experiment, discussed the influence on the compliance about material and structure factors of artificial vascular sample. If this instrument can be used in the actual clinical,it must have a wide market prospect and great significance in guiding the doctor using artificial vascular.