The Design Of Vascular Prostheses' Permeability Test Instrument And The Research About Characterization Of Vascular Prostheses' Permeability

All through the development of the society, the blood vessel disease is a serious killer to people's health. With the improvement of the living standard in our country, the incidence of arterous stenostic and dilative diseases are increasing steadily. In the recently forty years, with the research and development of vascular prostheses, the replacement and bypass of arteries with textile vascular prostheses has proved very successful in clinic operation. Each year many kinds of vascular prostheses are demanded all over the world. The design and manufacturing of vascular prostheses, the structure and performance of vascular prostheses are researched widely. But the products are developed in our country have not used in clinic successfully. Many elements restrict the exploitation of vascular prostheses in our country. One of the astriction maybe is the lack of a research on the biomechanical performance for vascular prostheses and the reasonable test methods.The research in this paper is one part of the subject on "characterization of biomechanical performance for vascular prosthesis". The characterizations of the vascular prostheses' permeability and the relative test methods have been established. The permeability is one of the important characterization indexes of the vascular prostheses, and the water permeability is reasonable to characterize the vascular prostheses' anti-blood permeability. We designed and manufactured the vascular prostheses' permeability test instrument based on the ISO/DIS 7198. Referring to this instrument two patents have been applied. The water permeability of vascular prostheses of diameter greater than 4mm can be tested with this instrument.Through plentiful repeated experiment and statistic analysis, the test data of each sample accord with the normal distribution, and the number of sample has been decided for each test to reduce the random error. The measuring performance and the measuring procedure of the instrument were studied, then the manipulating were given in detail.The influencing factors on permeability of the textile vascular prostheses have been studied in theory. The important influencing factors are wall thickness,porosity and pore distribution of the vascular. Furthermore we selected suitable sample and measured their permeability and every influencing factor. Through the synthetic analysis of the measuring data we knew the influence of porosity of the fabric to the permeability is larger than that of the fabric thickness. We measured the pore sizes and their distribution with the CFP-1100-AI Porometer. The results shown that the mean pore size is more correlative to the permeability than the porosity.In conclusion, in this paper we established the characterized index of the vascular prostheses' permeability, designed and manufactured the vascular prostheses' permeability test instrument, gave the optimal measuring method and test procedure. Based on the research, we applied two patents. The variation of the permeability in every process can be measured with the instrument we designed and the measuring data can be used to evaluate the products, to decide if the products can be implanted into human body directly without being preclotted. Some conclusions gained can supply the laboratory groundwork for the foundation of the theories of vascular prostheses' design.