Effects of testing conditions on radial compliance of textile vascular prostheses / 医用生物力学

ABSTRACT

Objective To explore influences of pre-tension and testing site on the radial compliance of vascular prostheses. Methods Three different textile vascular prosthesis samples (PET woven, PET/PPT woven and PET corrugate warp knitted) with the diameter of 8 mm were selected. Under various pre-tensions and testing sites, the pulsatile pressure and its corresponding radial diameter of these samples were measured by dynamic compliance testing instrument. The radial compliance was calculated according to the compliance formula in ISO 7198-1998. Results The radial compliance of all the three vascular prostheses increased along with the pre-tension increasing. When the pre-tension was 500~550 mN, all the radial compliance reached the maximum (1.03~1.72)%/100 mmHg (1 mmHg=0.133 kPa), and then began to decrease with pre-tension increasing. Furthermore, the radial compliance of corrugate vascular prostheses was slightly bigger at valleys than that at peaks, while the radial compliance at peaks was more stable than that at valleys. Conclusions The pre-tension and test site had vital effects on testing the radial compliance of vascular prostheses. Pre-tension of 500~550 mN should be right to apply to all the three kinds of textile vascular prosthesis at test. As for corrugate vascular prostheses, the radial compliance at peaks should be chosen as the test site to get more stable result and reliable data.