Jørgensen C S, Paaske W P
SAM Laboratory, Institute of Experimental Clinical Research, Aarhus University Hospital, Denmark.
Eur J Vasc Endovasc Surg. 1998 May;15(5):416-22. doi: 10.1016/s1078-5884(98)80203-7.
Determination of physical and mechanical characteristics and properties of thin-walled (0.39 mm) expanded polytetrafluoroethylene stretch vascular prostheses by time-resolved scanning acoustic microscopy (TR-SAM).
Samples of Stretch Gore-Tex were mounted on polymethylmethaacrylate substrate, and ethyl alcohol was used as acoustic couplant. A 10 MHz ultrasound transducer mounted on a SAM50 scanning acoustic microscope generated short, pulsed sound waves. Reflected signals were used for imaging and for computer analysis of time resolved wave forms acquired by a digital sampling oscilloscope to calculate physical and mechanical characteristics of the material.
Graft wall thickness: 0.395 (0.352/0.401) mm; graft wall sound wave penetration velocity: 1111 (1083/1129) ms-1; acoustic impedance: 3.685 (2.975/4.370) 10(6) kg m-3s-1; attenuation coefficient: 0.144 (0.096/0.229) dB mm-1 MHz-1; material density: 3360 (2712/3982) kg m-3; elastic stiffness: 4.06 (3.35/4.83) GPa (median and (25/75) percentiles; n = 8 samples, 10 measurements spaced 100 microns apart in each sample).
TR-SAM can effectively quantify ePTFE graft wall properties, and new data on graft properties have been provided. The acoustic impedance and elastic stiffness of the ePTFE graft wall are 2.2 and 1.6 times higher, respectively, than in human coronary arteries, and it is highly reflective of ultrasound.
通过时间分辨扫描声学显微镜（TR-SAM）测定薄壁（0.39毫米）膨体聚四氟乙烯拉伸血管移植物的物理和机械特性及属性。
将拉伸型戈尔特斯（Stretch Gore-Tex）样本安装在聚甲基丙烯酸甲酯基板上，并使用乙醇作为声耦合剂。安装在SAM50扫描声学显微镜上的10兆赫超声换能器产生短脉冲声波。反射信号用于成像，并通过数字采样示波器获取的时间分辨波形进行计算机分析，以计算材料的物理和机械特性。
移植物壁厚：0.395（0.352/0.401）毫米；移植物壁声波穿透速度：1111（1083/1129）米/秒；声阻抗：3.685（2.975/4.370）×10⁶千克·米⁻³·秒⁻¹；衰减系数：0.144（0.096/0.229）分贝·毫米⁻¹·兆赫⁻¹；材料密度：3360（2712/3982）千克·米⁻³；弹性刚度：4.06（3.35/4.83）吉帕（中位数及（25/75）百分位数；n = 8个样本，每个样本间隔100微米进行10次测量）。
TR-SAM能够有效量化ePTFE移植物壁的属性，并提供了关于移植物属性的新数据。ePTFE移植物壁的声阻抗和弹性刚度分别比人类冠状动脉高2.2倍和1.6倍，且对超声具有高度反射性。
