Nicholson N C, McDicken W N
Department of Medical Physics and Medical Engineering, Royal Infirmary, Edinburgh, UK.
Ultrasonics. 1996 Oct;34(7):747-55. doi: 10.1016/0041-624x(96)80002-b.
The performance of medical instruments utilising ultrasonic waveguides is largely dependent upon transmission efficiency between the tissue and the transducer. Loss occurring in the transducer-waveguide interface is appreciable enough to degrade the performance of such instruments under certain conditions. Transmission loss has been measured for a variety of differently shaped brass and stainless steel horns that have been used to try to reduce coupling lossed in a waveguide-transducer interface. Sound transmission measurements indicate that, for wavelengths of ultrasound much less than the diameter of the flared end of the horn, there appears to be little advantage of using a horn apart from practical considerations. However, the measurements were limited by significant repeatability errors which may have masked important horn-shape effects.
利用超声波导管的医疗器械的性能在很大程度上取决于组织与换能器之间的传输效率。在换能器 - 导管界面处发生的损耗相当可观，足以在某些条件下降低此类器械的性能。已对各种不同形状的黄铜和不锈钢喇叭进行了传输损耗测量，这些喇叭曾被用于试图减少波导 - 换能器界面处的耦合损耗。声音传输测量表明，对于波长远小于喇叭扩口端直径的超声波，除了实际考虑因素外，使用喇叭似乎没有什么优势。然而，测量受到显著的重复性误差的限制，这些误差可能掩盖了重要的喇叭形状效应。
