RIU 320 Lecture Notes - Lecture 31: Medical Ultrasound, Sound, Reflection Coefficient
6 May 2020
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Document Summary
Reflection and transmission, the reflection produced as sound moves from one medium to another forms the basis for ultrasonic imaging. In addition transmission is critical to ultrasound;s ability to image structures located deep in the body. The acoustic impedance is an important tissue property that influences the amount of reflection. Impedance m: the acoustic resistance to sound traveling in a medium. Acoustic impedance is calculated by multiplying the density of a medium by the speed at which sound travels in the medium. I: impedance is a calculated number associated with a medium through which sound travels. It is calculated, not measured: synonyms: also called characteristic impedance, note: a tissue"s impedance is calculated, not measured, impedance (rayls)= density (kg/m^3) x prop. ______: increases, as path length increases, the half boundary layer. 15. two media a and b have the same densities, the speed of sound in medium a is 10% higher than in medium b.
