Implementation of a Portable High Frequency Ultrasound Speed Meter for Body Fluid Characterization

• Main Authors: Chen-Sung Yang, 楊陳松
• Other Authors: Chih-Chung Huang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/40263645115586073242

碩士 === 輔仁大學 === 電機工程學系 === 99 === The main purpose of this study was to design a portable device for measuring the high frequency sound speed. In a general high frequency sound speed measured system, the sound speed was measured via a high speed A/D converter and processed by computer. However, this device only used analog components and micro-processor, and the advantages including low cost and real time display. This sound speed meter included a high frequency ultrasound pulser/receiver and a transducer with a center frequency of 42 MHz. The high frequency ultrasound pulser/receiver producted a native single pulse with -80 volt to excite high frequency ultrasound transducer and increased the ultrasound echo signal amplitude by 45 dB amplifier. The sound speed was measured by counting the timing between the analog pulse and reflect signal from the reflector by using a high speed counter and displayed by a LCD monitor. The device was tested by measuring the sound speed in water and blood. The measured results discussed the sound speed around 22℃ is difference between water and blood which speed is 1540 m/s and 1626 m/s, and were compared to the commercial device only 1% error was obtained. All the results indicated that this device can be used for measuring sound speed in real time.