現今超音波量測在醫學應用上已相當廣泛，除了其具有非侵入式的優點，更重要的是它不會產生輻射危險，且成本較低。而骨質疏鬆症及其併發症會嚴重的影響病患生活品質及浪費龐大的社會醫療資源，故近來也有相當多的研究投入在超音波骨質密度評估，所以本研究將建立一套自製可以使用穿透式以及反射式的超音波發射接收系統應用在骨質密度的評估。
本量測系統的設計以具功率因素校正(PFC)功能之高壓電源供應器提供超音波發射器驅動超音波探頭高穿透力的可調式穩定高壓，並且在接收器使用高增益、高頻寬之放大器接收超音波探頭微弱訊號。透過超音波接收器的前端保護設計，本研究設計的電路可以直接接收驅動超音波探頭的高壓脈衝後的微弱訊號，並且將其放大。而系統核心使用了FPGA簡化電路設計並且控制系統周邊電路的時脈。本量測系統除了可以類比輸出外，在電腦端則以LabVIEW設計了人機介面，可以即時的接收超音波訊號。
目前已完成超音波穿透式以及超音波反射式兩種量測模式的建立，並且利用此系統可以量測假體的寬度、波速(SOS)以及波衰減(BUA)等超音波參數，在壓克力假體的測試中量測值與實際值只有微小的誤差，證明本系統在未來量測應用上的可行性。

Ultrasound measurement technique has been widely used in medicine because of non-radiation; most importantly, it`s non-invasion, safe, and inexpensive. Osteoporosis and its complications seriously affect patients’ quality of life and cause a huge waste of social health care resources. For reasons outlined above, there has been considerable research into the ultrasound assessment of bone density in recent years. The objective of this study is to develop an ultrasound pulser-receiver system with transmission mode and reflection mode used on bone density estimation.
The measurement system includes a high-voltage power supply with PFC function which provides adjustable stable high-voltage and high- penetration to pulse generator drive ultrasound probe. The receiver can receive slightly signal from ultrasound probe by using high gain, high bandwidth operational amplifier. Through the design of protector, receiver is able to connect directly to the output of pulse generator and receive echo signal after the high-voltage pulse. The system core uses FPGA technique to miniaturize electronic systems and control the clock of peripheral circuit. This system provides analog output, and on the computer side, a human-computer interface is designed by using LabVIEW to receive ultrasound signal in time.
The transmission mode and reflection mode of this instrument have been accomplished. This system can measure the parameters such as thickness of phantom, SOS and BUA. In phantom validation studies, the error is less than 3.15%. The results prove the feasibility of this system.

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