portable acceleration recorder

• Main Author: 陳弘杰
• Other Authors: 劉華昌
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/59856536559820721188

碩士 === 國立臺灣大學 === 醫學工程學研究所 === 90 === This research is to develop a portable acceleration recording system. Thus, investigators can record ankle’s acceleration signals while people taking exercise in different environment and situation. The first step is to find a suitable acceleration sensor. Pasting up this sensor on a man’s right ankle to measure the acceleration signals while this person jumped from height of 45cm platform to floor. We used National Instruments’ AD/DA card to be the data acquisition system. After frequency analyzing, we can observed the dominant frequency located on 20~30Hz. Then, designing a small size A/D converter for people carrying with. Digital signals were transported to Pocket PC by RS232 connector. The height of 45cm to floor landing test, signals were recorded by our system and National Instruments’ AD/DA card. To compare with these two systems, there is no significant different. Hence, it is conclude that this device can function properly. The electrical system includes 2-axis acceleration sensor, low-pass filter, microcontroller, and RS232 interface. The total static current is about 9mA under the supply voltage of +5V. Practically, many times of acceleration recording can be performed without the need to change batteries. So the low-power aim has been achieved. The total weight( with batteries ) is nearly 820g. It is fit for carrying.