近幾年世界各國人口老化日益嚴重，老年人的健康評估受到重視，其中有項評估為「起身-行走測試」評估系統，用來評估老年人的行走能力以及跌倒的風險。本論文中，我們以智慧型手機與其內建的三軸加速度器實作一套能夠自動計時的系統來取代過往需要由醫護人員手動施測的量測方式，同時也在系統中增加步數量測與記錄的功能。

In recent years, elder population grows consistently in the world. In particular, Taiwan’s elder population grows faster than the others of the world because of the very low birth rate and the geriatric care become important issues in Taiwan. One important test about the geriatric care is called Timed Up and Go Test (TUG). It is recommended as a screening tool for fall risk in elder people. In traditional, occupational therapist uses stopwatch to achieve this test. In this paper, we implement a system to do the TUG automatically. Smartphone is a good choice, we analyzed human motion depends on the build-in three-axis Accelerator. In our system we use two smartphones as the measurement device. Subject wears one device to perform test, occupational therapist observe records data on another device. Our algorithm can determine the steps while subject walks, and can also distinguish between object’s state of sitting and walking.