Manohar C U, McCrady S K, Fujiki Y, Pavlidis I T, Levine J A
Case School of Medicine, Case Western Reserve University, Cleveland OH 44106.
J Obes Weight Loss Ther. 2011 Dec 20;1(106). doi: 10.4172/2165-7904.1000106.
Physical activity is important in health and weight management. Several cell phone platforms integrate an accelerometer onto the motherboard. Here we tested the validity of the cell phone accelerometer to assess physical activity in a controlled laboratory setting.
31 subjects wore the cell phone on their waist along with the validated Physical Activity Monitoring System (PAMS) with different body postures and during graded walking. Energy expenditure was measured using indirect calorimetry. 11 subjects also wore the iPhone at different locations such as arm, hand, pant pocket, etc.
The cell phone accelerometer was accurate and precise compared to the PAMS, with an intra-class correlation coefficient (r> 0.98). The cell phone accelerometer showed excellent sequential increases with increased in walking velocity and energy expenditure (r>0.9).
An accelerometer embedded into a cell phone was accurate and reliable in measuring and quantifying physical activity in the laboratory setting. Data from free-living users shows promise for deployment of a comprehensive integrated physical activity promoting and weight loss platform using such mobile technologies.
身体活动对健康和体重管理很重要。一些手机平台在主板上集成了加速度计。在此，我们在受控的实验室环境中测试了手机加速度计评估身体活动的有效性。
31名受试者在腰部佩戴手机以及经过验证的身体活动监测系统（PAMS），处于不同身体姿势并进行分级步行。使用间接量热法测量能量消耗。11名受试者还在手臂、手部、裤兜等不同位置佩戴了iPhone。
与PAMS相比，手机加速度计准确且精确，组内相关系数（r>0.98）。手机加速度计随着步行速度和能量消耗的增加呈现出良好的连续增加（r>0.9）。
嵌入手机的加速度计在实验室环境中测量和量化身体活动方面准确且可靠。来自自由生活用户的数据显示，使用此类移动技术部署一个全面的综合身体活动促进和减肥平台具有前景。
