Adamec Ondrej, Domingues Alexandre, Paiva Teresa, Sanches J Miguel
Faculty of Electrical Engineering and Computer Science, Department of Measurement and Control, VSB Technical University of Ostrava, Czech Republic.
Annu Int Conf IEEE Eng Med Biol Soc. 2010;2010:2342-5. doi: 10.1109/IEMBS.2010.5627774.
Human activity can be measured with actimetry sensors used by the subjects in several locations such as the wrists or legs. Actigraphy data is used in different contexts such as sports training or tele-medicine monitoring. In the diagnosis of sleep disorders, the actimetry sensor, which is basically a 3D axis accelerometer, is used by the patient in the non dominant wrist typically during an entire week. In this paper the actigraphy data is described by a weighted mixture of two distributions where the weight evolves along the day according to the patient circadian cycle. Thus, one of the distributions is mainly associated with the wakefulness state while the other is associated with the sleep state. Actigraphy data, acquired from 20 healthy patients and manually segmented by trained technicians, is used to characterize the acceleration magnitude during sleep and wakefulness states. Several mixture combinations are tested and statistically validated with conformity measures. It is shown that both distributions can co-exist at a certain time with varying importance along the circadian cycle.
人类活动可以通过受试者佩戴在手腕或腿部等多个部位的活动记录仪传感器进行测量。活动记录仪数据被应用于不同的场景，如运动训练或远程医疗监测。在睡眠障碍的诊断中，活动记录仪传感器本质上是一个三维轴加速度计，患者通常在非优势手腕佩戴一整周。在本文中，活动记录仪数据由两种分布的加权混合来描述，其中权重根据患者的昼夜节律周期在一天中变化。因此，一种分布主要与清醒状态相关，而另一种与睡眠状态相关。从20名健康患者获取并由训练有素的技术人员手动分割的活动记录仪数据，用于表征睡眠和清醒状态下的加速度大小。测试了几种混合组合，并通过一致性度量进行了统计验证。结果表明，两种分布可以在昼夜节律周期的特定时间以不同的重要性共存。
