Development of vital-sign telemetry system for long-term ambulatory monitoring of autonomic nerve activity

For the senior citizens living alone and the patients in home-care, a vital-sign telemonitoring technique has been proposed. A telemetry system for long-term ambulatory monitoring of pulse wave was developed. It is based on the two-step biotelemetry. In the first step telemetry, the pulse wave is measured with a ring-type sensor and is transmitted to the mobile phone terminal carried by the subject. In the second step telemetry, the data are transmitted from the cell phone to a personal computer. As the communication channel for the second step, a wireless LAN system is used in the home and a cell phone network is used outside the home. In this way, indoor-outdoor common telemetry was realized. With the developed system, we could measure the autonomic nerve activity in real-time without much hindrance in a common activity in a daily life. In the experiment, the sensitivity of the developed system to detect the change in the autonomic nervous system was verified.