ERCIM News No.29 - April 1997

Personal Health Monitor for Homes

by Timo Tuomisto and Vesa Pentikäinen

Personal Health Monitor prototype provides means of easily (self-)monitor physiological and psychological variables at home. The lap-top computer based system was developed together with Polar Electro Oy, Sondi Oy, VTT Information Technology and Tampere University Hospital. The project started in the beginning of 1995. The prototype is currently used to measure data for further evaluation, and to test the validity of the home monitoring concept.

Home Health Care is a modern trend in health care. The focus on home health care has been on elderly and already diseased patients, whose home care cuts the welfare costs by reducing necessary hospital visits and beds. Home health care affects the health care protocols, monitoring methods and technology. Moreover, there is a boom among individuals to follow up and maintain their own health. This is evident from ever increasing market of home monitoring devices such as blood pressure and heart rate monitors.

We have developed a personal health monitor prototype to obtain information about the physiological condition of the person, and to assess the usability and acceptability of the monitoring concept at home. The equipment is intended to be used by the person himself or by an assisting person. The equipment consists of a lap-top computer, temperature and blood pressure measuring systems, scales, portable heart rate monitor, and BioMatt monitoring system. The BioMatt monitoring system consists of a signal processing unit connected to a large static charge sensitive sensor which is inserted under the mattress. Basically it obtains information of any kinetic activity of a resting person, enabling the monitoring of eg heart rate, breathing rate and movements. The portable heart rate monitor is supplied with an accelerator sensor and a facility to measure extraordinary ECG-samples. The lap-top computer includes a diary which is used to record daily activities, food intake, consumption of alcohol, beverages, cigarettes and self-assessments about one's performance and mood.

The system has been in experimental use among fourteen healthy middle-aged men with no known serious diseases, and with no specific sports activities. Each person measured his temperature, blood pressure, and weight daily or twice a day. Moreover, the portable heart rate monitor measured all the daily beat to beat intervals. The BioMatt system recorded all nightly activity. All the measured data was transferred by electric means to the computer. The experimental period lasted two months. Currently analysis work is going on with the data, with main interest in correlations, long term trends, and possible weekly periods reflecting the habits of the subject.

The home monitoring prototype. Visible items within the case are the lap-top computer, digital thermometer, portable heart rate monitor, and the cuff for blood pressure measurements. The externally connected digital scale and BioMatt sensor are not shown.

The feasibility of the concept has also been tested with elderly people, who only partially can take care of themselves, the nursing staff being the users of the measurement system.

A cornerstone for the success of the personal follow-up is the feedback offered by the system. At the moment the computer presents the time history data to the users, but doesn't make any assessments. Our goal is to develop a system which would facilitate the monitoring of one's physical condition over months, years or decades. We study new approaches to reduce, analyze and display long term data, which could reveal causality between the lifestyle and unhealthy indicators such as overweight or high blood pressure. This will lead to better self-conscience, probable change of lifestyle, and prevention of consequent diseases.

Please contact:
Vesa Pentikäinen - Polar Electro Oy
Tel: +358 8 5202155

Timo Tuomisto - VTT Information Technology
Tel: +358 3 3163368

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