Unconstrained Biosignal Measurement Technology and Its Applications in Assisting Aged Society

The elderly population in developed countries experiences several issues, such as increased social security costs, the burden of nursing care, and a decrease in the working-age population that can support the elderly. Hence, the government can ensure the safety and security of the elderly by improving various systems; the industry and academia can contribute by providing scientific and technological assistance. Under these circumstances, we have developed biosignal measurement technologies to assist elderly individuals in living healthy lives in an aged society. Our research on biosignal measurement can be divided into two categories: wearable measurement systems that measure biosignal information with high precision by placing sensors on the human body and unconstrained (environmentally installed) measurement systems that measure biosignal information by installing sensors in the environment and not on the human body. In this chapter, we especially introduce unconstrained biosignal measurement technologies that have applications in heart sound detection during sleep and fall detection in elderly individuals.