Human health monitoring system of systems with fuzzy logic by sensor network

This paper describes a human health monitoring system by an ultrasonic sensor and an mat sensor systems. The system is realized with constrain-free, low cost and bed-side usage applicable. In it the ultrasonic sensor system obtains the state of a patient in bed by placing it under a bed frame. The mat sensor system detects heart beats and respiration signals by placing it to the mattress on the bed. This means that we can measure autonomic nerve system by using the heart rate and contribute the diagnosis of sleep apnea. This system employs fuzzy logic techniques to detect them. Thus, the system of systems with fuzzy logic can noninvasively and unconsciously provide human health information with high accuracy.

I. Introduction

GENERALLY conventional health monitoring system such as electrocardiographs and electroencephalographs constrain patients to measure the bio-signals. A constrain-free health monitoring system is essential for patients because the patients do not like attached sensors to their body and nurses/doctors do not have to concern themselves with the input sensor being detached. A number of health monitoring sensors for humans in bed have been developed [1]–[5]. In these, they employ one sensor to detect necessary signals with constrain-free. In our study, we attempt to detect three biological information by the sensor network. One is an ultrasonic sensor[6]. The ultrasonic sensor system has a cylindrical tank of 26mm (diameter) x 10mm (height) filled with water and an ultrasonic probe. It detects the vibration of a patient by obtaining echo signals reflected from the water surface. This sensor can noninvasively detect vibration of the patient by placing it under the frame of any bed with vibrations of 10Hz or less in the direction of all three axes. We propose a recognition system for humans by this sensor. It recognizes one of conditions; empty and wake or sleeping in bed. The other one is mat sensor to monitor heart rate [7] [8][9] [10]. The mat sensor is composed of a rubber tube inserted in a mat and an air pressure sensor. The air pressure sensor detects the air pressure change of vital information of a patient. We describe the system for detecting the heart beat. The heart beat shows an automatic nervous system activity [11], and its rate is an important parameter to influence a blood pressure change and a temperature control and so on. In addition, it can detect respiration signal. It is closely related to sleep apnea.