Smart mat system with pressure sensor array for unobtrusive sleep monitoring

Abstract

To improve the unobtrusiveness and comfortableness of sleep monitoring, we proposed the design and implementation of a smart mat which utilized flexible pressure sensor array and printed electrodes to monitor physiological and behavioral data during sleep. With the proposed novel soft seven-layer structure, the smart mat system can measure pressure distribution images and calculate respiratory rate of subjects. The function of this system was realized with pressure acquisition circuit controlled by Arduino processor. Experiments for pressure distribution tests and respiratory rate measurements were carried out to validate the performance of the proposed system. The experimental results demonstrated that the smart mat could be a viable option for unobtrusive sleep monitoring in the future.

A Compressed Sensing Based Method for Reducing the Sampling Time of A High Resolution Pressure Sensor Array System

“…It is worth noting that with different conditions the subject lay on the mat, the peaks or valleys represented the end of inhalation correspondingly. As it is demonstrated in our previous study [ 19 ], when the subject lay on the mat with a supine posture and the back or waist part of body is in the measured area, the valleys in the respiratory waveform represented the end of inhalation. On the contrary, when the subject lay with a prone posture and the chest or abdomen part of body is in the measured area, the peaks represented the end of inhalation.…”

“…The experimental results demonstrated that this system would consume about 0.2 s to gather all 1024 pressure values, in other words, it need about 0.2 s to generate one frame. The time consumption was much faster than our previous work mentioned in [ 19 ] due to the modified signal acquisition program, but the program was not mentioned in this paper because it’s not the emphasis of this study.…”

“…Those voltage values in pressure matrix between 0 from +5 V were normalized to 0–255, and the blue and red in color map represented 0 and 255 respectively, then the pressure distribution images for following analysis were transformed from the pressure matrix. Due to the high resolution of pressure sensor array, this prototype can clearly visualize the details of the pressure distribution and benefit the post analysis as described in our previous study [ 19 ]. For example, when the hand was put on the prototype, the computer can do the process and display the pressure distribution image as shown in Figure 8 .…”

“…To solve the problems mentioned above, we developed a prototype of smart mat system with flexible sensor array [ 19 ], which employed soft materials such as the sensors and printed fabric electrodes. In order to generate high-resolution pressure distribution image and offer more image details, the prototype was embedded with 1024 pressure sensors in a 28.8 cm × 28.8 cm area.…”

Design of an internet of things based real-time monitoring system for retired patients

“…Most studies show that the results of measurements using an accelerometer correspond to the values obtained from measurements by indirect and direct calorimetry, from monitoring physical activity. Sleep quality can be also evaluated by the movement during sleep time using the chip called the MPU-6050 [11].…”