Efficient Placement of Pressure Sensors of a Sitting Cushion Stitched by Conductive Thread for Sitting Position

Abstract

In this paper, efficient placement of pressure sensors is tested for correct posture under sitting cushion using conductive thread to connect the pressure sensors. Conductive thread Ada-641 from the Adafruit industries is used to connect sensors for the sitting cushion. In order to detect the correct sitting postures, an Arduino-based cushion seat with 16 pressure sensors is implemented. A conductive thread connects the sensors to accommodate the comfort of the sitting cushion. In order to test the efficient placement of the pressure sensors, several types of sensor locations are suggested to identify sitting postures. The least number of sensors included for a given type of pressure sensor location is four. Sitting posture detection with 8 and 12 sensors is also tested. The maximum number of sensors included in the experiment is 16. The efficient placement of the sensors is decided by comparing the detection probability of the correct sitting posture for a different number of sensors included in the sitting posture test. It is shown that the correct sitting posture can be detected 100% by using 8 sensors out of 16 sensors. The test results show a guideline for the minimum number of sensors required for reliable, correct posture detection. It is also shown that the performance of the sitting cushion with conductive thread type sensors is as good as the one with the copper wire connection.