Washable textile sensors
Smart fitness shirt
A smart shirt has been created for monitoring back posture. A straight back is neccesary for exercises in the gym to prevent injuries and maximize the effectiveness. Two sensors in the back of the shirt are placed at the optimal position to distinct between a straight back and a rounded back. The sensors are made of conductive and non-conductive fabric and are fully washable. The electronics at the sleeve are detachable and give feedback to the user through vibrations.
Capacitive stretch sensor
The sensors in the back of the shirt are based on capacitance. Two electrodes in the sensor can move along side each other. The overlapping area is a measure for capacitance, which will increase when the sensor is stretched due to stretchable and nonstretchable fabric. Conductive thread is used to make a connection between the sensors and the electronics at the left sleeve of the shirt. The electrodes are laminated to increase washability.
Detecting rounded back
A rounded back is detected when both of the sensors are at least 6% stretched. This is not the case when the torso is bend sideward or twisted. The sensors are used to measure relative stretch from the calibration value. The sensor are automatically calibrated when a measurement is started.