As graduation project for Integrated Product Design, Ruben Schevers designed Globus; a smart shirt that measures one’s back posture during exercise.
Fitness is the most practiced sport in The Netherlands, mostly due to the fact that fitness can be practiced as both a primary and secondary sport. The most important factor within fitness is posture. Mistakes in posture decrease the effectiveness of the workout and can even cause injuries, especially in the back and shoulders.
Globus is focused on non-professional athletes aged 18 to 49 years old that work out 1-2 times a week, with or without a training buddy. Observations in the gym showed that most mistakes people make are related to the back. An arched back puts too much pressure on the lower back, resulting in injuries. A natural curved back is considered to be between 165 and 195 degrees according to research performed for this project, any activity outside of this zone is considered to be bad.
Research of Mattmann & Tröster showed that placing stretch sensors in the back of a shirt can help in the distinction between several movements. This research was based on changes in resistance of stretch sensors. This project focused on capacitive plates, which have better washability than the stretch sensors used in earlier research, due to the possibility to laminate the electrodes together. The capacitive plates all have the benefit of having a linear response to stretch, which can be measured with ordinary electronic – as opposed to the earlier sensors that demonstrate a non-linear relation between resistance and stretch.
The capacitive stretch sensor has two fabric conductive electrodes moving in parallel. The overlapping area is a measure for the capacitance (as well as the distance between the electrodes); by measuring this overlap, the stretch in the shirt can be determined. Vibration are then used to provide feedback to the user when they have an incorrect posture. To make sure the readings are accurate, the device calibrates every time a measurement of back posture is started. Relative stretch is measured from this calibrated starting value.
The estimated retail price for the product bundle – shirt plus sensors – is set at €129,-
For more info, please visit: TU Delft repository