PAPAIOANNOU, G.; PROTOPAPPAS, V.C.; TSOPELAS, P.; MITROGIANNIS, C.; NIANIOS,
G.; TASHMAN, S. A New Method for Pressure Sensor Equillibration and Conditioning. Brazilian
Journal of Biomotricity, v. 2, n. 3, p. 176-195, 2008. Assessing pressure and contact stress
distributions between two adjacent surfaces is a well established research area in
biomechanics. Typical applications of measuring the interface pressure include human-machine
interfaces in ergonomics, joint congruency studies in orthopaedics, in-vitro cadaveric
experimentation and the design of Orthotic-Prosthetic devices. Tekscan pressure sensors are
widely used in both in-vivo and in-vitro experiments. An all-round efficient equilibration and
calibration approach of the Tekscan sensor system is yet to be clearly defined in the literature
and is attempted here for one type of Tekscan sensors. The response of individual sensels from
two 5315 Tekscan sensors for quasi-static, repeated constant and dynamic loading was
investigated with the use of two methods, namely the “Bladder Method†and the “Pin Methodâ€. In
the first method, uniform pressure was applied by a bladder-equilibrator, whereas in the second
loads were applied in a sensel-by-sensel approach by means of a pin attached to a frame
installed on a material testing machine. The “Pin Methodâ€, although far more laborious, is a
better method for equilibration and calibration of sensors, particularly when saturation is
prevalent. The pin-method also provides a better characterization of the sensor drift. It was shown that when test conditions resulted in some of the sensels being saturating due to high
pressure, the loss of load data from the sensor mat could be estimated using the individual
sensel output.
