Effects of sterilization on the Tekscan digital pressure sensor

Investigations into the effects of sterilization on a new biomechanical pressure sensor are necessary before contemplating in vivo use. Ten. designated Experimental, "K-Scan" digital pressure sensor arrays were sterilized with ethylene oxide gas (EtO), and their ability to accurately and reproducibly measure an applied load of 2225 N (500 lb) was assessed. Simultaneously, 10 un-sterilized sensor arrays. designated Control, were assessed. Each array was loaded 10 times inside a two-dimensional curved surface, and all arrays exhibited high reproducibility (coefficients of variation < 2.0%). Following sterilization, the Experimental sensors showed a 22.2% average decrease in recorded force, a statistically significant difference from the pre-sterile data (p < 0.002). However, when the Experimental sensors were re-calibrated post-sterilization, they showed only a 0.1% average decrease in recorded force, not a statistically significant difference (p > 0.05, beta < 0.05). Following 1-week storage, trial 2 data of the Control sensors showed a less dramatic yet significant 3.4% average decrease in recorded force when compared to trial 1 data (p < 0.02). Control trial 2, once re-calibrated. showed a 0.5% average decrease in recorded force, not a statistically significant difference (p > 0.05, beta < 0.05). Results suggest that, following EtO sterilization, accurate and reproducible pressure measurements can be obtained from K-Scan sensors when calibration is performed at time of use. (C) 2003 IPEM. Published by Elsevier Ltd. All rights reserved.