Temperature control of a saturated steam autoclave for sterilization of surgical equipment

Abstract

Surgery equipment sterilization is an important part of many serious medical procedures since it prevents infections and disease transmission. The saturated steam autoclave may be used to carry out the sterilization process according to the required medical standards. For this, certain temperature and pressure conditions must be granted in the sterilization chamber of the autoclave to perform an accurate sterilization process. However, the dynamical behavior of an autoclave tends to be complex, requiring the use of control strategies to perform a correct sterilization process. This paper presents the identification and temperature control of a saturated steam autoclave for the sterilization equipment employing the pole placement technique. Initially, temperature data of autoclave was acquired using a data acquisition system. Then, a linear model of the autoclave was obtained. Using the linear model, a PI and PID controllers were tuned to achieve the desired closed loop specifications. Controllers were validated in Simulink for the temperature conditions of the autoclave in presence of external disturbance and random noise in the feedback loop. Results show that the PID controller has a good performance on the autoclave temperature regulation in presence of external disturbances.