A Low Cost Intelligent Fuzzy-Controlled Multipass-Multibaffle Dry-Air Sterilizer Device for Small-Sized Surgical Instruments

Abstract

A major constraint in hospitals and clinics in the interior villages of low resource countries is the access to stable power supply. Decontamination of reusable metal-based surgical tools is an energy-intensive process, the power required for this procedure may not be accessible in many health centres in low resource countries. Hence, decontamination device with low-energy requirements could immensely benefit village clinical settings. The developed sterilizer utilizes a Fresnel lens in a multi-baffle multi-pass chamber to amplify radiation intensity. An intelligent scheme of air passage was achieved using Fuzzy logic control to ensure control of pressure and temperature regime thermal transport within the chamber. The Fuzzy logic controller program was designed on Matlab's fuzzy logic toolbox and simulated with Simulink to evaluate its accuracy. The performance evaluation of the device showed that at an ambient temperature of 27℃ and a solar radiation intensity of 1362 W/m2, the sterilizer was able to sterilize at a temperature of 169.69℃ which is within the range for efficient dry heat sterilization to take place (140℃-170℃). This work has demonstrated that fuzzy logic controlled dry air sterilizer could achieve temperature ~ 150℃ within the heater chamber which may be suitable for sterilizing used surgical equipment.