Plasma sterilization is a low-temperature sterilization technique which can increase the efficiency of medical equipment.April 17, 2019 Industrial Services
Sterilization of the medical equipment has always been a concern for the medical community. Today, due to the advent of new technologies and novel medical instruments such as arthroscopes, laparoscopes, endoscopes, optical fibers, etc., sterilization at low temperatures and moistures is continually increasing. The necessary factors in the sterilization of medical instruments are low temperature, safe operation, short time cycle, high efficiency, no environmental risks, and the ability to pack and maintain sterilized instruments for a suitable time. In order to perform this process, different methods, such as using autoclave, oven, ultraviolet light, ethylene oxide gas, and formaldehyde vapor have been implemented. These techniques, however, because of their disadvantages and problems have been superseded by other instruments like plasma sterilizers.
Plasma sterilization is a low-temperature sterilization technique which can increase the efficiency of medical equipment. In this technique, the device entry is hydrogen peroxide that is a non-poisonous raw material; water and oxygen are the device outputs. The maximum working temperature in this technique is 50 °C and the sterilization time is 60 to 90 minutes; moreover, in this technique aeration is not required.
In this technique, equipment is placed inside the device chamber and the vacuum pump is turned on. After reaching nearly the full vacuum, the hydrogen peroxide is injected into the chamber to diffuse through the chamber and expose all surfaces. In this step which plasma has not yet begun, hydrogen peroxide has the ability to kill microorganisms. Then the generated plasma flow is injected into the sterilization chamber which because of its ionizing effect leads to the formation of free radicals from hydrogen peroxide vapor. In short, under the influence of plasma, the last electron is ejected from the hydrogen peroxide molecule and accelerated towards the desired surface, and results in the electron bombardment inside the chamber. During these interactions, ultraviolet waves and also a number of atoms and molecules with kinetic energy are produced. The by-products in this method are only water and oxygen since the free radicals have a short half-life. The maximum temperature inside the sterilization chamber is 55 °C which all the medical instruments can withstand it. In different studies, the capability of this method to eliminate all human viruses and microorganisms has been confirmed.