Steri-freez: Flash Freeze Sterilization
Project Description :

The problem surgical site infections are leading causes of illness and death in hospitals in rural settings with one in three patients suffering from post-operation infection, due to, among other causes, the use of improperly sterilized equipment used in the procedure. the chronic challenges of sterilization in such settings are the deficiencies in sterile processing which are accentuated due to the lack of resources and poor protocols. this clearly indicates the need for a simple and rapid technique of disinfection and sterilization of surgical instruments which could be a life saver in rural/field settings. the challenge the current practice of sterilization involves collection and cleaning of contaminated medical instruments, preparation and packaging of such instruments for sterilization, sterilization via a sterilizer, cooling and drying followed by secure storage of the processed instruments. the widely used conventional methods are listed below: a) autoclave: most widely used method using pressurized steam for sterilization in hospital settings b) gaseous or chemical sterilization: ethylene oxide as anti-microbial is used for items that are moisture and heat sensitive c) dry heat sterilization: dry heat ovens burn the microorganisms away and are used on moisture sensitive items d) alternative sterilization: under conditions of non-availability of above mentioned amenities, alternative sterilization techniques have been practiced. such methods include microwave based sterilization which destroys micro-organisms via non-ionizing radiations, however needs electricity to run. chemical sterilization using various agents like per-acetic acid, formaldehyde, glutaraldehyde and hydrogen peroxide could leave behind trace residues which may cause toxicity. gaseous sterilization using ozone has also been used. however gases need specialised containers for transport and are not easy to handle. boiling in water although possible in most settings and used as a last resort is not considered effective enough. we present herein a simple technology for on-site sterilization which has manifold advantages. the technology we present is steri-freez based on a flash freeze elixir (ffe) which could provide enhanced antimicrobial properties of the components in combination aided by pathogen inactivation at extremely low temperatures. steri-freez - the concept: steri-freez is an amazingly simple, portable device which comprises of an insulator box housing a metallic vessel covered with a lid. sterilization is achieved using a combination of biocides at subzero temperatures. steri-freez is therefore a cold sterilization device where temperatures of less than -70 degree celsius are obtained by combination of biocides termed as flash freeze elixir (ffe). surgical instruments to be sterilized are kept immersed in ffe and removed just prior to use. the components of the “steri-freez” are: a) insulator box which can be chosen from low cost materials like styrofoam or thermocol and enables retention of the temperature for desired period of time. b) metallic vessel which can be made of stainless steel and c) insulator lid which covers the box designed in a manner that enables retention of subzero temperatures for prolonged periods. flash freeze elixir comprises a low cost antimicrobial agent combination (ffe) mixed to form a cryogenic liquid which is placed in the metallic vessel. the individual non-toxic components used in the mixture possess biocidal properties and when combined in a specific ratio could provide enhanced killing effect. a water free system, ffe enables rapid drying of the instruments after sterilization, and overcomes problems of rusting which is seen in moist heat sterilization methods. preliminary sterilization studies were carried out using a gram negative organism e.coli. appropriate contaminated ffe sample aliquots were added to nutrient broth medium and no growth was seen, confirming sterilization by ffe. advantage steri-freez • simple, portable and easy to use making it useful in rural/field settings • green technology • no energy input required • ffe is cost effective and ready to use within minutes • minimum manpower requirement • rapid sterilization technique • does not leave any toxic residue on the surfaces of instruments • provides ready to use sterilized instruments the applications • rural/semi-rural healthcare centres • medical camps eg.: eye camps • military base camps • emergency/refugee camps cost of steri-freez: a unit of capacity ~ 1 litre would cost approximately inr 200. the cost of flash freeze elixir ~ inr 100 per litre. the steri-freez concept of cold sterilization is novel and could play a crucial role in decreasing incidence of surgical site infections. steri-freez therefore presents great scope in field settings.

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Project Details :
  • Date : Nov 19,2016
  • Innovator : Saugandha Das
  • Team Members : Saugandha Das,Archit Devarajan
  • Guide Name : Prof. Padma V. Devarajan, Mrs. Vasihali Kavishwar
  • University : Institute of Chemical Technology
  • Submission Year : 2017
  • Category : Medical Science & Technology
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