Free radical sterilization system and method

Abstract

A free radical sterilization system having a chamber defining a region, and a generator for generating free radical reach effluent from a free radical electric generator and/or a vaporizer. A closed loop circulating system without a free-radical destroyer is provided for supplying the mixture of free radicals from the electric generator mixed with the hydrogen peroxide solution in the form of the effluent to the chamber. The free-radical sterilization system is used in sterilizing items in the chamber and, with an open-bottomed wound chamber, in treating wounds on a body.

What is claimed is: 
     
       1. A free radical sterilization system comprising:
 a) a chamber for containing items to be sterilized;   b) an effluent generator having an input coupled to the chamber and an output coupled to the chamber for closed-loop circulation, comprising:
 i) a blower/distributor comprising a blower having an input coupled to the input of the effluent generator and at least one output, and a flow distributor for distributing blower flow from the at least one output of the blower to at least a first output and a second output in selected portions; 
 ii) a plasma electric free radical generator having an input coupled to the first output of the blower/distributor and an output coupled to the output of the effluent generator; and 
 iii) a vaporizer having an input coupled to the second output of the blower, and an output coupled to the output of the effluent generator, the vaporizer contacting a liquid sterilizing agent with the output of the blower/distributor to produce bactericidal effluent at the output of the vaporizer; 
 such that bactericidal effluent from the effluent generator flows through the chamber and back through the effluent generator in a closed loop without an intervening free-radical destroyer. 
   
     
     
       2. The free radical sterilization system of  claim 1 , further comprising:
 c) an open loop pre-heater and dryer comprising:
 i) an input valve having an input open to atmosphere and an output; 
 ii) a heater having an input coupled to the input valve and an output coupled to the chamber; and 
 iii) an exhaust blower having an input coupled to the chamber and an output exhausting to atmosphere; 
 such that air is taken in through the input valve, heated by the heater, passes through the chamber and is exhausted to atmosphere in an open loop. 
   
     
     
       3. The free radical sterilization system of  claim 1 , in which the chamber comprises a tumbler. 
     
     
       4. The free radical sterilization system of  claim 1 , in which the chamber comprises a wound chamber having an open bottom surface. 
     
     
       5. The free radical sterilization system of  claim 1 , in which the liquid sterilizing agent is hydrogen peroxide. 
     
     
       6. The free radical sterilization system of  claim 1 , in which the vaporizer contains a determined amount of liquid sterilizing agent at a beginning of a sterilization run. 
     
     
       7. The free radical sterilization system of  claim 1 , in which the flow distributor of the blower/distributor distributes 30% of the flow to the first output and 70% to the second output. 
     
     
       8. The free radical sterilization system of  claim 1 , in which the blower/distributor comprises:
 a) a multiple-output centrifugal blower having an input coupled to the input of the effluent generator and a plurality of outputs, each of the plurality of outputs of the multiple-output centrifugal blower having an output flow which is a fraction of a total output flow of the multiple-output centrifugal blower approximately equal to the total flow divided by the number of outputs in the plurality of outputs; and   b) a flow distributor comprising at least:
 i) a first manifold having a plurality of inputs coupled to a first selected number of the plurality of outputs of the multiple-output centrifugal blower and an output comprising the first output of the blower/distributor; and 
 ii) a second manifold having a plurality of inputs coupled to a second selected number of the plurality of outputs of the multiple-output centrifugal blower and an output comprising the second output of the blower/distributor; 
 such that the portion of the total flow at the first output of the blower/distributor is equal to the sum of the fractions of the total output flow multiplied by the first selected number; and the portion of the total flow at the first output of the blower/distributor is equal to the sum of the fractions of the total output flow multiplied by the second selected number. 
   
     
     
       9. The free radical sterilization system of  claim 8 , in which at least one output of the multiple-output centrifugal blower is coupled to the chamber through a heater. 
     
     
       10. The free radical sterilization system of  claim 1 , further comprising a multiple-output centrifugal blower having an input coupled to the output of the effluent generator and a plurality of outputs, at least one of the plurality of outputs being coupled to the chamber. 
     
     
       11. The free radical sterilization system of  claim 10 , in which a plurality of the outputs from the multiple-output centrifugal blower further comprise fittings for coupling hoses for connection to objects in the chamber, such that effluent from the plurality of outputs passes through the fittings and the hoses and an inside of the objects to the chamber. 
     
     
       12. The free radical sterilization system of  claim 1 , further comprising a circulating blower for inducing turbulent flow within the chamber. 
     
     
       13. The free radical sterilization system of  claim 1 , further comprising a chamber heater, directly heating the chamber. 
     
     
       14. The free radical sterilization system of  claim 1 , further comprising a controller coupled to the blower/distributor of the effluent generator and the plasma electric free radical generator. 
     
     
       15. The free radical sterilization system of  claim 1 , further comprising a source of carrier gas coupled to the closed loop. 
     
     
       16. The free radical sterilization system of  claim 1 , further comprising a conduit for sterilizing interior passages in an instrument, having a first end coupled to the output of the effluent generator and a second end in the chamber having a connector for coupling with the instrument, so that a portion of the effluent passes through the internal passages in the instrument plugged into the connector. 
     
     
       17. A free radical sterilization system comprising:
 a) a chamber for containing items to be sterilized;   b) an effluent generator having an input coupled to the chamber and an output coupled to the chamber for closed-loop circulation, comprising:
 i) a blower having an input coupled to the input of the effluent generator and an output; and 
 ii) a source of effluent having an input coupled to the output of the blower and an output coupled to the output of the effluent generator, comprising one of a plasma electric free radical generator or a vaporizer having a liquid sterilizing agent; 
 such that bactericidal effluent from the effluent generator flows through the chamber and back through the effluent generator in a closed loop without an intervening free-radical destroyer. 
   
     
     
       18. The free radical sterilization system of  claim 17 , in which the chamber comprises a tumbler. 
     
     
       19. The free radical sterilization system of  claim 17 , in which the chamber comprises a wound chamber having an open bottom surface. 
     
     
       20. The free radical sterilization system of  claim 17 , in which the liquid sterilizing agent is hydrogen peroxide. 
     
     
       21. The free radical sterilization system of  claim 17 , in which the vaporizer contains a determined amount of liquid sterilizing agent at a beginning of a sterilization run. 
     
     
       22. The free radical sterilization system of  claim 17 , further comprising a multiple-output centrifugal blower having an input coupled to the output of the effluent generator and a plurality of outputs, at least one of the plurality of outputs being coupled to the chamber. 
     
     
       23. The free radical sterilization system of  claim 22 , in which a plurality of the outputs from the multiple-output centrifugal blower further comprise fittings for coupling hoses for connection to objects in the chamber, such that effluent from the plurality of outputs passes through the fittings and the hoses and an inside of the objects to the chamber. 
     
     
       24. A method of sterilization of items in a sterilization chamber using free radicals, comprising:
 a) drying and heating the items in the chamber by drawing heated air through the chamber and exhausting the air from the chamber in an open loop;   b) circulating free radical rich effluent comprising a mixture of free radicals and a sterilizing agent, in a closed loop from an effluent generator, through the chamber, then back through the effluent generator, the effluent generator having an input coupled to the chamber and an output coupled to the chamber for closed-loop circulation, the effluent generator comprising a blower/distributor comprising a blower having an input coupled to the input of the effluent generator at least one output, and a flow distributor for distributing blower flow from the at least one output of the blower to at least a first output and a second output in selected portions; a plasma electric free radical generator having an input coupled to the first output of the blower/distributor and an output coupled to the output of the effluent generator; a vaporizer having an input coupled to the second output of the blower, and an output coupled to the output of the effluent generator, the vaporizer contacting a liquid sterilizing agent with the output of the blower/distributor to produce bactericidal effluent at the output of the vaporizer;   c) turning off the effluent generator at the end of a determined sterilization period;   d) drying and heating the items in the chamber by drawing heated air through the chamber and exhausting the air from the chamber in an open loop; and   e) cooling the items in the chamber by drawing ambient air through the chamber and exhausting the air from the chamber in an open loop.   
     
     
       25. The method of  claim 24 , in which air is exhausted during step b, creating a negative pressure in the chamber. 
     
     
       26. The method of  claim 24 , in which steps d and e further comprise destroying free radicals before exhausting the air using a free radical destroyer. 
     
     
       27. The method of  claim 24 , in which step a is maintained for a determined period of time. 
     
     
       28. The method of  claim 24 , in which step a is maintained until a determined temperature or humidity is measured in the exhaust. 
     
     
       29. The method of  claim 24 , further comprising circulating the air in the chamber with a circulating blower at least during step b. 
     
     
       30. The method of  claim 24 , further comprising maintaining a determined temperature in the chamber during step b. 
     
     
       31. A method of treating a wound on a body, using a stream of a free radical rich effluent comprising a mixture of free radicals and a sterilizing agent from an effluent generator having an input and an output for closed-loop circulation, the effluent generator comprising a blower/distributor comprising a blower having an input coupled to the input of the effluent generator at least one output, and a flow distributor for distributing blower flow from the at least one output of the blower to at least a first output and a second output in selected portions; a plasma electric free radical generator having an input coupled to the first output of the blower/distributor and an output coupled to the output of the effluent generator; a vaporizer having an input coupled to the second output of the blower, and an output coupled to the output of the effluent generator, the vaporizer contacting a liquid sterilizing agent with the output of the blower/distributor to produce bactericidal effluent at the output of the vaporizer, using a wound chamber having an open bottom, an input coupled to the output of the effluent generator and an output coupled to the input of the effluent generator, the method comprising:
 a) placing the open bottom of the wound chamber on the body around the wound and applying pressure to seal the wound chamber against the body;   b) turning on the effluent generator;   c) for a determined treatment period, circulating the stream of effluent from the output of the effluent generator through the wound chamber and back to the input of the effluent generator in a closed loop;   d) turning off the effluent generator at the end of a determined sterilization period;   e) removing the wound chamber from the body; and   f) repeating the method at a determined interval for a determined treatment duration.   
     
     
       32. The method of  claim 31 , in which the treatment period is at least two minutes. 
     
     
       33. The method of  claim 31 , in which the treatment period is at least ten minutes. 
     
     
       34. The method of  claim 31 , in which the determined interval is a day. 
     
     
       35. The method of  claim 31 , in which the determined treatment duration is one week. 
     
     
       36. A sterilizing device comprising:
 a chamber for containing items to be sterilized, the chamber comprising a bactericidal effluent input and a bactericidal effluent output;   a blower/distributor comprising an input and at least a first output and a second output,
 wherein the blower generates blower flow, 
 wherein the distributor distributes blower flow to the first and the second output of the blower in selected portions; 
   a free radical generator having an input coupled to the first output of the blower/distributor and a free radical output,
 wherein the free radical generator generates free radicals; and 
   a vaporizer having an input coupled to the second output of the blower/distributor and a vaporizer output,
 wherein the vaporizer contacts a liquid sterilizing agent to produce vaporized sterilant; 
   wherein flow distributed to the free radical generator and vaporizer causes free radicals to flow through the free radical output and vaporized sterilant to flow through the vaporizer output,   wherein the free radical output and vaporizer output are coupled, such that the free radicals and vaporized sterilant are combined to form bactericidal effluent,   wherein the bactericidal effluent flows through the bactericidal effluent input and into the chamber and out the bactericidal effluent output and back through the blower/distributor input.    
     
     
       37. The sterilizing device of claim 36, further comprising a pre-heater and dryer comprising:
 i) a pre-heater input valve having an input open to atmosphere and an output;   ii) a heater having an input coupled to the pre-heater input valve and an output coupled to the chamber; and   iii) an exhaust blower having an input coupled to the chamber and an output exhausting to atmosphere;   such that air is taken in through the pre-heater input valve, heated by the heater, passes through the chamber and is exhausted to atmosphere in an open loop.    
     
     
       38. The sterilizing device of claim 36, wherein the vaporizer comprises a bubbler.  
     
     
       39. The sterilizing device of claim 36, wherein the vaporizer comprises a wick in contact with the liquid sterilizing agent and over which blower flow passes to generate the vaporized sterilant.  
     
     
       40. The sterilizing device of claim 36, wherein the liquid sterilizing agent is hydrogen peroxide.  
     
     
       41. The sterilizing device of claim 36, wherein the vaporizer contains a determined amount of liquid sterilizing agent at a beginning of a sterilization run.  
     
     
       42. The sterilizing device of claim 36, further comprising a circulating blower for inducing turbulent flow within the chamber.  
     
     
       43. The sterilizing device of claim 36, further comprising a chamber heater, directly heating the chamber.  
     
     
       44. The sterilizing device of claim 36, further comprising a controller coupled to the blower/distributor.  
     
     
       45. The sterilizing device of claim 36, further comprising a conduit for sterilizing interior passages in an instrument, the conduit having a first end configured to receive the bactericidal effluent and a second end in the chamber having a connector for coupling with the instrument, so that a portion of the bactericidal effluent passes through the internal passages in the instrument plugged into the connector.  
     
     
       46. The sterilizing device of claim 36, wherein the chamber comprises a tumbler.  
     
     
       47. A method for sterilizing items, comprising:
 generating a bactericidal effluent comprising a mixture of free radicals and a sterilizing agent,
 wherein the free radicals are generated by a free radical generator and a vaporized sterilant is generated by a vaporizer, 
 wherein an output of the free radical generator and an output of the vaporizer are coupled, and 
 wherein a blower/distributor distributes blower flow to the free radical generator and the vaporizer, respectively, via a first and second output of the blower in selected portions; 
   circulating, via the blower/distributor, the bactericidal effluent through a chamber containing items to be sterilized.