Process challenge device and methods

Abstract

A process challenge device comprising process challenge device comprising a container defining a space within the container, wherein the space can fully contain a process indicator; and at least one pressure-actuating valve associated with the container, wherein the at least one pressure-actuating valve regulates entrance of a sterilant into and exiting of a gas and/or liquid out of the space within the container, methods of using the device and a kit including the device are disclosed.

What is claimed is: 
     
         1 . A method of determining effectiveness of a sterilization process, the method comprising:
 providing a process challenge device comprising:
 a container defining a space within the container, wherein the space contains a process indicator; and 
 at least one pressure-actuating valve associated with the container, wherein the at least one pressure-actuating valve regulates entrance of a sterilant into and exiting of a gas or liquid out of the space within the container; 
   positioning the process challenge device in a sterilization chamber; and   exposing the process challenge device to the sterilant at an elevated temperature.   
     
     
         2 . The method of  claim 1 , further comprising determining whether or not the process indicator indicates that it has been exposed to sterilization process conditions effective for sterilizing an article. 
     
     
         3 . The method of  claim 1 , wherein the at least one pressure-actuating valve is actuated when there is a pressure difference between the space within the container and outside of the first container. 
     
     
         4 . The method of  claim 3 , wherein at least one pressure-actuated valve can be adjusted to increase or decrease the pressure difference required to actuate the valve. 
     
     
         5 . The method of  claim 4 , wherein the pressure difference required is at least 6.895 kPa (1 psi). 
     
     
         6 . The method of  claim 4 , further comprising adjusting the at least one pressure-actuated valve of the process challenge device to provide a targeted level of resistance to the sterilization process. 
     
     
         7 . The method of  claim 1 , wherein the space further contains a volume of gas of at least 5 cubic centimeters, where the volume of gas can be adjusted to at least 5 cubic centimeters and not more than 1000 cubic centimeters. 
     
     
         8 . The method of  claim 7 , further comprising adjusting the volume of the gas of the process challenge device to provide a targeted level of resistance to the sterilization process. 
     
     
         9 . The method of  claim 1 , wherein the at least one pressure-actuating valve is at least two pressure-actuating valves. 
     
     
         10 . The method of  claim 9 , wherein at least two pressure-actuating valves comprise:
 a first pressure-actuating valve associated with the container, wherein the first pressure-actuating valve regulates entrance of the sterilant into the space within the container; and   a second pressure-actuating valve, wherein the second pressure-actuating valve regulates exiting of the gas or liquid out of the space within the container.   
     
     
         11 . The method of  claim 1 , wherein the process challenge device further comprises a heat-transfer modulating body, wherein at least a portion of the heat-transfer modulating body at least surrounds the process indicator when present. 
     
     
         12 . The method of  claim 11 , wherein the at least a portion of the heat-transfer modulating body comprises walls which surround the process indicator when present, the walls having a thickness; wherein heat-transfer modulating body walls are comprised of at least one layer. 
     
     
         13 . The method of  claim 12 , wherein the thickness of the heat-transfer modulating body walls is at least 0.3 cm. 
     
     
         14 . The method of  claim 12 , further comprising adjusting the thickness of the heat-transfer modulating body walls to provide a targeted level of resistance to the sterilization process. 
     
     
         15 . The method of  claim 14 , wherein the thickness is adjustable by adding or removing at least one wall layer, to provide the thickness of the walls. 
     
     
         16 . The method of  claim 11 , further comprising adjusting a thermal diffusivity of the heat-transfer modulating body to provide a targeted level of resistance to the sterilization process. 
     
     
         17 . The method of  claim 16 , wherein the thermal diffusivity of the heat-transfer modulating body can be adjusted by exchanging at least one wall layer for another having a lower or higher thermal diffusivity. 
     
     
         18 . The method of  claim 16 , wherein the thermal diffusivity of the heat-transfer modulating body can be adjusted by exchanging the heat-transfer modulating body for another body having a lower or higher thermal diffusivity.