US 5,491,092 AGranted

Sterilizer test method and apparatus

OwnerRichard R. Colvininventor

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Abstract

The operation of a steam sterilizer is monitored by a test unit and a controller which together comprise a system which can be operated in two principal method schemes: (1) the testing for completeness of air removal from a sterilizer chamber, and (2) the testing for effective sterilization conditions. These methods each have two principal modes of operation: (a) the performance of a Bowie and Dick type test, as is usually done on a once-a-day basis; and (b) monitoring the sterilizer during load conditions. In a preferred embodiment a test unit including temperature and pressure sensors, a moisture sensor and a heat sink are positioned within the chamber of a steam sterilizer and transmit by radio the conditions therein to an external controller. The test unit can employ a replaceable cartridge to assure effective operation even after a large number of cycles of operation.

Claims20

Dependent claims

A method for determining the effectiveness of air removal from the chamber of a steam sterilizer, for the detection of air leaks and for monitoring the sterilization conditions within the chamber comprising:

placing within a chamber of a sterilizer a test device having a structure capable of concentrating and trapping small amounts of air critical to the sterilization process to the location of a temperature sensor and sensing a temperature by means of the temperature sensor and generating a signal (T.sub.1) indicative of the measured temperature, wherein said test device including wall members defining an elongated cavity with a predetermined length and cross section having an opening at one end of the cavity to permit the entrance of ambient gases, a temperature sensor capable of generating signal T.sub.1 indicative of the temperature at its location at the end of the test cavity opposite from said opening and a heat sink capable of condensing steam disposed within the cavity between the opening and the temperature sensor to thereby concentrate any air present in the chamber in the direct vicinity of the temperature sensor, said heat sink comprising a material of a density, porosity and thermal conductivity effective to condense a sufficient amount of steam to cause air, if present, to collect at the end of the test device where the temperature sensor is located;
generating a signal T.sub.1 ;
generating a signal (T.sub.r) indicative of a reference temperature;
comparing signal T.sub.1 to signal T.sub.r ;
and
generating a signal indicative of either a pass or fail condition based on the results of the comparison.

3 more elements

A system for determining the effectiveness of air removal from a steam sterilizer, for the detection of air leaks and for monitoring the sterilization conditions within the chamber comprising:

a test device capable of sensing a temperature at its location and generating a signal (T.sub.1) indicative thereof said test device comprising a temperature sensor and means for concentrating and trapping small amounts of air to the location of a temperature sensor, having walled members defining an elongated cavity with a predetermined length and cross section with an opening at one end of the cavity to permit the entrance of steam, a temperature sensor within the cavity displaced from the opening, and a heat sink located in said test module cavity disposed within the cavity between the opening and the temperature sensor, said heat sink, being capable of condensing steam to thereby concentrate any air present in the chamber in the direct vicinity of the temperature sensor, said heat sink comprising a material of a density, porosity and thermal conductivity effective to condense a sufficient amount of steam to cause air, if present, to collect at the end of the test device where the temperature sensor is located;
means for generating a signal (T.sub.r) indicative of a reference temperature, which can be either a preselected reference temperature such as the desired sterilization temperature or a calculated temperature such as the average of the last temperature reported in the latest 10 cycles of operation;
means for comparing signal T.sub.1 to signal T.sub.r ;
and
means for generating a signal indicative of either a pass or fail condition based on the results of the comparison.

2 more elements

Dependencies are inferred from the claim text.