(528 days)
SteriTer CROSS-CHECKS sterilization chemical monitoring strips are designed to be utilized in steam sterilizers operating at 132" (270°F to 276°F to 276°F). When used as directed, the SteriToc Cross.Checks indicator strips give visible indication that sterilizing conditions were met. During steritization, the check mark at the end of the strip changes from white to black, becoming as dark or darker in intensity than the black reference arrow printed on the strip.
The basic formula and concept of black to white chemical steam sterilization indicators has not changed dramatically since they were invented in 1932.
Below is the information regarding the acceptance criteria and the study proving the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for the "CROSS-CHECKS Steam Sterilization Indicator Strip" are primarily based on the visual color change of the strip from white to black, becoming as dark or darker than a reference arrow, indicating proper sterilization, and an incomplete color change for improper sterilization. This performance is validated against biological spore strips.
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Test 1: Completed Sterilization Cycle (3 Minutes @ 132°C (270°F)) | |
| Indicator strips change color to black. | |
| Biological spore strips show complete kill. | Results: All indicator strips changed color to black. All test spore strips showed a complete kill. All indicator strips passed this test. |
| Test 2: Incomplete Sterilization Cycle (20 Seconds @ 132°C (270°F)) | |
| Indicator strips show incomplete color change (none turn black). | |
| Biological spore strips show all survivors. | Results: All indicator strips showed incomplete color change (none turned to black). All test spore strips and the control strip showed all survivors. All indicator strips passed this test. |
| Test 3: Performance Data for Storage of Cross-Check Strips | A. Normal Storage: Strips appeared unchanged (white). |
| B. Normal Storage then Sterilized: All indicator strips changed color to black, indicating proper functioning and no change in performance due to normal storage. | |
| C. Extreme Temperature Storage (57°C (134°F) for 8 days): Color of the strip had NOT changed from its original normal white color. | |
| D. Extreme Temperature Storage then Sterilized: All indicator strips changed color to black, indicating proper functioning and no change due to extreme heat storage. | |
| E. Extreme Humidity Storage (75% humidity for 7 days): Color of the strip had NOT changed from its original normal white color. | |
| F. Extreme Humidity Storage then Sterilized: All indicator strips changed color to black, indicating proper functioning and no change due to extreme humidity storage. | |
| G. Extreme Temperature and Humidity Storage (57°C (134°F) and 75% humidity for 8 days): Color of the strip had changed from its original white color to a light tan. | |
| H. Extreme Temperature and Humidity Storage then Sterilized: All indicator strips changed color to black, indicating proper functioning and no change due to extreme heat and humidity conditions. | |
| Test 4: Performance Data for Cross-Checks Strips at Various Temperatures and Times | |
| Indicators should correlate with biological kill/survivor rates. | |
| "Passed as specified, and in all cases completed a color change only after the biological spore strips tested at the same time under the same conditions, had expired." | Results: Detailed in Tables 1, 2, 3, and 4 (presented across pages 6-9 in the document, but referred to as Tables 1-4 for clarity). The tables show the number of positive (Pos) and negative (Neg) reads for the indicator strips, along with the biological spore strip results (Bio +/-). The overall conclusion was that the product performed as specified. |
2. Sample Size Used for the Test Set and Data Provenance
- Test 1 & 2 (Completed/Incomplete Sterilization Cycle): The text mentions "All indicator strips" and one "spore strip" per run. The exact number of SteriTec and ATI strips per run is not explicitly stated, but it implies a small, controlled sample for these specific tests.
- Provenance: Not explicitly stated, but implies laboratory testing performed by an "independent testing laboratory."
- Retrospective/Prospective: Prospective (laboratory testing).
- Test 3 (Storage Tests): "SteriTec CROSS-CHECKS sterilization indicator strips" were used. The exact number is not stated, but the results are qualitative observations ("All strips appeared unchanged," "All indicator strips changed color").
- Provenance: Not explicitly stated, but implies laboratory testing performed by an "independent testing laboratory."
- Retrospective/Prospective: Prospective (laboratory testing).
- Test 4 (Various Temperatures and Times):
- Sample Size:
- For each temperature range (124°C, 128°C, 130°C, 132°C, 134°C): Approximately 300 strips (SteriTec Cross-Checks CI 102 and CI 111 combined) along with 12 biological spore strips.
- For each time duration (1 min, 2 min, 2.5 min, 3 min, 3.5 min at 132°C): Approximately 300 strips (SteriTec Cross-Checks CI 102 and CI 111 combined) along with 12 biological spore strips.
- Provenance: Not explicitly stated, but implies laboratory testing performed by an "independent testing laboratory."
- Retrospective/Prospective: Prospective (laboratory testing).
- Sample Size:
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
- Test 1, 2, 3 (Initial Interpretation): Implied that the "independent testing laboratory" personnel made the initial observations and recorded the results. Specific number and qualifications are not mentioned.
- Test 4 (Performance Data):
- First Interpretation: A panel of three people selected by the independent laboratory were used to make the PASS/FAIL determinations. Their specific qualifications are not mentioned.
- Second Interpretation: Another set of three interpreters were hired by SteriTec. Their qualifications are explicitly stated as nurses, who "generally have more experience in chemical indicator interpretations."
4. Adjudication Method for the Test Set
- Test 4 (Performance Data): The text indicates decisions were made by a panel of three for both rounds of interpretation, but it does not specify an adjudication method like 2+1 or 3+1. It simply states they were "used to make the PASS/FAIL determinations." The fact that a second panel was brought in due to a few results from the first set being "considered outside the product specifications" suggests a lack of consensus or issues with the first panel's interpretation, leading to a re-evaluation by the second panel.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
- No, an MRMC comparative effectiveness study was not explicitly done in the way typically understood for comparing AI to human-assisted AI.
- The study involved panels of human readers interpreting the chemical indicators. There was a comparison between two sets of human interpreters (first panel vs. nurses) for Test 4, noting that the "interpretations of the second set of interpreters (Nurses) were more uniform." This focuses on inter-rater variability and expertise among human readers, not on AI assistance.
6. If a Standalone (algorithm only without human-in-the-loop performance) was done
- No. The device is a physical chemical indicator strip that requires visual interpretation by a human. There is no algorithm or AI involved for standalone performance. The "performance" of the device itself (color change) is assessed by human observation.
7. The Type of Ground Truth Used
- For the indicator strips' performance: The primary ground truth for the effectiveness of the sterilization process itself (which the indicator is supposed to reflect) was established using biological spore strips. The indicator's color change was correlated directly with the kill/survival status of these biological indicators.
- For the interpretation of the color change: Expert consensus (from the panels of interpreters) was used to determine if the color change of the chemical indicator strip qualified as a "pass" or "fail."
8. The Sample Size for the Training Set
- Not applicable. This document describes the validation of a physical chemical indicator, not an AI or algorithm. Therefore, there is no "training set" in the context of machine learning. The "learning" for the product's design would have happened during its development, but this document focuses on its performance validation against established standards.
9. How the Ground Truth for the Training Set was Established
- Not applicable. As there is no training set mentioned for an AI/algorithm, there is no ground truth establishment for a training set.
§ 880.2800 Sterilization process indicator.
(a)
Biological sterilization process indicator —(1)Identification. A biological sterilization process indicator is a device intended for use by a health care provider to accompany products being sterilized through a sterilization procedure and to monitor adequacy of sterilization. The device consists of a known number of microorganisms, of known resistance to the mode of sterilization, in or on a carrier and enclosed in a protective package. Subsequent growth or failure of the microorganisms to grow under suitable conditions indicates the adequacy of sterilization.(2)
Classification. Class II (performance standards).(b)
Physical/chemical sterilization process indicator —(1)Identification. A physical/chemical sterilization process indicator is a device intended for use by a health care provider to accompany products being sterilized through a sterilization procedure and to monitor one or more parameters of the sterilization process. The adequacy of the sterilization conditions as measured by these parameters is indicated by a visible change in the device.(2)
Classification. Class II (performance standards).