(28 days)
The Getinge Biosign Steam-24 Biological Indicator is a steam sterilization monitor designed specifically for biological testing of 121°C, 134°C gravity and pre-vacuum and flash gravity and prevacuum steam sterilization cycles with results available after 24 hours incubation.
The Getinge Biosign Steam-24 Biological Indicator is a self-contained biological indicator designed for biological testing of steam 121°C and 134°C pre-vacuum and gravity and flash steam sterilization cycles. When used to monitor steam cycles, the product is intended to give the user results after 24 hours incubation. The Biosign Steam-24 Biological Indicator contains 10^6 Geobacillus stearothermophilus (nee Bacillus stearothermophilus) spores/carrier. The Biological Indicator is selfcontained with an ampule containing culture medium in the same vial as the spore strip.
Here's an analysis of the provided text, focusing on acceptance criteria and the study details:
Acceptance Criteria and Device Performance Study
The Getinge Biosign Steam-24 Biological Indicator is intended to show results after 24 hours of incubation. The primary acceptance criterion for this modified device over its predicate is improved incubation time while maintaining sterilization effectiveness.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Greater than 97% assurance for 24-hour incubation time (per CDRH Guidelines for incubation time) | "Results provided greater than 97% assurance for 24 hours (incubation time)." |
| All steam resistance criteria met, including Survival/Kill and D-value for 121°C and 134°C sterilization cycles (per CDRH Guidelines) | "All steam resistance criteria were met including Survival / Kill and D-values... for 121°C and 134°C." |
| (Implied: The Biosign Steam-24 Biological Indicator is equivalent to the unmodified Biosign BI for monitoring steam sterilization effectiveness.) |
2. Sample Size and Data Provenance
- Test Set Sample Size: The document states that "different lots of Biosign Steam-24 were tested." However, no specific number of lots or individual Biological Indicators (BIs) tested is provided.
- Data Provenance: The study was likely conducted internally by Getinge USA, Inc. The data is retrospective in the sense that the testing was performed, and the results were then compiled for the 510(k) submission. The country of origin for the data is implicitly the USA, where Getinge USA, Inc. is located.
3. Number of Experts and Qualifications for Ground Truth
- Number of Experts: Not applicable. This type of device relies on a physicochemical reaction (spore inactivation) for its function, not subjective expert interpretation. The ground truth is intrinsically linked to the biological viability of the Geobacillus stearothermophilus spores and their known resistance to steam sterilization, coupled with objective observation of growth in the culture medium.
- Qualifications of Experts: Not applicable.
4. Adjudication Method for the Test Set
- Adjudication Method: Not applicable. The assessment of spore growth/no growth (which determines positive/negative results) is an objective biological outcome based on a color change or turbidity in the culture medium. There is no mention of subjective interpretation or a need for expert adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- MRMC Study Done: No. An MRMC study is not relevant for this type of device. Biological indicators do not involve human readers interpreting complex imaging or data. Their function is to provide a clear, objective biological result (growth or no growth) indicating successful or failed sterilization.
6. Standalone Performance (Algorithm Only) Study
- Standalone Study Done: Yes, in effect. The evaluation of the Biosign Steam-24 Biological Indicator's performance (incubation time and steam resistance) is a standalone assessment of the device itself. It operates independently of human interpretation beyond observing the final growth result. There is no "human-in-the-loop" interaction in the function of the BI; it is a direct measurement of sterility conditions.
7. Type of Ground Truth Used
- Type of Ground Truth: The ground truth is based on biological viability and spore inactivation kinetics. For sterilization, the ground truth is whether the Geobacillus stearothermophilus spores, known to be highly resistant to steam, were successfully killed. This is objectively determined by the absence of growth (no color change/turbidity) in the culture medium after incubation. The D-value (Decimal Reduction Time) also represents a quantitative measure of resistance used to establish ground truth for effectiveness.
8. Sample Size for the Training Set
- Sample Size for Training Set: Not applicable. Biological indicators are not machine learning algorithms that require a "training set." Their performance is based on established biological principles and physical testing, not data-driven model training.
9. How Ground Truth for the Training Set Was Established
- Ground Truth for Training Set: Not applicable. As there is no training set for a biological indicator in the machine learning sense, there is no ground truth established for a training set. The performance characteristics (spore count, resistance, incubation time) are inherent properties of the biological system and its design, verified through standardized laboratory testing procedures as outlined by the CDRH Guidelines.
§ 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).