(180 days)
Use the 3M Attest™ Rapid Readout Biological Indicator 1295 in conjunction with the 3M Attest™ Auto-reader 490H as a standard method of routine monitoring of vaporized hydrogen peroxide sterilization processes in STERRAD® NX and 100NX systems.
The 3M Attest™ 1295 Rapid Readout Biological Indicator for Vaporized Hydrogen Peroxide Sterilization (pink cap, referred to hereinafter as the 1295 BI) is a self-contained biological indicator specifically designed for rapid and reliable routine monitoring of STERRAD® vaporized hydrogen peroxide sterilization processes when used in conjunction with the 3M Attest™ Auto-reader 490H (hereinafter referred to as the 490H Auto-reader). The 1295 BI is a single-use device.
The Attest™ 1295 BI is composed of a polycarbonate sleeve containing a spore carrier and media ampoule, enclosed with a color-coded cap. A chemical process indicator printed with stripes which change from blue to pink upon exposure to vaporized hydrogen peroxide is located on the top of the cap.
The 1295 BI utilizes the same fundamental technology that exists in current 3M Attest™ Rapid Readout and Super Rapid Readout BIs. All Attest™ Rapid Readout and Super Rapid Readout BIs for steam utilize the a-glucosidase enzyme system, which is generated naturally within growing Geobacillus stearothermophilus organisms. The a-glucosidase enzyme in its active state is detected by measuring the fluorescence produced by the enzymatic hydrolysis of a non-fluorescent substrate. The resultant fluorescent by-product is detected in the 3M Attest™ 490H Auto-reader. The detection of fluorescence upon incubation of the 1295 BI in the 490H Auto-reader indicates a sterilization failure.
The 1295 BI is similar in design to the 3M Attest™ 1492V Super Rapid Readout Biological Indicator for Steam cleared as K121484 for dynamic-air-removal (prevacuum) steam sterilization cycles. Minor modifications were made to 1492V that resulted in the 1295 BI for STERRAD® vaporized hydrogen peroxide sterilization cycles.
The Attest™ Auto-reader 490H is similar in design to the Attest™ Auto-reader 490 that has been cleared for use with the Attest™ 1491 Super Rapid Readout Biological Indicator under K103277 and Attest™ 1492V Super Rapid Readout Biological Indicator under K121484.
The Attest™ Auto-reader 490H is designed to incubate at 60°C and automatically read the Attest™ 1295 BI for a fluorescent result within 4 hours. The fluorescent readout at 4 hours met the FDA's requirement of > 97% alignment with the result after the conventional incubation time of 7 days. The Auto-reader 490H is also designed to allow further incubation of the 1295 BI for an optional visual pH color change result of the growth media at 7 days.
The provided document describes the 3M Attest™ Rapid Readout Biological Indicator 1295 (BI) and 3M Attest™ Auto-reader 490H. The primary study presented is a substantial equivalence comparison to predicate devices, rather than a direct study demonstrating absolute performance against highly specific, quantitative acceptance criteria for all aspects of a typical diagnostic device. However, some performance characteristics are outlined, particularly in comparison to the predicate.
Here's an analysis based on the document:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly state "acceptance criteria" for the new device as a set of a priori thresholds. Instead, it demonstrates substantial equivalence by comparing its characteristics and performance to legally marketed predicate devices, and against the FDA's Guidance for Industry and FDA Staff, Biological Indicator (BI) Premarket Notification [510(k)] Submissions.
The table below summarizes the key performance characteristics mentioned for the Attest™ 1295 BI compared to its "Intended Use Predicate," the STERRAD® CycleSure® 24 BI (K123017).
| Characteristic | Acceptance Criteria (Predicate Performance / Guidance) | Reported Device Performance (Attest™ 1295 BI) |
|---|---|---|
| Intended Use | Monitoring vaporized hydrogen peroxide sterilization processes (e.g., STERRAD® NX, 100NX). | Same as predicate. |
| Organism (Species, Strain) | Geobacillus stearothermophilus traceable to ATCC™ 7953. | Same as predicate. |
| Viable Spore Population | ≥ 10^6^ | Same as predicate. |
| D-value (Resistance) | D_2.5 mg/L_ ≥ 1 second (for predicate at 2.5 mg/L H2O2) | D_10 mg/L_ ≥ 1 second (at 10 mg/L H2O2). |
| Survival Time | ≥ 5 seconds | ≥ 5 seconds |
| Kill Time | = 60 seconds (for predicate at 2.5 mg/L H2O2) | = 7 minutes (at 10 mg/L H2O2) - Note: Much longer due to higher challenge. |
| Reduced Incubation Time (Fluorescent Result) | >97% correlation to 7-day visual pH color change (for predicate: 24 hours visual pH). | Fluorescent result in 4 hours (>97% correlation to 7-day visual pH color change not explicitly stated for 1295, but inferred by meeting FDA guidance). |
| Chemical Process Indicator | Changes from red to golden yellow or bronze. | Changes from blue to pink. |
| Incubation Temperature | 55-60°C | 60 +/- 2 °C |
| Shelf-life | 6 months | 6 months (with plans for extension). |
Note for Auto-reader 490H: The document states the fluorescent readout at 4 hours met the FDA's requirement of > 97% alignment with the result after the conventional incubation time of 7 days. This is a key "acceptance criterion" for the rapid readout functionality, implying the accuracy of the 4-hour fluorescent result vs. the traditional 7-day visual result.
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document states, "Multiple lots of Attest™ 1295 BIs were evaluated for performance." However, it does not provide a specific number or breakdown of the sample size (e.g., number of BIs, number of sterilization cycles, replicates) used for the resistance testing or reduced incubation time validation.
- Data Provenance: Not explicitly stated. Given it's a 510(k) submission, the studies would likely be conducted in a controlled laboratory setting (e.g., 3M's R&D facilities) in the country of origin of the manufacturer (USA, St. Paul, MN). The data would be prospective as it involves controlled testing of the new device's performance against defined parameters.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Experts
- This type of device (biological indicator) relies on a biological process (spore inactivation) and a chemical reaction for ground truth, rather than expert review of images or clinical assessments.
- Ground Truth Establishment: The ground truth for the BI performance studies is based on established microbiological methods for assessing spore viability (e.g., lack of growth after incubation for positive control, confirmed kill for negative control) and comparison to the predicate device's known performance characteristics. No human "experts" in the sense of clinicians or radiologists are involved in establishing the ground truth for this device's function.
4. Adjudication Method
- Not applicable in the conventional sense. The "ground truth" for a biological indicator is determined by the growth or non-growth of spores, and the optical detection of fluorescence by the auto-reader. This is a direct, objective measurement, not subject to human interpretation or adjudication in the study itself.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC comparative effectiveness study was not done. This type of study is relevant for diagnostic devices where human reader performance is being evaluated, often with or without AI assistance. The 3M Attest system is a standalone biological sterilization indicator and auto-reader, not a diagnostic device involving human interpretation of complex medical cases.
6. Standalone Performance Study
- Yes, a standalone performance evaluation of the algorithm (or device's intrinsic function) was performed.
- The "Reduced Incubation Time" validation demonstrates standalone performance, showing the 4-hour fluorescent readout reliably predicts the 7-day visual pH color change. This is the core "algorithm" of the rapid readout auto-reader.
- The resistance characteristics (D-value, Survival/Kill Time) are also standalone performance metrics for the BI itself.
- The comparison to the predicate device is also a form of standalone evaluation against a known standard.
7. Type of Ground Truth Used
- The ground truth used for performance evaluation is microbiological growth/non-growth of spores (indicating sterilization efficacy), and chemical pH change in growth media (for the traditional 7-day visual result).
- For the rapid readout function, the fluorescent signal's correlation to the 7-day visual pH change is the key ground truth.
8. Sample Size for the Training Set
- The document does not explicitly mention a training set in the context of an AI/ML algorithm development. This device uses a physiological detection mechanism (enzyme activity leading to fluorescence) rather than a machine learning model that would typically require a training set. The "development of a test cycle" and "evaluating multiple lots" suggests R&D and validation efforts, but not a distinct training set for an AI model.
9. How the Ground Truth for the Training Set was Established
- Not applicable, as a conventional AI/ML training set is not described or implied for this device. The development process would involve standard microbiology and engineering principles to ensure the BI and auto-reader accurately detect spore viability and fluorescence, respectively.
§ 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).