(37 days)
The Browne Sporicidin Phenol Indicator For Sporicidin Sterilizing and Disinfecting Solution (Browne Sporicidin Phenol Indicator) is a phenol concentration monitor for use in phenol-containing germicide solutions with a minimum effective concentration of 1.3% phenol.
The Browne Sporicidin Phenol Indicator is dedicated for use with Sporicidin Sterilizing and Disinfecting Solution.
The Browne Sporicidin Phenol Indicator and the substantially equivalent device are chemical indicator strips intended to monitor the concentration of the active ingredient of a liquid chemical germicide. The devices indicate, via a color change, if the concentration of the active ingredient exceeds the MEC for the solution.
The Browne Sporicidin Phenol Indicator consists of a polypropylene strip with an indicator pad on one end. The indicator pad is impregnated with an indicator solution which changes color from yellow to green in liquid chemical germicides with a phenol concentration above the MEC of 1.3%.
The Browne Sporicidin Phenol Indicator and the predicate device have a 2-year shelf life from the date of manufacture in the unopened bottle. Containers of both devices have a 90 day in-use life.
Here's an analysis of the provided text regarding the Browne Sporicidin Phenol Indicator device:
Acceptance Criteria and Study to Prove Device Meets Criteria
1. Table of Acceptance Criteria and Reported Device Performance
The core acceptance criterion for this device is its ability to accurately indicate whether the concentration of phenol in Sporicidin Sterilizing and Disinfecting Solution is at or above the Minimum Effective Concentration (MEC) of 1.3%. The device is designed to show a color change from yellow to green when the phenol concentration is sufficient, and remain yellow or partially yellow/green when it is not.
| Acceptance Criteria (What the device should do) | Reported Device Performance |
|---|---|
| 1. Indicate sufficient phenol concentration: The device should accurately register a "PASS" (green color) when the phenol concentration is at or above the MEC of 1.3%. Specifically, it should indicate sufficient concentration at ≥1.6% phenol. | 1. Consistent PASS at sufficient concentration: When tested in Sporicidin Solution with 1.6% phenol, the indicators showed the expected color change. The document states that at 60 seconds (1 minute), the strip exhibits a uniform green color if the concentration is ≥1.6%. The performance testing states "No false positives were recorded in any of the testing conducted." This implies that it correctly identified sufficient phenol. |
| 2. Indicate insufficient phenol concentration: The device should accurately register a "FAIL" (yellow or parchy green/yellow color) when the phenol concentration is at or below the MEC of 1.3%. | 2. Consistent FAIL at insufficient concentration: The test indicators showed a 100% failure rate in the 1.3% solution when testing was performed according to the Instructions for Use. This means it consistently showed a "FAIL" when the phenol was at the MEC, correctly indicating it needed to be discarded. |
| 3. Reliability and Consistency: The device should provide stable and consistent readings within the specified read window (1-2 minutes). | 3. Stable Read Window: The color of the strip is stable from 60 to 120 seconds (1 to 2 minutes), and a reading must be taken during this period for accuracy. Regression toward yellow occurs after 120 seconds. |
| 4. Minimal false negatives in ideal conditions: Under standard use and clean conditions, the device should not falsely indicate a "FAIL" when the solution is actually at or above MEC. | 4. False negatives observed under specific conditions: "Some false negatives were observed." Crucially, the frequency of false negatives increased "when the indicators were tested in the presence of high levels of detergent and salt contaminants, or when testing was performed by inexperienced users." This suggests that under ideal conditions (i.e., clean solution and experienced users), false negatives would be minimal or none, aligning with the 100% failure rate in the 1.3% solution (which is a correct failure). The observation of false negatives appears to be tied to user error or contaminated solution, rather than an inherent flaw in the indicator chemistry itself. The report clarifies, "The false negatives reported would have caused the user to discard the solution unnecessarily. No disinfection procedure would have been compromised," implying that these false negatives err on the side of caution. |
| 5. No false positives: The device should never falsely indicate a "PASS" when the solution is below the MEC. | 5. No false positives recorded: "No false positives were recorded in any of the testing conducted." This is a strong positive performance indicator. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: The document does not explicitly state the specific number of individual test strips used in the "Performance Testing." It refers to "test indicators" without specifying a count.
- Data Provenance: The document does not specify the country of origin of the data. It appears to be from internal testing conducted by the manufacturer, Albert Browne Ltd., located in the United Kingdom. However, the testing was done for a US FDA 510(k) submission. The data is retrospective as it pertains to testing performed prior to the submission date (December 1998 / February 1999).
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Experts
The document does not mention the use of experts to establish ground truth for the test set. Given the nature of the device (a chemical indicator with a clear, objective color change based on a known chemical concentration), the "ground truth" for the test was the known, precisely prepared chemical concentrations of phenol in the Sporicidin Sterilizing and Disinfecting Solution (1.6% and 1.3%). The assessment of the color change itself would be subjective to the human eye, but the underlying ground truth is the chemical concentration.
4. Adjudication Method for the Test Set
The document does not specify an adjudication method (like 2+1, 3+1, none) for interpreting the results of the color change. The description implies that the observation of the color (yellow, green/yellow, green) directly determines the outcome against predefined criteria. The mention of "inexperienced users" causing more false negatives suggests that user interpretation is a factor, but a formal adjudication process (e.g., multiple readers resolving discrepancies) is not described.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC comparative effectiveness study was not done. This type of study typically evaluates the performance of human readers (e.g., radiologists) with and without AI assistance on complex diagnostic tasks. The Browne Sporicidin Phenol Indicator is a simple chemical indicator, not an AI-powered diagnostic tool, and its assessment does not involve human interpretation in a comparative reader study context.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done
While this isn't an "algorithm" in the modern AI sense, the device's chemical reaction and color change are its "standalone" function. The core performance testing (100% failure rate at 1.3% phenol, no false positives) reflects the standalone chemical performance of the indicator strip in response to specific phenol concentrations. Human observation is required to read the result, but the chemical reaction itself happens independently. The document describes the chemical mechanism (STEP 1 & STEP 2) as its inherent standalone function.
7. The Type of Ground Truth Used
The ground truth used was known, precisely controlled chemical concentrations of phenol in the Sporicidin Sterilizing and Disinfecting Solution. The testing was performed at a known 1.6% phenol concentration (expected PASS) and a known 1.3% phenol concentration (expected FAIL/MEC).
8. The Sample Size for the Training Set
This concept does not strictly apply to this device. As a chemical indicator, there isn't a "training set" in the machine learning sense. The chemical formulation of the indicator pad is developed and validated through chemical and manufacturing processes, not by training an algorithm on a dataset. The "development" and "optimization" of the chemical components would be analogous to training, but no specific dataset size is provided.
9. How the Ground Truth for the Training Set Was Established
Similarly, without a "training set" in the conventional AI/machine learning context, there's no ground truth established in that manner. The ground truth for the development of the indicator's chemistry would have been based on established chemical principles and controlled experiments to ensure the indicator reacted specifically and consistently to the target phenol concentrations. This involves standard chemical laboratory practices to ensure the dye changes color at the desired pH, which is, in turn, produced by the reaction with phenol.
§ 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).