(98 days)
SteriChek ™ Total Chlorine Reagent Strips provide a quick convenient means of testing for low levels of total chlorine (i.e. total chloramines plus free chlorine) in water used to prepare dialysate. The color that develops in the pad after exposure to the sample according to the directions is compared to a color chart to determine the concentration of total chlorine present in the sample.
The device is made up of a 0.20 inch square off-white reagent pad that has been chemically treated and affixed to one end of a 3.25 inch by 0.20 inch white opaque polystyrene strip. The reagent pad is activated by exposing it to the sample. The color of the pad is visually compared to a color chart to determine the amount of total chlorine present in the sample.
The provided text describes the SteriChek™ Total Chlorine Reagent Strips, a device for testing total chlorine levels in water for dialysate preparation. Here's a breakdown of the requested information based on the provided document:
Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Stated or Implied) | Reported Device Performance |
|---|---|
| Detection Range: Detect total chlorine concentrations between 0 and 3 ppm. | The device is used as a quantitative method to detect total chlorine concentrations between 0 and 3 ppm. |
| Low-Level Detection: Reliably measure total chlorine concentrations as low as 0.1 ppm. | The device will reliably measure total chlorine concentrations as low as 0.1 ppm total chlorine. |
| Equivalence to Predicate Device: Performance characteristics should be equivalent to the predicate device (Serim™ HiSense Test Kit). | "The performance characteristics of SteriChek™ Total Chlorine reagent Strips and Serim™ HiSense Test Kit were analyzed with water samples... The performance was equivalent." |
Study Information
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Sample sizes used for the test set and the data provenance:
- Test Set Sample Size: The document states "water samples in which either sodium hypochlorite or chloramines were added to give a range of free chlorine or combined chlorine levels." However, it does not specify the exact number of samples or the range of concentrations tested beyond 0-3 ppm and 0.1 ppm low-level detection.
- Data Provenance: The document does not explicitly state the country of origin. Given the submission is to the FDA (USA), it's highly probable the testing was conducted in the USA. It's a retrospective analysis of the device's performance against controlled samples.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document does not mention the use of human experts to establish ground truth for visual comparison. The "color blocks are calibrated in terms of chlorine concentration," implying a predefined standard. The "color of the pad is visually compared to a color chart" by the user.
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Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- None is explicitly stated. The device relies on a direct visual comparison by the user to a color chart.
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If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No, an MRMC study was not done. This device is a simple reagent strip with visual comparison, not an AI-powered system or one that requires human readers in the traditional sense of medical image interpretation.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, a standalone performance assessment was done. The performance of the SteriChek™ strips was directly compared to the predicate device's performance using water samples with known chlorine concentrations. The "algorithm" here is the chemical reaction on the strip leading to a color change, which is then interpreted by visual comparison. The study assesses the inherent ability of the strip to accurately reflect chlorine concentration.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- The ground truth was established by known, precisely prepared chemical concentrations of free chlorine and chloramines in water samples. These were "water samples in which either sodium hypochlorite or chloramines were added to give a range of free chlorine or combined chlorine levels."
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The sample size for the training set:
- The document does not specify a separate training set. This is a chemical reagent strip, not a machine learning model that typically involves training data. The "calibration" of the color chart would have been done during the device's development, but details on that process or sample sizes are not provided within this summary.
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How the ground truth for the training set was established:
- As there's no explicitly mentioned training set in the context of machine learning, this question is not fully applicable. However, the ground truth for calibrating the color chart (which informs the "training" aspect of the device's functionality) would have been established through controlled laboratory experiments using precisely measured concentrations of chlorine to correlate color intensity with ppm values. This process is implied by the statement "The color blocks are calibrated in terms of chlorine concentration."
§ 876.5665 Water purification system for hemodialysis.
(a)
Identification. A water purification system for hemodialysis is a device that is intended for use with a hemodialysis system and that is intended to remove organic and inorganic substances and microbial contaminants from water used to dilute dialysate concentrate to form dialysate. This generic type of device may include a water softener, sediment filter, carbon filter, and water distillation system.(b)
Classification. Class II (special controls). The device, when it is a water purification subsystem disinfectant, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 876.9.