(349 days)
The Nelson Sentinel Series Basic Chlorine Sentinel is an instrument that is intended for use by hemodialysis professionals as an auxiliary device to provide continuous monitoring of Total chloramines plus ammoniated free chlorine) concentration. It is not intended to replace the primary method for monitoring total chlorine as part of the hemodialysis water treatment system. It functions completely independent of the water treatment system and does not come into direct contact with feed water used to prepare dialysate.
The Nelson Sentinel Series Basic Chlorine Sentinel is a complete system that attaches to the drain of a hemodialysis water treatment system sample port. The Basic Chlorine Sentinel detects dissolved chlorine by an auxiliary meter detection technology, self-monitors for maintenance-required conditions, loss of electrical power, as well as two other system conditions such as flooding and the status of RO shutdown alarm. The device chlorine monitoring probe is preferably placed after the second carbon filter, before the RO machine or at the beginning of the patient water treatment loop.
The device has three components - a lockable master control enclosure, a lockable probe/tester enclosure, and the remote module installed in the patient area.
A chlorine concentration equal to or above the set-point (default: 0.10mg/L) will activate the buzzers and the red CHLORINE alarm indicators for as long as the condition exists. The buzzers can only be muted for 3 minutes (then automatically reset) for as long as the condition exists. The yellow AUTO-TEST OK/CL DETECTED indication will latch. The AUTO-TEST/CL DETECTED indication can be deactivated after the event by pressing the blue RESET PUSHBUTTON on the front cover of the controller.
A probe failure or the activation of one of the auxiliary input relays will activate the yellow MAINTENANCE needed indicators as well as the Buzzers which will remain activated as long as the condition exists. However, the buzzers can be muted by the key mute switch while the maintenance issue is being resolved.
The provided document is a 510(k) summary for the Nelson Sentinel Series Basic Chlorine Sentinel, a device intended for continuous monitoring of total chlorine in water purification systems for hemodialysis.
However, the document does not contain the level of detail requested for acceptance criteria and the study proving the device meets these criteria in the context of an AI/ML-based medical device performance study. This document describes a hardware device for chemical measurement and its equivalence to predicate devices, not an AI/ML algorithm.
Therefore, many of the specific questions about AI/ML study design, such as sample size for test/training sets, data provenance, expert ground truth, adjudication, MRMC studies, and standalone algorithm performance, cannot be answered from the provided text.
Here's an attempt to extract what is available regarding acceptance criteria and performance, reinterpreting some points for a hardware device context where applicable, and explicitly stating where information is missing for an AI/ML context:
Acceptance Criteria and Device Performance (Based on the provided document for a hardware device)
The document primarily focuses on establishing "substantial equivalence" of the Nelson Sentinel Series Basic Chlorine Sentinel to predicate and reference devices, rather than defining explicit acceptance criteria in terms of metrics like sensitivity, specificity, or AUC as one would for an AI/ML diagnostic. The equivalence is shown through comparison of intended use, technological characteristics, and performance testing.
1. Table of Acceptance Criteria and Reported Device Performance
Since this is a hardware device for chemical detection and not an AI/ML algorithm, the "acceptance criteria" are implied by performance tests to demonstrate safety and effectiveness for its intended use and similarity to established devices. The "reported device performance" refers to the results of these bench tests demonstrating the device's operational range and accuracy within its specified function.
| Acceptance Criteria (Implied for Hardware Device) | Reported Device Performance (Summary from Bench Testing) |
|---|---|
| Electrical Safety (IEC 61010-1 compliance) | Testing performed; presumed compliant (no specific results provided beyond "performed") |
| Electromagnetic Compatibility (IEC 61326-1 compliance) | Testing performed; presumed compliant (no specific results provided beyond "performed") |
| Shelf-Life of Reagent | Shelf life testing performed for ammonium sulfate reagent |
| Linearity | A Linearity Study was performed. (No specific range or R-squared provided) |
| Precision | A Precision Study was performed. (No specific CV or std. dev. provided) |
| Limit of Blank (LoB), Limit of Quantitation (LoQ), Limit of Detection (LoD) | A LoB, LoQ, LoD Study was performed. (No specific values provided) |
| Method Comparison | A Method Comparison Study was performed. (No specific comparison metrics provided) |
| Peristaltic Pump and Tubing Validation | A Validation was performed. (No specific results provided) |
| Free Chlorine Study | A Study was performed. (No specific results provided) |
| 15 Weeks Calibration Study | A Study was performed. (No specific results provided) |
| Software Validation | Software validation was performed. (No specific details of validation or metrics provided) |
| Alarm Activation (Chlorine concentration ≥ 0.10mg/L) | Device activates buzzers and red CHLORINE alarm indicators. |
| Alarm Activation (Probe failure, auxiliary input relays) | Device activates yellow MAINTENANCE needed indicators and buzzers. |
| Continuous Monitoring | Device provides continuous monitoring. |
| Operation within specified ranges (e.g., sample pressure, temperature, humidity) | The device's operating ranges are described and compared to the reference device, with stated differences not affecting safety or effectiveness. Specific test results demonstrating compliance with these ranges are not detailed. |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: Not explicitly stated in the document. The document mentions various "studies" (Linearity, Precision, LoB/LoQ/LoD, Method Comparison, Free Chlorine, 15 Weeks Calibration), but does not provide details on the number of samples or measurements used in these bench tests.
- Data Provenance: The studies were performed as "Bench Testing." The origin of the water samples or the specific laboratory where tests were conducted is not specified, but it would be laboratory-based testing relevant to water purification for hemodialysis. The document does not specify if the data was retrospective or prospective in the context of an AI/ML study, as it's not an AI/ML device.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
- This question is not applicable as the device is a chemical sensor, not an AI/ML device requiring expert interpretation for ground truth. Ground truth for chlorine concentration would be established by analytical chemistry methods (e.g., lab-grade spectrophotometry, titration).
4. Adjudication Method for the Test Set
- Not applicable for a chemical sensor device.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
- Not applicable. This is a hardware device for chemical detection; MRMC studies are relevant for evaluating diagnostic image interpretation by humans, often with and without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
- Not applicable as this is not an AI/ML algorithm. The "performance" refers to the device's ability to accurately measure chlorine and provide alerts.
7. The Type of Ground Truth Used
- For the performance testing mentioned (Linearity, Precision, etc.), the ground truth for chlorine concentration would have been established by accurate chemical analysis methods in a laboratory setting (e.g., using reference standards and validated analytical techniques). It is not expert consensus, pathology, or outcomes data.
8. The Sample Size for the Training Set
- Not applicable. This device is not an AI/ML algorithm that requires a training set.
9. How the Ground Truth for the Training Set was Established
- Not applicable. This device is not an AI/ML algorithm that requires a training set.
Summary of Document Relevance to AI/ML Device Analysis:
This document is a regulatory submission for a physical medical device (a chlorine monitor) demonstrating its substantial equivalence to pre-existing devices. It details the device's functional characteristics, intended use, and bench testing performed to ensure safety and effectiveness. It does not provide information related to the development, validation, or performance of an AI/ML algorithm, which would require a significantly different set of acceptance criteria and study designs focusing on model performance metrics, data sets, and human-AI interaction.
§ 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.