(102 days)
The Nox T3 device is intended for ambulatory recording of physiological signals during sleep. The recorded signals are then downloaded to a PC where the signals can be viewed and analyzed by use of the Nox T3 application (Noxturnal). The Nox T3 system is indicated for use in patients greater than 2 years of age.
The Nox T3 system is NOT intended for any patient monitoring or automatic diagnosis.
The intended environments are hospitals, institutions, sleep centers, sleep clinics, or other test environments, including patient's home.
The Nox T3 system is used for patients suspected of suffering from Sleep Disordered Breathing (SDB) or Periodic Limb Movement Disorder (PLMD).
The Nox T3 is an ambulatory recording system. It includes a recording device, respiratory effort sensors, clip straps, filter tube connector and an USB cable for data download and the Nox T3 application (Noxturnal).
The Nox T3 device is a pocket size battery powered digital recorder that incorporates electronics to record and store up to three nights of physiological parameters. The Nox T3 device is worn on the patient's chest by snapping it to the thoracic respiratory effort sensor belt and securing its position with the clip straps. It has a display for status indication, signal integrity and preliminary results, and buttons for control.
The Nox T3 device records signals from five external sensors and three built-in sensors. The external sensors that can be used with the device are abdominal and thoracic respiratory effort sensors, oximeter (via wireless transmission), and two leads of the following: ECG, EMG, EEG or EOG. The built-in sensors include a pressure transducer allowing either recording of nasal pressure (via nasal cannula) or mask pressure and measuring of snoring, a three dimensional acceleration sensor for measure of patient's position and activity, and a microphone for true audio recording capabilities.
The Nox T3 device includes a class II Bluetooth transmitter/receiver to allow for wireless transmission of data from Nonin´s Model 4100 Patient Oximeter Module.
The Nox T3 application (Noxturnal) is used to configure the device for recording, and downloading, viewing and analyzing of recorded data on a PC.
Here's an analysis of the acceptance criteria and study detailed in the provided document for the Nox T3 device:
The document (510(k) summary) describes the Nox T3 as an ambulatory recording system for physiological signals during sleep. The primary goal of the "performance testing summary" is to demonstrate substantial equivalence to predicate devices, rather than establishing specific performance metrics against a predefined acceptance criterion. The key performance claims for this device focus on its ability to record reliable signals and the accuracy of its automated scoring software (Noxturnal) compared to manual scoring.
Here's the breakdown as requested:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Signal Reliability & Usability | "The signals recorded with the Nox T3 system were compared to signals recorded with the predicate device Embla N7000. The result demonstrates the reliability and usability of all signals recorded with the Nox T3 system." |
| Automatic Scoring Accuracy (AHI) | "The analysis comparison result demonstrates that the Noxturnal application scores AHI...events in a substantially equivalent manner to the manual scoring on full PSG recordings obtained using Embla N7000 recorders." (No specific numerical target or statistical metric [e.g., agreement percentage, correlation coefficient] is provided in the summary.) |
| Automatic Scoring Accuracy (ODI) | "The analysis comparison result demonstrates that the Noxturnal application scores ...ODI values in a substantially equivalent manner to the manual scoring on full PSG recordings obtained using Embla N7000 recorders." (No specific numerical target or statistical metric is provided in the summary.) |
| Ease of Operation | "The general process from configuration of device to reading out the results and generating report was validated by having untrained person perform this actions. The results demonstrates that the Nox T3 system has meet its objective of being easy to operate, the Noxturnal interface guides the user appropriately, minimizing the likelihood of errors and lapses, and the design of the Nox T3 components and user instruction allows the hook-up to be performed by untrained people." |
| Compliance to Standards | The device underwent external testing to comply with applicable standards regarding EMC and patient safety (e.g., IEC60601-1, IEC60601-1-2, IEC 60601-2-25, IEC 60601-2-26, IEC 60601-2-40) and FCC requirements for R&TTE approval. (Compliance is stated; no specific results of these tests and how they meet criteria are detailed in this summary.) |
Note: The document explicitly states that the comparisons "do not raise new questions of safety and effectiveness and demonstrate the same effectiveness and safety as that of the predicates." This implies that the 'acceptance criteria' are primarily based on demonstrating equivalence rather than achieving absolute performance thresholds.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Automatic Scoring Comparison: 1057 Embla N7000 recordings.
- Data Provenance: The document does not explicitly state the country of origin. It indicates the data consisted of "Embla N7000 recordings." Embla is a brand associated with sleep diagnostics, and both Medcare Flaga (the predicate's manufacturer) and Nox Medical are based in European countries (Medcare Flaga in the past was associated with Iceland, though it might have had broader presence; Nox Medical is in Iceland). Given the context of a 510(k) submission to the FDA, it's highly probable that the data was collected from clinical settings, likely retrospectively as they were "recordings which had all gone through the process of being manually scored."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts
- Number of Experts: Not explicitly stated as a specific number. The ground truth was established by "Sleep Technicians with RPSGT certification" and "then reviewed by a Physician." This suggests at least one technician and one physician per recording, but doesn't give an aggregate count of unique individuals.
- Qualifications of Experts:
- Sleep Technicians: "RPSGT certification" (Registered Polysomnographic Technologist).
- Physician: "reviewed by a Physician." (Specific specialization like a sleep physician is implied but not explicitly stated.)
4. Adjudication Method for the Test Set
- The method described is sequential: "manually scored by Sleep Technicians with RPSGT certification, and then reviewed by a Physician." This implies a form of hierarchical review, where the technician's scoring is the initial pass, followed by a physician's oversight. It is not explicitly stated if there was a consensus process (e.g., 2+1, 3+1) if the physician disagreed with the technician, or if the physician's review constituted the final ground truth.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done, What was the Effect Size of How Much Human Readers Improve with AI vs without AI Assistance
- No, a MRMC comparative effectiveness study involving human readers with vs. without AI assistance was not performed or reported in this summary. The study reported compared the device's standalone automatic scoring (Noxturnal application) against manual scoring by human experts. The study's focus was on the performance of the automated algorithm, not on improving human reader performance.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was Done
- Yes, a standalone performance evaluation of the algorithm was done. The "Analysis comparison was performed to validate the quality of the automatic scoring performed by the Noxturnal application compared to manual scoring of full PSG data." This directly assesses the algorithm's performance without a human in the loop during the scoring process.
7. The Type of Ground Truth Used
- The ground truth used was expert consensus/manual scoring. Specifically, "manual scoring of full PSG data" performed by "Sleep Technicians with RPSGT certification" and "then reviewed by a Physician."
8. The Sample Size for the Training Set
- The document does not specify a sample size for the training set. It only mentions the "recordings used consisted of 1057 Embla N7000 recordings" for the validation study. It is common for 510(k) summaries to omit details about training data, but its absence here means we cannot ascertain the training set size from this document.
9. How the Ground Truth for the Training Set was Established
- The document does not provide information on how the ground truth for the training set was established. Given the lack of detail on the training set itself, this information is not available in the provided text.
§ 868.2375 Breathing frequency monitor.
(a)
Identification. A breathing (ventilatory) frequency monitor is a device intended to measure or monitor a patient's respiratory rate. The device may provide an audible or visible alarm when the respiratory rate, averaged over time, is outside operator settable alarm limits. This device does not include the apnea monitor classified in § 868.2377.(b)
Classification. Class II (performance standards).