(181 days)
The Nurochek-II System is intended for prescription use in healthcare facilities for subjects aged between 16 and 46 years old, for the aid in diagnosis of mild traumatic brain injury (mTBI) in conjunction with a standard neurological assessment.
The Nurochek-II System is indicated for the generation of visual evoked potentials (VEPs) and to acquire, transmit, display, and store electroencephalograms (EEGs) during the generation of VEPs. Additionally, the system is indicated to analyze captured EEG signals to provide an aid in the diagnosis of mild traumatic brain injury (mTBI) in subjects aged between 16 and 46 years old who have sustained a potential head injury in the past 72 hours (3 days).
The Nurochek-II System is a portable system designed to generate visual evoked potentials (VEPs) in patients and acquire, transmit, display, and store the resulting electroencephalogram (EEG). It is intended for prescription use in healthcare facilities for subjects aged between 16 and 46 years, to aid in the diagnosis of mild traumatic brain injury (mTBI). The primary components of the Nurochek-II System are the wearable headset, the Nurochek-II software application, and the Nurochek-II server.
Here's a breakdown of the acceptance criteria and the study details for the Nurochek-II System:
1. Table of Acceptance Criteria and Reported Device Performance
The FDA 510(k) summary does not explicitly state "acceptance criteria" for sensitivity and specificity in a separate section. However, it presents the performance of the Nurochek-II System and compares it to a predicate and reference device, implying these metrics are key for demonstrating substantial equivalence. Given the context, the performance metrics reported for the Nurochek-II System are the results of its performance against a clinical diagnosis.
| Metric | Acceptance Criteria (Implied by reported performance for Nurochek-II System) | Reported Device Performance (Nurochek-II System) |
|---|---|---|
| Sensitivity (95% CI) | Achieved 86.05% (72.07-94.70) | 86.05% (72.07-94.70) |
| Specificity (95% CI) | Achieved 67.16% (54.60-78.15) | 67.16% (54.60-78.15) |
| Positive Predictive Value (PPV) (95% CI) | Achieved 62.7% (53.92-70.75) | 62.7% (53.92-70.75) |
| Negative Predictive Value (NPV) (95% CI) | Achieved 88.2% (77.79-94.13) | 88.2% (77.79-94.13) |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: 110 individual Steady-State Visual-Evoked Potential (SSVEP) readings.
- Data Provenance: The document does not explicitly state the country of origin. However, the manufacturer, Headsafe MFG Pty Ltd., is based in Surry Hills, NSW, Australia, suggesting the study may have been conducted in Australia or related clinical sites.
- Retrospective or Prospective: The study is described as a "clinical investigation" with a "clinical research protocol" and the collection of readings within 72 hours of suspected head injury, followed by a clinical evaluation. This indicates a prospective study design.
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 document mentions "Each highly trained physician." This phrasing suggests multiple physicians were involved, but the exact count is not provided.
- Qualifications of Experts: "Highly trained physician" using "their education and experience to deliver their mTBI determination." This included a neurological examination, a concussion-related signs and symptom evaluation, and a review of all relevant information provided by the study subject.
4. Adjudication Method for the Test Set
The document does not explicitly describe a formal adjudication method (e.g., 2+1, 3+1). It states that "Each highly trained physician used their education and experience to deliver their mTBI determination." This implies that the individual physician's diagnosis served as the ground truth without a stated consensus or adjudication process among multiple ground truth experts for each case.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not explicitly described. The study focuses on the standalone performance of the Nurochek-II System against a clinical diagnosis. There is no information provided about human readers improving with AI vs. without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance study was done. The reported sensitivity, specificity, PPV, and NPV are for the Nurochek-II System's classification algorithm in differentiating between subjects with and without mTBI, based solely on the analysis of captured EEG signals.
7. The Type of Ground Truth Used
The ground truth used was expert clinical diagnosis. This was established by "a licensed healthcare professional" (a "highly trained physician") based on a standard neurological assessment, a concussion-related signs and symptom evaluation, and a review of relevant patient information.
8. The Sample Size for the Training Set
The classification algorithm was "generated with 372 individual steady-state visual-evoked potential (SSVEP) readings." This indicates that the training set consisted of 372 individual SSVEP readings.
9. How the Ground Truth for the Training Set Was Established
The ground truth for the training set was established through the same method as the test set: a clinical evaluation by a licensed physician. The protocol required readings to be collected within 72 hours of suspected head injury, in addition to a clinical evaluation by a licensed physician. Their determination was based on a neurological examination, a concussion-related signs and symptom evaluation, and a review of all relevant information.
§ 882.1450 Brain injury adjunctive interpretive electroencephalograph assessment aid.
(a)
Identification. A brain injury adjunctive interpretive electroencephalograph assessment aid is a prescription device that uses a patient's electroencephalograph (EEG) to provide an interpretation of the structural condition of the patient's brain in the setting of trauma. A brain injury adjunctive interpretive EEG assessment aid is for use as an adjunct to standard clinical practice only as an assessment aid for a medical condition for which there exists other valid methods of diagnosis.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The technical parameters of the device, hardware and software, must be fully characterized and include the following information:
(i) Hardware specifications must be provided. Appropriate verification, validation, and hazard analysis must be performed.
(ii) Software, including any proprietary algorithm(s) used by the device to arrive at its interpretation of the patient's condition, must be described in detail in the software requirements specification (SRS) and software design specification (SDS). Appropriate software verification, validation, and hazard analysis must be performed.
(2) The device parts that contact the patient must be demonstrated to be biocompatible.
(3) The device must be designed and tested for electrical safety, electromagnetic compatibility (EMC), thermal, and mechanical safety.
(4) Clinical performance testing must demonstrate the accuracy, precision-repeatability and reproducibility, of determining the EEG-based interpretation, including any specified equivocal zones (cutoffs).
(5) Clinical performance testing must demonstrate the ability of the device to function as an assessment aid for the medical condition for which the device is indicated. Performance measures must demonstrate device performance characteristics per the intended use in the intended use environment. Performance measurements must include sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with respect to the study prevalence per the device intended use.
(6) The device design must include safeguards to ensure appropriate clinical interpretation of the device output (
e.g., use in appropriate patient population, or for appropriate clinical decision).(7) The labeling and training information must include:
(i) A warning that the device is not to be used as a stand-alone diagnostic.
(ii) A detailed summary of the clinical performance testing, including any adverse events and complications.
(iii) The intended use population and the intended use environment.
(iv) Any instructions technicians should convey to patients regarding the collection of EEG data.
(v) Information allowing clinicians to gauge clinical risk associated with integrating the EEG interpretive assessment aid into their diagnostic pathway.
(vi) Information allowing clinicians to understand how to integrate the device output into their diagnostic pathway when the device is unable to provide a classification or final result.