(90 days)
The Neurosign® V4 Intraoperative Nerve Monitor is intended for locating and identifying cranial and peripheral motor and mixed motor-sensory nerves during surgery, including spinal nerve roots.
Indications for Neurosign® V4 EMG Monitoring Procedures include: Intracranial, Extracranial, Extratemporal, Neck Dissections, Thoracic Surgeries, and Upper and Lower Extremities.
Indications for spinal procedures which may use Neurosign® V4 EMG monitoring include: Degenerative Treatments, Pedicle Screw Procedures, Fusion Cages, Rhizotomy, Orthopedic Surgery and Open and Percutaneous Lumbar Procedures.
The Neurosign® V4 Intraoperative Nerve Monitor (IONM) is a multi-channel nerve monitor designed for use in Ear, Nose and Throat (ENT) surgery and neurosurgery. The subject device differs from its primary predicate due to the introduction of improved Pre-amplifier and Stimulator pod cables, as well the addition of an 8-channel Pre-amplifier variant.
Using needle or surface electrodes connected to the Pre-amplifier, the nerve monitor detects electromyographic (EMG) signals within muscles caused by the contraction of the muscle due to mechanical manipulation or electrical stimulation of the nerve controlling it. The Neurosign® V4 then amplifies the EMG data into an audible signal and displays the data as a waveform on the active monitoring screen.
The Neurosign® V4 Intraoperative Nerve Monitor is used for patient treatment by prescription only under the supervision of a licensed physician.
The Neurosign® V4 is an integrated system consisting of a combination of hardware, software, and accessories.
The provided document is a 510(k) Premarket Notification from the FDA for the Neurosign® V4 Intraoperative Nerve Monitor. This type of submission is for demonstrating substantial equivalence to a legally marketed predicate device, not typically a study that establishes performance against discrete clinical acceptance criteria in the same way a PMA (Premarket Approval) submission would.
Therefore, the document does not contain a study with acceptance criteria and reported device performance in the typical sense of a clinical trial for a novel device. Instead, the "acceptance criteria" are compliance with various recognized standards and the "study" is non-clinical bench testing to demonstrate that modifications to an existing predicate device do not alter its safety or effectiveness.
Here's an analysis based on the information available:
1. Table of Acceptance Criteria and Reported Device Performance
| Criteria Category / Test | Acceptance Criteria (Method) | Reported Device Performance / Results |
|---|---|---|
| Electrical Safety / Mechanical Safety | ANSI/AAMI ES60601-1:2005/(R)2012 and A1:2012 - Medical electrical equipment - Part 1: General requirements for basic safety and essential performance | A sample Neurosign® V4 (4-Channel and 8-Channel Variants) was tested and found compliant with IEC 60601-1 by independent test laboratory Element Materials Technology. |
| Electromagnetic Compatibility (EMC) | IEC 60601-1-2: 2014 - Medical electrical equipment - Part 1-2: General requirements for basic safety and essential performance - Collateral standard: Electromagnetic compatibility - Requirements and tests | A sample Neurosign® V4 (4-Channel) was tested and found compliant with EN 60601-1-2 by independent test laboratory Eurofins Hursley. Non-clinical bench testing by Magstim confirmed no discernable difference in EMC performance of new cable design vs. old. |
| Alarm Systems | IEC 60601-1-8 - Medical electrical equipment - Part 1-8: General requirements for basic safety and essential performance - Collateral Standard: General requirements, tests and guidance for alarm systems in medical electrical equipment and medical electrical systems | A sample Neurosign® V4 was tested and found compliant with IEC 60601-1-8 by independent test laboratory Element Materials Technology. |
| Biocompatibility | ISO 10993-1:2009 - Biological Evaluation of Medical Devices - Part 1: Evaluation and testing within a risk management process; ISO 10993-5:2009 - Tests for in vitro cytotoxicity; ISO 10993-10:2010 - Tests for irritation and skin sensitization | The Neurosign®V4 Nerve Monitor itself does not contact the patient. The Stimulator Pod, Pre-amplifier, and connecting leads, which may contact the patient, had samples of their materials tested and found compliant with ISO 10993-1, ISO 10993-5, and ISO 10993-10 by an independent test laboratory. |
| Human Factors Testing / Usability Engineering | AAMI/ANSI HE75 - Human Factors Engineering - Design of Medical Devices; IEC 62366-1 - Medical Devices - Part 1: Application of Usability Engineering To Medical Devices | Usability testing was performed to analyze the user experience of the 8-Channel Neurosign® V4. The Human Factors Engineering report verifies the Neurosign V4, using the 8-channel pre-amplifier, to be safe and effective for the intended users, uses, and use environments. |
| Software Verification and Validation (V&V) | Software documentation for a "major" level of concern. Completion of software V&V testing according to specifications and risk mitigation in accordance with ISO14971. | Software verification and validation testing demonstrated that the software performs as intended and in accordance with specifications. Risks associated with the Neurosign® V4 were identified, assessed, and mitigated to an acceptable level per ISO14971. |
| Performance (Pre-amplifier & Stimulator Cables) | Demonstrated no discernable difference in isolation parameters and EMC performance compared to the old cable design. | Non-clinical bench testing performed by Magstim confirmed no discernable difference in the isolation parameters and EMC performance of the new cable design in comparison to the old. This testing specifically addressed the design changes to the Pre-amplifier and Stimulator Pod cables. |
| Performance (8-Channel Pre-amplifier vs. 4-Channel Predicate) | Substantial equivalence in function to the existing 4-channel pre-amplifier and secondary predicate device (Neurosign® 800) that already offers 8 channels. | The 8-channel Pre-amplifier is stated to be substantially equivalent, with the only difference being the addition of 4 extra electrode channels. Its functionality is supported by the existence of the secondary predicate (K053141) which also monitors up to eight separate neural pathways. |
2. Sample Sizes used for the Test Set and Data Provenance
This submission is based on non-clinical bench testing and does not involve human subjects as a "test set" in the sense of a clinical study.
- Electrical Safety, EMC, Alarm Systems, Biocompatibility: "A sample Neurosign® V4 (4-Channel and 8-Channel Variants)" or "A sample Neurosign® V4 (4-Channel)" or "Samples of these materials" were tested. The exact number of units/samples is not specified beyond "a sample" or "samples."
- Human Factors Testing: Not specified, but "Usability testing was performed to analyze the user experience of the 8-Channel Neurosign® V4." This typically involves a small group of representative users, but the size is not disclosed.
- Data Provenance: All testing appears to be retrospective relative to the design changes, commissioned by Magstim Company Ltd. and conducted by either Magstim or independent test laboratories (Element Materials Technology, Eurofins Hursley). The country of origin for the tests is not explicitly stated for all labs, but Magstim is a UK company.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This type of submission does not involve "ground truth" established by clinical experts in the context of diagnostic accuracy or treatment effectiveness. The "ground truth" here is compliance with recognized engineering and safety standards, as verified by independent test laboratories and Magstim's internal testing. The qualifications would be expertise in those specific standards and testing protocols, which are inherent to the testing bodies but not explicitly detailed for individual experts in this document.
4. Adjudication Method for the Test Set
Not applicable. This is not a clinical study requiring adjudication of clinical outcomes. The "adjudication" is essentially the determination of compliance with the specified standards by the testing bodies.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. This document does not describe a MRMC comparative effectiveness study. The device is an intraoperative nerve monitor, and the study focuses on its safety and performance based on engineering and safety standards, and its substantial equivalence to predicate devices, not on human reader performance with or without AI assistance.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
Yes, in a way. The testing described (electrical safety, EMC, alarm systems, biocompatibility, and software V&V) assesses the device's technical performance and safety characteristics in isolation, or as an integrated system, without necessarily involving a human-in-the-loop performance assessment of its diagnostic or treatment guidance capability in a clinical setting beyond usability testing for user experience. The "performance" mentioned for cables is also standalone bench testing.
7. Type of Ground Truth Used
The ground truth used in this context is:
- Compliance with recognized international and national standards (e.g., IEC 60601 series, ISO 10993 series for biocompatibility, AAMI/ANSI HE75, IEC 62366-1 for human factors).
- Performance specifications (e.g., isolation parameters, EMC performance, software functions) as tested against predefined engineering requirements.
- Usability metrics defined in the human factors engineering report.
8. Sample Size for the Training Set
Not applicable. This device is not an AI/ML algorithm that requires a "training set" in the computational sense. It is a hardware medical device with embedded software. The software underwent verification and validation, but this refers to traditional software testing, not AI model training.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no AI/ML training set in this context.
§ 874.1820 Surgical nerve stimulator/locator.
(a)
Identification. A surgical nerve stimulator/locator is a device that is intended to provide electrical stimulation to the body to locate and identify nerves and to test their excitability.(b)
Classification. Class II.