(212 days)
Non-invasively monitoring of the laryngeal nerves during thyroid surgery, and of the Xth cranial nerve during skull-base surgery.
The Neurosign® Laryngeal Electrode, which was specially developed for use with the Neurosign® 100, 400 and 800 models, consists of: a single-use electrode constructed from medical-grade inks suspended in a polyester substrate; a connector made of polypropylene; and a cable assembly. The electrode is available in two sizes to suit different sexes and age groups. The 6/7mm electrode should be used with a 6 or 7mm endotracheal tube; the 8/9mm electrode should be used with an 8 or 9mm tube. The cable assembly is available separately and will have a long life if it is not abused and is stored appropriately.
Using the laryngeal electrode lowers the risk of damage to the laryngeal or Xth cranial nerve (the Vagus nerve) during thyroidectomy or parathyroidectomy and, since it is noninvasive, it also lessens the risk of infection during the monitoring procedure.
The Neurosign® Laryngeal Electrode is a device intended for intraoperative monitoring of laryngeal nerves during thyroid surgery and the Xth cranial nerve (Vagus nerve) during skull-base surgery. The device consists of a single-use electrode attached to an endotracheal tube, which then connects to a Neurosign® machine for EMG readout.
The submission does not contain specific acceptance criteria for performance metrics (like sensitivity, specificity, accuracy) of the device. Instead, the FDA's clearance is based on a determination of substantial equivalence to predicate devices. This means that the Neurosign® Laryngeal Electrode is considered as safe and effective as existing legally marketed predicate devices.
1. Table of Acceptance Criteria and Reported Device Performance:
Since this is a submission based on substantial equivalence, there are no predefined numerical acceptance criteria or reported performance metrics in the traditional sense (e.g., sensitivity, specificity, accuracy) as would be found in a clinical study evaluating diagnostic performance. The "acceptance" is based on the device having similar characteristics, intended use, and safety/effectiveness profiles to the predicate devices.
| Feature | Acceptance Criteria (based on predicate equivalence) | Reported Device Performance (Neurosign® Laryngeal Electrode) |
|---|---|---|
| Laryngeal surface electrode | Yes | Yes |
| Monitoring site | Trachea/larynx or Larynx/Oesophagus | Trachea/larynx |
| Monitoring type | Continuous EMG monitoring | Continuous EMG monitoring |
| Compatibility | May be used with commercial EMG units | Yes (implicitly, for Neurosign® 100, 400, 800 models) |
| Electrode attachment | Attached to surface or embedded within endotracheal tube | Attached to the surface of the endotracheal tube |
| Number of electrodes | 2 or 4 | 2 |
| Number of channels | 1 or 2 | 2 |
| Surface of electrode | Conductive materials (Stainless steel wire, Carbon w/Ag) | Conductive ink on a polyester substrate |
| Single-use only | Yes | Yes |
| Safety characteristics | Non-invasive | Non-invasive |
2. Sample size used for the test set and the data provenance:
This document does not describe a clinical study with a "test set" for performance evaluation in the typical sense of diagnostic or AI device studies. The clearance is based on substantial equivalence to existing devices. Therefore, there is no sample size for an independent test set or information on data provenance.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
Not applicable, as no clinical study with a "test set" requiring expert-established ground truth is described in this submission.
4. Adjudication method for the test set:
Not applicable, as no clinical study with a "test set" and adjudication is described.
5. 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:
Not applicable. This device is a laryngeal electrode for nerve monitoring, not an AI-powered diagnostic tool requiring human reader interpretation or MRMC studies.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
Not applicable. This device is a physical electrode used in conjunction with a nerve monitor, not an algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
Not applicable. The basis for clearance is substantial equivalence based on technical characteristics and intended use, not a clinical trial with a ground truth established by expert consensus or other clinical endpoints.
8. The sample size for the training set:
Not applicable. This device is a physical electrode, not a machine learning algorithm.
9. How the ground truth for the training set was established:
Not applicable. This device is a physical electrode, not a machine learning algorithm.
Summary of the "Study" (Basis for Acceptance):
The "study" or basis for acceptance in this 510(k) submission is a comparison to predicate devices to demonstrate substantial equivalence. The manufacturer, The Magstim Company Ltd., compared the Neurosign® Laryngeal Electrode to two predicate devices:
- Neurovision LSE500 Laryngeal Surface Electrodes (K003745)
- Medtronic NIM™ EMG Endotracheal Tube (K925640)
The comparison focused on technical characteristics, intended use, and safety features. The conclusion drawn by the manufacturer (and accepted by the FDA for clearance) is that the Neurosign® Laryngeal Electrode is "both safe and is similar in its risks and benefits, as well as its manner of performance, to the predicate devices." This substantial equivalence determination means the new device is considered as safe and effective as the predicate devices that are already legally marketed. No new clinical trials demonstrating specific performance metrics for the Neurosign® Laryngeal Electrode were necessary for this type of submission.
§ 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.