(177 days)
The NuFACE Trinity is intended for facial and neck stimulation and is indicated for over-the-counter cosmetic use.
The NuFACE Trinity Device(proposed) is intended for facial and neck skin stimulation and is indicated for over-the-counter cosmetic use. It is identical to that of its NuFACE Plus (predicate) and its technological characteristics remain unchanged. It produces microcurrent discharged through the two spherical probes.
Here's an analysis of the provided text regarding the acceptance criteria and study for the NuFACE Trinity Device:
1. Table of Acceptance Criteria and Reported Device Performance
The FDA 510(k) summary for the NuFACE Trinity Device does not present typical "acceptance criteria" in the sense of performance metrics with specific thresholds (e.g., sensitivity > X%, specificity > Y%). Instead, it establishes substantial equivalence to a predicate device (NuFACE Plus). The primary "acceptance criteria" appear to be that the proposed device (NuFACE Trinity) is identical in technological characteristics and performance standards to the predicate device, with an expanded intended use to include the neck.
The table presented is a "Substantial Equivalence Comparison Table" which compares the proposed NuFACE Trinity Device to its predicate, the NuFACE Plus. The performance is "reported" by asserting that the devices are critically similar or identical in most technical specifications.
| Characteristic | Acceptance Criteria (based on Predicate) | Reported Device Performance (NuFACE Trinity) | Result/Comment |
|---|---|---|---|
| Intended Use | Facial stimulation for cosmetic use. | Facial and neck stimulation for cosmetic use. | Different (expanded to include neck), but deemed substantially equivalent. |
| Anatomic Sites | Face | Face and Neck | Different (expanded to include neck), but deemed substantially equivalent. |
| Technological Characteristics | Microcurrent, materials (injection molded thermoplastic resin, chrome-plated spheres), lithium-ion battery, biphasic square wave, 10 positive/10 negative pulses, alternating microcurrent, adjustable output, conductive gel requirement, 5-second usage cue. | Identical to predicate. | Same |
| Product Safety (IEC 60601-1) | Compliance with IEC 60601-1. | Compliance with IEC 60601-1. | Same (Based on non-clinical testing and assertion of identity to predicate). |
| EMC (IEC 60601-1-2) | Compliance with IEC 60601-1-2. | Compliance with IEC 60601-1-2. | Same (Based on non-clinical testing and assertion of identity to predicate). |
| FDA Performance Standards (21 CFR 898) | Compliance with 21 CFR 898. | Compliance with 21 CFR 898. | Same (Based on non-clinical testing and assertion of identity to predicate). |
| Power Source | Internal rechargeable Lithium ion battery. | Internal rechargeable Lithium ion battery. | Same |
| Output Waveform | Pulsed Biphasic, Modulated Square. | Pulsed Biphasic, Modulated Square. | Same |
| Maximum Output Voltage | 28 VDC. | 28 VDC. | Same |
| Maximum Output Current | 400 μA @ 500Ω. | 400 μA @ 500Ω. | Same |
| Maximum Output Current Density | 0.419 mA/cm². | 0.419 mA/cm². | Same |
| Pulse Width | 60 msec. | 60 msec. | Same |
| Frequency | Approximately 8.3 Hz. | Approximately 8.3 Hz. | Same |
| Other Output Specs (Burst Mode, ON/OFF Time, etc.) | Identical to those of the predicate. | Identical to predicate specifications. | Same (Specifically: Pulses per burst 20, Pulses per second 8.3, Burst duration 2.4s, Duty Cycle 20.2s, ON Time 60msec, OFF Time 60msec). |
2. Sample Size Used for the Test Set and Data Provenance
The document states: "Literature provided and usability studies conducted demonstrate that the device is substantially equivalent to the predicate given the new indications." This implies that some form of usability study was performed for the new indications (neck stimulation). However, the document does not specify the sample size for any test set, nor does it provide details on the data provenance (e.g., country of origin, retrospective or prospective nature). The primary reliance is on the device being identical to the predicate from a technical standpoint.
3. Number of Experts and Qualifications for Ground Truth
The document does not mention any experts being used to establish ground truth for a test set in the traditional sense of clinical performance evaluation. The "ground truth" for substantial equivalence rests on the comparison of specifications and the assumption that the predicate device (NuFACE Plus) already established its safety and effectiveness.
4. Adjudication Method
There is no mention of an adjudication method for a test set. This type of method is typically used in studies where human readers evaluate cases and their discrepancies are resolved. Since this submission relies on substantial equivalence through technical and functional identicality, such a method does not apply here.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was done as described. The submission focuses on substantial equivalence of a new device (NuFACE Trinity) to an existing one (NuFACE Plus), not on improving human reader performance with AI assistance. The device itself is an electrical stimulator, not an AI-powered diagnostic tool.
6. Standalone Performance Study
A standalone performance study (algorithm only performance without human-in-the-loop) was not explicitly done or reported in the traditional sense. The "performance" assessment focuses on the identical nature of the NuFACE Trinity to the NuFACE Plus in terms of electrical output, safety, and EMC. The non-clinical testing for electrical safety, EMC, and biocompatibility, as well as the usability studies, implicitly serve as a standalone performance assessment to demonstrate that the expanded use (neck) is safe and effective when delivered by an identical device.
7. Type of Ground Truth Used
The "ground truth" in this context is the established safety and effectiveness of the predicate device (NuFACE Plus), as accepted by the FDA when it was cleared (K103472). The submission's argument for the NuFACE Trinity is that its identical technological characteristics and performance standards mean it also meets those same safety and effectiveness criteria, even with the expanded anatomical site (neck), which was further supported by usability studies.
8. Sample Size for the Training Set
The document does not mention a training set sample size. This is because the device is not an AI/machine learning device that requires a training set for model development. The approval pathway is an equivalence pathway, not one that requires de novo clinical validation with training and test sets for an algorithm.
9. How Ground Truth for the Training Set Was Established
As there is no training set for an AI/ML algorithm for this device, there is no ground truth established for a training set. The entire premise is based on the previously cleared predicate device.
§ 882.5890 Transcutaneous electrical nerve stimulator for pain relief.
(a)
Identification. A transcutaneous electrical nerve stimulator for pain relief is a device used to apply an electrical current to electrodes on a patient's skin to treat pain.(b)
Classification. Class II (performance standards).