(139 days)
The firefly™ T-1 device is intended for the stimulation of healthy muscles in order to improve or facilitate muscle performance. The firefly™ T-1 device is not intended to be used in conjunction with therapy or treatment diseases of medical conditions of any kind.
The firefly™ T-1 device is a disposable, fully integrated neuromuscular stimulator for muscle conditioning composed of a constant current pulse generator with embedded software and battery enclosed in an over-molded plastic casing, and a silver electrode with a hydrogel coating which provides a means of attachment of the device and electrical contact with the patient. A single button controls the On/Off function and the intensity level of the device, which is achieved through changes in the delivered pulse width. The firefly™ T-1 is applied so that the electrodes lie over the common peroneal nerve behind the knee. Stimulation of the common peroneal nerve causes contraction of the calf muscles through the direct activation of the motor neurons, resulting in increased blood flow.
Here's an analysis of the acceptance criteria and supporting studies for the firefly™ T-1 device, based on the provided 510(k) summary:
This device is a Powered Muscle Stimulator, which typically focuses on performance characteristics rather than diagnostic accuracy like AI-powered imaging devices. Therefore, the traditional metrics of sensitivity, specificity, AUC, and multi-reader multi-case studies are not applicable in this context. Instead, the acceptance criteria relate to its functionality, safety, and effectiveness in stimulating muscles as intended.
1. Table of Acceptance Criteria and Reported Device Performance
Given the nature of a powered muscle stimulator, acceptance criteria are generally based on meeting industry standards for electrical safety, biocompatibility, and demonstrating the intended physiological effect. The document focuses on demonstrating substantial equivalence to a predicate device and proving its safety and effectiveness through non-clinical and limited clinical studies.
| Acceptance Criteria Category | Specific Criteria/Standard | Reported Device Performance (firefly™ T-1) |
|---|---|---|
| Electrical Safety | IEC 60601-1 | Complies |
| IEC 60601-2-10 | Complies | |
| IEC 60601-1-2 (EMC) | Complies | |
| Biocompatibility | ISO 10993-1 | All tests (cytotoxicity, dermal sensitization, dermal irritation, repeat dermal irritation) passed for hydrogel skin-contacting material, suitable for prolonged (up to 30 days) contact. |
| Software Verification | Moderate level of concern | All software requirement specifications met, all software hazards mitigated to risk level 1 (Accept). |
| Output Waveform | Net charge | 0 at all intensity settings (demonstrated via oscilloscope tracings). |
| Intensity Levels | 7 discrete levels (pulse widths 70us to 560us) | Device provides these 7 levels, allowing user control within comfort zone. |
| Shelf Life | 24 months (labeled) | Fully operational after 27 months of accelerated aging at 30°C. |
| Physiological Effect (Muscle Conditioning) | Significant increase in venous volume flow, blood flow velocity, microcirculatory flux (compared to control). | Tucker et al. study: Significant increases (p |
§ 890.5850 Powered muscle stimulator.
(a)
Identification. A powered muscle stimulator is an electrically powered device intended for medical purposes that repeatedly contracts muscles by passing electrical currents through electrodes contacting the affected body area.(b)
Classification. Class II (performance standards).