EVE Synergy (EVE-20M)

The EVE Synergy (EVE-20M) is an electrical muscle and nerve stimulator device with two modes: EMS (electromuscular stimulation) for muscle relaxation, atrophy prevention, blood circulation, muscle re-education, and range-of-motion maintenance; and TENS (transcutaneous electrical nerve stimulation) for chronic and post-surgical/post-trauma pain relief. The device consists of a console with LCD touchscreen, handpieces (Synergy and Pro models), interchangeable tips, and power supply.

The subject device delivers symmetrical biphasic rectangular waveforms at 3–200 Hz with regulated voltage and current limiting. EMS output is 34–48V depending on load impedance with 68 mA maximum current at 500Ω and pulse widths of 100–155 μs. TENS output is 10V with 20 mA maximum current at 500Ω and pulse widths of 100–150 μs. It has 3 output channels (vs. 6 on primary predicate), a 24V power supply (vs. 48V on predicates), and a temperature sensor that auto-shutoff at 43°C skin surface temperature. It lacks a patient override control present in predicates.

IEC 60601-1:2005/A2:2020 (basic safety and essential performance); IEC 60601-1-2:2014/A1:2020 (electromagnetic compatibility); IEC 60601-2-10:2012/A2:2023 (nerve and muscle stimulator requirements); ISO 14971:2019 (risk management); IEC 60601-1-6:2010/A2:2020 (usability); IEC 62304:2015 (software); ISO 10993-1 (biocompatibility).

The subject device uses identical EMS and TENS technology, intended uses, and design principles as the predicate devices (EVOLVE System with T3 and Tone Applicators). Although minor differences exist in number of channels (3 vs. 2–6), power supply voltage (24V vs. 48V), console dimensions, weight, and output voltage/current ranges, all performance specifications are within or comparable to those of predicates. Output waveforms, frequencies, pulse shapes, and power/current densities are similar or fall within predicate ranges. Maximum current density (1.31 mA/cm² in EMS, 0.83 mA/cm² in TENS) remains below the IEC 60601-2-10 safety limit of 2 mA/cm², and maximum power density is comparable to predicates. Comprehensive testing to IEC 60601-1, 60601-2-10, and 62304 confirms design specifications and safety margins equivalent to predicates. Biocompatible materials (SUS 304, polycarbonate) are identical to those previously cleared. These differences do not raise new safety or effectiveness questions.