Patch-TEA (Model TRI-21)

The Patch-TEA (Model TRI-21) is a battery-operated, over-the-counter transcutaneous electrical nerve stimulator for adults to provide temporary pain relief from sore and aching muscles in the shoulder, waist, back, neck, arm, and leg caused by strain from exercise or household work. The system includes the device, charging case, electrode pads, USB cable, and a smartphone app for control and adjustment of treatment time (5–240 minutes) and intensity.

The device uses a rechargeable lithium polymer battery, microprocessor-controlled biphasic rectangular waveform output, frequency of 1–50 Hz, pulse width of 50–750 microseconds, maximum voltage of 5–55 V depending on impedance, and single-channel output with safety features including automatic shut-off, overload, overcurrent, and no-load protection. Electrode design uses reusable, round-shaped, self-adhesive conductive hydrogel pads. Key output parameters (maximum current, charge per phase, average current and power density) are similar to the predicate device K212377.

IEC 60601-1-2:2014 (electrical safety), IEC 60601-2-10 (nerve stimulator safety), IEC 62133-2:2017 (lithium battery systems), ANSI/AAMI/IEC 62304:2006+A1:2016 (software life cycle), ANSI/AAMI/ISO 14971:2019 (risk management), IEC 60601-1-6:2020 (usability), ISO 10993 series (biocompatibility), FCC 47 CFR Part 15 Subpart C (radio frequency devices), and AAMI TIR57:2016 (device cybersecurity).

The subject device has identical indications for use, mode of action, and principle of operation as the predicate (K212377). Technological characteristics are substantially equivalent: both use rechargeable batteries, biphasic waveforms, single-channel output, and similar safety mechanisms. Although the subject device has a smaller battery capacity and slightly smaller electrode dimensions, these differences do not raise safety or effectiveness concerns because similar maximum average current density and maximum average power density are maintained, which are the primary determinants of therapeutic effect. Verification and validation testing confirmed compliance with recognized consensus standards equivalent to the predicate.