Synchrony (20-3000)

The Synchrony (20-3000) is a functional electrical stimulation (FES) and neuromuscular electrical stimulation (NMES) device designed to improve hand function and range of motion in adult patients (≥22 years) with arm paralysis or paresis caused by upper motor neuron injury such as stroke or C5 spinal cord injury. The system consists of a battery-powered stimulator, wireless sensor, patient interface electrodes, motor point probe, and clinician app; therapy is programmed by a clinician and applied by the patient at home.

Synchrony uses balanced biphasic rectangular waveforms with regulated current output, delivering stimulation through 1–4 electrodes at preset amplitudes of 20, 40, or 60 mA with pulse widths programmable from 1–250 microseconds at 32–37 Hz. It incorporates a wireless sensor using a Class I laser compliant with 21 CFR 1040.10/1040.11 for hand motion feedback, and supports three therapeutic modes: contralaterally controlled electrical stimulation (CCFES), cyclical NMES, and functional task practice (FTP). The device is battery-powered, wirelessly charged, and constructed from biocompatible ABS Cycoloy with IP22 ingress protection.

IEC 60601-1:2020, IEC 60601-1-2:2020, IEC 60601-1-6:2020, IEC 60601-1-11:2020, IEC 60601-2-10:2016, IEC 62304:2015, ISO 14971:2019, ISO 10993-1:2018, ISO 10993-5:2009, ISO 10993-10:2021, ISO 10993-23:2021, IEC 60825-1:2014, IEC 62366-1:2020, IEC 62133-2:2021, ASTM D4169:2022, AAMI ST98:2022, ANSI C63.27:2017, 47 CFR Part 15 Subpart B:2023, AAMI TIR57:2019, AAMI TIR97:2019, ASTM F899-20:2023.

Synchrony is substantially equivalent to the Bioness H200 predicate because both are battery-operated FES/NMES stimulators with identical indications for use, both use clinician applications to program patient therapies, and both employ wireless control mechanisms—though Synchrony's hand-opening sensor replaces H200's trigger switch. The Motor Point Probe is supported by comparison to the EMS-2C predicate, a powered muscle stimulator with similar probe design. Despite minor technological differences (programmable vs. preset pulse width, single output mode vs. multiple modes), these variations do not raise new safety or effectiveness concerns because Synchrony's output parameters (voltage, current, current density, frequency) remain within safe limits established by predicate devices and comply with IEC 60601-2-10 for nerve and muscle stimulators.