WiTOF

The WiTOF is a neuromuscular transmission (NMT) monitoring station used in operating rooms, recovery rooms, and intensive care units to measure neuromuscular blockade in adult patients receiving anesthetic agents. It uses electrical nerve stimulation and a three-dimensional accelerometer in a thumb splint to objectively and subjectively monitor the patient's muscle response and curare level.

Both devices use acceleromyography with surface electrodes and a thumb-mounted accelerometer sensor. The WiTOF differs by offering wireless data connection (versus cable connection in ToFscan) and performing 100 Hz tetanic stimulation (versus 50 Hz in the predicate). Both support TOF, PTC, ATP, DBS, and single-twitch stimulation modes with identical current output specifications (0–60 mA constant current, 200 microsecond monophasic pulses, maximum 300V).

IEC 60601-1 (general safety), IEC 60601-1-2 (EMC), IEC 60601-2-10 (specific safety for nerve stimulators), and ISO 10993-1 (biocompatibility). Software was evaluated as moderate-concern per FDA guidance on premarket submissions for software in medical devices.

The devices share identical product code (KOI), regulation (21 CFR 868.2775), and indication for use (NMT monitoring in adult patients under anesthesia). Both use the same acceleromyography principle with accelerometer sensors and surface electrodes. The wireless connection difference does not affect clinical performance per software verification and validation testing. The 100 Hz tetanic stimulation addition is supported by software testing and clinical literature showing it is standard practice. No new safety or effectiveness questions arise because the devices perform comparably in the same clinical conditions with the same user population.