Model note · EEG
Cadwell Arc EEG platform
Arc is Cadwell's EEG software platform, used with a family of amplifiers: the Essentia E1 for routine EEG, the 32 channel E2 for long term and epilepsy unit monitoring, E3 for ICU brain monitoring, the Alterna ambulatory recorder, and the high channel Zenith amplifier for intracranial EEG and cortical stimulation mapping. Essentia amplifiers connect to the PC by a single USB cable, with optional remote input boxes, cameras and a USB photic stimulator. A Zenith system cascades up to four 144 channel amplifiers and adds an IOMAX base module and optional cortical stimulator module behind a built in switch matrix.
The model
Maker, model and type.
- Maker
- Cadwell Industries, Inc.
- Model
- Arc EEG platform with Essentia (E1, E2, E3) and Zenith amplifiers
- Device type
- EEG
- Main document
- Open the public document
Key specifications
What the public record says.
| Item | Value | Source |
|---|---|---|
| Essentia E2 amplifier | 32 EEG channels with seven active and reference pairs; storage rates up to 2000 Hz | Source |
| Essentia storage rates by model | 250 and 500 Hz on all Essentia models; 1000 and 2000 Hz on E2 and E3 | Source |
| Essentia PC connection | Single USB cable; photic stimulator also USB powered and controlled from the software | Source |
| Zenith channel count | 144 channels per amplifier (144 referential, 8 differential, no DC channels); up to four amplifiers, 576 channels | Source |
| Zenith input impedance and noise | 1 Gohm; below 1.5 uV peak to peak (0.1 to 100 Hz) | Source |
| Zenith input range and DC offset | Above 25 mV peak to peak signal range; DC offset tolerance beyond plus or minus 500 mV | Source |
| Zenith CMRR | Above 110 dB at 60 Hz | Source |
| Zenith digitising | 24 bit; 1 MHz sampling with storage rates up to 8 kHz | Source |
| Zenith FDA clearance | K181466, Cadwell Zenith System, product code GWQ (secondary GYC, GWF, ETN); predicates Natus Quantum (K143440, K180181) and Cadwell Cascade IOMAX (K162199) | Source |
| IOMAX Cortical Module (Zenith option) | 16 channel amplifier and low current constant current stimulator, 0.01 to 20 mA, one output pair | Source |
Recalls
Known FDA recalls.
- Z-0141-20272026-08-18
IOMAX Cortical Module (190296-200): defective PCBA after a supplier change may deliver unintended stimulation or current; risk stated as specific to the Cascade Surgical Studio host, but all affected modules recalled because they can move between Zenith, Arc and CSS.
FDA record - Z-2349-20242024-05-17
Class 2: Cascade IOMAX Cortical Module may contain a defective PCB that can damage internal parts and cause unintended stimulation; 26 units.
FDA record - Z-1882-20242024-04-23
Class 2: Cascade IOMAX Cortical Module insulator may be installed incorrectly, risking arcing to patient connections and shock; 54 units.
FDA record
Safety
Safety warnings from the record.
- Zenith is to be used by or under the direction of a licensed physician, surgeon or neurologist in a professional healthcare setting. Source
- Zenith relays stimulation signals to the patient through its switch matrix, and affected IOMAX Cortical Modules were recalled because they could deliver unintended stimulation or current. Source
- Do not use a Cortical Module named in recall Z-1882-2024 until returned and corrected, because of the risk of arcing and shock at patient connections. Source
Sources
Where this note comes from.
- Cadwell Arc Essentia E2 brochure, PN 100870-937 Rev 00
- Cadwell Essentia E3 flyer, PN 100870-938-E3 Rev 03
- FDA 510(k) K181466 summary, Cadwell Zenith System
- openFDA recall record Z-0141-2027, IOMAX Cortical Module
- openFDA recall search, Cadwell
Not covered: Cadwell sells the Arc Essentia technical manual on CD or USB and no original copy was publicly reachable, so there are no amplifier input specifications for Essentia (impedance, noise, CMRR), no error messages, troubleshooting steps or maintenance intervals; errorCodes is empty. No 510(k) summary for the Essentia amplifier itself was found (its GUDID record lists no premarket number), so Essentia figures come only from Cadwell brochures dated 2015 to 2017. Zenith figures come from the K181466 summary. The recalls are for the IOMAX Cortical Module, an optional part of the Zenith system; none names the Essentia amplifiers. The 2026 recall record page could not be opened directly, so the openFDA record was used. MAUDE holds too few Arc or Zenith reports to show a trend.
BMEssentia knowledge drafted from public information, reviewed by Hasan Khaled Ismail on 2026-10-24. Always follow the manufacturer's instructions for use and service manual.