ESTIMPRO

g.Estim PRO includes an integrated electrode impedance check and monitors the applied stimulation current and voltage, allowing stimulation conditions to be verified during use. Stimulation sessions can additionally be reviewed with StimLogViewer, including stimulation sites, current amplitudes, timing and system states.

g.Estim PRO provides digital outputs for synchronization with external equipment. In integrated g.tec workflows, stimulation can be synchronized with electrophysiological acquisition using g.HIamp or g.USBamp. This enables stimulation events to be related to recorded EEG/ECoG activity and incorporated into real-time experimental workflows.

Yes. g.Estim PRO can be combined with the g.Estim PRO Switching Unit and g.HIamp to create an integrated stimulation and electrophysiological recording system. The Switching Unit provides programmable electrode routing for up to 256 channels, allowing selected cortical electrodes to be routed between stimulation and recording pathways. The setup enables cortical activity to be recorded between and during stimulation.

This architecture has also been used in published intraoperative research. Noll et al. used g.Estim PRO, the Switching Unit, a 256-channel g.HIamp and g.HIsys in a real-time ECoG and direct cortical stimulation language-mapping workflow.

The Switching Unit completes electrode switching within 6 ms after a digital trigger and provides a digital output indicating the switching state, enabling the switching event to be recorded together with the electrophysiological signals.

Yes. The g.Estim PRO research software upgrade provides programmatic control of stimulation parameters. Together with g.HIsys, g.Estim PRO can be controlled from the MATLAB/Simulink environment and integrated with g.HIamp or g.USBamp for real-time EEG/ECoG acquisition, signal processing and stimulation control. Signal parameters or classification results can therefore be incorporated into closed-loop research workflows.

Yes. g.Estim PRO can be integrated with g.HIamp, g.HIsys and the g.Estim PRO Switching Unit for stimulation and intracranial electrophysiological recording workflows used in CCEP and functional connectivity research. Programmable electrode routing allows stimulation and recording configurations to be changed systematically across implanted electrodes, while electrophysiological responses can be acquired and processed within the same g.tec ecosystem.

g.Estim PRO is a programmable constant-current cortical stimulator with a stimulation range of 0.2–15 mA, 10 µA current resolution and an accuracy of ±10% or ±50 µA, whichever is greater. It provides a maximum electrode output of ±80 V DC and rectangular stimulation phases from 0.1–1.0 ms in 10 µs increments, with an accuracy of ±10% or ±20 µs, whichever is greater. Pulse rates can be configured from 2–100 pulses/s with 0.1 pulses/s resolution, pulse onset intervals from 10–500 ms, and train durations from 1 pulse to 20 seconds. The inter-phase duration is 0 ms.

The voltage required to maintain the programmed current depends on electrode-tissue impedance according to U = I × R. g.tec recommends an electrode-tissue impedance below 5 kΩ. For loads below 5 kΩ, specified rise and fall times are <5 µs; for loads between 5 and 800 kΩ, the specified relationship is tr = tf < Rload × 1 ns.

g.Estim PRO provides two digital outputs, DO1 and DO2, for synchronization with g.HIamp, g.USBamp and compatible external equipment. In g.HIsys research workflows, digital outputs can be configured for TRAIN, PULSE or PHASE triggers, with programmable pre- and post-trigger timing. Hardware-triggered stimulation of up to 250 Hz is supported in the documented g.HIsys workflow.

With the g.Estim PRO Switching Unit, a rising or falling digital-input edge results in completed electrode switching within 6 ms, while the minimum Active State is 1 ms. In the documented g.HIsys Fast Stimulation configuration, the shortest achievable combined switching and stimulation-onset delay is approximately 13 ms. For Stimulate-and-Record workflows, a pre-trigger of at least 6 ms allows electrode switching to complete before stimulation begins.

The Switching Unit supports up to 256 electrode channels, a maximum stimulation voltage of 80 V, maximum stimulation current of 15 mA and maximum stimulation frequency of 500 Hz.

g.Estim PRO provides DO1 and DO2 digital outputs with high-level voltages of 2.4–3.3 V DC and low-level voltages of 0.0–0.4 V DC. DI1 uses high-level voltages of 2.0–5.0 V DC and low-level voltages of 0.0–0.8 V DC. Trigger-output cables use a push-pull connector to BNC and have a length of 1 m. The PC interface is USB with an operating range of 4.75–5.25 V DC.

For research applications, g.HIsys provides MATLAB/Simulink integration and the

gEstimPRO_ParameterUpdate()

function. Programmatically controllable parameters include phase amplitude, phase duration, pulse rate, number of pulses, polarity, modality, fade-in/fade-out parameters, digital-output mode, pre- and post-trigger timing, electrode surface area, Start/Abort and Active/Stop. Most parameter changes are transmitted immediately and become effective with the next stimulation, while phase amplitude and phase duration can take effect immediately under the documented conditions.

For the Switching Unit, the digital input uses 2.0–3.3 V high and 0.0–0.8 V low, with a minimum trigger duration of >200 µs. Its digital output indicates the active switching state and can be recorded by g.HIamp for precise synchronization.

In g.HIsys ECS workflows, separate post-processing files can be generated for each stimulation site containing the acquired electrophysiological data, stimulation-site information, stimulation-onset triggers and stimulator state. StimLogViewer can additionally be used for reviewing stimulation-session information.

g.Estim PRO is a Class II medical electrical device with a Type BF, galvanically isolated applied part, IP40 protection and S1 continuous operating mode. EMC compliance includes IEC 60601-1-2, and the device requires periodic technical inspection every 12 months according to EN 62353:2014.

Operating conditions are +10 to +35 °C, 20–80% relative humidity, non-condensing, and 800–1060 hPa atmospheric pressure. Transport and storage conditions are −20 to +60 °C, 10–95% relative humidity and 700–1060 hPa.

The system uses 2 × 9 V lithium batteries plus USB, with rated power consumption of 1.75 VA via USB and 3.6 VA via battery. The documented PC configuration includes USB 3.0, Windows 11 Pro 64-bit, at least 8 GB RAM, more than 100 GB storage and an Intel processor with at least two cores at 2.30 GHz.

g.Estim PRO is CE marked, identified as a prescription device in the USA, carries UDI information and is classified as Class II electrical protection with a Type BF applied part. The product documentation references IEC 60601-1, IEC 60601-1-2, IEC 60601-2-40, IEC 62304, IEC 62366, ISO 14971 and EN 62353.

For simultaneous cortical stimulation and electrophysiological recording, the g.Estim PRO Switching Unit additionally specifies a ±340 mV channel input range, AC coupling from 0.16–70 kHz, ≤−70 dB channel crosstalk, ≤6 µV peak-to-peak input-referred noise from 0.5–50 Hz at 256 Hz sampling, typical noise of <1 µV RMS from 1–30 Hz, and calibrated channel offset of <±50 µV.

For tenders, I would still add EU MDR classification, CE/Notified Body certificate identifier, FDA 510(k) number, Basic UDI-DI, device dimensions, weight and battery runtime once these values have been confirmed internally.