g.Estim FES: Specs & Features

fully programmable constant-current electrical stimulator for functional electrical stimulation

Functional Electrical Stimulation (FES)

The g.Estim FES is a constant-current, biphasic electrical stimulator intended for powered muscle stimulation. g.Estim FES has an applied part of type BF with connectors for bipolar stimulation electrodes (anode and cathode). The device is controlled by a computer via USB connection. It also has digital outputs for synchronization with other devices. An optional hand-switch allows you to perform stimulation manually. Alternatively, an optional foot-switch can be used to explicitely enable/disable stimulation. g.Estim FES includes an impedance measurement function and contains a high-impedance stop mechanism that stops stimulation when electrode contact becomes loose.

The g.Estim FES is intended for temporary relaxation of muscle spasms, prevention or retardation of disuse atrophy, increasing local blood flow in the treatment area, muscle re-education, prevention of post-surgical phlebo-thrombosis through immediate stimulation of calf muscles, maintaining or increasing range of motion.

Therapeutic use of g.Estim FES

The indication for usage of the g.Estim FES for muscle stimulation is given when muscles of the body that are partly or fully paralyzed due to injury to the central nervous system should be contracted to generate movement. This is the case for example in patients with stroke, spinal cord injury, multiple sclerosis, or cerebral palsy, where rehabilitation programs or assistive devices such as orthoses are indicated that aim for recovery or substitution of the impaired function.

For closed-loop experiments, g.USBamp, g.HIamp or g.Nautilus with g.HIsys is used to record EEG/ECoG data, perform real-time analysis and to control the g.Estim PRO for cortical stimulation.

Product Highlights

  • Delivers bi-phasic constant current pulses
  • Stand-alone device that can be controlled from a computer system
  • Can send triggers to other devices for synchronization
  • Includes electrode impedance check and stimulation current monitoring
  • CE-certified and FDA-cleared medical device for use in human

Product details

The hand switch is an accessory of the g.Estim FES. Users connect the hand switch to the hand/foot switch input of the g.Estim FES. The hand switch allows them to start stimulation by pressing the blue STIMULATE button after the device has been set active via the software and the 'active' LED is on. During stimulation, the hand switch allows users to abort stimulation by pressing the grey ABORT button.
The foot switch is another accessory of the g.Estim FES and can be connected to the hand/foot switch input of the g.Estim FES. When the foot switch is used and pressed, the stimulator accepts a cue to start stimulation from the software or from devices connected to the digital input ports. When the foot switch is released, stimulation is aborted.
Stimulation electrodes are used as medium between the stimulator and the tissue to be stimulated.
The g.Estim FES Simulink Interface contains a g.Estim FES block which controls the connected g.Estim FES electrical stimulator for research applications. Use the sliders to change phase amplitude and duration while stimulation. A manual switch is used to start and stop stimulation. This allows to realize close-loop experiments with g.USBamp, g.HIamp or g.Nautilus. The model needs g.HIsys Highspeed Online Processing for SIMULINK.

Every device that is found is listed with its serial number in the drop-down box at the left side of the panel. Via the drop-down box, another connected device can be selected. As soon as a device is selected an initial self-test is executed on the device to assure correct functionality. During the self-test, the LED indications of the device are switched on and off. Passing this test is crucial for a safe and accurate operation of the device. The button Refresh updates the device list when a new device was connected to the computer since the software was started. The button Selftest repeats the self-test for the selected device. The button Device Info displays information about the selected device, like its hardware and firmware versions.The battery gauge at the very right side displays the battery charge of the selected device.

In the second line of the group it is possible to select whether the optional accessories hand switch or foot switch should be used in the stimulation session.

  • When Software only control is selected, the g.Estim FES is solely controlled by the user interface application.
  • The hand switch allows users to start stimulation by pressing the STIMULATE button after the device has been set active via the software and the ‘READY’ LED is on. During stimulation, it allows users to abort stimulation by pressing the ABORT button.
  • When the foot switch is pressed, the stimulator accepts starting stimulation from the software. When the foot switch is released, stimulation is aborted and it is not possible to start.

The Settings group summarizes the settings for the stimulation session. There is a simple structure of Work times and Rest times that divides the delivery of the stimulation with resting periods. The Ramp up time and the Ramp down time is the amount of time it takes the stimulation to ramp up to full intensity at the beginning of the work period and to ramp down at the end of the work period, respectively. The Pulse rate per second specifies how many individual stimulation pulses per second are presented during the work time. The Phase length is the duration of each of the individual phases within a biphasic pulse. The No of trains field allows for specifying the number of delivered work/rest periods in the stimulation session.

By delivering only biphasic pulses, the g.Estim FES assures that a stimulation pulse is balanced and there is no DC component. This means that during a stimulation session, there is no residual aggregation of energy at the electrode site. A safety feature of the g.Estim FES is the high-impedance detection that monitors the correct connection of the electrodes to the user.

Available configurations


product no.: 0155 read more g.Estim FES Simulink Interface — provides a graphical interface to the g.Estim FES hardware, which can be used under Simulink to specify the properties of the electrical stimulator; intended to be used for research applications only; requires g.tec Highspeed Online Processing, MATLAB, Simulink and Signal Processing Toolbox.

Hardware and Accessories

product no.: 1160 read more g.Estim FES: Specs & Features — functional electrical stimulator, one channel (for one muscle), battery powered, USB controlled, programmable; symmetrical AC output with amplitudes up to 60mA and pulsewidth between 0 and 1ms; can be triggered from g.Estim FES Simulink Interface or used as stand alone product (Parameter tuning: current, pulse width, ramp up and down)

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