FAQs

ExG is a term used to summarize all electrograms: EEG, ECG, EMG, EOG, and EGG. Whatever ExG you are using, Mentalab has the appropriate caps, electrodes, and cables. In fact, depending on your set-up, a single Mentalab Explore system can handle different electrograms simultaneously, as long as they use a shared reference.

Combining ECG and EEG recording is possible. However, both electrograms must share the same reference electrode, which may affect EEG signal quality. To minimize this effect, put the ground electrode on the scalp (not chest) and measure ECG with respect to that. The remaining cross talk will be:
10Hz input : -64dB
25Hz input : -75dB

Yes, our Clip9 and Clip5 cables can connect to standard stick and peel electrodes as long as they have a little conductive knob on the back.

The internal memory of your Explore+ amplifier is full. The Explore+ amplifier will refuse to record any more data while its memory is full. To solve this, either transfer the data from your Explore+ amplifier to a computer, or double click your Explore+ amplifier. Double-clicking the button will delete the internal memory of your Explore+ amplifier and allow you to start recording. See our Light Guide and Button Guide for more.

Recorded files are saved in the current command line folder. The default locations are:

• Windows: C:\Users\USER_NAME
• Ubuntu: /home/USER_NAME
• Mac OSX: /Users/USER_NAME

Yes, LabChart Lightning can perform custom calculations like this live. This cannot be done in explorepy directly, but it can be achieved with basic post-processing. Simply subtract the signal of the second reference channel from the subset of other channels. As a result, the values for these other channels will look as if they were recorded against the second reference.

Choose a XS, XS/S, or S cap, as there is a lot of variability between infants. Remove the chin strap for added comfort, and use tights, stretched out over EEG cap, to keep electrodes in place if need be. For more on infant EEG research, check out our blog post on the subject.

Unfortunately, we cannot help with data processing, as this is the responsibility of the research group. However, we can provide resources as needed. For instance, have a look at Artifact Subspace Reconstruction and automated correction methods like this. For more information on noise removal, check out our blog post on the subject.

With ease! Simply subtract your second reference channel from the other channels. This can be done in OpenViBE or a Python script. For more, please reach out to us at support@mentalab.com

The internal storage has 512MB. When recording with 8 channels, you can record for the following times:
~13.7 hours at 250 Hz
~8.8 hours at 500 Hz
~3.98 hours at 1 kHz

ExG data is recorded at 250/500/1000 Hz (users' choice), but visualized at 125 Hz; orientation data is both recorded and visualized at 20 Hz.

ADS applies a 3rd order sinc filter as an anti-aliasing filter. The cut-off frequencies depend on the sampling rate.

The accelerometer measures gravitational acceleration (G: ~9.8 m/s/s) and the amplifier's relative acceleration. Most of the time, the acceleration of the amplifier relative to G is tiny, which means one accelerometer line will be offset by G. Which of the three lines is offset depends on the orientation of the amplifier.

The magnetometer is a piezoelectric sensor. To be more explicit, Mentalab Explore+ has a built-in magnet which, like a compass, measures the external magnetic field applied to it. Earth's magnetic field creates a coordinate system that moves with the amplifier (since the magnetometer is located in the amplifier). We are interested in the orientation of this magnetic field so that we can build a fixed coordinate system.

Yes. The Mentalab Explore+ amplifier is always DC-coupled. However, do note that its working range is ±400mV.

The LED color and blinking pattern convey relevant information about your amplifier's status. A complete list can be found in our LED Light Guide.

The single button can be used to send a number of commands to the amplifier. A complete list of button commands can be found in our Button Command Guide.

A full charge takes about 2 hours depending on the charger and environmental conditions.

If you leave your Explore+ amplifier plugged in when it is fully charged, there will be some decline in its battery capacity. We recommend unplugging your amplifier after each full charge, which normally takes 2 hours. If your battery has declined so much that it is unusable, please contact us at support@mentalab.com and we can repair or replace your amplifier's battery.

explorepy our free in-house software, offers a feature that will indicate impedance values for individual channels to verify good signal quality before you start recording.

If you want synchronize data streams from different hardware components, we recommend using software platforms specifically designed for this. explorepy can push data to lab streaming layer and LabChart Lightning has built-in multi amplifier support.

Yes, if you use LabChart Lightning. Other software solutions support multiple amplifiers but it requires a few additional steps. A step-by-step guide using explorepy, lab streaming layer, and Openvibe can be found under the Integrations section.

Our dry electrodes are made of a conductive carbon-filled polymer with AgCl-coating. This material feels similar to soft rubber. The combination provides high comfort with great conductivity.

The life expectancy of your equipment depends on how you care for it. Under optimal conditions, you can use your materials for 10 years or longer. We provide a 2 year warranty on both cables and electrodes, and have tested these components for 200 sessions without degredation.

The Mentalab Explore+ system combines REF and GND electrodes into a single channel. This is possible because the amplifier is so mobile, which means it doesn't draw heavy noise from the power line. Since we have short cable lengths, we can afford not to use a bias current and connect the ground to the "mass" shield of the PCB.

Mentalab Explore+ uses Bluetooth Classic 2.1 embedded SPP profile to maximize data throughput and provide higher sampling rates.

Please see the Integrations section for a complete list of analysis software that works with Mentalab Explore+. As a general guideline, our open source API explorepy can push data directly to lab streaming layer, and we have integrations for Java and MATLAB. We are also fully integrated with LabChart Lightning. If you would like to build your own integration, we provide an open source SDK and our technical team is always happy to help.

Transmission to cloud storage has been tested successfully. For more details, please contact our support.

The time stamps generated by the Mentalab Explore+ amplifier are very precise. There is a slight yet consistent delay of ~50ms because of how Bluetooth works. Syncing with other amplifiers can be done using third-party software, like lab streaming layer and LabChart Lightning. Please contact support for more detailed information on the topic.

All data is stored in CSV or EDF format. Filters that are applied in explorepy only affect visualization. The recorded data files will always contain raw data. Files recorded with explorepy are saved in the current command line folder. By default this is C:\Users\❮USER_NAME❯ on Windows; /home/❮USER_NAME❯ on Ubuntu; and /Users/❮USER_NAME❯ on Mac. You can record data in other formats using and other third-party software solutions that supports lab streaming layer (e.g. LabRecorder, OpenVibe etc.).

You can find an overview as well as a detailed list of available command line inputs in our explorepy Command Guide.

You can use explorepy from most Python command terminals. However, we do recommend using Anaconda to manage your virtual environment dependencies, and Anaconda prompt to run custom Python scripts. If you use the executable installer, you can also operate explorepy from a Windows command prompt.

We have heard reports that some terminals do not run explorepy smoothly. These terminals include:

• Spyder Shell
• Jupyter Notebook Shell