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Technology
Overview

Helping Researchers Get Fast, Accurate EEG Results

CGX enjoys the reputation for designing the most accurate data-rich dry EEG systems for researchers and practitioners. We’ve earned this reputation through engineering prowess and best-in-class technical assistance. Our team of engineers focuses on dry-EEG technology, bringing the benefits of no-prep, accurate results to neurophysiological researchers.

Highest Wireless Data Quality

We design noise reduction into our hardware, with active electrodes, active shielding, and extremely low-noise electronics.

We provide raw, unfiltered data in several formats:

.EEG / .EDF / .BDF / .CSV

Typical CGX data recording after 5-minute set-up

CGX Dry Electrode Systems: How Do They Work?

 

Of course, the two questions we are most often asked are: how do your electrodes work, and how do they compare against conventional wet electrodes? 

 

The answer to the first is simple in theory but complex in practice. CGX dry electrodes work because they are backed by sophisticated mechanics and electronics while most companies focus on a single element, such as the electrode.

 

The answer to the second is equally nuanced. At CGX, we focus on rigorous internal testing and validation to international standards. Which is why researchers around the world use our systems in independent, peer reviewed publications.

CGX Dry Is A System

 

CGX dry electrode headsets are designed holistically: the electrode, headset mechanics, and electronics are optimized to function as a whole.

The end result is the product of thousands of hours of engineering—modeling, prototyping, and optimizing. This results in an advanced mechanical system that's comfortable, secure across a variety of head sizes, and extremely easy to operate.

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The Industry’s Best Wireless Amplification

 

Our electronics are more than just an amplifier in a box. It's a chain beginning at the tip of the electrode. Each electrode has advanced electrical shielding and pre-amplification which reject extraneous external noise.

 

From there, the signal travels through a custom-configured wire harness to our sophisticated amplifier. We use the best, low-noise, high resolution data acquisition electronics on the market. Precise 24-bit A/D converters with >100dB CMRR, microVolt noise floors and active noise cancellation enable robust data collection even under tough, real-world environments.

 

We do no signal filtering or massaging—delivering a research-grade raw EEG signal unmatched in the industry.

Conventional Active Electrode

Active Electrode With CGX Active Shielding

Bluetooth Transmission

And because our systems are so lightweight and power efficient they can be incorporated into the headset itself and operate for hours with standard batteries. Built-in Bluetooth Low Energy offers up to a 10 meter range for wireless telemetry.

CGX Dry High Density Systems are also equipped with a custom Bluetooth implementation to transfer higher data rates than what is normally possible with conventional technology.

Real-Time Impedance Checking

 

CGX Dry systems contain a variety of advanced circuitry to support researchers. All systems are equipped with a patented real-time impedance monitor to gauge sensor contact quality. For precision timing experiments such as evoked potentials, our systems support an ultra-low latency link to transfer markers with 1 millisecond accuracy without wires.

Our Mechanics Are The Key To Our Success

 

Unlike many competing products, CGX systems don't simply mate sensors to a conventional EEG cap and hope for the best. Each element of the headset including the base, legs, and sensor pods, are integral to the performance of the system.

Drypad

Flex

We Offer Two Electrode Options

The Drypad Sensor is flat — used directly on bare skin. The Flex Sensor has rigid fingers with rounded tips that brush through hair. All sensors contain biocompatible patent-protected materials and construction techniques minimizing contact impedance and noise without the use of electrolytic gels.

CGX Dry vs. Wet Signal Test

 

As part of our design process, we subject all of our systems to detailed testing against standard wet electrodes.

Data was recorded at the exact same time from our dry Flex Sensors and with gel Ag/AgCl sensors. To simulate a wet sensor overlaid directly on a dry sensor, two wet sensors were placed adjacent to the dry sensor (while taking care not to contaminate the gel) and the wet signals were averaged. The example demonstrates the high raw signal quality of the CGX Dry system as the wet and dry signals are virtually indistinguishable with correlations exceeding r>0.9 between wet and dry data taken at the same time.

 

For more information, download sample data from our product pages and refer to our peer reviewed publications.

Two wet electrodes placed on either side of a CGX Dry electrode

Test Results​

EEG/ERP Bandwidth​

Device: Cognionics Quick-20. Resolution: 24-bits, 1,000 sps. Power spectrum over 5 minutes.

Oddball Experiment

Normal Tone: 150 Trials Odd Tone: 50 Trials

Normal Tone

Odd Tone

Wet vs. Dry

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Wet vs. Wet

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EEG Acquisition Settings

Device: Cognionics Quick-20. Resolution: 24-bits, 1,000 sps. Bandwith: Raw 0.4 - 100 Hz

Wet vs. Dry

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Wet vs. Wet

High Frequency Noise Floor

Low Frequency Noise Floor

Alpha Peak

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Comparison Chart: CGX Dry vs. Traditional Wet Headsets

TECHNOLOGY PARTNERS

CGX Dry Electrode Systems are the result of a decade of research.

 

In part sponsored by the Department of Defense, NASA and the National Institute of Health. Our patented and patent-pending technologies utilize an optimized combination of electronics, mechanics and materials to achieve a dry electrode EEG system that delivers on the promise of quick, clean, and no-fuss signal quality.

DARPA

NASA

NIH

Office of Naval Research

Air Force Research Laboratory

Army Research Laboratory