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.
Compared, to wet electrode systems, our Dry EEG Headsets provide a superior experience for both operator and subject, without compromising on signal quality for the majority of EEG use cases. A quick summary of the advantages of dry versus wet is presented below.
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 straightforward yet nuanced. At CGX, we focus on rigorous internal testing and validation to international standards, which is why researchers around the world have used our systems in independent, peer reviewed publications.
CGX Dry Is A System
First and foremost, CGX dry electrode headsets are designed holistically: the electrode tip, headset and electronics are optimized to function as a whole.
The end result is the product of thousands of hours of engineering time to model, prototype and optimize an advanced mechanical system to enable, comfortable, secure electrode placement across a variety of head sizes and shapes while being extremely easy to operate.
The industry’s best wireless amplifiers
Our electronics are more than just an amplifier box. They start right at the tips of electrodes with advanced electrical shielding and pre-amplification to reject extraneous external noise.
Systems level design is key: unlike wet electrodes, which have hardly changed in decades, dry electrodes present a much more challenging engineering challenge, which is why previous attempts at simply inserting prongs into wet caps have failed.
CGX systems are equipped with three electrode options
The Drypad Sensor is flat — used directly on bare skin. The Flex Sensor has rigid fingers with soft rounded tips that brush through hair. Our super-soft HydroFlex Sensors are perfect for subjects with sensitive skin — and since they can be moistened, HydroFlex sensors return a signal equivalent to wet sensors throughout the frequency range. All sensors contain patent-protected materials and construction techniques minimizing contact impedance and noise without the use of electrolytic gels.
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.
Conventional Active Electrode
Active Electrode + CGX Active Shield
Our active electrodes are backed by 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.
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.
Built for research
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.
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.
All of our products offer unrestricted access to raw data, including at the hardware level.
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.
EEG Acquisition Settings
Device: Cognionics Quick-20
Resolution: 24-bits, 1,000 sps
Bandwith: Raw 0.4 - 100 Hz
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.