EGI's HydroCel Geodesic Sensor Net

The HydroCel Geodesic Sensor Net holds each electrode in place with gentle radial compression that allows the Net to adjust to each patient's head shape, which prevents pressure points and gaps. Comfort is further enhanced by the elimination of scalp abrasion and the use of a mild, fragrance-free, saline-based electrolyte for routine EEGs, and a gel-based electrolyte for extended monitoring EEGs.

 Patient-friendly EEG is a great tool to differentiate your services.   

Superior Patient Comfort

In study after study, patients report that they prefer EEGs performed with Geodesic Sensor Nets over conventional EEG sensor arrays. Patients report that the GSN is more comfortable than other EEG methods. Children are far less likely to cry because the process is rapid and abrasion-free. Patients also comment that the electrolyte formulation does not smell or damage their hair.

Superior Patient Safety

The Geodesic Sensor Net uses abrasion-free application methods and the electrodes themselves are held in place by gentle radial compression afforded by the unique geodesic tension structure. Because no abrasion is required, the scalp on the skin is not compromised, which reduces the risk of infection. Often, it is argued that mild abrasion during the course of skin preparation does not compromise the integrity of the skin. However, studies have shown that this is not an accurate assumption. For further information, see

No Sedation

Sedating children to obtain useful EEG is often done in clinical settings. This is not required when you use the Geodesic Sensor Net; rapid application time and the comfortable fit make sedation unnecessary.

Patient Populations

Suitable for all patient ages and hair types (with the exception of corn rows and dreadlocks) Geodesic Nets have been used successfully with difficult-to-record populations, such as autistic children, elderly patients with dementia, and ADHD teens.

Quick Application Time

Application times for the routine monitoring HydroCel Geodesic Sensor Net range between 5 minutes for 32 channels to 15 minutes for 256 channels. EEG staff rapidly learn the application technique.

Complete Head Coverage

Complete head coverage ensures that all clinically relevant info is captured. Guaranteeing complete head coverage requires attention to both appropriate intersensor distance and coverage of the underside of the head.

The first aspect of complete head coverage refers to the intersensor distance (that is, how far apart one sensor is from another sensor). Smaller intersensor distances translate to a more accurate measurement of the voltage field.

The second aspect refers to coverage of the underside of the head (for example, below the ears, including the face). It is common to believe that electrodes on the inferior surface of the head do not pick up EEG. However, voltage fields generated by the brain are volume conducted throughout the entire head. Moreover, certain brain regions, such as the inferior temporal lobes and ventral aspects of the frontal lobe, are oriented such that the voltage fields generated by these brain regions are best detected by electrodes on the inferior surface of the head.

The consequence of incomplete head coverage is that clinically significant EEG signals can be missed by sparse electrode placement and by lack of electrode placement on the underside of the head. For detailed information, see:

Various Channel Counts

The Geodesic EEG System 300 is available in 256-, 128-, 64- and 32-channel configurations.  The 32-, 64-, and 128-channel Nets are available for all patient populations, from infants to adults.  The 256-channel Nets are currently available for pediatric through adults.