Significance of EEG

EEG is the primary technology to study the brain and different brain dysfunctions in real-time. Portable and low-cost EEG equipment for monitoring neuronal dysfunctions can have significant societal and economical benefits since they allow remote supervision by the clinicians and self-administration (possibly assisted by a nurse) of a treatment at home avoiding hospitalization.

Challenges

Even though the rapid progress in high-tech electronics have enabled wearable and compact EEG devices, the accompanied generic software does not fulfill the requirements for accurate EEG source analysis. The way to unlock the secrets of the brain (i.e. to visualize the electric brain activity) is to build a model that connects the underlying brain activity with the EEG recordings. Because generic models have been shown to be unreliable and can result in misleading interpretations or diagnosis, personalised modelling is of high importance.

Personalization in EEG (Skull concern!)

Here, personalisation means constructing a model that includes the electrical tissue properties and the geometry of the person's head who undertakes the EEG measurements. Underestimation or overestimation of the tissue conductivities can have a detrimental effect on identifying accurately the brain activity. Particularly, the skull is of primary concern since it acts as a insulating barrier between the recordings and neuronal activity. The breakthrough character of this project is to bridge the gap between the new high-end neuro-monitoring devices and highly sophisticated device-embedded software that allow the design of patient-tailored protocols for precise (focal) high spatial resolution imaging of the brain activity.

Electrical Impedance Tomography

To achieve this aim, we have embedded an in-line estimation procedure of the tissue conductivities via electrical impedance tomography (EIT) in the EEG Source Imaging software. EIT is a type of non-invasive medical imaging that, in principal, can be used to infer electric conductivity profiles of tissues. So far, the EIT studies of the human head have been rather limited: only few (4 or less) tissue conductivity values have been reconstructed, and their impact on mitigating EEG localization errors remains unexplored. The bottleneck has been the lack of appropriate EIT imaging software.

Our breakthrough

In this project, we developed an EIT-EEG imaging software that first constructs a high-resolution conductivity profile of the head, particularly the skull, and then includes this information in the EEG Source Imaging software. Our state-of-the-art algorithms can recover scalp conductivity and a detailed locally varying skull conductivity profile of the head which subsequently improve the accuracy of the EEG source imaging estimates significantly when compared to using bulk tissue conductivities or ‘standard’ tissue conductivities from literature. For the ATTRACT Phase 2, we are looking for reinforcing our consortium with partners who have (i) experience in clinical use of standard EIT, (ii) facilities to build a prototype EIT-EEG device, and (iii) expertise in wearable technologies.

Partnership wanted!

We would be interesting in collaborating with researchers/labs that have

(i) expertise in wearable technologies

(ii) experience in clinical use of standard EEG or Electrical Impedance tomography (EIT)

(iii) facilities to build a prototype EIT-EEG device