Assessment of electrode pressure and signal quality of improved wearable EEG headset prototypes

The human body appears in many sizes and shapes. Traditional anthropometry aims to map linear-1D- geometrical body characteristics and their statistical distributions. Advancements in 3D scanning, image construction and image processing resulted in a realm of databases containing true and accurate 3D forms of the human body, with accelerated construction of new body forms and databases. A statistical shape model is a collection of 3D forms such that each point on a given form has a corresponding point on any other form of that collection. Moreover, in a statistical shape model of the human body (or body part), similar anatomical landmarks ought to correspond, for example the tip of each nose; statistical shape models take account of the true-3D- geometrical variation of the human body. With the appropriate design tools to make the wealth on geometrical information contained in statistical shape models available for the purpose of product development, better products can be developed, especially: more comfortable, better fitting and thereby better functioning products. In current optical 3D scans, subjects wear a hairnet to prevent artifacts and to reconstruct the form of their skull. However the actual skull form is only approximated due to the presence of hair layer, lacking abilities in traditional 3D scanning to construct a true and accurate statistical shape model of the human skull. In the doctorate of D. Lacko, statistical shape models of the human skull are constructed from medial images (CT and MRI scans) thereby excluding the effect of hair. Complementing CAD tools and methods for parametric design, sizing systems and true generic manikins [22] allow developing new products that closely interact with the human skull such as hearing aids and wearable electroencephalogram (EEG) headsets.EEG is a technique to measure brain activity through detection of small electric field fluctuations by sensitive electrodes, amplification and signal processing. EEG registration has a myriad of potential clinical and off-site applications comprising diagnosis of e.g. ALS, Alzheimer, polysomnography, epilepsy monitoring, enriched, augmented, supplemented or alternative communication, research e.g. cognitive processing and didactics, associations, commercial applications such as gaming and neuro-marketing,... The development of wearable, comfortable, acceptable and calibrated EEG headsets is needed to improve clinical use and to boost potential off-site applications. With the accurate shape model of the human skull combined with CAD tools, non-functional wearable EEG headsets (mock-ups) are developed within the research groups Product Development and Vision Lab with the following prperties: 1) better fit and stability and 2) reproducible electrode positioning on the skull after successive mounting, compared to current commercially available EEG headsets. The research hypothesis is that our EEG headsets with these assets will also allow capturing EEG signals with improved signal quality. This hypothesis was never investigated due to the lack of stable fitting EEG headsets with calibrated and reproducible electrode positioning on the skull. Within this project, resources are asked to endow our EEG mock-ups with pressure and impedance/admittance measurements for testing this hypothesis.

Keywords:EEG SIGNAL ACQUISITION, WEARABLES, SKULL GEOMETRY

Disciplines:Electronics, Medical imaging and therapy, Morphological sciences, Other paramedical sciences