Headset that train your brain : how a research team wired a complex technology into an everyday product

A passionate team of neuroscientists, engineers and designers dreams about making a technology until then restricted to the clinical environment accessible to everybody. Their idea: an EEG headset that enables anyone into measuring its brain activity using the neuro-feedback technology, a method based on an electro-encephalogram system (EEG) capable of measuring your brain activity. A high stakes challenge! How to wired a clinical solution into an everyday product like headphones while making sure to keep a high quality EEG measure? Four years of research later, the first brain-training solution was born: Melomind.

neuroscience scheme

From the idea to the first hardware.

EEG (an electroencephalogram) is a non invasive electrophysiological monitoring method used to record electrical activity of the brain. Using electrodes placed along the scalp, an EEG tracks and records brain wave patterns. The headset that the team wants to create focuses on recording brain activity in the parietal lobe of the brain where alpha waves, the specific waves engaged in the natural process of relaxation, are the strongest. At the time where the team is studying the feasibility of the project, only two alternatives can be found on the market: a clinical EEG headset hardly usable outside of a clinical environment but offering high quality measures on one side. On the other side, a more accessible EEG headset with unsatisfactory EEG measures.

This first assessment motivates the team into building their own solution: an audio EEG headset able to measure a high quality signal of the brain activity in a few seconds.

First step for the team: creating its own supply chain to achieve a high quality EEG signal.

Inspired by existing open source EEG, the team starts with developing its own supply chain. That means creating all the needed elements to capture, transmit et receive the physiological data, aka the brain signal. The team starts with testing the supply chain by successively measuring the muscular, cardiac and brain activity. Once stabilized, the supply chain is first tested with electrodes using a conductive gel like the ones used in clinical environments. Those electrodes offer a high quality measure but are pretty difficult to use outside of a clinic. Then, the supply chain is tested with dry active electrodes which allows a fastest set up. Exactly what the team is looking for! Dr Yohan Attal, CEO of MyBrainTechnologies, remembers that moment when the first EEG signal was recorded and the supply chain approved. The first Eureka of the Melomind project! But still, far from the goal, which is to measure a stable and high quality EEG. A few experiments later, the solution is found by combining pin and textile electrodes. A few weeks later, we can say it … Eurêka !

At the end, the Melomind headset is made of four main elements: the headphones, the branches that connect dry electrodes to the headset, the textile electrodes hidden in the earplugs, and the mobile app that treats the data.

At this stage, the electronic is the size of a cigarette pack. The team is working on miniaturizing it while designing a headset that would enable the measure of a high quality EEG signal. To do so, the researchers team up with a specialized industrial company. The design is imagined by Martin Vandendriessche, design project manager of the Melomind headset.

To measure a high quality EEG, it is necessary to use magnetic materials that are conductive but don’t transform the transmitted brain signal: the team choose gold for dry electrodes touching the scalp, and stainless steel for the branches connecting the electrodes to the headset. The twelve cable protective shields situated in the branches and the hoop are sized to the millimeter to balance the elasticity of the frame with the insulation needed to protect the signal from exterior noises. Two textile electrodes are added right behind the ears; they touch the mastoids, the portion of the temporal bone of the skull located behind the ears, and allow a neutral measure of the brain signal by voltage difference.

In the end, the device melomind™is made up of four main components: the headset, the armature allowing the two dry electrodes (in contact with the scalp) to be connected to the headset, the textile electrodes located in the earphones, and the mobile application allowing data processing.

Improving comfort without losing quality signal: a difficult act to balance

Remember: the Melomind headset aims to measure the signal in the parietal lobe of the brain where the alpha brainwaves are the strongest.

To get a high quality signal, the headset needs to pressure the scalp enough, especially with the use of dry active electrodes. The problem: this pressure is uncomfortable for the user.

The team carries out a feat unique on the market: by creating a flexible hoop that leans on the two pressure points behind the ears, the pressure of the two dry electrodes touching the scalp is strong enough to both receive a high quality signal and maintaining a comfort for the user. This subtle balance makes the headset adjustable to every type of skull and therefore suitable to most people.

The audio signal and the EEG signal are synchronously managed in a same headset.

The Melomind headset is unique in its duality: it includes specific features of standard headphones as well as features of an EEG headset. Using the bluetooth connexion, the user immerses himself into a musical session through the Melomind app. Among the different sounds, Melomind asks you to pay attention to one sound in particular, which is the reflection of your own personal relaxation level, and the foundation of the brain training using neurofeedback. The bluetooth connection enables the EEG signal to be transmitted to the phone as well, allowing the user to follow its training sessions on the Melomind app.

The minimalist and evolutive design of melomind™, offering the possibility to remove or change the armature connected to the electrodes, testifies to a product thought in system mode: today, in just a few seconds, melomind™allows everyone to do EEG, accompanying the learning of relaxation and stress management in an extremely innovative way. melomind™Is the EEG a leader in well-being management oriented towards autonomy and responsible consciousness?