Components

Description of the Mindtooth Headset and Software.
The Touch headset is patented worldwide and protected by copyright.


1 MINDTOOTH HEADSET: TOUCH  

The Mindtooth headset is made in two main parts: front part and rear part. The two parts are held together with an adjustable elastic band. The amplifier will be a click-on amplifier, connected to the headset by magnetic connectors. 

Figure 1. 

Picture of the chosen headset prototype used for validation 1

Figure 2. 

Perspective views of the headset

1.1.1 Headset Front Part
The front part of the headset is hosting five EEG sensors and designed to fit the users forehead. To maximize comfort it is flexible and made of a combination of materials (plastic and textile).
All electrodes pellets and bases for the sponge electrode holders are embedded in the headset together with the wires. The 5 wires are hosted in one flexible sheath that exits on the right side from the front part and enters into the rear part. The sheath with the 5 wires is long enough to permit the elastic bands maximum extension.

1.1.2 Headset Rear Part
The rear part is hosting the ground and reference sensors, the three parietal EEG sensors and the click-on amplifier (Click-On Amp) socket and is made in plastic with a shape that permits it to be slightly flexible to fit the head comfortably.
Ground and reference sensors are fitted to two separate “fingers” on the mastoids. Their position makes it possible to use glasses and headphones while wearing the headset.
The three parietal EEG sensors’ “fingers” are made as a separate part that is fitted and fixed to the rear part of the headset.
The “fingers” have been designed to adapt to the users head shape and all of the parietal EEG sensors’ holders have been prolonged, the center finger is fixed while the other two are fitted to a rotating end-piece of the flexible “finger” in order to make it easier to adapt to all head shapes, split the hair and touch the scalp (see Figure 19).  

Figure 3. 

Illustration of parietal end-finger rotation in order to fit the electrode to the head shape

Figure 4. 

Exploded view of the rear part with Click-On Amp and part with parietal EEG sensor fingers.

The position of the Click-On Amp socket has been chosen in order to distribute the weight of the Click-On Amp evenly on the back part of the head. To fit and connect the amplifier onto the headset two magnetic pogo-pin connectors clicks onto each other, hence the name “Click-On Amp”. The task is extremely easy and due to the fact that the magnets only allow clicking on in one way, the right way, it is not possible to make a mistake.
The front piece of the housing has the user-interface:
- an entry for the micro USB used to recharge the Click-on Amp’s rechargeable battery. The micro USB entry is placed in this position so that the Click-On Amp can be recharged lying flat on the table.
- an on/off push button and three LEDs to display status information. When the Click-On Amp’s batteries are recharging the LEDs will light up depending on the level of recharge. 

Figure 5. 

Click-On Amp exploded views

Figure 6. 

Click-On Amp interface and status information explained. A push button is provided to switch on/off the amplifier: a) When charging all LEDs flashes. When the battery is full the flashing stops. When the Click-On Amp is connected to the headset the LEDs flash until connection is made and then stops. b) Two LEDs are on - the batteries are 75% full c) One LED is on – the batteries are 50% full d) All of the LEDs are off, only the ON/OFF button is on – the batteries are 25% full.

Figure 7. 

Renderings of the headset. View top left to bottom right:
prospective view from the back with Click-On Amp detached, front view, prospective view from the back with Click-On Amp attached, top view, rear view with Click-On Amp. 

2 MINDTOOTH SOFTWARE

The Mindtooth Software allows to record biosignals from the Touch EEG Headset, and even additional devices (e.g. emphatica, shimmer sensing), to compute Neurometrics of Workload, Vigilance, Stress and Cooperation, and transmit these neurometrics to any kind of 3rd party application.
In particular, the Mindtooth core will be the module delegated to the Neurometrics computation and transmission.
It is written in python given its powerful scientific libraries and its multiplatform adaptability.
It will run on Windows machines such as laptop, tablet and also minicomputer (i.e. Odroid), if required.
The API has been designed, and will be developed accordingly, to allow the consumer applications (namely the third party apps) to use the computed neurometrics. Thus, the API will implement two kinds of communication protocol:
1. Web Socket communication for the Pilot’s training app and for the ITCL car simulator app;
BLE communication (GATT Attributes) for the IBM industrial safety app.
2. BLE communication (GATT Attributes) for the IBM industrial safety app. 

Figure 8

Mindtooth system architecture design. https://swagger.io/ could be employed to describe the API third-party apps

Designed with Mobirise html web theme