Hydrating the saline sensor felts
Before you start a recording session, you’ll need to hydrate the sensor felts before fitting them to the FlexCap.
To hydrate the sensor felts you’ll need:
- a glass; and
- saline solution.
Then follow these steps:
- Place the sensor felts into a glass and then soak them with saline solution.
- When they are fully hydrated, squeeze each one gently to remove any excess fluid.
- Fit the hydrated sensor felts into the sensor locations on the FlexCap.
Fitting the FlexCap to your participant’s head
Fitting the FlexCap to your head is similar to a swimming cap.
Start by placing the front of the FlexCap over your participant’s forehead, then stretch it to the back of their head, pull it down and insert their ears through the ear holes.
When fitting the FlexCap, always make sure that the rear pocket is at the back of your participant’s head.
Always ensure that position Cz is in the middle of the FlexCap and the sensors are symmetrical.
Positions Fp1 / Fp2 on the FlexCap should be directly above the eyebrows.
Setting up the saline sensors
Saline sensors can dry out while you’re fitting the FlexCap to your participant’s head. This is due to absorption from your participant’s hair and scalp. To ensure the best contact quality during your recording session, please follow these steps.
When the FlexCap is fitted to your participant’s head and you’re ready to start recording, you must do the following:
- Open the contact quality map in EmotivPRO and ensure that your EPOC Flex is connected.
- The contact quality map will show you the contact quality for each sensor. Each sensor should show as green on the contact quality map. Starting with the references DRL/CMS, top up sensors with saline solution (as required) until each sensor turns green. The contact quality should be 100% and green on all channels.
If the sensor felts dry out during your recording session, or you have a long recording session, you can re-hydrate them through the hole at the top of the sensor.
When you see the contact quality change from green to orange in EmotivPRO, it’s time to top-up the saline solution.