The AD8232 is a great chip, from Analog Devices, for reading bio-electrical signals (mainly muscle and heart - but may be good for EEG). The chip only comes in a 4 mm × 4 mm, 20-lead LFCSP package but thankfully SparkFun carries a breakout for it SparkFun Single Lead Heart Rate Monitor – AD8232 ,SEN-12650.

SparkFun even has a hookup guide and a repository on Github for code examples. The code on Github hasn't been updated for a few years but I've tested the Arduino code and it works fine (the Processing code does not seem to work on the newest release of Processsing - 3.3). To visualize the heart data I just used the Arduino code and the Serial Plotter in the Arduino IDE (located in the “Tools” tab). Here's an example:

I'll go into further detail later.

But, for now I built up a VK model using card stock (the front is fairly accurate but the top is missing a lot of details):

In the foreground are some of the sensors and screens I've been testing.

I mainly put this model together to:

1. See if my measurements and scale were correct.
2. To use as a physical comparison for parts (to see if screens, etc actually fit correctly).

Thankfully, it seems that I'm on the right track!