The original Typeface Demo was built using a commercial EEG reader - the MUSE headband. It's an amazing piece of hardware and anyone interested in EEG or Computer Brain Interfaces should definitely check one out if they get the chance. The reader was able to reliably detect blinks and allowed us to get a working demo of our idea up quickly.
Nonetheless the device ended up imperfect for our purposes for a number of reasons:
- Although much cheaper than typical assistive typing interfaces, the MUSE headband still runs $299 and a lot of that cost goes towards unneeded functionality.
- Testers with large earrings, odd-shaped heads, or lots of hair had trouble reliably typing during the project demonstration.
- The MUSE is a closed source platform which does not jive well with our own beliefs in open hardware and also limits our ability to control the data which the device reports.
- The MUSE really only works on people's foreheads. Our hope is to build a generic platform that could be mounted on any muscle over which a paralyzed individual has retained control.
As such, we intend to build our own hardware to connect with our software. At present we intend to try out the following technologies:
- Replace EEG with an EMG - EMG sensing can be vastly more affordable and more reliable than the electrodes involved in EEG. It's also less invasive and will not require the use of electrode pastes. The sort of unary singals we rely on do not require the nuanced differentiation EEG enables so there's no real reason to inflict the disadvantages and risks of EEG on our users. EMG is also better suited to helping us broaden the use-cases of our platform from just forhead-signals to generic anywhere-on-the-body detection.
- Experiment with IR instead of Bluetooth and keeping signal processing hardware-side. By using an IR transmitter/receiver pair we can greatly decrease the size, power requirements, and expense of the device. Some of our testers also expressed trepidation about attaching wrapping a bluetooth device around their cerebrum. Given that our platform is built around reducing input complexity to a single signal, IR may be a good fit for our purposes. Normal concerns with IR communication (sunlight, directionality, etc.) are less of a concern as the device will be used indoors and by a user who necessarily maintains line of sight with the UI.
- Look into building a USB-receiver that exposes a keyboard interface - allowing users to type into any application instead of just the Typeface communicator.