A wonderful thing happened since my last post on this project. The friendly folks at Emotiv listened to their devoted users and opened up the raw electrode data from their amazing EPOC neuroheadset (just $299). That’s a 14-channel fire hose of brainwave data, streaming via Bluetooth at a sampling rate of 128Hz. I wanted to see if I could whip up a quick WPF control that that would display all that data in realtime. 
As it turned out, “quick” wasn’t in the cards -- delivering new Visual Studio 2010 content took priority -- but finally, I have a working prototype that shows it’s doable. The code’s not quite ready for public consumption, but here’s a teaser. I wrote a managed wrapper in C#, named EmoEngineClient, that polls the neuroheadset for state and also collects the electrode data. That was the easy part. Much more challenging was designing the rendering pipeline. A couple of seconds of data generate several thousand points, and painting all of those within the 7.8ms frame rate is not straightforward. For highest performance, you’d probably write a pixel shader and do everything in the GPU, but I’m not a Shader Language jock, and I want to use native WPF features. The next best thing is to draw each channel’s data trace with a Polyline, and as long as I do very little clipping, it should render very quickly. Even so, that’s too much data for the UI thread to render and still remain responsive to user input. The trick is to render each Polyline on its own thread, which is simpler than you might think, but still tricky. Read more: Jim Galasyn's Learning Curve
As it turned out, “quick” wasn’t in the cards -- delivering new Visual Studio 2010 content took priority -- but finally, I have a working prototype that shows it’s doable. The code’s not quite ready for public consumption, but here’s a teaser. I wrote a managed wrapper in C#, named EmoEngineClient, that polls the neuroheadset for state and also collects the electrode data. That was the easy part. Much more challenging was designing the rendering pipeline. A couple of seconds of data generate several thousand points, and painting all of those within the 7.8ms frame rate is not straightforward. For highest performance, you’d probably write a pixel shader and do everything in the GPU, but I’m not a Shader Language jock, and I want to use native WPF features. The next best thing is to draw each channel’s data trace with a Polyline, and as long as I do very little clipping, it should render very quickly. Even so, that’s too much data for the UI thread to render and still remain responsive to user input. The trick is to render each Polyline on its own thread, which is simpler than you might think, but still tricky. Read more: Jim Galasyn's Learning Curve