The data set is 7729 blood sugar readings from my Dexcom 7 CGM (continuous glucose monitor), representing all the CGM readings for November, 2011. I produced the visualization in Processing, then generated a PDF for the entire month on top and additional PDFs for every individual day of the month below. The circle spans the respective time frames starting at the top (12:00), progressing clockwise.
I changed the color scheme to blue from an earlier yellow version. I think the blue looks better. But it also builds on a comment a classmate made about an earlier version, stating that it reminded her of an eye. I thought changing it to blue would enhance this feeling even more. The blue represents in-range readings (80-140 mg/dL). The gray represents low blood sugar readings (79-40 mg/dL) and the outside white contains all the high blood sugars readings above 140 mg/dL.
I am encouraged by the results of this visualization. The feedback at the show was also positive and supportive. I already have some thoughts about changes I can make in the future. It will be nice to add other data variable to provide greater context. I am convinced that there are better ways of quickly and effectively communicating to patients the message hidden in thousands of data points. This could be part of a more responsive feedback look, giving patients both the motivation and ability to change their behavior and improve their control.
I am excited about taking the Data Representation class at ITP this coming term with Jer Thorpe. Check back later for future iterations!