RockHealth is a San Francisco based organization that funds and supports innovative ventures in digital health. (For their portfolio of 60 funded and/or affiliated company, see here.)
RockHealth has released an online essay that provides an overview of digital biomarkers in healthcare. (For the full report, $99, click their "Download Report" button.)
While, in a sense, everything in healthcare has a digital mirror - for example, medical records notes from a patient interview become a digital EHR- RockHealth and others like Evidation Health are defining digital biomarkers as "consumer generated physiological and behavioral measures connected through digital tools that can be used to explain, influence, or predict health related outcomes" but excluding "patient reported measures, genetic information, and data collected through traditional medical devices."
This framework is a little confusion from the outset. For example, an MRI is excluded because it is digital information collected through a "traditional medical device." However, how fast you type on your smartphone is a "digital biomarker" and could be correlated to Alzheimer's or Parkinson's disease. In this vein might be SF startup Big Health's product "Sleepio" - which raised $12M in July 2016. Here.
The essay is worth a look.
For example, they make a classic four-box classification (sometimes called Roman Square) where the measurement can be "novel or known" and the insight can be "known or novel." For example, using today's point blood pressure to predict your ten year risk of a stroke is "known" technology and "known" insight. Using continuous smartphone tracked blood pressure to predict your chance of depression would be "novel" tech and "novel" insight (if it worked).
The web essay goes on to talk about possibilities in extrapolated data, continuous data, and big data. The $99 file is in PowerPoint PDF format and runs about 30 pages.