Google announced plans to buy Fitbit for more than $2 billion, and make no mistake, it’s not for the wristbands. Last year, it announced an effort to use artificial intelligence to scan electronic health records to make predictions about what might happen with hospitalized patients. Kirsten Ostherr, the director of the Medical Futures Lab and the medical humanities program at Rice University, said Fitbit’s trove of data is all about social determinants.