Epic Systems, America's largest electronic health records company, maintains medical information for 180 million U.S. patients (56% of the population). Using the slogan, "with the patient at the heart," it has a portfolio of 20 proprietary artificial intelligence (AI) algorithms designed to identify different illnesses and predict the length of hospital stays. As with many proprietary algorithms in medicine and elsewhere, users have no way of knowing whether Epic's programs are reliable or just another marketing ploy. The details inside the black boxes are secret and independent tests are scarce. One of the most important Epic algorithms is for predicting sepsis, the leading cause of death in hospitals.

Stadia's potential derives from the massed power of Google's data centers and Google's deep expertise in machine learning and natural language …