An AI System with Detailed Diagnostic Reasoning Makes Its Case

Researchers at Harvard Medical School are developing Dr. CaBot as a medical education tool. The system, which operates in both presentation and written formats, shows how it reasons through a case, offering what’s called a differential diagnosis — a comprehensive list of possible conditions that explain what’s going on — and narrowing down the possibilities until it reaches a final diagnosis. Dr. CaBot’s ability to spell out its “thought process” rather than focusing solely on reaching an accurate answer distinguishes it from other AI diagnostic tools. It is also one of only a few models designed to tackle more complex medical cases. “We wanted to create an AI system that could generate a differential diagnosis and explain its detailed, nuanced reasoning at the level of an expert diagnostician,” said Arjun (Raj) Manrai, assistant professor of biomedical informatics in the Blavatnik Institute at HMS. Manrai created Dr. CaBot with Thomas Buckley, a Harvard Kenneth C. Griffin School of Arts and Sciences doctoral student and a member of the Manrai lab.