A growing number of high-level Silicon Valley executives from the "sandwich generation" - those who are simultaneously caring for children and parents - have left their jobs to launch mobile and digital health startups. In interviews with Reuters, many say they have been prompted by their experience of helping aging parents with one or more chronic conditions, and the discovery of how the U.S. healthcare system fails to serve them. Some say they are finding both customers and partners in the large technology employers where they once worked.