The precision with which some personal monitors perform their tasks is advancing rapidly, offering medical professionals much keener insight into what's happening with their patients. And while data behemoths Google, Apple and Amazon are driving much of the innovation, private companies are also making significant contributions.

Much of the research targets a group of chronic and pervasive diseases that are costly to treat — especially if they go undetected for too long — and that can be contained if detected early to reduce their toll on the patient. Among them: diabetes, cardiovascular diseases, asthma, Parkinson's disease and breast cancer.

Apple continues to pump out health-monitoring devices, and while its attempts to tap into the consumer market have had uneven results, the company's foray into the medical device realm appears to have brighter prospects.