Redwood City, California-based digital medicine company Proteus Digital Health has raised $50 million from undisclosed investors. The company’s existing investors include Medtronic, Itochu, St. Jude Medical, and Kaiser Permanente Ventures. This brings the company’s total funding to at least $450 million.

The Proteus digital medicine platform, called Proteus Discover, is a medication management and adherence system that includes measurement tools like sensor-enabled pills, a peel-and-stick biometric sensor patch worn on the body, and companion smartphone apps. The patch records when a pill is ingested and can also track other things like sleep patterns and physical activity levels. The ingestible sensor component secured FDA clearance in July 2012, while the company’s sensor-laden patch got FDA clearance in 2010.

The ingestible sensor is made up of an integrated circuit, two "active" layers, "excipient materials" that provide adhesive, and a "skirt, which contains ethyl cellulose, hydroxypropyl cellulose, and triethyl citrate." The company explains that the ingestible is made entirely of ingredients found in the food chain.

Proteus said it will use the funds to increase adoption of Proteus’ offering by partnering with healthcare systems. In early January, Proteus announced its first US healthcare provider customer, Barton Health, which would start prescribing the company's Proteus Discover to patients.

At the time, Barton Health, a health system in Lake Tahoe, California, said it would use the medication adherence platform in populations with uncontrolled and co-morbid hypertension. And implementation for other chronic conditions would follow if the first use case goes well.

“In the hands of doctors and patients it’s a very valuable tool for physicians like myself who provide exceptional care to our patients because we understand their daily activity levels, how they use their medication, how compliant they are,” Barton Health CEO Clint Purvance told MobiHealthNews at the time. “And that allows me to have a better relationship to work with the patient on how to motivate them and how to improve their health, how to get them on to a journey to their own health improvement, which is a very different conversation then ‘We’re tracking you, you need to do this.’”

Most recently, Proteus announced interim study results from a randomized control study of its Proteus Discover timed with the American College of Cardiology event, ACC.16. The study included 96 patients with uncontrolled hypertension and type 2 diabetes and showed that a majority of the patients using the digital offering achieved the blood pressure target at week four. Specifically, by the fourth week, some 85 percent of subjects using the digital offering (n=72) and 33 percent of the usual care arm (n=24) achieved the BP target.