In medicine, compliance describes the degree to which a patient correctly follows medical advice. Most commonly, it refers to medication or drug compliance, but it can also apply to other situations such as medical device use, self care, self-directed exercises, or therapy sessions.

Poor compliance with drug regimens is a common problem in many disease areas, especially when patients suffer from chronic conditions. In particular, low rates of adherence to therapies for asthma, diabetes, and hypertension are thought to contribute substantially to the human and economic burden of those conditions. Estimates from the World Health Organization indicate that only about 50% of patients with chronic diseases living in developed countries follow treatment recommendations.

But new technology may help improve compliance statistics. The FDA has approved the first digital pill with an embedded sensor to track if patients are taking their medication properly, marking a significant step forward in the convergence of healthcare and technology.

The medicine is a version of Otsuka Pharmaceutical Co Ltd’s established drug Abilify for schizophrenia, bipolar disorder and depression, containing a tracking device developed by California based Proteus Digital Health.

The system offers doctors an objective way to measure if patients are swallowing their pills on schedule, opening up a new avenue for monitoring medicine compliance that could be applied in other therapeutic areas.

The system works by sending a message from the pill’s sensor to a wearable patch, which then transmits the information to a mobile application so that patients can track the ingestion of the medication on their smartphone. The underlying technology is Proteus Discover which is comprised of ingestible sensors, a small wearable sensor patch, an application on a mobile device and a provider portal.

About the size of a grain of salt, the sensor has no battery or antenna and is activated when it gets wet from stomach juices. That completes a circuit between coatings of copper and magnesium on either side, generating a tiny electric charge.

In the longer term, such digital pills could also be used to manage patients with other complicated medicine routines, such as those suffering from diabetes or heart conditions.

Proteus has been working on the pill tracking system for many years and the sensor used in Abilify MyCite was first cleared for use by the FDA in 2012.

The California company has attracted investments from several large healthcare companies, including Novartis AG, Medtronic Inc and St. Jude Medical Inc, as well as Otsuka.