Managing pain is a primary medical function, as it affects quality of life for millions of patients and is often an indicator of underlining medical problems. In spite of the importance and prevalence of pain, there are currently no clinically accepted tools to objectively monitor changes in pain level, requiring physicians to rely on patients’ subjective assessment, or to simply guess, when patients – whether sedated, demented, or too young – cannot describe their pain. Lack of objective and timely assessment of pain leaves many patients either under-treated or overdosed.

Annual healthcare costs associated with pain exceed $300 billion in the U.S. alone. Pain is the most common reason for medical consultation. 40% of the 30 million patients undergoing surgery each year continue to suffer from severe pain after surgery, while 15,000 people die every year of overdoses involving prescription painkillers.

There is a general consensus among healthcare providers that an objective assessment of pain could revolu-tionize pain management, contributing to better clinical outcomes and to decreased costs. Considering the im-portance of recognizing in a timely manner changes in patient’s pain level – whether in the hospital, or when treated in the clinic and even at home – monitoring the body’s reactions to pain might become ubiquitous and a standard practice, just as the monitoring of other common vital signs such as blood pressure, heart rate and blood oxygen levels.