PROJECT SUMMARY/ABSTRACT While patient self-report of pain is currently the gold standard of pain measurement, accurate self-reports of pain may not be feasible in critically ill patients who are sedated and intubated, unconscious patients, or patients who are unable to verbally communicate their pain. Current research has shown that pupillary dilation (PD) is a reliable indicator of acute pain, and that measurement of pupil size changes may be useful in determining the intensity of pain experienced as well as the efficacy of an analgesia. There is also research demonstrating the value of pupillary unrest under ambient light (PUAL) as an objective marker of sensitivity to opioids, and the use of facial expression analysis to detect pain. IMPACT proposes pupillometry with a proprietary algorithm to measure both PD and PUAL, and facial expression analysis using computer vision. Through IMPACT, Benten proposes to provide clinicians with a device that helps them objectively determine the presence or absence of pain, assess opioid efficacy, and assist in deciding whether opioids should be the treatment of choice for a patient. The utimate goal of IMPACT is to revolutionize measurement and management of pain. The novel approach of measuring PD, PUAL, and facial expressions will help eliminate subjectivity in the diagnosis of pain, and avoid over-administration of opioids or administration of opioids to patients who are not suitable candidates for opioid treatment. IMPACT will demonstrate the feasibility of using pupil size changes and facial expressions to guide the diagnosis and treatment of pain, and compare results obtained to pain scores reported by patients on the NRS, to assess accuracy of pain measurement and effectiveness in pain alleviation. IMPACT will be designed and developed to serve the needs of patients who experience severe pain, and provide them with pain relief, through objection clinical decision-making. The aims of IMPACT are as follows: 1) Phase I Specific Aims: Develop IMPACT prototype and conduct a validity test with 25 subjects, to demonstrate the efficacy and validity of IMPACT versus a commercial pupilometer, and 2) Conduct a feasibility pilot test of IMPACT with 20 patients in the post-anesthesia care unit (PACU) of Christiana Care Health System (CCHS), to demonstrate the feasibility of IMPACT in determining pain and assessing opioid efficacy. The short-term impact will be an improvement in pain detection, and more objective clinical decision making regarding opioid administration. The long-term impact will be a decrease in the misuse of opioid medication, and the facilitation of objective measurement of symptoms in clinical settings.