Abstract – Three million Americans and 16 million individuals worldwide have had or currently suffer from opioid use disorder (OUD). OUD afflicts individuals from all socioeconomic and educational backgrounds with devastating consequences, including a rising incidence of neonatal abstinence syndrome and the spread of infectious diseases, i.e., HIV and hepatitis C, associated with syringe sharing. The most recent provisional data from the Centers for Disease Control and Prevention (CDC) indicate that approximately 81,230 drug overdose deaths occurred in the United States in the 12 months leading up to May 2020—the largest annual number of drug overdoses ever recorded. In 2019, hospitals estimated an annual cost of OUD of $787B to society, $93B to taxpayers, and $89B to the healthcare sector. Medications for opioid use disorder (e.g., methadone, buprenorphine, or naltrexone) are central to the treatment of OUD. Methadone, a proven and effective opioid medication for treating OUD, extends retention in care, reduces mortality, and inhibits illicit drug use. However, methadone treatment is limited to federally certified Opioid Treatment Programs (OTPs), which must meet complex regulatory requirements for certification. The regulations require new patients to take their dose in person six days per week and limit the locations where patients may receive methadone. Finding an OTP can be challenging, especially for those in rural areas as only 3% of OTPs are rurally located. The greatest barriers that keep individuals with OUD from receiving treatment include 1) Availability; 2) Accessibility (i.e., daily visits for directly observed dosing); 3) Acceptability (i.e., need for detox for other non-methadone treatment options); and 4) Privacy. To address these barriers, Elpidatec has developed Elpida, an OTP-specific, mobile- and desktop-friendly web-application that combines video, tamper-evident barcode labels, facial recognition, and machine learning (ML) to enable accelerated take-home methadone regimens while maintaining safety and diversion prevention. Elpida enhances patient access to treatment, aligns with OTP workflow, and improves physician assessment and management of OUD patients, providing previously inaccessible patient information via real-time, ecological momentary assessments (EMAs). In this project, Elpidatec will complete feasibility testing, iterative product development, and market fit testing of Elpida in partnership with Adapt Oregon, a rural OTP, and Oregon Health and Science University. The Phase I SBIR application has three aims: 1) Conduct feasibility testing of the minimum viable product (MVP) with patient- and clinician-facing web- applications and evaluate tracking performance; 2) Develop and integrate key ML-enhanced features such as facial recognition and methadone vial position tracking for automated dosing event interpretation; and 3) Assess the demand and acceptability of Elpida among providers and patients. Insights gathere...