Project Summary This proposal is submitted in direct response to RFA-DA-23-021 Developing Regulated Therapeutic and Diagnostic Solutions for Patients Affected by Opioid and/or Stimulants use Disorders (OUD/StUD) (R43/R44). Persons of all ages with Opioid Use Disorder (OUD) are at risk for opioid overdose, which can cause Opioid Induced Respiratory Depression (OIRD), leading to hypoxia and death. Most overdose deaths in the U.S. occur without anybody else present, preventing bystander administration of the lifesaving drug naloxone. Technology to detect OIRD and issue an emergency signal could help ensure responders arrive at the scene of an overdose to administer naloxone in a timely fashion. Currently, there are no FDA-approved products to detect opioid overdose or OIRD that are designed for continuous wear in a discreet location on the body. Resilient Lifescience’s goal is to develop a wearable medical device that can detect OIRD and issue an emergency alert, calling a friend, loved one, or emergency medical service to the scene. The central hypothesis to test in this proposed work is that a patch-based wearable medical device worn on the abdomen will be effective at detecting OIRD in patients and will be a well-accepted form factor for use by individuals with OUD. The overall objective of Phase I in this proposal is to determine technical feasibility of the project by showing that the device is effective at measuring oxygen saturation using reflective photoplethysmography (PPG) on the abdomen and to demonstrate commercial viability of the product by showing that individuals with OUD will adhere to use of the product. Resilient Lifescience will do this by 1) completing feasibility research to evaluate the device’s ability to measure oxygen saturation using reflective PPG on the abdomen, 2) executing user-centered industrial design, and 3) demonstrating that opioid users will adhere to use of the device during a two-week pilot study. The overall objective of Phase II in this project is to de-risk the commercialization of the device by demonstrating that the device is suitable for manufacture, passes required compliance testing, and is effective at detecting OIRD within patients receiving opioid analgesia in a hospital setting. The research team will accomplish this by 1) reaching design-freeze and soliciting quotes for small batch production of the device, 2) testing the ability of the device to detect OIRD in a hospital setting, and 3) completing required electromagnetic compatibility, biocompatibility, ingress protection, and human factors testing for the device.