Project Abstract Urinary incontinence (UI) and difficulties with toilet training are significant and common challenges faced by children and young adults with autism spectrum disorder (ASD) and/or intellectual and developmental disabilities (IDD). For these individuals, toileting problems can result in slower progress and lower overall success rates with toilet training compared to their neurotypical same-aged peers, and a substantial negative impact on their independence and ability to participate in educational and community settings. Unfortunately for many, these difficulties with incontinence can continue into adulthood, creating physical and psychological quality of life barriers, such as physical discomfort, social isolation, improper hygiene, and lowered self-confidence and independence. The available support tools for children struggling with toilet training have not advanced significantly in decades, and there is an urgent need for approaches to help these individuals achieve long-term successful toileting. In this work, a technological support tool will provide a proactive solution to help with toilet training. By proactively alerting before an accident occurs, it is expected that the use will be able to learn to recognize and attend to the sensation that triggers the alert. Further, a proactive response will reduce accident risk, minimize associated embarrassment from accidents, and decrease the likelihood of developing toileting averse behaviors. The project takes a multi-disciplinary approach, combining expertise from Electrical Engineering and Special Education, in order to tackle two key aims. The first aim is to identify the highly population-dependent set of needs and constraints for an ideal toileting support tool through engagement with key stakeholders (i.e., parents and caregivers of children with ASD/IDD, care providers, educators, and clinical professionals) through focus groups and survey-based questionnaires. The second aim is to design, implement, and pilot test a user-centered bladder monitor that aims to uniquely provide a support tool to proactively alert of bladder fullness and support dignity and independence for children and young adults with ASD/IDD and others suffering from UI. Built based on radiofrequency (RF)-based technology, the bladder monitor is non-invasive and enables real-time, safe, and continuous measurement and monitoring of the bladder state through a sensor array that is flexible, discreet, and wireless. The resulting monitor will meet the diverse needs of this population and will be the first tool ever to provide a proactive alert when the bladder is approaching full to support toilet training and avoid accidents. Initial validation testing will be conducted through electromagnetic computational simulations and experimental demonstrations, followed by pilot testing with stakeholders to establish real world feasibility and social validity, with expanded behavioral studies in individuals with ASD/ID...