Management of critically ill patients (e.g., trauma, myocardial infarction, and stroke) during ambulance transport requires fast care coordination and shared decision making between prehospital and hospital teams. Despite its critical role, care coordination and communication between prehospital and hospital teams remain ineffective and challenging. Current mechanisms (e.g., radio and phone) are not optimal for information sharing and care coordination in prehospital encounters due in part to their ineffectiveness and limited capabilities of emergency care professionals in interacting with handheld computing devices. Therefore, novel technologies and modes of interactions are needed for supporting prehospital care coordination while allowing emergency care professionals to keep their hands on the patient. Smart glasses have high potential for serving as an unobtrusive technological conduit between prehospital and hospital care providers because they promise advantages such as hands-free operation and context-aware user interaction. To that end, the overarching goal of this project is to design, develop, and evaluate smart glass applications and unobtrusive interaction mechanisms to improve prehospital care coordination while taking into consideration the socio-technical challenges involved in developing technology for the complex, fast-paced prehospital care context. This research is significant because it is an essential early step toward developing novel ?hands-free? technology that can be seamlessly integrated into hands- and eyes-busy medical environments, and in turn, streamlining the workflow of emergency care professionals in coordinating patient care across geographical and organizational boundaries, and enhancing care coordination in prehospital and other critical care settings. We propose two compelling specific aims: 1) To design and develop technologies that support real-time prehospital care coordination; and 2) To evaluate the impact of technology solutions on prehospital care coordination. We will pursue the first aim using a multi-phased, user-centered design approach, combining participatory design workshops, rapid prototyping, and formative evaluation. We will pursue the second aim by assessing care coordination and teamwork efficiency during prehospital encounters through simulations. The proposed research is innovative because it represents a substantive departure from the status quo in the technology development for care coordination during prehospital encounters, focusing on developing novel wearable system with unobtrusiveness interaction techniques to support hands-free, real-time care coordination in emergency care and other critical care processes. In addition, our study approach is novel? despite participatory design (PD) has shown promise in the design of patient-facing technology, surprisingly few researchers have used PD to inform the design of clinician-focused systems, especially in the context of emergency care. Our long-term goal is to build an integrated computerized system that can support shared decision-making and care coordination between prehospital and hospital teams to improve patient outcomes while reducing their cognitive and physical workload. This high impact proposal will be an essential step toward achieving our long-term goal and supporting better patient-centered care delivery and coordination. This proposal aligns with the priorities of both AHRQ and this specific solicitation in developing novel health IT systems that facilitate data sharing to support treatment decision-making and care coordination across multiple care providers, and ultimately, improving health care quality and outcomes.