In addition to summarizing and detailing developed diagnostic devices, this book will attempt to point out the possible future trends of development for point-of-care diagnostics using both scientifically based research and practical engineering needs with the aim to help novices comprehensively understand the development of point-of-care diagnostics. This includes demonstrating several common but critical principles and mechanisms used in point-of-care diagnostics that address practical needs (e.g., disease or healthcare monitoring) using two well-developed examples so far: 1) blood glucose meters(via electrochemistry); and, 2) pregnancy tests (via lateral flow assay). Readers of this book will come to fully comprehend how to develop point-of-care diagnostics devices, and will be inspired to contribute to a critical global cause – the development of inexpensive, effective, and portable in vitro diagnostics tools (for any purpose) that can be used either at home or in resource limited areas.