This book constitutes the proceedings of the Fourth International Conference on Internet of Things (IoT) Technologies for HealthCare, HealthyIoT 2017, held in Angers, France, in October 2017. The IoT as a set of existing and emerging technologies, notions and services can provide many solutions to delivery of electronic healthcare, patient care, and medical data management. The 17 revised full papers presented were carefully reviewed and selected from 23 submissions. The papers cover topics such as healthcare support for the elderly, real-time monitoring systems, security, safety and...