A roadmap for the development of human body digital twins

A digital twin (DT) of the human body is a virtual representation of an individual's physiological state, created using real-time data from sensors and medical devices, with the purpose of simulating, predicting and optimizing health outcomes through advanced analysis and modelling. Human body DTs have the potential to revolutionize healthcare and wellness, but their responsible and effective implementation requires consideration of multiple intertwined engineering aspects. This Perspective presents an overview of the status and prospects of the human body DT and proposes a five-level roadmap to guide its development, from the sensing components, in the form of wearable devices, to the data collection, analysis and decision-making systems. The support, security, cost and ethical considerations that must be addressed are also highlighted. Finally, we provide a framework for the development and a perspective on the future of the human body DT, to aid interdisciplinary research and solutions for this evolving field. The rapid development of on-body sensors and multimodal artificial intelligence is accelerating the emergence of the human body digital twin (DT) as an interdisciplinary research topic. This Perspective outlines a roadmap for applications of human body DTs in health monitoring, disease prevention and treatment.