摘要

Understanding of human cognitive and physical state is a basis for effective control or management of human-machine systems. The first step to achieve this is the development of sensors that are designed to be nonintrusive and measured in real-time. For the purposes of this paper, such sensors will be called biosensors. There are two existing paradigms for biosensors: wearable sensor and noncontact sensor. A wearable sensor had potential to be intrusive, and noncontact sensor methods may still be intrusiveness to a certain extent, while a noncontact sensor is limited in its capability of acquiring physiological signals. The overall objective of this paper is to propose a new paradigm called "natural-contact biosensor" upon a comprehensive evaluation of the existing paradigms. In this paper, the problem dimension for this new paradigm is defined, technical challenges are identified, and technologies to cope with these challenges are presented.