Imaging photoplethysmography (iPPG) is a powerful set of methods for measuring physiological signals from video. Recent advances have shown that a low-cost webcam can be used to measure heart rate, blood ﬂow, respiration, blood oxygen levels and stress. While these methods have many beneﬁcial applications, the unobtrusive and ubiquitous nature of the sensors risk exposing people to unwanted measurement. WepresentInPhysibletheﬁrstcamouﬂagesystemagainstvideobased physiological measurement. The infra-red system can be embedded into any pair of glasses, or other headwear, and disrupts the measurement of the iPPG signal while being imperceptible by the human eye. Our system is ﬂexible and can simulate realistic pulse signals to hinder heart rate measurement. In this paper we present the design of our prototype and a user study validating its efﬁcacy. Finally, we discuss the limitations and implications for data privacy and security.
InPhysible: A camouﬂage system that protects the wearer from measurement by video-based physiological monitoring systems. Note: The blue color on the face image is just for illustration - the IR LEDs are not visible to the unaided eye.
Electronic schema with the triggered LEDs and our initial prototype of the 3D printed glasses.