Remote measurement of breathing rate in real time using a high precision, single-point infrared temperature sensor

Abstract

This paper presents a novel approach for remotely monitoring a user's breathing rate in real-time using a high precision, single-point infrared sensor. Remote breathing detection is especially useful for rehabilitative robotic applications such as post-stroke and post-operative cardiac therapies, where continuous monitoring of a patient's physical stress level can be used to adjust the level and duration of physical exertion throughout the course of therapy. Additionally, socially assistive robots which discreetly collect breathing information from their users, can customize interactions based on the perceived physiological state of the patient. The proposed approach is an important potential improvement for therapies where user mobility is an inherent part of the therapy and when users have a general aversion to being fitted with sensors. Further, due to its relatively small size and modular design, existing rehabilitative robot systems can be retrofitted with the proposed breathing detection system to enhance and extend their functionality. This research delivers a new technique for capturing changes in the sub-nasal skin surface temperature to monitor breathing events. Temperatures are obtained by tracking the sub-nasal region of the face, continuously targeting and sampling the infrared sensor. The breathing rate is automatically extracted using a sinusoidal curve-fitting function which provides an estimated rate in breaths per minute. Results from preliminary tests show this system effectively captures breathing rates within an error rate of under 2 breaths per minute in excess of 70% of typical test cases.