Contact-Free Respiration Rate Monitoring Using a Pan–Tilt Thermal Camera for Stationary Bike Telerehabilitation Sessions

One typical remote consultation envisioned for in-home telerehabilitation involves having the patient exercise on a stationary bike. Making sure that the patient is breathing well while pedaling is of primary concern for the remote clinician. One key requirement for in-home telerehabilitation is to make the system as simple as possible for the patients, avoiding, for instance, to have them wear sensors and devices. This paper presents a contact-free respiration rate monitoring system measuring temperature variations between inspired and expired air in the mouth–nose region using thermal imaging. The thermal camera is installed on a pan–tilt unit and coupled to a tracking algorithm, allowing the system to keep track of the mouth–nose region as the patient exercises. Results demonstrate that the system works in real time even when the patient moves or rotates its head while exercising. Recommendations are also made to minimize limitations of the system, such as the presence of people in the background or when the patient is talking, for its eventual use in in-home telerehabilitation sessions.