Estimation of breathing rate in thermal imaging videos: a pilot study on healthy human subjects

Abstract

Diverse studies have demonstrated the importance of monitoring breathing rate (BR). Commonly, changes in BR are one of the earliest and major markers of serious complications/illness. However, it is frequently neglected due to limitations of clinically established measurement techniques, which require attachment of sensors. The employment of adhesive pads or thoracic belts in preterm infants as well as in traumatized or burned patients is an additional paramount issue. The present paper proposes a new robust approach, based on data fusion, to remotely monitor BR using infrared thermography (IRT). The algorithm considers not only temperature modulation around mouth and nostrils but also the movements of both shoulders. The data of these four sensors/regions of interest need to be further fused to reach improved accuracy. To investigate the performance of our approach, two different experiments (phase A: normal breathing, phase B: simulation of breathing disorders) on twelve healthy volunteers were performed. Thoracic effort (piezoplethysmography) was simultaneously acquired to validate our results. Excellent agreements between BR estimated with IRT and gold standard were achieved. While in phase A a mean correlation of 0.98 and a root-mean-square error (RMSE) of 0.28 bpm was reached, in phase B the mean correlation and the RMSE hovered around 0.95 and 3.45 bpm, respectively. The higher RMSE in phase B results predominantly from delays between IRT and gold standard in BR transitions: eupnea/apnea, apnea/tachypnea etc. Moreover, this study also demonstrates the capability of IRT to capture varied breathing disorders, and consecutively, to assess respiratory function. In summary, IRT might be a promising monitoring alternative to the conventional contact-based techniques regarding its performance and remarkable capabilities.

Monitoring of Cardiorespiratory Signals Using Thermal Imaging: A Pilot Study on Healthy Human Subjects

“…For the remaining 16 subjects, Table 2 shows excellent agreement between IRT and piezoplethysmography, with a RMSE of 0.71 ± 0.30 breath/min and a mean relative error of 0.03 ± 0.01. These results are similar to those reported previously [ 4 , 31 ].…”

Bipedal Steps in the Development of Rhythmic Behavior in Humans

“…Maternal breathing is audible in utero (Parncutt, 2016). The resting mother's breathing creates a rhythm of 12-20 BPM (Barbosa Pereira et al, 2017). In a walking mother, breathing may be coupled to footfall, since locomotion and respiration are frequently coupled (Bramble & Carrier, 1983;Funk, Milsom, & Steeves, 1992).…”

“…Respiration-Locomotor Coupling. Human gait is usually in the range of 100-120 BPM (Nessler et al, 2011) and breathing is 12 to 20 cycles per minute (cpm) ( Barbosa Pereira et al, 2017). Since locomotion and respiration are frequently coupled (Bramble & Carrier, 1983;Funk et al, 1992) this may result in coupling of footfalls, breathing sounds, and passive tactile stimulation.…”

Non-Contact Respiration Monitoring and Body Movements Detection for Sleep Using Thermal Imaging

“…Previously, several approaches have been proposed to monitor respiration with a thermal camera by detecting the temperature change around the nostrils [18,[21][22][23][24][25][26][27][28] or the airflow [19,20,29] in seated positions. They set the nose or the mouth as the region of interest (ROI) that can be defined manually or automatically by using anatomical features integrated with tracking algorithms [18,[21][22][23]25]. They performed by simulated breathing following scenarios that the researcher designed, i.e., regular breathing, fast breathing, and hold breathing [18,21,[24][25][26].…”