Background: Respiratory rate is a vital physiological measurement used in the immediate assessment of unwell children and adults. Convenient electronic devices exist for the measurement of pulse, blood pressure, oxygen saturation, and temperature. Although devices which measure respiratory rate exist, none have entered everyday clinical practice for acute assessment of children and adults. An accurate and practical device which has no physical contact with the patient is important to ensure readings are not affected by distress caused by the assessment method.
Objective: The aim of this study was to evaluate the use of a thermal imaging method to monitor the respiratory rate in children and adults.
Methods: Facial thermal images of adult volunteers and children undergoing elective polysomnography were included. Respiration was recorded for at least 2 min with the camera positioned 1 m from the subject's face. Values obtained using the thermal imaging camera were compared with those obtained from contact methods such as the nasal thermistor, respiratory inductance plethysmography, nasal airflow, and end tidal CO2.
Results: A total of 61 subjects, including 41 adults (age range 27-46 years) and 20 children (age range 0.5-18 years) were enrolled. The correlation between the respiratory rate measured using thermal imaging and the contact method was r = 0.94. Sequential refinements to the thermal imaging algorithms resulted in the ability to perform real-time measurements and an improvement of the correlation to r = 0.995.
Conclusion: This exploratory study shows that thermal imaging-derived respiratory rates in children and adults correlate closely with the best performing standard method. With further refinements, this method could be implemented in both acute and chronic care in children and adults.
Keywords: Respiratory rate; Thermal imaging; Vital signs.
© 2019 S. Karger AG, Basel.