Contactless portable respiratory rate monitor (CPRM) accurately measures respiratory rate in children

Background: Respiratory rate (RR) is an important vital sign used in the initial and ongoing assessment of unwell children. It is used in Paediatric Early Warning Scores to assess a child’s clinical status and as a predictor of serious deterioration. Convenient electronic devices exist for the measurement of pulse, blood pressure, oxygen saturation and temperature that provide accurate and prompt measures of vital signs. Devices for monitoring RR have entered the commercial market but there is no device currently available that gives an accurate and rapid assessment of RR in clinical practice. Aim: We have developed a contactless portable respiratory rate monitor (CPRM) and aimed to measure agreement with existing methods of RR measurement. Method: Respiratory rate data were collected from 30 children undergoing polysomnography sleep studies at a tertiary children’s hospital. Measurements from respiratory inductance plethysmography (RIP) bands (established contact method), visual counting of chest movements (established non-contact method) and the CPRM (developed device) were all obtained simultaneously and compared. Two to three data sets were collected for each child. A total of 61 recordings were obtained from children ranging from 8 months to 15 years. Results: Data showed substantial agreement between measurements from the CPRM and the gold standard RIP (Interclass correlation coefficient 0.762: 95% CI 0.633–0.850). When two patients with significantly dysfunctional breathing were removed from the analysis, the CPRM showed a much higher correlation with the gold standard RIP method (Interclass correlation coefficient 0.981: 95% CI 0.968- 0.989) with 95% limits of agreement –2.49–0.77 breaths/min. Conclusion: A portable contactless device developed in this study can accurately and quickly measure respiratory rate. Such a device will be an important tool in the initial assessment of unwell children. There is currently no such device on the market. More testing is needed to explore outlying measurements and to evaluate in different clinical settings. Further development and modification of the device and software are ongoing.