Objective To evaluate a novel device (Respimometer) for objective measurement of respiratory rate (RR) in low-resource settings.
Design Description of prototype development, with proof-of-concept pilot field study at four paediatric healthcare facilities in Butembo, Democratic Republic of the Congo (DRC). The instrument was tested in healthy adult volunteers (n=10) and Congolese children (n=42) and compared with timed breaths (adults) or by reference comparator capnography (children). Correlation and Bland-Altman plots were generated for paired measurements.
Results The Respimometer is shaped like an oral thermometer and is placed in the mouth of the participants. RR is measured by thermistors positioned at the nasal outlet, which detect the temperature change between inhaled and exhaled breaths. In adult volunteers, the correlation coefficient between the delivered RR and the Respimometer measurement was median 0.992 (IQR 0.980–0.999). Measurement bias was −0.50 min−1 (95% CI −1.1 to +0.07, p=0.093), with upper and lower limits of agreement of −5.2 min−1 and 4.2 min−1, respectively. Among Congolese children, there was no evidence of bias: mean difference in RR +1.0 min−1 (95% CI −2.1 to +4.1, p=0.52). The upper and lower limits of agreement were −18 and +20 min−1, respectively.
Conclusion The Respimometer can accurately measure the RR in healthy adults and children in DRC. A simple and accurate instrument could facilitate the diagnosis of pneumonia by community health workers in low-income and middle-income countries, leading to reduced pneumonia-related deaths.
- remote diagnostics
- respiratory rate
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Contributors HT wrote and reviewed the manuscript. KMC performed the data collection, wrote and reviewed the manuscript. IA conceived the study, oversaw the data collection and reviewed the manuscript. SSE collected the data and reviewed the manuscript. IS designed and modified the device and reviewed the manuscript. YA designed and modified the device and reviewed the manuscript. MTH collected the data, performed the statistical analysis, wrote and reviewed the manuscript.
Funding This study was supported by USAID, the Association for Health Innovation in Africa (AFHIA) and Grand Challenges Canada.
Competing interests IS and YA are employees of RespiDx Ltd, a company which is developing the Respimometer for use in low-income settings as well as commercial markets in higher-income countries.
Patient consent Parental/guardian consent obtained.
Ethics approval Comité d’Ethique du Nord Kivu and Research Ethics Board of the University of Alberta.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement Unpublished data from this study are available from the corresponding author on request.
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