Pulmonary function deterioration screening using a patch-type multimodal sensor: a pilot study

The progressive decline in pulmonary function contributes to the risk of chronic respiratory diseases and reduction in quality of life. However, the conventional pulmonary function test, Spirometry, is only available after the patient acknowledges the symptoms. In case of structural damage to the lungs, it is irreversible, and complete treatment is difficult. Therefore, we aimed to establish a simple pulmonary function monitoring system using the photoplethysmography (PPG) sensor on the patch-type multimodal sensor. As a pilot study, we conducted trend analysis of the proposed sensor during simulated hypoxemia and comparison based on smoking history. From hypoxia simulation, respiratory PPG signals are likely to be affected not only by physical respiratory dynamics, but also by internal pulsatile indices. The degree of deformation in signal amplitude and intensity differed by smoking history. In addition, it showed a mild correlation with poor pulmonary function. Although further evaluation with a broader participant pool and clinical pulmonary evaluation is necessary, these findings suggest potential application for early pulmonary function monitoring with the proposed sensor.Clinical Relevance- This suggests the potential use of the PPG signal from the patch-type multimodal sensor for early screening of pulmonary function deterioration, for which many patients remain undiagnosed due to its asymptomatic symptoms.