Accuracy of the Interpolated Surface Mesh Method for OEP Volume Measurement

Background: Optoelectronic plethysmography (OEP) is a non-invasive technique that can be used to assess both respiratory volumes and chest wall kinematics. An interpolation surface method (ISM) has been recently developed to enhance OEP kinematic analysis. The aim of this study was to test whether ISM is as accurate as the conventional method (CM) for volume measurement when compared with conventional spirometry. Methods: Pneumotachographs and OEP were recorded simultaneously on a healthy subject who performed quiet and deep breathing. Results: In total, 124 tidal volumes (TV) and 50 vital capacities (VC) were obtained. ISM introduced a lower bias for both TV and VC, with narrower limits of agreement for CM in both conditions. Mean discrepancies were systematically <2.15%. Correlation coefficients were in the interval [0.978; 0.991], with an ICC in the interval [0.968; 0.991] for both TV and VC. Conclusions: ISM and CM have similar volume measurement accuracies. ISM preserves the accuracy of OEP volume measurements and its software environment. Although ISM represents a promising approach for breathing motion analysis, its contribution to improving kinematic analysis remains to be evaluated across a broader range of morphologies and breathing patterns.