Measurement of Respiratory Function by Electromagnetic Induction

Abstract

Continuous sensing of metrics for respiratory function, such as respiratory volume and oxygen intake, is useful for predicting disease and evaluating exercise capacity. Recently, respiratory sensing methods using the chest displacement were proposed as simple methods. However, the stability of measurement and the robustness to noise are the issues for the methods. This research proposes a method to detect the chest displacement by using electromagnetic induction to achieve respiratory sensing with the lower mechanical interference. Specifically, the electromagnetic induction between the coils attached to the chest is used to estimate respiratory volume with a regression model. Then, oxygen intake is calculated by using the estimated respiratory volume. For an evaluation experiment, respiratory volumes were recorded by using the proposed system and a calibrated spirometer. As a result, the estimation error was 15 % of the maximum respiratory volume. Moreover, the oxygen intake could be calculated from the respiratory volume.