A Near-Field Radio Frequency System for Continuous Left and Right Lung Volume Sensing

Many respiratory disorders are diagnosed by lung function tests, typically performed using spirometers in clinical settings. Non-invasive measures of lung function are of increasing interest to enable convenient, at-home wellness monitoring of respiratory distress. In this work, we used near-field radio-frequency (NFRF) sensors on mechanically ventilated porcine models for continuous acquisition of pulmonary dynamics for each lung independently under various cardiopulmonary interventions. NFRF sensors, previously shown to detect internal tissue motion, were deployed laterally across the pig chest to measure tidal volume during a stepped intervention. A reference spirometer was used for validation. We used bronchial blockers to isolate each lung, allowing us to demonstrate the novel capability of individually monitoring lung volumes. We demonstrated lung volume measurements with an average error of 9.2% between NFRF and reference spirometry. We also showed individual lung dynamics during one-lung obstruction. The results of this work demonstrates NFRF sensors as a novel wearable method for continuous monitoring of individual lung volumes, aiding the management of respiratory distress during acute and chronic conditions, as well as for detecting early onset of life-threatening conditions such as pneumothorax.