Estimating Thoracic Movement with High-Sampling Rate THz Technology

Abstract

We use a high-sampling rate terahertz (THz) homodyne spectroscopy system to estimate thoracic movement from healthy subjects performing breathing at different frequencies. The THz system provides both the amplitude and phase of the THz wave. From the raw phase information, a motion signal is estimated. An electrocardiogram (ECG) signal is recorded with a polar chest strap to obtain ECG-derived respiration information. While the ECG showed sub-optimal performance for the purpose and only provided usable information for some subjects, the signal derived from the THz system showed good agreement with the measurement protocol. Over all the subjects, a root mean square estimation error of 1.40 BPM is obtained.

Human Respiration Rate Measurement with High-Speed Digital Fringe Projection Technique

“…To measure the chest wall movements and extract respiration parameters, several technologies have been used, including marker-based systems [9], laser vibrometry [11], radiofrequency sensors [12,13], terahertz sensors [14], ultrasound [15], RGB cameras [16][17][18] and depth sensors [2]. While marker-based systems are classified as contactless, they still require markers to be attached to the body.…”