Respiratory parameters via tilt angles at the human upper body

• Published in: IFAC-PapersOnLine Vol. 58; no. 24; pp. 508 - 513
• Main Authors: Laufer, B., Murray, R., Docherty, P.D., Krueger-Ziolek, S., Hoeflinger, F., Reindl, L., Moeller, K.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2024
• Subjects: IMU; Motion Capturing; Respiratory parameters; Tidal volume; Tilt angles; IMU; Respiratory parameters; Tilt angles; Tidal volume; Motion Capturing
• ISSN: 2405-8963; 2405-8971; 2405-8963
• DOI: 10.1016/j.ifacol.2024.11.089

Determination of respiratory parameters via surface motions of the upper body has been the subject of research since the 1960s. Since then, many studies and approaches yielded only minor success regarding the accuracy required for clinical applications. By the synchronous measurement of a motion capture system and a spirometer the surface motion of the upper body could be mapped to human lung activity. A compression shirt was equipped with 102 motion capture markers and was worn by eight different volunteers during spirometry. Various respiratory manoeuvres were performed to cover most common breathing actions, including normal or deep breathing. Based on the motion capture data, the respiration induced changes of tilt angles at the positions of the motion capture markers were calculated. A linear regression analysis showed that based on changes in 7 tilt angels, maximal tidal volumes can be determined with a R2 of 0.97 and a mean error over all subjects of 5%. The usage of 8 tilt angles allowed the determination of maximal tidal volumes with a R2 of 0.98 and a mean error over all subjects of 4%. This method showed an adequate accuracy for clinical applications focusing on deeper and maximal breaths, while at tidal volumes smaller than 1.5 L the errors were more significant. A combination of approaches using changes of tilt angles and circumferential changes for volume determination may be able to obtain clinically relevant and accurate respiratory parameters