A novel minimal-contact biomotion method for long-term respiratory rate monitoring

Abstract

Purpose In this study, we assessed the diagnostic accuracy of the device VitaLog (SWG Sportwerk GmbH & Co. KG, Dortmund, Germany) for estimation of respiratory rate (RR) variability. Methods VitaLog is a minimal-contact biomotion device that is placed under the mattress topper. It senses respiratory effort and body movement using a piezoelectric sensor. Diagnostic accuracy was determined in 103 patients referred to our sleep laboratory for suspected sleep-disordered breathing (SDB). SDB was defined by AHI >= 15/h. Results provided by VitaLog were compared with nasal flow measurement obtained by polysomnography (PSG). Results Diagnostic accuracy of VitaLog was excellent. We obtained a correlation of r = 0.99 and a bias of 0.2 cycles per minute (cpm) between VitaLog and PSG-provided nasal flow. Detection RR variability worked nearly identically in patients with and without SDB. Conclusion VitaLog is an appropriate method for determination of RR variability based on a minimal-contact biomotion sensor. This device is easy to handle, available at low cost, and suitable for long-term monitoring in the hospital or at home.