||Recognition of Respiratory Instability using a Photoplethysmography of Wrist-watch type Wearable Device
||(Seungyoon Nam) ; (John Lorenzo Bautista) ; (Chanyoung Hahm) ; (Hyunsoon Shin)
|| Apnea; Sleep apnea; Sleep disorder breathing; Apnea-hypopnea index (AHI); Respiratory disturbance index (RDI); Obstructive sleep apnea; Respiration-induced intensity variation (RIIV); Respiratory effort strength index (RESI); Photoplethysmogram; Wearable device
||The photoplethysmography signal is composed of a cardiac-synchronous pulsatile waveform and different parts, which is modulated in amplitude by respiration. This paper presents a new indexing method similar to the apnea-hypopnea index and respiratory disturbance index for the self-diagnosis of sleep apnea symptoms (central and obstructed apnea) by using only a photoplethysmogram (PPG) signal. Sleep apnea is a sleeping disorder from several chronic conditions in which partial or complete cessation of breathing occurs many times throughout sleep at night. A respiratory rate signal (respiration-induced intensity variation) is modulated by synchronizing with the breathing rhythm extracted from PPG using a reflected light on the top of the wrist. This paper presents a new automated recognition and estimation method for daytime apnea and sleep-induced apnea using a wristwatch-type wearable device that can recognize irregular breathing using respiratory rate frequency-based features. The new respiratory effort strength index is proposed to quantify sleep apnea by determining how much a patient is suffering.