Development of a home screening system for pediatric respiratory sleep studies

To develop a simple and portable home screening monitor for sleep-disordered breathing (SDB) in children. In such a system, identifying the respiratory events and occurrences of motional artifacts are two essential elements that can affect the accuracy of the study. Moreover, such a system needs to be easy to set up and user friendly. The proposed system includes the following: electrocardiogram, pulse oximeter, microcontroller-based computation device, and a tri-axial accelerometer. Three physiologic parameters derived with this device were used to identify central (CE) and obstructive (OE) respiratory events. The criteria used were based on documented evidence and compared against corresponding standard polysomnographic scorings. In addition, a module was constructed in conjunction with a RS232 chip to transmit the recorded data to a personal computer. The accelerometer was used as a motion artifact detector. Detectable signals were acquired from the accelerometer when artifacts were induced on the photoplethysmography by motions in three regulated test activities lasting at least 30 seconds each. In classifying respiratory events, the combined use of oxygen saturation, heart rate, and pulse transit time to produce a complex classification (logic OR) showed promise. For OE, the sensitivity and specificity were 0.828 and 0.859, respectively. For CE, these values were 0.868 and 0.762, respectively. The proposed system potentially fulfils the criterion as a home screening tool and can form an indispensable addition to the SDB investigation in the pediatric population.