Evaluation of the cardiorespiratory monitor SpiroGuard C for infants

Objectives: The SpiroGuard C is a commercially available cardiorespiratory monitor working with field plethysmography, wireless signal transmission an d a novel alarm management system. In order to determine the recognition ra tes for central, mixed and obstructive apneas, a prospective clinical trial was performed comparing frequency and kind of signals from the monitor wit h those simultaneously registered by polysomnographic studies. Design: Norm al respiratory and alarm signals of the monitor under investigation were in tegrated into a polysomnographic setting. All central, mixed and obstructiv e apneas lasting more than 10 seconds as well as all alarms obtained from t he monitor were evaluated. Results: 47 series of monitor recordings could b e evaluated In parallel to polysomnographic studies: the detection rate for central apneas was 298/328 (90.85%), for mixed apneas 9/41 (21.95%) and fo r obstructive apneas 0/36 (0%). Out of the total of 708 registered alarms 3 59 (50.71%) were false alarms, 307 (43.36%) were apnea-related and 42/708 ( 5.93%) were alarms due to technical problems. 177 of the 359 false alarms ( 49.30%) occurred during apneas that were shorter than 10 seconds, 119 (33.1 5%) were related to bad signal quality, and 55 (15.32%) were caused by move ment artifacts. Conclusion: The recognition rate for central apneas was hig h (>90%), while sensitivity For mixed and obstructive apneas was not satisf actory. Approximately half of the alarms were false alarms. These could be reduced by setting the apnea detection time to >15 seconds, by tighter fast ening of the respiration belt (improving the signal transmission), and by t urning off the instrument when the child is awake and physically active. Th e wireless system renders the SpiroGuard C an attractive alternative for ho me monitoring.