Cardiopulmonary monitoring at home: the CHIME monitor

Abstract

A new physiologic monitor for use in the home has been developed and used forthe Collaborative Home Infant Monitor Evaluation (CHIME). This monitormeasures infant breathing by respiratory inductance plethysmography andtransthoracic impedance; infant electrocardiogram, heart rate and R-Rinterval; haemoglobin O2 saturation of arterial blood at theperiphery and sleep position. Monitor signals from a representative sample of24 subjects from the CHIME database were of sufficient quality to beclinically interpreted 91.7% of the time for the respiratory inductanceplethysmograph, 100% for the ECG, 99.7% for the heart rate and 87% for the16 subjects of the 24 who used the pulse oximeter. The monitor detectedbreaths with a sensitivity of 96% and a specificity of 65% compared to humanscorers. It detected all clinically significant bradycardias but identified anadditional 737 events where a human scorer did not detect bradycardia. Themonitor was considered to be superior to conventional monitors and, therefore,suitable for the successful conduct of the CHIME study.