Continuous non-contact vital sign monitoring in neonatal intensive care unit

[摘要] Current technologies to allow continuous monitoring of vital signs in pre-term infants in the hospital require adhesive electrodes or sensors to be in direct contact with the patient. These can cause stress, pain, and also damage the fragile skin of the infants. It has been established previously that the colour and volume changes in superficial blood vessels during the cardiac cycle can be measured using a digital video camera and ambient light, making it possible to obtain estimates of heart rate or breathing rate. Most of the papers in the literature on non-contact vital sign monitoring report results on adult healthy human volunteers in controlled environments for short periods of time. The authors' current clinical study involves the continuous monitoring of pre-term infants, for at least four consecutive days each, in the high-dependency care area of the Neonatal Intensive Care Unit (NICU) at the John Radcliffe Hospital in Oxford. The authors have further developed their video-based, non-contact monitoring methods to obtain continuous estimates of heart rate, respiratory rate and oxygen saturation for infants nursed in incubators. In this Letter, it is shown that continuous estimates of these three parameters can be computed with an accuracy which is clinically useful. During stable sections with minimal infant motion, the mean absolute error between the camera-derived estimates of heart rate and the reference value derived from the ECG is similar to the mean absolute error between the ECG-derived value and the heart rate value from a pulse oximeter. Continuous non-contact vital sign monitoring in the NICU using ambient light is feasible, and the authors have shown that clinically important events such as a bradycardia accompanied by a major desaturation can be identified with their algorithms for processing the video signal.

[学科分类] 肠胃与肝脏病学

[关键词] paediatrics;biomedical optical imaging;patient monitoring;patient care;medical image processing;pneumodynamics;oxygen;oximetry;biochemistry;cardiology;blood vessels;estimation theory;video recording;video cameras;biomedical equipment;feature extraction;continuous noncontact vital sign monitoring;neonatal intensive care unit;continuous vital sign monitoring technologies;continuous pre-term infant monitoring;hospital;adhesive electrodes;adhesive sensors;direct patient contact;infant stress;infant pain;infant skin damage;superficial blood vessel colour change measurement;superficial blood vessel volume change measurement;cardiac cycle;digital video camera;ambient light;continuous heart rate estimation;breathing rate estimation;adult healthy human volunteers;clinical letter;high-dependency care area;NICU;video-based noncontact monitoring methods;continuous respiratory rate estimation;continuous oxygen saturation estimation;infant nursing;incubators;stable sections;minimal infant motion;mean absolute error;camera-derived estimates;reference heart rate value;electrocardiogram;ECG-derived value;pulse oximeter;bradycardia identification;major desaturation;video signal processing algorithms;time 4 day;O2