A simple method for measuring calorie expenditures during sleep

A simple method for the continuous determination of O2 consumption and CO2 production in sleeping subjects is described. Face masks and mouth pieces have been eliminated and the method has been successful with babies and adults. The apparatus consists of a ventilated hood connected to a vacuum cleaner. The subject sleeps with his head on a pillow inside the hood and fresh air is sucked over his face. Diluted expired air leaves the hood through an outlet in the rear wall and its volume is measured with a gas meter. A side-arm fitted to the outlet enabes continuous samples of diluted expired air to be diverted by an aquarium pump into a sampling bag. Safety circuits are incorporated into the hood. (Summary)