Patent ID: 8663127
Filing Date: 2014-03-04
Classification: A61B

Abstract:
1. A method for determining a volume related to the lungs of a patient, comprising the steps of: supplying breathing gas to the lungs of a patient with an apparatus having an inspiration part, through which said breathing gas passes prior to introduction into the patient and an expiration part through which expired breathing gas from the patient passes, said lungs being ventilated with an alveolar flow, and exhibiting a functional residual capacity (FRC) that is a volume remaining in the lungs following a normal exhalation; in said inspiration part, initiating a change in gas composition of said breathing gas passing therethrough; in said expiration part, measuring a parameter that exhibits a variation dependent on said change in said gas composition of said breathing gas, and determining a time constant that characterizes said variation; and in a processor, determining said FRC of the lungs of the patient from a multiplication product consisting of a first multiplicand consisting of said alveolar flow and a second multiplicand consisting of said time constant.