Patent ID: 6626845
Filing Date: 2003-09-30
Classification: A61B

Abstract:
An apparatus for measuring gas volumes of a cavity of unknown compliance in a subject having a heart cycle comprising,:(a) an air cavity with induction means for inducing calibrated mass and volume changes in said air cavity; (b) a means for interfacing said air cavity to said subject; (c) a means for interfacing said air cavity to the volume to be measured; (d) a means of interfacing said air cavity to ambient environment to facilitate ordinary breathing activity of said patient during measurement; (e) a means for measuring air pressure variations in said air cavity; (f) a processing means electrically coupled to said induction means; (g) a means for monitoring pulse, wherein said means allows each induced volume change to occur at the same phase in the heart cycle and wherein said means is coupled to said processing means and (h) measuring means for calculating the gas volume.