Abstract
In 1870, Frick pointed out that the output of the heart per minute could be determined from the difference in either the carbon dioxide or the oxygen tension of the blood before and after it passed through the lungs by direct determination of these gases in the arterial and venous blood. Subsequently, many attempts to adapt the Frick principle to the determination of the circulation rate in man were made by various investigators. The first of these attempts were based on equilibration of either the oxygen or the carbon dioxide in the lungs with the oxygen or the carbon dioxide in the blood, thus avoiding the dangers inherent in direct cardiac puncture as used originally. Bornstein, in 1910, suggested the use of high concentrations of nitrogen for equilibration, instead of carbon dioxide or oxygen, because it is an inert gas which does not enter into the various metabolic processes. The
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
