Principles of the Bohr integration procedure and their application to measurement of diffusing capacity of the lung for oxygen

This paper deals with the physiological implications of the successive steps which are involved in the determination of the diffusing capacity of the lungs for oxygen. In the course of the presentation, a ‘Bohr integral chart’ is derived and its geometrical and mathematical bases are indicated. The chart is of theoretical interest in elucidating physiological events, such as the rate of increase in the oxyhemoglobin saturation of blood traversing the pulmonary capillary. It also illustrates the principles which are entailed in use of two levels of oxygenation for the estimation of the diffusing capacity of the lungs for oxygen. An enlarged version of the chart has the practical advantage of simplifying the calculation of the diffusing capacity while keeping before the operator the assumptions and potential sources of error. Submitted on November 23, 1959