Pulmonary pressure and volume measurement

Claim 2

Method of determining mechanical properties of the lung of a patient comprising - inflating and deflating the lung with a predetermined gas volume - measuring the pressure changes generated in the lung during inflation and deflation - transforming the volume and the measured pressure data into digital form - calculating typical or clinically significant volume to pressure ratios - displaying the result of the calculation.

Claim 3

Method of determining mechanical properties of a patient's lung comprising - inflating and deflating the lung with a predetermined gas volume - measuring the pressure changes generated in the lung during inflation and deflation - correcting the volume data according to the formula wherein V eff is the corrected or compensated volume, V is the volume displaced by piston 18 based on the cylinder and piston geometry, the factor 0,116 is an experimental factor found to be an optimum by the inventor, v comp is a volume which compensates for the net oxygen loss (C0 2 generation taken in consideration), T is cycle time in seconds - calculating typical or clinically significant volume to pressure ratios - displaying the result of the calculation.

Claim 4

Method of determining mechanical properties of a patient's lung comprising - inflating and deflating the lung with a predetermined gas volume - measuring the pressure changes generated in the lung during inflation and deflation - correcting the volume data according to the formula wherein V eff is the corrected or compensated volume, V is the volume displaced by piston 18 based on the cylinder and piston geometry, the factor 0,116 is an experimental factor found to be an optimum by the inventor, v comp is a volume which compensates for the net oxygen loss (C0 2 generation taken in consideration), T is cycle time in seconds - calculating typical or clinically significant volume to pressure ratios - displaying the result of the calculation.

Claim 5

Method according to claim 1 or 2 wherein the inflating and deflating is effected stepwise with incremental volume changes.

Claim 6

Device for determining mechanical properties of a patient's lung comprising - pump means (13) to feed to and withdraw from a patient's lung (16) a predetermined gas volume - pressure sensor means (26) for sensing the gas pressure in the lung - data processing means (14) for processing the volume and pressure data to result in continuous generation of volume pressure ratio data - control means (43, 23, 21) for controlling the pump means.

Claim 7

Device for determining mechanical properties of a patient's lung comprising - pump means (13) to feed to and withdraw from a patient's lung (16) a predetermined gas volume - pressure sensor means (26) for sensing the gas pressure in the lung - data processing means (14) for processing the volume and pressure data to result in continuous generation of volume pressure ratio data - control means (43, 23, 21) for controlling the pump means.

Claim 8

Device according to claim 4, wherein the pump means (13) contains a motor-driven piston pump connected to the patient's lung (16).

Claim 9

Device according to claim 4, wherein the data processing means contain a microprocessor (37) and memory means (38, 39) for permanent storage of program data and for preliminary storage of input and output data.

Claim 10

Device according to claim 6 wherein the data processing means moreover contain display and indicating means (32 - 35).