Patent ID: 7584752

Claim:
A process for controlling a respirator in combination with an electroimpedance measuring device, which receives impedance measured signals U via an electrode application arranged on the upper body of a test subject, the process comprising the steps of: setting a mode for pressure-controlled or volume-controlled, mechanical respiration on the respirator during a first respiration phase; obtaining end-expiratory values of said impedance measured signals U during one respiration phase of a respiration cycle of mechanical respiration, said values being correlated with the respiration cycle; calculating a first reference value U ref1 from the obtained end-expiratory values of the impedance measured signals U; obtaining other end-expiratory values of said impedance measured signals U during another respiration phase during mechanical respiration; forming a second reference value U ref3 from the other end-expiratory values of said impedance measured signals; and forming a difference from the second reference value U ref3 and the first reference value U ref/1 to provide an indicator of a change in the functional residual capacity (FRC) of a lung of the test subject.