Abstract: Method and apparatus for determining the volemic status and vascular tone of the haemodynamic system. The method comprises: receiving a photoplethysmography (PPG) signal by a computer, which signal comprises an alternating AC component as PPG amplitude and the DC component as PPG baseline from a sensor in data communication with a living tissue; determining, in each case by a computer, a multiplicity of PPG signals from the living tissue; determining a multiplicity of AC components of the PPG signals, determining a multiplicity of DC components of the PPG signals, determining a multiplicity of AC waveforms from the AC components and identifying differences in the AC waveforms over time by comparing at least two AC waveforms; determining a DC signal trend over time by comparing at least two DC components; and determining the volemic status and/or vascular tone of the haemodynamic system of the living tissue as a reaction to at least one AC waveform difference and/or a DC signal trend over time.

Abstract: In a method and breathing apparatus for prediction of fluid responsiveness of a subject connected to a breathing apparatus, at least one parameter is monitored that is indicative of a degree of carbon dioxide elimination of the subject, and a positive end expiratory pressure PEEP regulator of the breathing apparatus is operated to apply a PEEP maneuver in which a PEEP applied to the subject is changed from a first PEEP level to a second PEEP level. A processor predicts the fluid responsiveness of the subject based on a change in the monitored parameter, following the change in PEEP.

Abstract: In a method and breathing apparatus for prediction of fluid responsiveness of a subject connected to a breathing apparatus, at least one parameter is monitored that is indicative of a degree of carbon dioxide elimination of the subject, and a positive end expiratory pressure PEEP regulator of the breathing apparatus is operated to apply a PEEP maneuver in which a PEEP applied to the subject is changed from a first PEEP level to a second PEEP level. A processor predicts the fluid responsiveness of the subject based on a change in the monitored parameter, following the change in PEEP.

Abstract: In a CO2-based method for estimating shunt of a subject, a first value related to alveolar CO2 of the subject is obtained from CO2 measurements on expiration gas exhaled by said subject, a second value is obtained related to arterial CO2 of the subject, a third value is obtained related to cardiac output [QT] or effective pulmonary perfusion [EPP] of the subject, a fourth value is obtained related to CO2 elimination [VCO2] of the subject, the shunt of the subject is calculated based on said first, second, third and fourth values. The method allows the shunt of the subject to be determined in a non-invasive or minimally-invasive way without requiring determination of the venous or capillary CO2 contents of the subject, which in turn allows the method to be carried out at the bedside, enabling reliable monitoring of shunt in clinical practice.

Abstract: Method for providing ventilatory settings with regard to the airway pressure levels of an artificial ventilator, the artificial ventilator is connected to a lung, including the steps of obtaining data samples of a gas concentration of the expired gas over a single breath; selecting a plurality of data samples from the obtained data samples; calculating a tracing value being sensitive to changes of alveolar dead space on the basis of the selected data samples; repeating steps a), b) and c) for obtaining a plurality of tracing values; and changing at least one airway pressure level of the artificial ventilator, wherein from an observation of a resulting course of the plurality of calculated tracing values an airway pressure level at which alveolar opening or lung overdistension or lung open condition or alveolar closing occurs is detected. Apparatus for providing ventilatory settings with regard to the airway pressure levels of an artificial ventilator is also disclosed.

Abstract: The invention refers to a method and apparatus for changing the concentration of a target gas at the blood compartment of a patient's lung from an actual target gas concentration to a desired target gas concentration during artificial ventilation with an inspiratory gas composition by a respirator being controlled via a set of ventilation parameters. In order to decrease the negative effects of general anaesthesia during artificial ventilation even further, the method according to the invention comprises the following steps: a) ventilating the lung in a first ventilation stage, and b) ventilating the lung in a second ventilation stage in which alveolar recruitment is promoted.

Abstract: The invention concerns a method and apparatus for determining the status of a ventilated lung. For determining the status of a lung ventilated, which enables in real time optimal ventilatory settings for a recruitment maneuver of an ailing lung, the invention comprises a sensor for measuring a gas concentration in the expired gas during a single breath, an analog to digital converter for obtaining data samples of said gas concentration in the time domain, means for selecting a plurality of data samples, means for calculating a mean tracing value being sensitive to changes of alveolar dead space based on said samples, and a data processor which detects during a change of the airway of the ventilator from the resulting course of calculated mean tracing values the peak inspiratory pressure at which alveolar opening or lung overdistension occurs and/or the PEEP at which lung open condition or alveolar closing occurs.