Abstract: A device for supplying a patient with breathing gas, in which an initially high initial pressure Paw(t=0) applied from the outside is automatically lowered by means of a control circuit to a lower inspiratory pressure Paw(t) as soon as a pulmonary internal pressure Plung(t) threatens to exceed a predetermined pulmonary target pressure Plung,soll. Overinflation of the lungs due to the respiration is thus ruled out according to the present invention. The device permits, moreover, rapid filling of the lungs with breathing gas and makes thus possible a comparatively long phase of expiration. A process is also provided for regulating a respirator and for respirating a patient.

Abstract: Operating a respirator with an inspiration pressure-vs.-time curve (1), which has an airway target pressure (paw—target) and a PEEP (3), in which the inspiration pressure-vs.-time curve (1) reaches the airway target pressure (paw—target) on a ramp-like curve (17) starting from a starting airway pressure (paw—Start), which is greater than the PEEP (3).

Abstract: A process with a corresponding device for lung ventilation involves recording an image of the lung status with an electric impedance tomography (EIT) system (2) and the total area of ventilated lung areas is determined by a computing unit (4) from all image values, subsequently divided into at least two lung areas and the extent of the homogeneity of the ventilated lung areas is determined by comparison of the impedance changes within these areas. In case of a homogeneity rated as being too low, the respiration pressures are increased step by step by means of the respirator (1) and the respiration pressure at which the greatest possible homogeneity is obtained from subsequently determined status images is determined by means of the EIT system (2).

Abstract: An electroimpedance tomograph with a plurality of electrodes (1) is provided, which can be placed on the body of a patient and are connected via a selector switch (60) with a control and evaluating unit (20). The control and evaluating unit (20) cooperates with the selector switch (60) such that two electrodes each are supplied with an alternating current from an AC power source (22) and the detected analog voltage signals of the other electrodes are processed in order to reconstruct therefrom the impedance distribution of the body in the plane of the electrodes, wherein a symmetrical AC power source is used to reduce common-mode signals.

Abstract: An electro-impedance tomography (EIT) system (2), with a computing unit (4) and a respirator (1) is described for gentle mechanical lung ventilation especially in case of atelectases. The presence, the extent and/or the spatial distribution of atelectases is detected by the EIT system (2) and sent to the respirator (1) so that the respiration pressure is increased step by step by the respirator (1) until the current image of the lung status corresponds to a first status image of healthy lungs or comes close to it with minimal deviations. The respiration pressure is subsequently reduced again step by step by the respirator (1) until the computing unit (4) detects a reduction of the ventilated lung areas and the respiration pressure is subsequently increased again by means of the respirator (1) to the last value at which no change occurred in the ventilated lung areas.

Abstract: A method, system and device are provided for the determination of leaks in a respirator. An inspiraton pressure pinsp is recorded during an inspiration time Tinsp with a measuring device. The inspiration pressure pinsp is varied during consecutive breaths I. Leaks are determined as to leak volumes VLi from the product of pinspi and Tinspi in accordance with the equation VLi=A×pinspiB×Tinspi while the parameters A and B are determined in an analyzing unit by a regression model with pinsp as the regressor.

Abstract: A respirator for breath-supporting respiration has improved sensitivity of triggering breathing support. A pre-inspiratory inspiratory gas flow is set, which flows off via the expiration valve (9). The closing pressure pv of the expiration valve is measured with a pressure sensor (11) in the process. The gas flow is increased in case of an inspiratory effort of the patient to the extent that the closing pressure pv of the expiration valve (9) is restored. Breath support is generated when the difference between the preset gas flow and the gas flow that is needed to maintain the closing pressure pv at a constant level exceeds a predetermined threshold value.

Abstract: A device and a process for determining the change in the functional residual capacity (FRC) in a simple manner. Based on a first respiration phase for mechanical respiration, a recruitment maneuver is performed for this during a second respiration phase, and respiration is switched back to mechanical respiration during a third respiration phase. Reference values Uref/1, Uref/3 are formed from the end-expiratory values of the impedance measured signals U during the first respiration phase and the third respiration phase, and the difference ?U (?FRC) between the reference value Uref/3 of the third respiration phase and the reference value Uref/1 of the first respiration phase is an indicator of the change in the functional residual capacity of the lung of the test subject.

Abstract: Operating a respirator with an inspiration pressure-vs.-time curve (1), which has an airway target pressure (paw—target) and a PEEP (3), in which the inspiration pressure-vs.-time curve (1) reaches the airway target pressure (paw—target) on a ramp-like curve (17) starting from a starting airway pressure (paw—Start), which is greater than the PEEP (3).

Abstract: A device for supplying a patient with breathing gas, in which an initially high initial pressure paw(t=0) applied from the outside is automatically lowered by means of a control circuit to a lower inspiratory pressure paw(t) as soon as a pulmonary internal pressure plung(t) threatens to exceed a predetermined pulmonary target pressure plung,soll. Overinflation of the lungs due to the respiration is thus ruled out according to the present invention. The device permits, moreover, rapid filling of the lungs with breathing gas and makes thus possible a comparatively long phase of expiration. A process is also provided for regulating a respirator and for respirating a patient.

Abstract: An electroimpedance tomograph is provided with a plurality of electrodes (1), which can be placed on the body of a patient and are connected to a control and evaluating unit (20) via a selector switch (60). The control and evaluating unit (20) cooperates with the selector switch (60) such that two electrodes each are supplied with alternating current from an AC power source (22). The detected analog voltage signals of the other electrodes are sent into the control and evaluating unit (20) via a measuring amplifier (62) and AD converter (64) and are processed there in order to reconstruct the impedance distribution of the body in the plane of the electrodes therefrom. A symmetrical AC power source (22) is used to reduce common-mode signals.

Abstract: A process with a corresponding device for lung ventilation involves recording an image of the lung status with an electric impedance tomography (EIT) system (2) and the total area of ventilated lung areas is determined by a computing unit (4) from all image values, subsequently divided into at least two lung areas and the extent of the homogeneity of the ventilated lung areas is determined by comparison of the impedance changes within these areas. In case of a homogeneity rated as being too low, the respiration pressures are increased step by step by means of the respirator (1) and the respiration pressure at which the greatest possible homogeneity is obtained from subsequently determined status images is determined by means of the EIT system (2).

Abstract: A process and a device is presented with an electro-impedance tomography (EIT) system (2), with a computing unit (4) and with a respirator (1) for gentle mechanical lung ventilation especially in case of atelectases following surgical procedures. A first image of the healthy lungs is first recorded prior to anesthetization by means of the EIT system (2) and the total area and/or the spatial distribution of ventilated lung areas are determined from the image values by means of the computing unit (4). Second or additional status images are recorded after assumed lung damage and the total area and/or the spatial distribution of ventilated lung areas are determined. The total areas and/or the spatial distribution of the ventilated lung areas from the first and second or further status images are compared by means of the computing unit (4) and analyzed for the presence of lung areas that have no or reduced ventilation due to atelectases.

Abstract: A method, system and device are provided for the determination of leaks in a respirator. An inspiration pressure pinsp is recorded during an inspiration time Tinsp with a measuring device. The inspiration pressure pinsp is varied during consecutive breaths I. Leaks are determined as to leak volumes VLi from the product of pinspi and Tinspi in accordance with the equation VLi=A×pinspiB×Tinspi while the parameters A and B are determined in an analyzing unit by a regression model with pinsp as the regressor.

Abstract: A respirator for breath-supporting respiration has improved sensitivity of triggering breathing support. A pre-inspiratory inspiratory gas flow is set, which flows off via the expiration valve (9). The closing pressure pv of the expiration valve is measured with a pressure sensor (11) in the process. The gas flow is increased in case of an inspiratory effort of the patient to the extent that the closing pressure pv of the expiration valve (9) is restored. Breath support is generated when the difference between the preset gas flow and the gas flow that is needed to maintain the closing pressure pv at a constant level exceeds a predetermined threshold value.

Abstract: An electroimpedance tomograph with a plurality of electrodes (1) is provided, which can be placed on the body of a patient and are connected via a selector switch (60) with a control and evaluating unit (20). The control and evaluating unit (20) cooperates with the selector switch (60) such that two electrodes each are supplied with an alternating current from an AC power source (22) and the detected analog voltage signals of the other electrodes are processed in order to reconstruct therefrom the impedance distribution of the body in the plane of the electrodes, wherein a symmetrical AC power source is used to reduce common-mode signals.

Abstract: An electroimpedance tomograph is provided with a plurality of electrodes (1), which can be placed on the body of a patient and are connected to a control and evaluating unit (20) via a selector switch (60). The control and evaluating unit (20) cooperates with the selector switch (60) such that two electrodes each are supplied with alternating current from an AC power source (22). The detected analog voltage signals of the other electrodes are sent into the control and evaluating unit (20) via a measuring amplifier (62) and AD converter (64) and are processed there in order to reconstruct the impedance distribution of the body in the plane of the electrodes therefrom. A symmetrical AC power source (22) is used to reduce common-mode signals.

Abstract: A device and a process for determining the change in the functional residual capacity (FRC) in a simple manner. Based on a first respiration phase for mechanical respiration, a recruitment maneuver is performed for this during a second respiration phase, and respiration is switched back to mechanical respiration during a third respiration phase. Reference values Uref/1, Uref/3 are formed from the end-expiratory values of the impedance measured signals U during the first respiration phase and the third respiration phase, and the difference ?U (?FRC) between the reference value Uref/3 of the third respiration phase and the reference value Uref/1 of the first respiration phase is an indicator of the change in the functional residual capacity of the lung of the test subject.

Abstract: A process is provided for controlling at least one parameter of the breathing gas supply of a respirator with a patient connected to it as well as to a corresponding control device. The respiration pressure, the breathing gas flow generated by the respirator as well as the respiration rate may be used as parameters. The process presents the advantage that the control of the current respiration needs of the patient are taken into account by the muscle pressure (PMUS), i.e., the percentage of the airway pressure caused by the patient's own effort, being maintained at a value close to zero. An airway pressure (PAWC) is first calculated for this purpose from previously measured values for the airway pressure (PAW) and the breathing gas flow (d/dt V) and the mechanical parameters resistance (RL) and compliance (C) of the patient's lungs, which were determined therefrom, and this is subsequently compared with the actually measured value for the airway pressure (PAW).

Abstract: A device and process are provided for determining the concentration of at least one gas component in a breathing gas mixture. The device is used especially to determine the concentration of a trace gas for a lung function measurement. The requirements on such a device are compact design with low weight, and the requirement on the process is high speed of measurement. For the case of the determination of the concentration of a gas component in a breathing gas mixture, the device has two detectors designed as thermopiles (3, 4) for the infrared optical radiation of a radiation source (1), of which the first thermopile (3) is used alternatingly as a reference detector and for the determination of the concentration of a trace gas for the lung function measurement, and the second thermopile (4) is used to determine the concentration of a gas component in the breathing gas mixture.