Drager Medical Gmbh

Dråger Medical Ag & Co. Kg

Draeger Medical Gmbh

Dieter Weismann

Hans Matthiessen

Marcus Eger

Yvo Gärber

Eckhard Teschner

Jianhua Li

Markus Steeger

Hermann Hopermann

Arndt Pöcher

A device for supplying a patient with breathing gas, in which an initially high initial pressure Papplied from the outside is automatically lowered by means of a control circuit to a lower inspiratory pressure Pas soon as a pulmonary internal pressure Pthreatens to exceed a predetermined pulmonary target pressure P. 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.

Device for supplying a patient with breathing gas and process for regulating a respirator

Operating a respirator with an inspiration pressure-vs.-time curve (), which has an airway target pressure (p) and a PEEP (), in which the inspiration pressure-vs.-time curve () reaches the airway target pressure (p) on a ramp-like curve () starting from a starting airway pressure (p), which is greater than the PEEP ().

Respirator and a process for operating a respirator

A process with a corresponding device for lung ventilation involves recording an image of the lung status with an electric impedance tomography (EIT) system () and the total area of ventilated lung areas is determined by a computing unit () 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 () 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 (). The respiration pressure is subsequently lowered again by the respirator () until the computing unit () detects a reduction in the homogeneity of ventilated lung areas, so that the respiration pressure is subsequently increased again by means of the respirator () to the last value at which no reduction in the homogeneity of the ventilated lung areas occurred.

Process and device for lung ventilation

An electroimpedance tomograph with a plurality of electrodes () is provided, which can be placed on the body of a patient and are connected via a selector switch () with a control and evaluating unit (). The control and evaluating unit () cooperates with the selector switch () such that two electrodes each are supplied with an alternating current from an AC power source () 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. To further suppress interferences due to common-mode signals, provisions are made for the control and evaluating unit () to be set up, furthermore, for detuning the common-mode signal of the alternating current on the body against the ground by means of a common-mode signal measuring electrode () and, based on this, the symmetry of the symmetrical AC power source such that the common-mode signal on the body is minimized, and the corresponding detuning parameters are stored for each electrode pair.

Electroimpedance tomograph with common-mode signal suppression

An electro-impedance tomography (EIT) system (), with a computing unit () and a respirator () 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 () and sent to the respirator () so that the respiration pressure is increased step by step by the respirator () 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 () until the computing unit () detects a reduction of the ventilated lung areas and the respiration pressure is subsequently increased again by means of the respirator () to the last value at which no change occurred in the ventilated lung areas.

A method, system and device are provided for the determination of leaks in a respirator. An inspiraton pressure pis recorded during an inspiration time Twith a measuring device. The inspiration pressure pis varied during consecutive breaths I. Leaks are determined as to leak volumes Vfrom the product of pand Tin accordance with the equationwhile the parameters A and B are determined in an analyzing unit by a regression model with pas the regressor.

Device and method for determining leaks of a respirator

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 (). The closing pressure pof the expiration valve is measured with a pressure sensor () in the process. The gas flow is increased in case of an inspiratory effort of the patient to the extent that the closing pressure pof the expiration valve () 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 pat a constant level exceeds a predetermined threshold value.

Device and process for breath-supporting respiration

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 U, Uare 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 &#x394;U (&#x394;FRC) between the reference value Uof the third respiration phase and the reference value Uof the first respiration phase is an indicator of the change in the functional residual capacity of the lung of the test subject.

Device and process for controlling a respirator

An electroimpedance tomograph is provided with a plurality of electrodes (), which can be placed on the body of a patient and are connected to a control and evaluating unit () via a selector switch (). The control and evaluating unit () cooperates with the selector switch () such that two electrodes each are supplied with alternating current from an AC power source (). The detected analog voltage signals of the other electrodes are sent into the control and evaluating unit () via a measuring amplifier () and AD converter () 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 () is used to reduce common-mode signals. To make it possible to suppress errors due to common-mode signals, provisions are made for the control and evaluating unit () to be set up for making available an additional common-mode signal at an output during an adjusting mode of operation and to send it to the body via common-mode signal electrodes () that can be placed on the body. The control and evaluating unit () is prepared, furthermore, to adjust the measuring amplifier () according to value and phase for each electrode pair connected by the selector switch () such that the common-mode signal at the output of the measuring amplifier () is minimized, and the adjusted parameters are stored for each electrode pair.

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Gross Groenau, Germany

Dieter Weismann