Dragerwerk Aktiengesellschaft

Dieter Weismann

Eric Hecker

Peter Gebhardt

Helge Frank

Marcel Baum

Dirk Fiebelkron

Gregory-Alan Colla

A process and device for determining mechanical properties of a respiratory system of a patient connected to a respirator, wherein a short-term occlusion of the patient's airways is performed during an inspiration phase and/or an expiration phase. Initiating of the occlusion is at different points in time within the breathing cycle and during a plurality of breaths. The respiratory flow and the inhaled or exhaled volume of the patient is determined at the beginning of this occlusion. The airway pressure is also measured during this occlusion. The change occurring over time in the airway pressure during a measurement time falling within the occlusion time is determined. Also determined is the course over time of the change occurring over time of the muscle pressure of the patient from the measured values. The course over time of the muscle pressure is calculated by integrating this course over time.

Process for determining the mechanical properties of the respiratory

A respirator with a delivery device, which draws in ambient air via an inlet line and pumps it into an outlet line, with a discharge opening, which branches off from the outlet line and via which a partial flow of the gas being delivered, which can be set with a discharge valve, escapes. Oxygen is added with the smallest possible loss of gas and with good constancy of the concentration by: providing the inlet line with a buffer volume, via which the ambient air drawn in can flow; providing a return line which introduces the partial flow into the buffer volume is present between the discharge opening and the buffer volume; and providing the oxygen source connected to the inlet line and/or to the buffer volume.

Respirator with oxygen enrichment

A ventilating system for supplying a patient with respiratory gas has an apparatus for measuring a respiratory gas flow curve 27 and a respiratory gas pressure curve 28 and has an evaluation circuit 8 for processing at least the respiratory gas flow curve and switching over the respiratory phases. As switchover values from one respiratory phase to the other, the evaluation circuit 8 utilizes predetermined trigger thresholds T.sub.IL, T.sub.EL of the respiratory gas flow curve 27. The ventilating system is improved in such a manner that a good adaptation thereof to the breathing effort of the patient 2 is provided even when leakage is present. This task is solved in that, in the evaluation circuit, the respiratory gas flow curve 27 and the respiratory gas pressure curve 28 are logically coupled during both the inspiratory phase and the expiratory phase. This logic operation takes place in accordance with a predetermined function. From the foregoing, an inspiratory trigger ancillary threshold Z.sub.I and an expiratory trigger ancillary threshold Z.sub.E are computed as an additional switchover criterion. These trigger ancillary thresholds Z.sub.I and Z.sub.E are added to the trigger thresholds T.sub.IL and T.sub.EL, respectively. A method for triggering the respiratory phase in the system is also disclosed.

Ventilating system for supplying a patient with respiratory gas and

The invention relates to a method for recognizing the respiratory phases of a patient for controlling a ventilating apparatus. The time-dependent trace of a signal, which represents the respiratory flow curve and is emitted by a signal device, is determined and from this trace, a trigger criterium is obtained for the switchover of the ventilating apparatus from the expiration phase into the inspiration phase and/or from the inspiration phase into the expiration phase. The method is improved in that even for chronically obstructive patients, a reliable and early recognition of the inspiration and expiration attempts is possible. A significant increase of the slope of the respiratory flow curve between each two zero crossovers of this curve is used as a trigger criterium.

Method for detecting the respiratory phases of a patient during an

The invention is directed to a controllable expiration valve having a control valve for generating an end expiratory overpressure with the control valve providing the changeable control pressure. The expiration valve is improved so that it is made controllable for compensating dynamic end expiratory overpressure. For this purpose, the membrane chamber of the expiration valve as well as the outflow chamber of the control valve are connected with a device for generating an underpressure.

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Gross Gronau, Germany

Dieter Weismann