摘要:
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.
摘要:
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.
摘要:
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. To further suppress interferences due to common-mode signals, provisions are made for the control and evaluating unit (20) 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 (4) 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.
摘要:
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 ΔU (ΔFRC) 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.
摘要:
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.
摘要:
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. To make it possible to suppress errors due to common-mode signals, provisions are made for the control and evaluating unit (20) 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 (4, 90) that can be placed on the body. The control and evaluating unit (20) is prepared, furthermore, to adjust the measuring amplifier (62) according to value and phase for each electrode pair connected by the selector switch (60) such that the common-mode signal at the output of the measuring amplifier (62) is minimized, and the adjusted parameters are stored for each electrode pair.
摘要:
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.
摘要:
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.