Siemens Aktiengesellschaft

Siemens Elema Ab

Dan Linden

Sven-Gunnar Olsson

Goeran Rydgren

Goeran Cewers

Mats Iderup

Goeran Skog

Bo Dahlstroem

Magnus Schnuerer

A passive device for reducing the relative humidity of a flowing gas has a container in which a tube is disposed. A flowing gas passes into the-container-through a inlet and then flows downwardly through a cavity in the container, whereupon the gas transfers heat to the tube and the walls of the container. As a result, liquid water condenses from the water vapor content of the gas. The flowing gas then flows upwardly through a channel in the tube and is then warmed by the heat previously transferred to the tube, whereupon the relative humidity of the flowing gas decreases.

Device for reducing the relative humidity of a flowing gas

A respirator has a bypass gas flow and respective valves in the inspiration and expiration lines for setting the gas flow through these lines. A control unit actuates the valves so that a respiratory cycle is produced and such that the bypass gas flow is maintained during expiration. The expiration pressure is identified by a pressure sensor. When this expiration pressure falls below a prescribed value, a new inspiration phase is triggered. To improve this triggering, the patient gas flow is identified by a flow meter, and the prescribed pressure value is varied dependent on the identified patient gas flow.

Respirator having a trigger sensitivity dependent on the patient gas flow

In a respirator having an inspiration gas flow controlled by the expiration gas flow, in order to avoid triggering difficulties, particularly in the neonatal respiration therapy, the respirator is controlled such that a continuous gas flow flows through the inspiration and expiration lines. The gas flow is measured in the inspiration line by a gas flow sensor. The measured signal from the gas flow sensor is used to control a valve in the inspiration line, or a common line connected to the inspiration and expiration lines so that a constant gas flow is maintained in the expiration line.

Respirator having an inspiration gas flow controlled by the expiration

An apparatus, such as a ventilator, for regulating the flow-through amount of a flowing medium, such as a gas, has a valve with a variable orifice operated by a first regulating circuit with negative feedback. The regulating variable generated by the first regulating circuit controls the size of the orifice so that the difference between a desired value and an actual value for the flow-through amount os minimized, toward zero. To achieve rapid changes in the flow-through amount with a high regulating precision, at least one further regulating circuit is provided to which the regulating variable of the first regulating circuit is supplied as the desired value. The actual value for the further regulating circuit may be the measured position of the closure element for the orifice. The bandwidth and the gain can be optimized for each regulating circuit. The energy consumption can be lowered by current recovery and battery operation can be simplified, in the event of a power outage.

Growing community of inventors

Stockholm, Sweden

Dan Linden