Siemens Aktiengesellschaft

Siemens Elema Ab

Goeran Cewers

Sven-Gunnar Olsson

Goeran Rydgren

Mats Iderup

Dan Linden

Goeran Skog

Jan Johansson

Bo Dahlstreom

Bo Dahlstroem

In a method for supplying fresh gas in manual ventilation of a patient and in a ventilator system for practicing the method, the supply of fresh gas to a breathing bag is regulated. During inspiration, the breathing bag is squeezed, imposing an inspiration on the patient. A detector at the breathing bag senses when the patient exhales, and an identical flow of gas is fed to the system via an inspiratory valve, the flow of fresh gas is directed into the breathing bag and expired gas is prevented from entering the breathing bag. An expiratory valve simultaneously opens to conduct expired gas out of the system.

Method and apparatus for supplying fresh gas to a patient during manual

A ventilator to be connected to the airways of a human or an animal includes several functional units, each functional unit being controlled and/or supervised by a separate microprocessor. At least one of the functional units has an analog control unit whereby the microprocessor only compensates for the coarseness in the regulating function of the analog control unit to increase the accuracy. This makes the ventilator efficient, accurate and safe.

Ventilator

A device for displaying a parameter value has at least one row of light-emitting diodes in which each light-emitting diode has a position input, and the device has a control circuit with address outputs connected to the position inputs. Faults, such as a short-circuit can be detected more easily by an improved interconnection of the address outputs and position inputs such that two adjacent address outputs are connected to two position inputs physically separated by at least one position input.

Device for displaying a parameter value

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.

Apparatus for regulating the flow-through amount of a flowing medium

An apparatus for the registration of drops in an infusion device has a drip chamber from which fluid is supplied from a reservoir through a tube to a patient, with a drop sensor disposed in the region of the drip chamber. The drop sensor is divided into at least two levels, each level having a processing channel allocated thereto including an amplifier, a comparator and a memory. The outputs of each channel are supplied to a logic unit. As long as signals are supplied by each channel to the logic unit, normal and proper operation is assumed, however, a discriminator unit triggers a fault display or an alarm when a signal from only one channel is present within a predetermined time.

Apparatus for the registration of drops in an infusion device

In order to be able to regulate in a simple and reliable manner the quantity of liquid that is administered to a patient through a hose in an infusion device, there is provided, according to the invention, a motor-driven eccentric, which presses the hose against a blocking device and clamps it off to a greater or lesser degree. The blocking device forms a part of at least one guide for the hose and can assume two positions. In one of the positions the guide is released; in the other position it is closed. A lever mounted with freedom to rotate, which can be spring-loaded, is particularly well suited for the blocking device. In addition, a clamping lever which can be activated through an electromagnetic latch, can be provided as an emergency stop.

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Lund, Sweden

Goeran Cewers