General Electric Company

Instrumentarium Corporation

Mika Hietala

Timo Holopainen

Kurt Peter Weckstrom

Heikki Haveri

Kurt Weckström

Kurt Peter Weckström

Flow sensor

Cap for use with a respiratory system

A method for determining a sample flow volume is disclosed herein. The method includes withdrawing the sample flow at a first and second flow rate from a gas flow, measuring a concentration of at least one gas component and measuring at least one of an airway pressure and flow. The method also includes generating first measurement results based on the concentration, generating second measurement results based on the at least one of the airway pressure and flow and setting a suitable point of comparison. The method further includes determining a first and second time delay between the point of comparison of the first and second measurement results of the first and second flow rate, providing information about the first and second sample flow rate and determining the sample volume based on differences between the first and second time delay. A corresponding arrangement is also provided.

Method and arrangement for determining sample flow volume

Method and arrangement for measuring breath gases of a patient in which the patient is connected to a breath gas unit by using a sampling line to enable flowing a sample of the breathing gases with a pre-determined sample flow rate to the breath gas measuring unit. The sample flow rate is adjusted in case it is not within limits set by the patient's breathing rate.

Method and arrangement for measuring breath gases of a patient

The invention concerns a gas analyzer comprising: a measuring volume (), a radiation source () for providing a beam to pass said measuring volume; a heat sink () for said radiation source; at least one thermal detector () having a hot junction within a support structure and receiving the radiation and a cold junction for reference within the same support structure and protected from said radiation; at least one optical bandpass filter () between said hot junction and said radiation source; and a thermal mass (), which is formed of a material having high thermal conductance. The thermal mass has a cavity with a bottom step () and a rim (), and a first length therebetween. The support structure has a frontal edge () and a base plate lip (), and a second length therebetween. There is a radial gap between the thermal mass and the support structure. Press means urge said support structure in the cavity, whereupon a more efficient thermal contact is either between said frontal edge and said bottom step, or between said base plate lip and said rim. A first thermal barrier () is between the heat sink and the thermal mass, and a second thermal barrier () surrounds the thermal mass. A shield () formed of a material having high thermal conductance covers said second thermal barrier and is in thermal contact with said heat sink.

Method and apparatus for eliminating and compensating thermal transients in gas analyzer

The invention relates to a gas analyzer comprising a measuring volume ( ) for a sample gas mixture (G), a radiation source ( ) for providing a beam ( ) of electromagnetic radiation to pass said measuring volume, a heat sink ( ) for said radiation source, at least one thermopile detector ( ), at least one optical bandpass filter ( ), electrical contact pins ( ) for signal(s) in the housing of said detector, a thermal mass formed of a material having high thermal conductance. Said thermal mass has a cavity ( ) and an outer surface ( ), surrounding at least said detector housing in the cavity, being in contact with said detector housing, and extending towards the radiation source. There is a thermal barrier between the heat sink ( ) and the thermal mass ( ). The gas analyzer further comprises electrical wires ( ), which are composed of materials and having dimensions producing an overall thermal conductance substantially lower than that of said electrical contact pins. Said wires are connected with the electrical contact pins either directly or indirectly, and enclosed in the thermal mass together with said detector housing(s), and extend from the cavity through the thermal mass ( ) to the outside thereof.

Growing community of inventors

Espoo, Finland

Mika Hietala