Instrumentarium Corporation

Instrumentarium Oy

Jan Petri Ekstrom

Erkki Paavo Heinonen

Borje T Rantala

Kurt Peter Weckstrom

Antti L Martikainen

Osmo Toikka

Olli Aaltonen

A method for non-invasively determining functional cardiac output (FCO) and/or venous blood COpartial pressure (PvCO). The amount of CO(VCO) released from the blood and end capillary blood COcontent (CcCO) are determined from measurements from exhaled breathing gases. The COcontent of the breathing gases inhaled by the subject is increased and values for VCOand CcCOare obtained. A regression analysis is performed using the obtained VCO, VO, CcCO, and CcCOvalues. The regression line is extrapolated to obtain a value for CcCOwhen (VCO) is zero so that CvCObecomes known. The CvCOthus determined can be inserted in a non-differential form in the Fick equation, along with VCOand CcCOvalues from normal breathing, to determine FCO. To determine PvCO, CvCOis altered in accordance with the amount of oxygen in the venous blood, to correctly indicate PvCO. The continuing validity of the FCO measurement can be examined on a breath-by-breath basis by noting changes in an indicator variable, such as VCOor end tidal COamounts.

Non-invasive determination of conditions in the circulatory system of a subject

A method and apparatus for measuring a blood alcohol content value by means of a breath alcohol concentration as well as for securing the reliability of this measured value. The apparatus comprises: sensor elements (1) for obtaining a measured alcohol concentration value from an incoming exhalation air stream; sensor elements (1) for obtaining a measured carbon dioxide concentration value from the same exhalation air stream (9); as well as first output elements (2) for producing, if necessary, a result proportional at least to a blood alcohol content. The apparatus further includes a first memory (M1) for storing a predetermined carbon dioxide lower threshold value or lower threshold values (R1, R2, R3 and/or Rf) and/or an upper threshold value or upper threshold values (R4, R5, R6 and/or Rg) and a first comparing element (C1) for comparing the measured carbon dioxide concentration value to said threshold values as well as a first logic element (L1) for producing outputs of a preset type depending on whether the measured carbon dioxide concentration fails to reach or exceeds the predetermined lower threshold values or upper threshold values.

Blood alcohol concentration measuring from respiratory air

An apparatus for determining the alcohol concentration in a gas mixture, which may contain a number of such interference components that have substantial absorption within the range of the alcohol absorption line to be presently determined, by means of a method based on the absorption of infrared radiation. The apparatus comprises: a radiation source (1); a chamber (4) for receiving a gas mixture (6) to be measured, said chamber being provided with windows (7a, 7b) whereby a radiation (2) passes through the gas mixture; a detector (13) which receives the radiation having passed through the gas mixture and transforms it to an electric state for further processing; between the radiation source and the detector an optical interference filter (10), which has a narrow radiation transmission band and which is pivotable (P) relative to the main traveling direction of radiation for changing the wavelength range of the filter's transmission band. The transmission band of the optical interference filter (10) has a mean wavelength which is within the range of 7.5 .mu.m-12.5 .mu.m and this transmission band of the interference filter (10) has a half-width which is more than 1.5% of said mean wavelength.

Method and apparatus for determining the alcohol concentration in a gas

The invention relates to a water separator for a gas analyzer, comprising a tube (12) for passing a gas sample into the water separator, wherein water separation is effected in a tubular passage by dividing the flow into two partial flows. The wall or walls (3) of a first tubular passage (17) are made of a porous material, readily permeable to gas, and this main flow, which has penetrated the wall, is passed into a second tubular passage (4) and via a tube (10) on to measuring sensors (5 and 6) but the water, which is not able to penetrate the porous wall of first passage (17), is passed along with a minor amount of gas down a passage (17, 13) into a water receiver (15) and this many times lesser side flow further via a tube (14) into a third tubular passage (16), through its porous wall (3) into a fourth tubular passage (18) and via a tube (11) through a flow throttle (7) on to a pump (8).

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Helsinki, Finland

Jan Petri Ekstrom