Abstract: Methods and systems for adjusting ventilator settings in a patient based on information obtained by measuring anatomical dead space VD in a lung are provided utilizing controlled indicator gas delivery over multiple breaths, including related measurements and calculations of lung inhomogeneity, functional residual capacity, avelolar volume VA, dead space VD, and pulmonary blood flow {dot over (Q)}P.

Abstract: A method for measuring anatomical dead space in a lung, the method comprising: (a) providing, in a supply of inspired gas, at least one indicator gas for inhalation by a patient during a test, the concentration of the indicator gas being controlled such as to follow a sinewave pattern over successive breaths; (b) measuring, over successive breaths, the flow rate and concentration of the indicator gas during both inspiration and exhalation of the patient; (c) fitting sinewave envelopes to the measured concentration values of the indicator gas over the successive breaths and, from the fitted sinewave envelopes, determining the inspired concentration, the mixed expired concentration, and the end expired concentration in respect of the indicator gas for each breath; and (d) calculating the anatomical dead space for each of a plurality of inspirations based on a conservation-of-mass principle.

Abstract: The present invention provides a component for use in an optical sensor, said component comprising a substrate, a surface of the substrate being coated with a layer of a composition comprising: (i) carbon nano-tubes; (ii) an optically-active substance and (iii) a matrix material.

Abstract: A method for measuring anatomical dead space in a lung, the method comprising: (a) providing, in a supply of inspired gas, at least one indicator gas for inhalation by a patient during a test, the concentration of the indicator gas being controlled such as to follow a sinewave pattern over successive breaths; (b) measuring, over successive breaths, the flow rate and concentration of the indicator gas during both inspiration and exhalation of the patient; (c) fitting sinewave envelopes to the measured concentration values of the indicator gas over the successive breaths and, from the fitted sinewave envelopes, determining the inspired concentration, the mixed expired concentration, and the end expired concentration in respect of the indicator gas for each breath; and (d) calculating the anatomical dead space for each of a plurality of inspirations based on a conservation-of-mass principle.

Abstract: An analyte sensor is disclosed that comprises: a light source arranged for emitting light to a probe; a detector arranged to receive fluorescence light emitted from said probe in response to the light incident from the light source, and to generate an output signal; and a signal processor arranged to determine information related to the presence of an analyte at the probe based on at least the output signal of the detector, wherein the probe comprises nano-particles comprising fluorescent material for which the fluorescence changes in response to the presence of analyte.

Abstract: A method of determining the concentration of oxygen gas, [O2] and the concentration of carbon dioxide gas, [CO2], in a fluid, which method comprises: (a) applying the fluid to one side of a membrane permeable to the gases, the other side of the membrane retaining a solvent for the gases, (b) using a working micrelectrode in contact with the solvent to apply a first electric potential which is effective to reduce oxygen in the solvent and a second electric potential which is effective to reduce carbon dioxide in the solvent, (c) measuring a first steady-state limiting electric current, i1 corresponding to the reduction of O2 to O2.? and a second steady-state limiting electric current, i2 corresponding to both further reduction of O2 and reduction of CO2, and (d) de-convoluting i1 and i2 to determine [O2] and [CO2].

Abstract: Method and device for determining the concentration of one or more gases, e.g. O.sub.2 or CO.sub.2 or an anaesthetic gas, in a fluid e.g. a body fluid or a gas mixture. A membrane (12) permeable to the gases retains a solvent (22) e.g. dimethylsulphoxide. In contact with the solvent is a working electrode (24) of a surface area preferably less than 10 .mu.m.sup.2. The potential of the working electrode is sept, over a range to reduce each of the one or more gases, and at a rate to minimize cross-reactions between gases and their reduction products.

Abstract: A method of determining one gas in the presence of another, where the one gas is reactive with an electrochemical product of the other, comprisesapplying the gases to one side of a membrane permeable to the two gases, the other side of the membrane retaining a solvent for both gases and for the electrochemical product,applying, for the predetermined duration through a working electrode in contact with the solvent, a potential which electrolyses (e.g. reduces) the (dissolved) other gas to form the said electrochemical product,applying, through the working electrode, a potential for reconverting the product to the dissolved gas,measuring, at a predetermined instant or integrated over a predetermined time slot, the current flowing at the reconversion potential, and,from the amount by which the measured current (or integrated current, i.e. charge) falls short of the current when the said one gas is absent, determining the concentration of the said one gas.