公开(公告)号：EP1005632A2

公开(公告)日：2000-06-07

申请号：EP98940805.9

申请日：1998-08-18

申请人： Metasensors, Inc.

发明人： DRZEWIECKI, Tadeusz, M.

IPC分类号： G01N1/00

CPC分类号： G01F1/3227 ,  A61M16/0051 ,  A61M16/021 ,  A61M16/0808 ,  A61M16/085 ,  A61M2016/1025 ,  A61M2016/103 ,  A61M2016/1035 ,  A61M2230/432 ,  A61M2230/435 ,  G01N2291/02872 ,  G01N2291/02881 ,  Y10T137/2234 ,  Y10T137/2506

摘要： A method and apparatus for real time gas analysis involving determining individual concentrations of fluid constituents in a mixture of known constituents by measuring properties of such mixture via sensor array and solving a set of equations relating the individual gas concentrations to the measured properties of the mixture, for the unknown individual gas concentrations or identities. The individual concentrations of four gases in a mixture are determined by: passing the mixture through a flowmeter (65), capillary (71), orifice (72) or sonic oscillator (76); transducing temperature (69), pressure (73, 74) and acoustic frequency measurements taken from the sensors; determining density (72), viscosity (71) and specific heat (76) of the mixture; forming three equations which respectively relate these three properties to individual gas concentrations; then solving the three equations under a condition requiring the sum of the concentrations to equal unity for the four unknown individual gas concentrations. A single oscillator can serve as both a sensor (flowmeter, acoustic velocimeter) and orifice.

公开(公告)号：EP1155318A1

公开(公告)日：2001-11-21

申请号：EP00913607.8

申请日：2000-02-25

申请人： Metasensors, Inc.

发明人： DRZEWIECKI, Tadeusz, M.

IPC分类号： G01N31/00 ,  G01N27/16 ,  G01N29/00 ,  A61M16/00 ,  A61B5/00

CPC分类号： G01N29/4472 ,  A61B5/083 ,  A61B5/087 ,  A61B5/097 ,  G01N29/022 ,  G01N29/024 ,  G01N2291/011 ,  G01N2291/0215 ,  G01N2291/02818 ,  G01N2291/02836 ,  G01N2291/02872 ,  G01N2291/02881 ,  G01N2291/0423

摘要： A gas analyzer (10) integrated into the main passageway (11) of a breathing circuit includes pressure-drop flow element (12) that measures a pressure drop across an orifice, an acoustic flowmeter (14) measures the speed of sound in the gas mixture, and a SAW device (20) from which the viscosity of the gas mixture is determined. The dielectric constant of the gas mixture is determined from the capacitance of spaced-apart charged plates of a capacitor (22) through which the mixture passes. The gas mixture density is determined from the measured pressure drop and flow rate, while the gas mixture specific heat is determined from the density and speed of sound in accordance with known relationships. The individual concentrations of five constituents of a mixture of gasses can be determined by solving five equations relating the independently measured properties of the gas mixture to the individual constituent concentrations.

公开(公告)号：EP1152688A1

公开(公告)日：2001-11-14

申请号：EP00904476.9

申请日：2000-01-21

申请人： Metasensors, Inc.

发明人： CALKINS, Jerry, M. ,  DRZEWIECKI, Tadeusz, M.

IPC分类号： A61B5/00

CPC分类号： A61B5/0836 ,  A61B5/029

摘要： A cardiac output monitoring system (10) includes a respiratory flowmeter (14) and a gas analyzer (20, 22) capable of determining cardiac output on a breath-by-breath basis by non-invasively measuring properties of respiratory gasses and applying the Fick principle. The gas analyzer has the capability to simultaneously quantify multiple gas concentrations, including inhaled and end-tidal concentrations of any constituent of respiratory gas mixtures of a known number of possible constituents, in real time on a breath-by-breath basis, by measuring independent properties of the mixture. The respiratory flowmeter determines the volumetric and mass flow rates of any gas/gasses as calculated from the product of measured total respiratory flow and the measured volumetric concentration in real time on a breath-by-breath basis. From these measurements, cardiac output can be determined on a breath-by-breath basis by applying appropriate numerical algorithms based on the Fick principal, including corrections for physiological conditions such as shunts and deadspace.