Automated regression analysis and its applications such as water analysis

Abstract

Methods and instrumentation based on the concept of an “Absolute Principle” are relatively rare but, when applicable, offer some very unique advantages. This patent teaches how to automate the use of non-linear curve fitting to widen this concept enabling the determination of multiple properties instead of typically only a single entity as well as dealing systematically with more complex relationships between entities. As a possible application, the invention further deals with analyzing the composition of water regarding inorganic as well as organic species and the use hereto of conductivity measurements as a function of temperature or the mixing ratio with another fluid.

1 . An instrument, device, method or procedure to determine one or more features, properties or parameters, hereinafter called analyzed feature, of an object, sample or process, hereinafter called object, where the object has another feature, property or parameter, hereinafter called the characteristic feature that is measurable as a function of yet another feature, property, or parameter, of the object hereinafter called the scanned feature, comprising the following 
 (a) a mathematical model that given a value of the object's analyzed feature and given a value of the object's scanned feature calculates the corresponding value of the object's characteristic feature, and    (b) measurement means measuring the object's characteristic feature, and    (c) variable entity determination means to measure or to control the value of the object's scanned feature, and    (d) scanning means to actively or passively vary the object's scanned feature, and    (e) object preparation means to set the scope of the analyzed feature, or to adapt the object to the characteristics of the scanning means, and    (f) data collection means that, in conjunction with the scanning means, collects data from the measuring means and the variable entity determination means regarding the relationship between the object's characteristic feature and object's scanned feature, and    (g) data interpretation means determining the most likely object's analyzed feature based on the comparison between the relationship's data from the data collection means and calculated relationships based on the said mathematical model where the calculated relationships are given candidate analyzed feature values by a non-linear regression or curve fitting algorithm such as that of Levenberg-Marquardt to find the candidate analyzed feature value that provides the best match in the comparison.    
   
   
       2 . An instrument, device, method or procedure of  claim 1  wherein the best matching candidate analyzed feature value is frequently updated using ongoing scanning, data acquisition and interpretation with means that takes older data less into account when doing the comparisons.  
   
   
       3 . An instrument, device, method or procedure of  claim 2  wherein upon startup or otherwise the data interpretation means can activate a wide scan means generating a grid of initial analyzed feature values with whom a series of runs of a non-linear regression or curve fitting algorithm such as that of Levenberg-Marquardt is started in order to distinguish the overall best fit out of a possible multiple local best fitting analyzed feature values.  
   
   
       4 . An instrument, device, method or procedure of  claim 3  wherein a quality of the fit value is generated by the data interpretation means that is used as a decision criteria to activate said wide scan means.  
   
   
       5 . An instrument, device, method or procedure of  claim 1  wherein the best matching candidate analyzed feature value is generated as an automated operation on a given set of recently acquired or stored data.  
   
   
       6 . An instrument, device, method or procedure of  claim 5  wherein upon startup or otherwise the data interpretation means can activate a wide scan means generating a grid of initial analyzed feature values with whom a series of runs of a non-linear regression or curve fitting algorithm such as that of Levenberg-Marquardt is started in order to distinguish the overall best fit out of a possible multiple local best fitting analyzed feature values.  
   
   
       7 . An instrument, device, method or procedure of  claim 6  wherein a quality of the fit value is generated by the data interpretation means that is used as a decision criteria to activate said wide scan means.  
   
   
       8 . An instrument, device, method or procedure of  claim 1  where the analyzed feature include offset or span correction parameters for sensors involved in the measurement means or involved in the variable entity determination means.  
   
   
       9 . An instrument, device, method or procedure to determine chemical species selected from the group consisting of ions, dissolved gases and neutral species, hereinafter called the composition, present in analytes selected from the group consisting of aquaous solutions, liquids and fluids, hereinafter called the analyte, whereby the analyte features an electrical conductivity property that is measurable as a function of a scannable parameter selected from the group consisting of the analyte's temperature and the degree by which the analyte is mixed with another fluid, hereinafter called the scannable parameter, comprising the following 
 (a) model calculation means that given values of a composition and given an analyte temperature produces the corresponding calculated value of an analyte's conductivity, and    (b) measurement means measuring the analyte's conductivity, and    (c) scannable parameter determination means for the determination of the value of the analyte's scannable parameter, where determination is selected from the group measurement, derivation and control, and    (d) scanning means to actively or passively vary the value of the analyte's scannable parameter, and    (e) analyte preparation means to selectively change the type of chemical species that contribute to the analyte's conductivity or to adapt the analyte to the characteristics of the scanning means, and    (f) data collection means that in conjunction with the scanning means collects data from the measuring means and the scannable parameter determination means regarding the relationship between the analyte's conductivity and the analyte's scannable parameter, and    (g) data interpretation means determining the analyte's composition based on the comparison between the relationship's data from the data collection means and relationships calculated by the mathematical model where the calculated relationships are given candidate analyte's composition values by a non-linear regression or curve fitting algorithm such as that of Levenberg-Marquardt to find the candidate analyte's composition value that provides the best match in the comparison.    
   
   
       10 . An instrument, device, method or procedure of  claim 9  wherein the analyte preparation means selectively changes the type of chemical species that contribute to the analyte's conductivity by irradiating the analyte with UV light converting non conductive species such as organic molecules into other species from which some of them conductive.  
   
   
       11 . An instrument, device, method or procedure of  claim 9  wherein the analyte preparation means adapt the analyte to the characteristics of the scanning means by isolating, stopping or stabilizing part of the analyte stream so that its analyte's composition is no longer subject to further changes while it is being measured, other than changes resulting from the scanning means or resulting from other analyte preparation means, while its conductivity is measured by the measuring means.  
   
   
       12 . An instrument, device, method or procedure of  claim 11  where the actual isolating, stopping or stabilizing of a part of the analyte stream takes place by analyte streams redirecting means that flush areas suspect of building up contamination with bypassed, non measured, analyte thus preventing their interfering with the measurement.  
   
   
       13 . An instrument, device, method or procedure of  claim 10  wherein the analyte preparation means adapt the analyte to the characteristics of the scanning means by isolating, stopping or stabilizing part of the analyte stream so that its analyte's composition is no longer subject to further changes, other than those resulting from the scanning means or resulting from UV light irradiation, while its conductivity is measured by the measuring means.  
   
   
       14 . An instrument, device, method or procedure of  claim 9  wherein the analyte is flowing while the analyte's conductivity is measured by the measurement means and where the measuring means can consist of more than one conductivity sensor or an array of miniaturized conductivity sensors.  
   
   
       15 . An instrument, device, method or procedure of  claim 10  wherein the analyte is flowing while the analyte's conductivity is measured by the measurement means and where the measuring means can consist of more than one conductivity sensor or an array of miniaturized conductivity sensors.  
   
   
       16 . An method, procedure, instrument or device to generate numerical values for unknown parameters in a mathematical model describing a phenomena involving multiple known or given values for known parameters where known and unknown parameters are linked by a number of mathematically described relationships and where one still has a valid but simpler phenomena by successively leaving unknown parameters out and where an analytical solution is available for an initial simple case featuring none or only few unknown parameters consisting of the following 
 (a) the initialization step creating numerical values using formulas derived from the analytical solution for the initial simple case, and    (b) an iterative step that calculates numerical solutions for a certain phenomena based on the numerical solution for the same but slightly simpler phenomena featuring one unknown parameter less, and    (c) an loop step that starts with the solution from the initialization step (a) to which it adds successively new unknown parameters while solving each time the next more complex case using the iterative step (b) to end up with a solution for the original phenomena.    
   
   
       17 . An method, procedure, instrument or device as  claim 16  where the phenomena is the chemistry taking place in aquaous solutions and where the known parameters are the total concentrations of species added to a pure water independent of the ionic or molecular forms that will end up having in the solution and where said ionic or molecular forms are the unknown parameters and where the mathematical model is based on the laws of chemistry associated with aquaous solutions.  
   
   
       18 . An method, procedure, instrument or device as  claim 17  aking activity coefficients into account build into the mathematical model calculation to reflect effects taking place when dealing with higher concentrations of species.  
   
   
       19 . An method, procedure, instrument or device of  claim 17  wherein the involved pH range is such that certain strong acids or bases can be considered fully ionized and are treated mathematically that way in the mathematical model.