WO2022058016A1

WO2022058016A1 - Method and analysis device for analyzing a sample liquid

Info

Publication number: WO2022058016A1
Application number: PCT/EP2020/076030
Authority: WO
Inventors: Berthold Limbach
Original assignee: Berthold Limbach
Priority date: 2020-09-17
Filing date: 2020-09-17
Publication date: 2022-03-24

Abstract

According to the invention, in the method for analyzing at least one sample liquid: (2) at least one parameter of a physical property of the sample liquid is measured by means of an analysis device; (3) after a predefined time, a controller of the analysis device evaluates the measurement; (4) within the predefined time, at least one determination parameter is changed by the analysis device on the basis of the measured at least one parameter of the physical property and on the basis of at least one predefined criterion stored in the controller.

Description

Method and analysis device for analyzing a sample liquid

technical field

The invention relates to a method for analyzing at least one sample liquid using an analysis device and a corresponding analysis device. During the measurement of at least one parameter of a physical property of the sample liquid, at least one determination parameter is changed by the analysis device based on the measured at least one parameter and at least one predefined criterion.

State of the art

The aim of every analytical procedure is to determine whether a defined substance is present in a specific sample (qualitative determination) and, if so, in what concentration (quantitative determination). Due to the ever-increasing demands on the purity of substances and a large number of newly developed analysis methods, especially in the biological field, quantitative determination in particular is becoming increasingly important. At the same time, the ever-increasing volume of analyzes requires ever greater automation of these analysis methods.

Despite this automation, however, there has been no change in the basic execution of the analyzes compared to the manual execution. The sample to be examined is—possibly after sample preparation—combined with one or more reactants in one or more defined reactions in various linked analytical processes. With these defined reactions, a specific measurement signal is formed, which is registered with the help of a measuring device. Using a defined calculation formula, this signal can be used to calculate the concentration of the substance being searched for. In analytics there are a large number of corresponding measurement methods and evaluation algorithms famous. In all of these measurement methods, each determination of the concentration is carried out according to the same procedure that is stored in the programming of the device software.

It is obvious that the measurement methods can only be carried out in a specific window. If the concentration of the substance to be analyzed is outside the predetermined measurement range (be it too high or too low), the measurement will be disturbed by some specific individual properties of the sample (false positive or false negative values). If the specified boundary conditions of the measurement method are not applicable when determining a specific sample, the concentration cannot be calculated. In the case of an automatic measurement process, the analysis system will then at best indicate that the framework conditions are not applicable. The measurement must then be repeated under different conditions. However, this repetition is very time-consuming and involves additional costs.

Presentation of the invention

The object of the invention is to create a method belonging to the technical field mentioned at the outset, in which repetitions of analyzes can be avoided as far as possible.

The solution to the problem is defined by the features of claim 1. According to the invention, in the method for analyzing at least one sample liquid with an analysis device using predetermined determination parameters, at least one parameter of a physical property of the sample liquid is measured. After a predetermined time has elapsed, a controller of the analysis device evaluates the measurement. Within the predetermined time, at least one of the determination parameters is changed by the analysis device on the basis of the measured at least one parameter of the physical property and at least one predefined criterion that is stored in the controller. By changing at least one of the determination parameters before the predetermined time has elapsed, ie while the analysis itself is being carried out, it is possible to react automatically to certain properties of the at least one sample liquid. For example, an analysis that is otherwise unusable, for example if the concentration of a substance to be determined is too high or too low in the at least one sample liquid, can still deliver usable analysis results through a targeted change in at least one of the determination parameters.

The at least one sample liquid is preferably an aqueous solution in which at least one substance to be analyzed is present. The at least one sample liquid can also be a suspension or emulsion in which the at least one substance to be analyzed is present. Furthermore, the at least one sample liquid can also be a body liquid, such as urine or blood. Instead of blood, blood plasma or blood serum can also be used as the at least one sample liquid.

The at least one substance to be analyzed is preferably a chemical compound, in particular an organic compound, or a biomolecule.

In the method according to the invention, the at least one sample liquid is preferably present in a vessel, in particular in a cuvette, a vial, a sample tube, a microreaction vessel or a test tube. Furthermore, the at least one sample liquid can also be present in a well of a microtiter plate or on a slide.

The volume of the at least one sample liquid varies depending on the type of sample liquid and the physical property to be measured. Accordingly, the volume ranges in particular from 1 μl to 500 ml, preferably from 1.5 μl to 500 μl. In special applications, however, the at least one sample liquid can also be present in a larger or smaller volume.

At least one solution is preferably added to the at least one sample liquid before the start of the measurement, in particular a dilution solution, a Buffer solution, a solution with at least one reactant and/or a solution of an educt of a detection reaction for the substance to be analyzed.

The at least one sample liquid is preferably tempered during the method, in particular during the measurement, i.e. heated or cooled to a certain temperature. Furthermore, the at least one sample liquid can be shaken or stirred during the method, in particular during the measurement, for example by a shaking or stirring unit of the analysis device.

The analysis device is particularly suitable for measuring the at least one parameter of the physical property of the sample liquid for the at least one sample liquid. This means that the analysis device has at least one measuring unit with which the at least one parameter of the physical property can be measured. The analysis device is preferably designed in such a way that one or more sample liquids can be analyzed at the same time. For this purpose, the analysis device has at least one receptacle for a vessel for the at least one sample liquid or one receptacle for at least one corresponding microtiter plate or slide. In particular, the analysis device allows the simultaneous analysis of a large number of sample liquids using the method according to the invention.

The at least one physical property is preferably an optical, rheological or thermodynamic property of the at least one sample liquid. The at least one parameter of the physical property that is measured is therefore a parameter of the respective physical property, such as the extinction value of the at least one sample liquid at a specific wavelength, the viscosity of the at least one sample liquid or its heat capacity. The at least one parameter is preferably measured using an optical, calorimetric, electrochemical, chromatographic or reflectometric measuring method.

In the method according to the invention, one parameter of the physical property or several parameters of the same physical property can preferably be measured simultaneously be measured. Alternatively, one or more parameters of different physical properties can be measured simultaneously in the method according to the invention, for example a parameter of an optical property and a parameter of a rheological property of the at least one sample liquid.

The predetermined time is that time of the analysis method in which the analysis is carried out. Following the predetermined time, the measurement of the at least one parameter of the physical property is then evaluated.

The at least one physical property parameter is preferably measured throughout the predetermined time, i.e. throughout the analysis of the at least one sample liquid. In a further preferred embodiment, however, the at least one parameter of the physical property is only measured selectively at predefined points in time or during at least one defined period of time. In this embodiment, the vessel in which or on which the sample liquid is located is moved into or onto a measuring unit by means of a transfer unit, in particular by means of a manipulator. In a preferred embodiment, the analysis device has a sample carousel in which a plurality of vessels for sample liquids can be arranged, with the controller being able to rotate the sample carousel accordingly, so that the vessel with the sample liquid in which the at least one parameter of the physical property is to be measured, lies on the position at which a measurement of the at least one parameter of the physical property by the measuring unit is possible.

The predetermined time varies depending on the at least one sample liquid, the at least one physical property parameter being measured, and the analyte in the at least one sample liquid. The predetermined time is in particular between a few minutes and several hours, in particular from 1 minute to 6 hours. In special cases, however, the predetermined time can also be shorter or longer. The at least one parameter of the physical property of the sample liquid and the predetermined time each represent one of the determination parameters of the method according to the invention. The method preferably includes further determination parameters which are dependent on the analysis carried out with the method according to the invention. These determination parameters preferably include adding a predefined amount of at least one liquid solution to the sample liquid at a predefined point in time, for example a liquid solution of a reactant or starting material for a reaction, in particular a detection reaction of the substance to be analyzed. The determination parameters preferably also include parameters for evaluating the measurement.

The at least one determination parameter is changed using the at least one criterion and the measured at least one parameter of the physical property. For this purpose, the controller preferably compares the respectively measured value of the at least one parameter of the physical property with the at least one criterion during the predetermined time. Instructions are also stored in the controller as to which of the determination parameters is changed and in what way, provided the measured at least one parameter of the physical property satisfies the at least one criterion.

When the at least one determination parameter is changed, the at least one parameter of the physical property, the physical property and/or the predetermined time can therefore preferably be changed.

The analysis of the at least one sample liquid is preferably based on an enzymatic or chemical color formation reaction or turbidity reaction, with the extinction or turbidity of the sample liquid, for example, being measured accordingly as a parameter of the physical property.

The evaluation is carried out by the controller, in particular using at least one analysis parameter, which preferably represents one of the determination parameters. The at least one analysis parameter is preferably stored in the controller of the analysis device. Preferably, for each substance that can be analyzed with the analyzer at least one analysis parameter is stored, which is based on at least one measurement of a parameter of a physical property that can be measured with the analysis device. To store the at least one analysis parameter, the controller of the analysis device preferably has a non-volatile memory and input means.

The at least one analysis parameter is preferably a mathematical analysis, in particular in the form of a mathematical function. Using the mathematical analysis or function, a result can be calculated using a measured value or a series of measured values of the at least one parameter of the physical property, for example the concentration of a substance to be analyzed in the at least one sample liquid.

With the at least one criterion that is stored in the controller, the controller can change the at least one determination parameter in a predetermined way, provided that the at least one criterion is met. The at least one criterion can be, for example, exceeding or falling below a specific measured value of the at least one parameter of the physical property.

Overall, the method according to the invention allows a very flexible and adaptive adjustment of the analysis based on the measured at least one parameter of the physical property in real time during the measurement, i.e. during the predetermined time. This enables optimization of the time required for an analysis. In addition, it is also possible to prevent analyzes from having to be repeated, since the method according to the invention enables active adaptation of at least one determination parameter using at least one predefined criterion or also using a plurality of predefined criteria, so that an optimal analysis result can be achieved for each sample liquid .

In the case of analysis methods from the prior art, measurement and evaluation are always carried out according to the same test scheme for each measured sample liquid. In this way, analyzes in which it would actually be clear at an early stage that the analysis under the given conditions would lead to no or an incorrect result would, brought to an end. The consequence of this is that these analyzes then have to be repeated under changed conditions, which leads to a greater expenditure of time and material. With the method according to the invention, based on the measured values of the at least one parameter of the physical property and using the at least one criterion, a determination parameter can be changed at an early stage such that the analysis can still be completed or a reliable result is obtained.

For example, an analysis parameter can be changed as a determination parameter, e.g. the number of measured values of the at least one parameter of the physical property used for the analysis.

In certain analyses, it is first necessary to wait for the sample liquid, which is cloudy, for example due to a pre-reaction, to clear before a reliable measurement of the at least one parameter of the physical property, in particular an optical parameter, can be reliably measured. In the case of methods from the prior art, there is always a sufficiently long wait before the measurement is started, so that it is ensured that the sample liquid has also been reliably clarified. However, this waiting time is too long for most sample liquids. By choosing a suitable criterion, it can be ensured with the method according to the invention that only measured values of at least one parameter of the physical property, which were measured after the clarification of the initially turbid sample liquid, are used for the analysis. In addition, no waiting time is necessary, so that the time required overall for the method can be reduced compared to the prior art.

In a similar way, it is also possible to individually respond to pre-reactions of different lengths (e.g. the so-called lag phase) or the breakdown of interfering substances contained in a matrix (e.g. breakdown of bilirubin at high pH or high pyruvate-LDH concentrations by adding LDH). react. When the at least one determination parameter changes, another parameter of the physical property or at least one parameter of another physical property of the at least one sample liquid is preferably measured.

As a result, based on the at least one criterion, it is possible to switch dynamically between the measurement of different parameters of the same physical property or between the measurement of parameters of different physical properties of the at least one sample liquid. This offers the advantage that if it can be seen from the at least one criterion that the measurement with the current parameter will not be reliable or correct, for example because the substance to be analyzed has a concentration that is too high or too low, the measurement of a parameter can be changed, which enables a more reliable or more correct measurement.

The physical property of the at least one sample liquid is preferably an optical property. Parameters of an optical property of the at least one sample liquid can be measured without contact, which means that a corresponding measuring unit of the analysis device does not have to be cleaned between measurements of different sample liquids. The measurement of parameters of optical properties is also widespread in the field of chemistry, biology and medicine and has long been established, which is why numerous measurement protocols, reactants, sample vessels and measurement units are known and also available.

Preferably, the at least one physical property parameter is absorbance of light of at least one predetermined wavelength.

In an absorbance measurement, the absorbance of light at a predetermined wavelength is preferably measured as a parameter of the physical property. Alternatively, preferably, the extinction of light can be measured at more than one predetermined wavelength, in particular at two predetermined wavelengths, as a parameter of the physical property. Alternatively, the absorbance of light within a wavelength range, ie the absorbance of all wavelengths within this range, can be measured as a parameter of the physical property. In principle, the extinction can be measured in the entire light spectrum, preferably between a wavelength of 10 nm to 10 nm, ie in the ultraviolet, visible and infrared range. The absorbance is preferably measured in the visible range of light at at least one wavelength from 350 nm to 800 nm.

By measuring the extinction at a large number of wavelengths, in particular all wavelengths within a specific spectrum or within a wavelength range, the control can be compared with stored extinction curves of interfering substances, in particular of hemoglobin, bilirubin and triglycerides (serum indices - Sl), their concentration estimate and adapt the analysis accordingly or reduce its interference with the measurement by changing at least one determination parameter, e.g. by adding a diluting solution or by changing the measured at least one physical property parameter.

The at least one parameter of the physical property is preferably a fluorescence at at least a second predetermined wavelength when excited with light of at least one predetermined wavelength.

Preferably, fluorescence is measured at a second predetermined wavelength. Alternatively, preferably, the fluorescence can also be measured at a number of second predetermined wavelengths, in particular in a second wavelength range. In this case, the excitation preferably takes place with a predetermined wavelength. Alternatively, the excitation preferably takes place using a plurality of predetermined wavelengths or a predetermined wavelength range.

In principle, the fluorescence can be measured in the entire light spectrum, preferably between a wavelength of 10 nm to 10 μm, ie in the ultraviolet, visible and infrared range. Fluorescence is preferably measured in the visible range of light at at least one wavelength from 350 nm to 800 nm.

When measuring the fluorescence as at least one parameter of the physical property, the excitation can take place with light from the entire spectrum, preferably between a wavelength of 10 nm to 10 μm, i.e. in the ultraviolet visible and infrared range. The excitation preferably takes place in the visible range of light at at least one wavelength of 350 nm to 800 nm.

When measuring the fluorescence, the selection of the at least one second, predetermined wavelength of the light for excitation and the at least one wavelength for measuring the fluorescence depends on the substance to be analyzed in the at least one sample liquid.

If the extinction or fluorescence is measured as a parameter of the physical property, the at least one predetermined wavelength is preferably changed as the at least one determination parameter. If the extinction or the fluorescence is measured at a number of predetermined wavelengths as a parameter of the physical property, one of the number of predetermined wavelengths or several or all of the number of predetermined wavelengths can be changed as the determination parameter. If the extinction or fluorescence is measured in a wavelength range, this wavelength range can be reduced or increased when the at least one determination parameter changes. Alternatively, another wavelength range can also be used.

Alternatively, when the at least one determination parameter changes, the extinction or fluorescence can be measured at an additional wavelength.

If the extinction or fluorescence is measured at several wavelengths as a parameter of the physical property, the measurement can be stopped at at least one wavelength when the determination parameter changes, i.e. after the change in the determination parameter the extinction or fluorescence is measured at fewer wavelengths will.

Preferably, the at least one criterion is exceeding or falling below a predefined value or a predefined change over time in the extinction or fluorescence at at least one predefined wavelength or a predefined difference in extinction or fluorescence at a number of predefined wavelengths. The predefined value thus corresponds to a threshold value, if it is exceeded or not reached during the predetermined time, the at least one determination parameter is changed. If the extinction or fluorescence is measured at several wavelengths as a parameter of the physical property, the at least one criterion can be exceeding or falling below a predefined value at a specific wavelength. Alternatively, the at least one criterion can be exceeding or falling below a predefined value for each measured wavelength at any of the plurality of wavelengths or at a specific number of wavelengths. Alternatively, the point in time within the predefined time when a predefined value is exceeded or not reached can also be used as the at least one criterion. Furthermore, when measuring the extinction or fluorescence at several wavelengths, a mathematical calculation can be carried out with the measured values, with the at least one criterion used being that the result of the mathematical calculation exceeds or falls below a threshold value. For example, an addition, subtraction or division of measured values of absorbance or fluorescence at at least two wavelengths can be used as a mathematical calculation.

The at least one criterion can also be that the extinction or fluorescence exceeds or falls below a predefined change over time. This means that the change over time, which is measured in units per millisecond, for example, is greater or less than the predefined change over time.

When using a difference in absorbance or fluorescence, the difference in absorbance or fluorescence can be formed at two specific wavelengths of the plurality of wavelengths. In a further embodiment, a number of differences can also be used as the at least one criterion, for example of two or three pairs of extinction or fluorescence values at two different wavelengths in each case.

More preferably, the at least one criterion can be based on an evaluation of the profile, in particular in the form of a measurement curve, of the measured extinction or fluorescence values at one wavelength or at a plurality of wavelengths. For example, exceeding or falling below a threshold value for a calculated integral under the measurement curve, a deviation of the profile from a reference profile, or exceeding or falling below a correlation value with a reference profile can be used as the at least one criterion.

More preferably, the at least one criterion can be the achievement of a constant extinction value. In the case of endpoint measurements, in which a constant absorbance value is achieved at the end of the measurement, the end of the necessary measurement time can therefore be determined based on the achievement of a constant absorbance value. Since the necessary measurement time can vary depending on the age and concentration of an educt or reagent solution, a sufficiently long measurement time is used as standard in analysis methods according to the prior art, regardless of the solutions used. However, this means that the measurement time is unnecessarily long for analyzes in which the end point (constant absorbance) is reached quickly. With the method according to the invention, the measurement time can therefore be shortened by changing the predetermined time as the determination parameter, which means that a higher throughput of analyzes is made possible with an analysis device. The measurement time corresponds in particular to the predetermined time.

In the case of kinetic determinations, minor changes in extinction require a longer measuring time in order to achieve a sufficiently precise analysis result compared to the signal-to-noise ratio of the photometer. If the changes in absorbance are too large, the end of the measuring range of the photometer is reached very quickly, from which point there are no further changes in absorbance can be measured more reliably. In such a case, the method according to the invention can be used to measure the extinction at a number of wavelengths, with the measured extinction values of one wavelength only being used for the evaluation using a criterion such as the greatest possible correlation to an optimum change in extinction.

Preferably, the method comprises a step in which at least a defined volume of a liquid solution is added at a defined point in time during the predetermined time, with the change in the at least one Determination parameters, the defined volume and / or the defined time are changed or the liquid solution to be added is changed.

In this step, for example, a reactant or an educt can be added to the at least one sample liquid in order to start a detection reaction for the substance to be analyzed in the at least one sample liquid. The defined volume and the defined time can be changed on the basis of the measured at least one parameter of the physical property, in particular in order to optimize the result of the analysis. The defined volume can be increased or decreased. The defined point in time can be moved forward or backward within the predefined time, which means that the defined point in time is earlier or later within the predefined time.

Furthermore, the solution to be added can also be changed based on the measurement of the at least one parameter of the physical property. For example, depending on the measured at least one physical property parameter, a liquid solution with a higher concentration of the reactant or educt or a liquid solution with a different reactant or educt can be used.

The at least one liquid solution is preferably added by pipetting. For this purpose, the analysis device preferably has at least one pipetting unit, which is controlled in particular by the controller. The pipetting unit preferably has at least one pipette or dosing device with which the at least one defined volume of the liquid solution can be added to the at least one sample liquid. The pipetting unit or its at least one pipette or at least one dosing device can be moved in at least one spatial direction, but preferably in two or three spatial directions, so that it can be moved between the at least one sample liquid and at least one other container, e.g. a storage container with the at least one liquid Solution can be moved back and forth. If several sample liquids are analyzed simultaneously, the pietting unit or its at least one pipette or dosing device can also be moved between the sample liquids. In certain embodiments, the pipetting unit can have several pipettes or Dosing devices have, so that they can deliver the same or different liquid solutions simultaneously in several sample liquids.

If, in the case of a simultaneous analysis of several sample liquids using the method according to the invention, the same liquid solution is to be added to several of the sample liquids at the same time, a sufficiently large volume of the liquid solution is preferably taken up with the pipetting unit in order to add the defined volume of the liquid solution to the corresponding sample liquids one after the other - or if several pipettes or dosing devices are present at the same time - to be able to deliver. This multiple pipetting can reduce the time required to perform analysis of multiple sample liquids. The same analysis does not necessarily have to be carried out for each sample liquid. Multiple pipetting is also possible for different analyzes in which the same liquid solution is used, e.g. the same buffer or the same starting material for a detection reaction, such as NADH.

When the at least one determination parameter changes, a defined volume of an additional liquid solution is preferably added to the sample liquid.

By adding a defined volume of an additional liquid solution, for example, if the concentration of the substance to be analyzed in the at least one sample liquid is too high, additional dilution solution can be added in order to dilute the substance to be analyzed in the at least one sample liquid, so that a more accurate measurement of the at least one parameter of the physical property is possible.

Furthermore, the concentration of a further substance to be analyzed in the at least one sample solution can be measured, for example, by adding a further starting material for an additional detection reaction and/or by adding a further reactant. At the same time, the at least one parameter of the physical property can also be changed if this is necessary for measuring the concentration of the other substance to be analyzed. The addition of a defined volume of an additional liquid solution makes it possible to add further educt even in the event of an unexpectedly high consumption of an educt of a detection reaction, for example due to a high concentration of an enzyme to be detected, with which the analysis can be completed. With a method from the prior art, the educt would be consumed before the end of the specified time, which means that the analysis would have to be repeated, which is not the case with the method according to the invention.

With certain liquid solutions, their effectiveness decreases over time. With the method according to the invention, the decrease in effectiveness can be compensated for using a correspondingly selected criterion, in that correspondingly more of the liquid solution is added. Alternatively, by measuring the extinction value of a marker solution at a specific wavelength, the change in the pH value of the sample liquid, which can be reduced by dissolving CO ₂ from the ambient air in the sample liquid, can be measured. If the pH value falls below a certain level, this can be corrected to a value required for the analysis method by adding a basic solution.

In addition, depending on the measured values of the at least one parameter of the physical property, a second substance to be determined can be analyzed by adding a further starting material and/or a further reagent. For example, when analyzing a blood sample for creatine kinase activity when a defined threshold value is exceeded, the activity of the MB type of creatine kinase (CK-MB) can also be measured using the same sample liquid and in the same process run. In the prior art, both activity determinations are carried out in parallel in order to keep the time short when diagnosing heart attacks. However, this means that CK-MB activity is measured unnecessarily even in cases in which a heart attack can be ruled out based on creatine kinase activity alone. The method according to the invention therefore makes it possible to save time and reagents, since the activity of the CK-MB is only carried out when this is really necessary. The second reaction is therefore only carried out when it is required. It occurs only through the additional addition of CK-MM antibodies to the normal CK- Approach. This saves a large part of the reagent costs and the result is available almost simultaneously with the CK result, saving time and increasing throughput.

The at least one liquid solution and/or the at least one additional liquid solution is preferably a dilution solution, a reagent, a calibration solution, a measurement standard or other sample liquid.

By adding a dilution solution, for example a buffer, if the concentration of the substance to be analyzed in the at least one sample liquid is too high, its concentration can be brought into a range in which the at least one parameter of the physical property can be measured reliably and precisely.

For example, a starting material for a detection reaction or a solution for quenching or activating a reaction or for complexing certain substances in the sample solution, e.g. for complexing certain ions, can be added as a reagent.

A solution is added to quench a reaction or to complex certain substances in particular in situations in which the measurement of the at least one parameter of the physical property indicates that another reaction is taking place in the at least one sample liquid or that ions or substances are present , which could interfere with or even prevent reliable measurement and/or analysis.

The measurement of the at least one parameter of the physical property can be carried out more precisely by adding a calibration solution or a measurement standard.

In particular in the case of homogeneous immunoassays which are based on turbidity due to an antigen-antibody reaction, interference from the substances contained in the serum matrix is conceivable. These can neither be estimated by analysis of the reaction curves nor by additional tests. However, this disturbance should be comprehensible, ie a defined concentration of the substance to be determined is given after completion of the determination reaction to the entire test mixture, the interference would also have to affect this added substance and also change its value. This "internal calibration" makes it possible to estimate the influence of unknown substances that occur individually in a sample.

If the concentration of the substance to be analyzed is too low, for example due to excessive dilution of the sample liquid before or during the method, its concentration can be increased by adding further sample liquid in order to enable a reliable measurement of the at least one parameter of the physical property.

If a reactant is used up too quickly (e.g. substrate exhaustion), the relevant reactant can be added in the required additional concentration by pipetting in a solution that differs in composition and volume from the original pipetting. It is also possible to achieve a measurable absorbance by adding a diluent if the measured absorbance is above the linearity limit. It is also possible to return to the original conditions if the reaction conditions are changed (e.g. changing the pH value by adding NaOH by pipetting).

Since the liquid solution or the additional liquid solution is added purely as a function of at least one predefined criterion, it can be much more flexible than methods from the prior art in which liquid solutions or additional liquid solutions are added using a fixed time schedule and adapted to the respective situation. Specifically, this means that the duration of the individual steps within the method can be shortened or lengthened depending on predetermined criteria compared to a fixed standard method, which always enables the best possible result of the analysis method at any time and for any sample liquid.

The predetermined time is preferably shortened or lengthened when the at least one determination parameter is changed. This enables the extension Shortening of the analysis depending on the measured at least one parameter of the physical property.

As a result, for example, in a situation in which it can be derived from the at least one measured parameter of the physical property that the analysis is complete, for example because a maximum value has been exceeded, the predetermined time can be shortened, which correspondingly reduces the overall time duration of the method can be. Compared to analysis methods from the prior art, in which a predetermined time is always awaited before the measurement is evaluated, the method can be carried out more efficiently as a result.

Furthermore, in a situation in which it can be deduced from the at least one measured parameter of the physical property that the analysis will not be completed within the specified time, it can be extended. This prevents an analysis from having to be repeated because there was not enough time before the evaluation.

In analysis methods from the prior art, the same time is always used for a specific analysis for all sample liquids, which is chosen long enough so that it is long enough for reactants and educts of different ages and varying concentrations of the same for the measurement to be successfully completed can. However, this means that the time for the vast majority of analyzes is too long. With the method according to the invention, the predetermined time can now be adjusted dynamically on the basis of the at least one criterion, so that only the time actually required for this is used for each analysis. This enables a higher throughput of analyzes per analysis device.

At least one predetermined mathematical analysis of at least one measured value of the at least one parameter of the physical property measured during the predetermined time or of a measurement curve of the measured at least one parameter of the physical property is preferably used in the evaluation. For example, the mathematical analysis may be an average or a moving average of multiple measurements of the at least one physical property parameter. Furthermore, measured values from different points in time during the predetermined time can be added, subtracted or their relationship to one another can be calculated. Alternatively, the mathematical analysis can be a statistical evaluation of the measurement curve of the at least one measured parameter of the physical property or an integral of this measurement curve or only part of this measurement curve.

When changing the at least one determination parameter, a different or additional mathematical analysis is preferably used for the evaluation.

Preferably, when the at least one determination parameter is changed, the number of measured values used for the mathematical analysis is changed or at least one other measured value is used for the mathematical analysis.

For the analysis of the at least one sample liquid, a sequential sequence of process steps is preferably carried out during the predetermined time, the process steps comprising at least one addition of a defined volume of a liquid solution to the at least one sample liquid and at least one measurement of the at least one parameter of the physical property of the at least one Includes sample liquid.

The at least one addition of a defined volume of a liquid solution and the at least one measurement of the at least one parameter of the physical property are preferably carried out at predetermined points in time, which are stored in the controller in particular. The predetermined times differ depending on the substance to be analyzed in the at least one sample liquid and the measured at least one parameter of the physical property.

When the at least one determination parameter is changed, the sequential sequence of the method steps is preferably changed.

In this case, the order of the individual method steps is preferably changed, ie at least one of the method steps in the sequential sequence is moved by one position is moved forward or backward. The predetermined point in time at which a method step takes place can preferably also be changed, ie a method step can take place at an earlier or later point in time.

More than one sample liquid is preferably analyzed at the same time. A different, sequential sequence of method steps is carried out for each of the sample liquids, with the controller coordinating the method steps for the analysis of all sample liquids in such a way that the method steps for the analysis of more than one sample liquid are carried out while maintaining the sequential sequence of the method steps for the analysis of each individual sample liquid are carried out one after the other as an overall sequence. When the at least one determination parameter is changed, the order of the method steps in the overall sequence is changed.

This means that depending on the at least one parameter of the physical property measured for a sample liquid, a method step for the analysis of the sample liquid can be brought forward or delayed within the overall sequence. Among other things, this also means that the predetermined time within which the method steps for the analysis of a sample liquid are carried out can be adjusted.

In contrast to an analysis device from the prior art, in which the method steps are carried out in succession for each of the sample liquids, the time required for carrying out an analysis can be significantly reduced with this embodiment. This is because, based on the measurement of at least one parameter of the physical property of each of the sample liquids, the predetermined time required to carry out all the respective method steps can be adjusted depending on the situation, so that only the time effectively required for the analysis of the sample liquid is used, instead of as in the prior art to wait for a fixed predetermined time, which is sometimes set too long for the analysis of most sample liquids. This embodiment has a significant advantage, particularly in the case of rotary analysis devices which have a sample carousel, so that each container with a sample liquid is guided past the pipetting, washing and measuring unit. This is because rotary analysis devices from the prior art have the disadvantage that all method steps are carried out at specified times using a specified sequence. The individual requirement for the analysis of a specific sample liquid cannot be taken into account, nor can the extinction values required for the evaluation be dynamically adjusted.

When changing the at least one determination parameter, decision criteria can now be used to change the direction of rotation and the number of vessels skipped individually on the basis of the at least one predefined criterion. In order to avoid collisions of several process steps of the sample liquids present in the analysis device, which should run simultaneously, the individual process steps to be carried out for the analysis of all sample liquids present in the analysis device are divided into priority classes, so that the individual process steps can be processed one after the other according to this classification.

The consequence of this is that each individual method step can be individually adapted to its requirements and thus a greater throughput and better adaptation of the reaction conditions of an individual analysis method can be guaranteed.

When using this embodiment in a rotary analysis device with a sample carousel, the cycle time could be reduced from 15 minutes to just 4 minutes, which means that a significantly higher throughput of analyzes could be achieved with the same analysis device.

When the at least one determination parameter changes or after the measurement has been evaluated by the controller, a message is preferably sent to an external device, in particular to a mobile device, via a communication network. As a result, an operator can always be informed about the current changes in the determination parameters during the analysis of the at least one sample liquid. The transmission preferably takes place via a wireless network, in particular via WiFi or a cellular network. Alternatively, however, the transmission can also take place via a wired network, for example via a LAN network. The message is preferably transmitted in encrypted form. If the message is transmitted to a mobile device, such as a mobile phone or tablet computer, the mobile device preferably has an application in which the message can be displayed and, in particular, saved. Furthermore, the report can also be transmitted to a database application in which all changes to the determination parameters are stored.

Furthermore, after the measurement has been evaluated, a message on the result of the analysis can be sent to an operator.

The message preferably includes an unambiguous identification of the at least one sample liquid, e.g. an identification number, as well as information on changing the determination parameter.

A parameter of the analysis device is preferably changed when the at least one determination parameter is changed. For example, the temperature of the at least one sample liquid can be changed by a temperature control device of the analysis device depending on the measured parameter of the physical property of the sample liquid.

The present application also relates to an analysis device for carrying out the method described above. The analysis device comprises at least one receptacle for a sample container with a sample liquid, a detector for measuring at least one parameter of a physical property of the sample liquid and a controller, characterized in that the controller is designed in such a way that the at least one parameter of the physical property is measured with the detector measured and then the measurement is evaluated by the controller, based on the measured at least one parameter and at least one predefined Criterion, which is stored in the controller, at least one determination parameter is changed.

The analysis device also preferably comprises at least one pipetting unit, with which at least one liquid solution can be added to the at least one sample liquid.

Further advantageous embodiments and combinations of features of the invention result from the following detailed description and the entirety of the patent claims.

Brief description of the drawings

The drawings used to explain the embodiment show:

1 shows a schematic sequence of an embodiment of the method according to the invention.

In principle, the same parts are provided with the same reference symbols in the figures.

Ways to carry out the invention

1 shows a schematic sequence of an embodiment of the method according to the invention. Before the start of the method, in a preparatory step 1, at least one sample container with a sample liquid is placed in an analysis device. In this preparatory step 1, the analyzer is set up for the analysis to be carried out. Through the settings, the analyzer then measures the correct physical property parameter for the analysis to be performed and applies the appropriate criteria for the analysis to be performed. In this preparatory step 1, a solution can be added to the sample liquid in at least one sample container, for example a dilution solution, a buffer or a solution with a reactant or educt for a detection reaction. The analysis is then started. In this case, the at least one parameter of the physical property is measured in a measurement step 2 . A controller of the analyzer compares the at least one measured parameter physical property or its measured value with at least one criterion in a decision step 3. If the measurement of the at least one parameter of the physical property does not meet the at least one criterion, the measurement of the at least one parameter of the physical property is continued until a predetermined time T, which corresponds to a measurement time is reached. After the predetermined time has been reached, the controller of the analysis device evaluates the measurement in an evaluation step 5 using at least one analysis parameter. If the measured at least one parameter of the physical property meets the at least one criterion, at least one determination parameter is changed in a change step 4 after decision step 3 . The measurement is then continued.

example 1

The concentrations of creatinine in serum and urine are different. The normal range for serum samples is 0.6-1.3 mg/dl, while the values for urine are 40-90 mg/dl. This entire measuring range is not possible with conventional analysis systems, which is why two different programs are entered in the analyzer for urine and serum samples, whereby the urine sample normally first has to be pre-diluted in the device or manually outside. However, this means more cumbersome handling and a reduction in throughput. With the method according to the invention it is now possible to carry out serum and urine samples in a single determination batch and without loss of throughput. The analyzer is able to differentiate between serum and urine samples based on the different absorbance curves and to process them in different test batches. In a corresponding test approach, 200 μl of a reagent containing 160 mmol/l NaOH and 6.7 mmol/l Na ₂ HPO ₄ are mixed with 12 μl of sample, which can consist of serum or urine, and after mixing to 37 °C thermostatted. After 3-5 minutes, this solution is mixed with 40 μl of a second reagent containing 20 mmol/l picric acid and also mixed. In alkaline solution, creatinine forms a colored complex; the speed of this reaction depends on the concentration of creatinine. Therefore becomes too fixed Times the extinction difference dE / min of the reaction at 505 nm measured over 3-5 minutes and evaluated. The value obtained is continuously registered. If this value is below 0.2 U/min, this value is multiplied by the factor previously determined by a calibration with a calibrator of known concentration and the analysis result is determined. If a value above 0.1 dU/min is reached, 30 μl of a reagent containing 100 mmol/l picric acid are added again. After mixing, the extinction values are again determined at specified times with a change in the measurement wavelength from 505 nm to 545 nm. Multiplication with the factor also previously determined by calibration results in the new measured value.

The decision criterion for this determination is the determined dE/min value.

This resulted in changes in the way the test was carried out: a) another pipetting of a solution of the reactant picric acid in an increased concentration and the resulting increase in reaction time b) a change in the wavelength selected for the evaluation and the calculation factor This enables the simultaneous determination of serum and urine samples without additional actions on the part of the user.

example 2

The requirements for analytical measurement methods have increased immensely in recent times. On the one hand, this is due to the fact that new processes or requirements are constantly emerging, and on the other hand, the demand has expanded to include more and more areas and the number of tests has increased significantly. It has proven to be particularly disadvantageous that the rigidly defined analysis process is a major obstacle to the new requirements, especially in the case of photometric analyses. This is documented, for example, in a possible measuring range that is no longer sufficient for many requirements. For example, a large measuring range is required in the production or processing of substances, or in food analysis, such as in wine or beer tests, or in waste water investigations. It has now been found that a particularly large change in the measuring range can be obtained by changing a number of parameters at the same time. The kinetic determination of lactate dehydrogenase is given as an example. The measurement time, the concentration of a reactant and the selected wavelength should be changeable.

Programming 1: 10 μl sample are added to 200 μl of a reagent which contains 50 mmol/l Tris buffer with a pH of 7.5 and 360 μl/l pyruvate, mixed and incubated for 2-5 min at 37° C . Then 40 μl of a solution buffered at pH 9.6 with 2.1 mmol/l 15 NADH is added. The absorbance of the total solution at 340 nm is measured continuously at fixed times and the respective dE/min is calculated.

Programming 2: Depending on the decision criterion de/min, 40 μl of a solution buffered at pH 9.6 with 10 mmol/l NADH are added to the above total solution, mixed and again measured at 380 nm at specified times.

Decision Criteria:

1) Measurement at 340 nm, programming 1 and different measurement times depending on dE/min 2) If the limit value of 0.9 dE/min at 340 nm is exceeded, additional pipetting and change to 380 nm (Prog 2), also different measuring times depending on dE/min. Depending on the dE/min value, the measurement ends at different times. As the evaluation shows, this method gives you a measuring range that is 50 times larger than with the normal method.

The LDH value is obtained by multiplying dU/min by the factor previously determined by calibration.

Example 3

Usually a certain wavelength or a mathematical function, e.g. an addition, of measured values at several specific wavelengths is selected for a measurement. With today's diode array photometers, a defined wavelength is usually not selected exactly, but the range used is only a few nm wide and is the same for all measurements at this wavelength. In some reactions, however, the increase in extinction obtained is not limited to a narrow wavelength range, but a broader peak is obtained up to an increase over the entire wavelength range, as in the case of the immunological turbidity tests. The lowest wavelength (340 nm) is usually used as the measuring wavelength for such tests, since the greatest change in absorbance is obtained in this range. Changing to a different wavelength would not bring any advantage for samples with a very low concentration, nor would increasing the volume of the sample by additional pipetting bring any advantage, since the influence of interfering matrix components cannot be eliminated. A significant improvement, on the other hand, is the inclusion of extinction changes at other wavelengths by addition or integral formation over several wavelengths.

This can be seen, for example, in the determination of CRP, the most important immunological test in clinical chemistry (inflammation parameters), which is now one of the routine parameters. The detection limit for a test using turbidity due to normal antigen-antibody reaction is around 1 - 2 mg/l. For special diagnoses, however, the range from 0 to 1 mg/L is significant. In order to be able to make this statement, another test that has latex-enhanced antibodies and therefore provides higher absorbance values must therefore be used. However, this test is up to 5 times more expensive and requires an additional reagent, additional calibrations, etc. A normal measurement with a measurement length interval of 2 to 3 nm enables a maximum detection limit of around 1 mg/l with the commercially available analyzers. 15 μl of a serum sample are added to 250 μl of an 80 mmol/l Hepes buffer solution pH 7.6 with 20 g/l polyethylene glycol and thermostated at 37° C. for 5 minutes. Then the extinction values are determined simultaneously at 340, 405 and 450 nm. Then 50 μl of a 10 mmolar phosphate buffer solution containing CRP polyclonal antibodies against human CRP are added and again after 5 minutes the extinctions are measured at 340, 405 and 450 nm. The following table contains the corresponding difference values of both measurements for a sample with a concentration below the detection limit.

The change in extinction at 340 nm after addition of the antibody solution serves as a decision criterion. If it is less than 0.05 E, the alternative determination is carried out over several wavelengths or wavelength ranges.

As can be seen, the addition of several values from different wavelengths leads to a significant improvement in precision at very low concentrations, so that the use of the much more expensive latex reagent can be avoided.

An even greater effect can be achieved by expanding the range further and calculating an area integral over the extinction values obtained instead of adding them up:

Example 4:

The most frequent interference by the serum sample matrix occurs through the so-called Sl parameters (triglycerides, hemoglobin, biliurbin), whereby the concentrations of the parameters bilirubin, hemoglobin and triglycerides in the range can be determined by comparing the curves by measuring the extinctions with diode arrays used today with 12 possible wavelengths +/- 10% can be determined. This is usually done using a separate test, in which the sample is diluted with water or a buffer solution and the absorbances are measured at several wavelengths, allowing statements to be made about the possible interferences. However, the possible statements are very limited and the additional test requirement in normal analysis operation is disruptive, so that this method - even if offered - is usually not used.

Surprisingly, it has now been found that when all 12 wavelengths or a larger wavelength range are used, this determination of the SI values is possible within the framework of the determinations carried out. Each of the interfering SI parameters has a specific absorbance curve at specific wavelengths. The simultaneous measurement of the absorbance of these specific wavelengths enables the concentration of each of these SI parameters to be determined using a mathematical calculation. If the measured values are below a predefined threshold value as a criterion, e.g. because the concentration of one of the SI values is very low or other interfering substances are present in the sample liquid, the absorbance at at least one additional wavelength can be included in the calculation as a change in a determination parameter .

In addition, it is possible to use the determined concentrations of the SI parameters to calculate their extinction curves over the entire extinction range and to subtract them from the obtained extinction curve of the serum matrix, so that an extinction curve of other parameters present in the matrix can be determined. A Comparison with data from an internal library could therefore make it possible to identify other substances present in the matrix. Depending on the importance for a possible diagnosis or influence on the test result, a message would then be possible via the device or via special apps for external devices.

Example 5:

Another option is to use decision criteria to intervene in the mechanical processes of the analyzer. The normal process consists of fixed actions that are repeated at certain time intervals and are caused by the fixed rotation of the cuvette rotor. It is determined in specific step sequences in which the rotor is moved a specific number of cuvettes in one direction. This makes it possible for pipetting, measurements or washing processes to be carried out at precisely defined times. On the other hand, this avoids the possibility of collisions between possible simultaneous actions. For the complexity and variety of today's analysis processes, however, this means a major restriction in the flexibility of test execution with regard to different test methods and different requirements from different samples. Surprisingly, it has now been found that this is possible if the urgency of different processes running at the same time is prioritized. There are actions that have to be carried out as precisely as possible at a specific time, while others have a time window of several seconds. The direction of movement of the cuvette ring, the number of cuvettes skipped, pipetting and measurement processes as well as washing cycles can therefore be carried out individually using decision criteria that take into account both the conditions of the respective test and the special conditions of the respective sample.

Claims

33 patent claims

1. A method for analyzing at least one sample liquid with an analysis device using predetermined determination parameters, wherein at least one parameter of a physical property of the at least one sample liquid is measured, and wherein after a predetermined time has elapsed, a controller of the analysis device evaluates the measurement, characterized in that within the predetermined time based on the measured at least one parameter of the physical property and at least one predefined criterion, which is stored in the controller, at least one of the determination parameters is changed by the analysis device.

2. The method as claimed in claim 1, characterized in that when the at least one determination parameter changes, another parameter of the physical property is measured.

3. The method as claimed in claim 1, characterized in that when the at least one determination parameter changes, at least one parameter of another physical property of the at least one sample liquid is measured.

4. The method according to any one of claims 1 to 3, characterized in that the physical property of the at least one sample liquid is an optical property.

5. The method according to claim 4, characterized in that the at least one parameter of the physical property is an extinction of light of at least one predetermined wavelength.

6. The method according to claim 4, characterized in that the at least one parameter of the physical property is a fluorescence at at least a second predetermined wavelength when excited with light of at least one predetermined wavelength. 34

7. The method according to claim 5 or 6, characterized in that the at least one predetermined wavelength is changed when the at least one determination parameter is changed.

8. The method according to any one of claims 5 to 7, characterized in that the at least one criterion is exceeding or falling below a predefined value or a predefined temporal change in extinction or fluorescence at at least one wavelength or exceeding or falling below a predefined difference of absorbance or fluorescence at multiple wavelengths.

9. The method according to any one of claims 1 to 8, characterized in that the method comprises a step in which at least one defined volume of a liquid solution is added at a defined point in time during the predetermined time, with the change in the at least one determination parameter defined volume and/or the defined point in time are changed or the liquid solution to be added is changed.

10. The method as claimed in any of claims 1 to 9, characterized in that when the at least one determination parameter changes, a defined volume of an additional liquid solution is added to the sample liquid.

1 1. Method according to one of claims 9 or 10, characterized in that the at least one liquid solution and/or the at least one additional liquid solution is a dilution solution, a reagent, a calibration solution, a measurement standard or other sample liquid.

12. The method according to any one of claims 1 to 11, characterized in that when the at least one determination parameter changes, the predetermined time is shortened or lengthened.

13. The method according to claim 1 to 12, characterized in that in the evaluation of the measurement at least one predetermined mathematical analysis of at least one measured value measured during the predetermined time or a Measurement curve of the measured at least one parameter of the physical property is used.

14. The method according to claim 13, characterized in that a different or additional mathematical analysis is used when the at least one determination parameter is changed.

15. The method as claimed in claim 13 or 14, characterized in that when the at least one determination parameter is changed, the number of measured values used for the mathematical analysis is changed or at least one other measured value is used for the mathematical analysis.

16. The method according to any one of claims 1 to 15, characterized in that for the analysis of the at least one sample liquid during the predetermined time, a sequential sequence of process steps is carried out, the process steps at least one addition of a defined volume of a liquid solution to the at least one sample liquid and at least one measurement of the at least one physical property parameter of the at least one sample liquid.

17. The method according to claim 16, characterized in that when the at least one determination parameter is changed, the sequential sequence of the method steps is changed.

18. The method according to any one of claims 16 or 17, characterized in that more than one sample liquid is analyzed at the same time, and that a different, sequential sequence of process steps is carried out for each sample liquid, the control of the process steps for the analysis of all sample liquids such coordinated in that the process steps for the analysis of more than one sample liquid are carried out one after the other as an overall sequence in compliance with the sequential sequence of the process steps for the analysis of each individual sample liquid, further characterized in that when changing the at least one Determination parameters, the order of the process steps in the overall sequence is changed.

19. The method as claimed in one of claims 1 to 18, characterized in that when the determination parameter changes or after the measurement has been evaluated by the controller, a message is sent to an external device, in particular to a mobile device, via a communication network.

20. The method as claimed in one of claims 1 to 19, characterized in that when the at least one determination parameter changes, a parameter of the analysis device is changed.

21. Analysis device for carrying out a method according to any one of claims 1 to

20, comprising at least one receptacle for a sample container with a sample liquid, a measuring unit for measuring at least one parameter of a physical property of the sample liquid and a controller, characterized in that the controller is designed in such a way that the at least one parameter of the physical property is measured with the measuring unit measured and then the measurement is evaluated by the controller, at least one determination parameter being changed based on the measured at least one parameter of the physical property and at least one predefined criterion which is stored in the controller.