DE19933277A1 - Method and device for displaying and monitoring functional parameters - Google Patents

Abstract

The invention relates to a method and device for representing and monitoring functional parameters of a physiological system, especially electrocardiographic data which can be derived from electronic measurement signals. The aim of the invention is to provide a method and device with which a direct evaluation of the determined functional parameters and a diagnosis of the physiological system is made possible. To this end, the invention provides that a plurality of measuring transducers, which are independent of one another, record the measurement signals, that the measurement signals are assigned to particular areas of the topological model, and that the assignment of the measurement signals to the areas is carried out according to the position of the physiological system with regard to the measuring transducers.

Description

The invention relates to a method and a device to display and monitor function parameters a physiological system, especially electrocardiogra phical data derived from electronic measurement signals be tested.

In the patent application DE 198 01 240 a method and described a device in which with a standard based 3-point derivation of ECG data recorded and in electrical signals are converted from which a dreidi dimensional topological model is generated. With that the subject of patent application DE 198 01 240 generated topological model, which is a kind of portrait of the examined Heartfelt are very precise information about that Emergence and in particular the change of heart receive. So that the method and the device can do well for the early detection of heart attacks and for monitoring Heart condition changes, e.g. B. after surgery or in the case of drug therapy.

In the process, an analysis cycle is first defined and which is included within this analysis cycle Data is digitized. Then the di gitalized data supplied to a storage unit and it a color code is assigned as a function of the digitized data. The data becomes space coordinates determined as surface support points between  which pixels to generate an essentially closed surface are interpolated and calculate th image information of an evaluation or output device tion are fed.

Due to the limited information available through a 3-point derivation from the one that arises during cardiac activity action potentials can be determined, are precise slides gnoses, especially quantitative statements about existing Diseases with the described subject are not always possible. By increasing the number of leads more information about the action potential available be provided, for example, by simultaneous users of twelve standardized ECG leads.

When processing the twelve derivation determined by the subject of patent application DE 198 01 240 would recorded signals are processed one after the other and a corresponding topological model would be based on the Processing of the last derivative can be output.

Due to the different orientation of the heart axis in within the body of different people Application of the subject matter of patent application DE 198 01 240 with several standardized ECG leads to the Result that depending on the position of the heart axis for two hearts in the same state of health different heart pores traits can be determined. For creating an independent diagnosis that does not rely on changes, this situation is unsatisfactory, as with similar ones The topological models also have similar heart states should go.

The object of the present invention is therefore a method ren and provide a device that a direct Evaluation of the determined function parameters and a Diagnosis of the physiological system enables.  

According to the invention, this object is achieved by a method according to claim 1 and a device according to claim 14 ge solves.

By assigning certain standardized EKG leads certain areas of the graphic portrait it is possible that despite different heart axis positions in the Processing the recorded action potentials various achieved comparable results with one another even a quantitative classification of the measurement enable gene.

The assignment of the respective derivation to the areas takes place depending on the position of the heart axis, so that an independent representation takes place. It takes place like this a standardization with regard to the position of the heart axis instead.

In a further development of the invention, the respective Derivatives in different, but based on beforehand empirically determined data set the order assigned to different areas, the selection of Order depending on a significant size of the Action potentials. Based on the significant size the position of the heart axis can be determined by the action potentials be because the different parts of a body attached transducer, expediently Electrodes, depending on the location of the heart within the body record differently strong signals so that determine the position of the heart axis based on the signal strength leaves. The order is then based on the measured signals determined the processing of the derivatives.

The sequence is advantageously selected based on the largest measured amplitude of the R wave Heartbeat because the R wave has great significance Has.  

When determining the order based on empirically determined The comparison data contain the comparison data Results of investigations, which the physiological loading special features of the standardized ECG leads clear and therefore precise statements about the heart condition allow on the basis of the determined data. Conveniently are the comparison data in an electronic memory filed and are retrieved from there.

In a further development of the invention, the EKG leads each with a conversion factor depending on the order of the assignment area. It is in one Embodiment of the invention by the conversion factor only the sign of the measured signal of the respective Derivation changes the amount, if this is provided is not changed, which also changes in amount have comparable data generated. But it can also be one change in amount due to the application of the conversion factor.

In a further development of the invention, the graphi diagnosis, based on the measured action potentials is created automatically and is output in parallel to the graphic portrait. there the data is subjected to a computer-aided evaluation gene in which the ECG leads are based on comparison data a finding is assigned. The diagnosis or the finding can be done with different methods of evaluation can be created with the respective method selected can be. So a measurement can be made by application several evaluation methods, several diagnoses, for example for internal comparison. Likewise is one parallel display of several diagnoses possible.  

The device for carrying out the method also has the facilities for the graphic processing of the several independent devices for data took up a switching device that is dependent the order of a determined significant size Processing of the determined signals.

This causes the derivative signals to be in the correct Order assigned to the areas of the graphic portrait net, so that similar results for similar conditions be determined.

The switching device is advantageously the Vorrich data acquisition and conversion into electri cal signals, the devices for determining a Analysis cycle and the analog-digital converters of the received signals with the switching device, whereby the recorded signals before the graphical recording horse riding are bundled and according to their determined Order to be forwarded.

In one embodiment, the switching device has the Invention a first evaluation device for determining the significant size of the signal, a switch to choose from the device for data acquisition and a second evaluation device for controlling the switch, the Devices for data acquisition with both the switch and are also connected to the first evaluation unit. The The first evaluation unit has at least two inputs connected to the second evaluation unit and transmits the significant size and the information which derivative has the greatest amplitude of the significant size. The second evaluation controls on the basis of this information is the switch, which accordingly the signals of the respective derivation in the given order switches. The respective signals become the second rake  unit fed this after a possibly necessary application of a conversion factor for graphical presentation.

The evaluation units are advantageously made of micropro are built up in which empirically determined Comparative data are stored on the basis of which the Sequence of processing and is determined. Likewise the signals with conversion are based on the comparison data factors applied to a graphical representation to get a comparison between different Hearts and an independent classification of the state possible chen. In addition, it is automatic, computer-based te diagnosis possible, but different Types of evaluation of the measured data are optionally possible are.

Based on the drawings, examples are given below games of the invention explained in more detail. Show it:

Fig. 1 is a representation of a topological Mo dells with a division into areas;

Fig. 2 is a sectional representation of a topological model in a plane;

Fig. 3 is an illustration of two topological model le of heart-like condition with different axis positions;

Fig. 4 is a block diagram of the device;

Fig. 5 is a mapping table;

FIG. 6 shows a table with conversion factors and FIG. 7 shows the models according to FIG. 3 using the method according to the invention.

Fig. 1 shows a topological model of an examined heart, in which the recorded action potentials after the conversion into electrical signals and digitization were provided with color codes and spatial coordinates, and a three-dimensional model was thus generated. Certain sections of the EKG signal were assigned to certain areas of the topological model in order to provide the examining doctor with a representation of the EKG signal, which enables a quick and precise diagnosis and which provides the information about all in a clear manner Prepared derivatives.

Fig. 1 shows the model based on twelve standar ized ECG leads formed and in that correspond to the areas was divided. The upper area of the model shows the stress state of the examined heart. Underneath there is an area that contains the information of the individual derivatives with regard to the P wave, below this in turn the information about the T wave is arranged and finally the information about the QRS complex is shown. From left to right, the information of the leads is shown in the order in which the leads were recorded. The order here is I, II, III, aVR, aVL, aVF, V1, V2,. , ., V6. This sequence is exemplary and can also be set differently.

When using multiple leads, changed the shape and color of the topological model Depends on the processing order of the respective Derivatives because the information from the derivatives can be assigned to different areas. The information the leads also change depending on  the location of the heart axis, d. H. with a constant Arrangement of the transducers, usually electrodes, the representation of the model changes when the location the heart axes with otherwise the same heart states is.

With a fixed order of processing the Derivatives and a fixed arrangement of the electrodes the representation of the topological model changes to Shape and color depending on the location of the heart axis.

For the sake of clarity, this connection is illustrated by means of a cut through the topological model on a level in which the information about the T wave is arranged. Such a section is shown in FIG. 2, the designations T1 to T6 indicating the sequence of the processing. Below the topological model, the projection is shown in a two-dimensional representation.

In FIG. 3, the respective sections are defined by two topological models were made of two hearts with the same health status. The sequence T1 to T6 of the processing is listed between the two sectional views and in this case is I, II, III, aVR, aVL, aVF.

The difference between the two hearts is that Location of the heart axis within the body. The location type of the At the heart of the illustration above, the link type (αQRS = 0 °) and that of the lower representation as a steep type (αQRS = 90 °) designated. In both cases the same editing was done order applied, and it is that the representations is different, although the condition is the same for both was. The different presentation of ECG leads same heart conditions is not for a quick diagnosis conducive. Rather, the goal is the differences  between the topological models of different people with the same heart condition (e.g. the same disease) to minimize, because only then a quick and precise diagnosis is possible.

In order to make the topological model independent of the position of the heart axis, the data or the electrical signals of each derivation are supplied after digitization to a switching device 50 which is connected upstream of the processing of the signals. A block diagram of the device is described in FIG. 4.

In FIG. 4 twelve transducer 1 are shown, which has a processing unit 2, respectively, and an analog-to-digital converter 3 verbun to the switching device 50 the are. The switching device 50 consists of two evaluation devices 51 , 52 and a switch 53 . The first evaluation device 51 has six inputs, which correspond to the first derivatives I, II, III, aVR, aVL and aVF, and two outputs 51-1 and 51-2 . The outputs 51-1 and 51-2 are connected to the second evaluation device 52 .

In addition to inputs for the signals from the first evaluation device 51, the second evaluation device 52 has three outputs 52-1 , 52-2 and 52-3 , the output 52-1 with the storage unit 4 and the output 52-2 with the computing unit 6 is connected, which are provided for graphic processing of the signals. The third output is connected to the switch 53 .

The switch 53 has twelve inputs for each ECG lead and one input for the signal from the second evaluation device 52 . The interaction of the elements of the switching device 50 and the method according to the invention is explained by way of example below.

The signals of the twelve leads are applied to the twelve inputs of the switch 53 and at the same time the signals of the first six leads, namely I, II, III, aVR, aVL and aVF, are fed to the six inputs of the first evaluation device. In the first evaluation device 51 , which is based on microprocessors, a significant size of the leads is determined, which is, for example, the amplitude of the R wave of the EKG. At the output 51-1 of the evaluation device, the lead is present with the greatest amplitude of the R wave , that is, at the output 51-1 there is information at which of the first six leads the greatest amplitude of the R wave of a measurement was determined. At the output 51-2 , the amount and the sign of the derivative with the greatest amplitude of the R wave are passed on to the evaluation device 52 .

In the second evaluation device 52 , the order of the processing and the corresponding assignment of the respective derivation to the areas of the topological model are determined on the basis of the information on which derivation the R wave has been measured with the greatest amplitude. How the sequence is determined is explained below. On the basis of this sequence, a signal is sent from the output 52-3 to the switch 53 , which is controlled accordingly and releases the signals of the respective derivation to the second evaluation unit 52 in the specified sequence.

In the second evaluation unit 52 , the sequence of processing and thus the assignment of the derivations to specific areas of the topological model is determined on the basis of empirically determined data which are stored as comparison data in the second evaluation device 52 . Two tables Top 1 and Top 2 are used for the calculation, which are shown in FIGS . 5 and 6.

In FIG. 5, the table is shown with which the sequence of the processing is set. The table consists of 14 columns and twelve rows, the first column containing the name of the derivative that has the largest amplitude value of the R wave; the first six leads from I to aVF are evaluated. This information is made available by the first evaluation device 51 at the output 51-1 . In the second column the sign of the respective derivative is given, the value 1 meaning a positive sign and the value 0 signifying a negative sign. In the remaining twelve columns, the order of processing and thus the assignment to the areas is given in the topological model. The switch 53 is activated in accordance with the order given in the lines.

Is z. B. the greatest amplitude of the R wave through the lead device I determines and has a negative sign (a 0 in the second column) will be in the rows follow the seventh line the derivatives processed and assigned.

In addition, the signals are applied with a conversion factor, which is shown in Table Top 2 of Fig. 6 Darge. On the basis of empirically determined comparison data, the measured value of the derivative is subjected to a conversion factor which, if appropriate, causes a change of sign, that is to say either assumes the value +1 or -1. According to the example above, derivative II would have -1, derivative aVR +1, etc., according to the conversion factors of the seventh row of table Top 2 .

The second evaluation device 52 therefore carries out the following steps in accordance with the number of leads, here twelve leads:

• 1. Determination of the column i to be processed, where i is the Represents step number and runs from 1 to 12.
• 2. Determine the applicable row based on the first two columns of the table Top 1 .
• 3. Determination of the derivation to be processed (intersection of column i and the relevant row in Top 1 ).
• 4. Determination of the conversion factor (intersection of column i and the relevant row in Top 2 ).
• 5. Activate the switch and link the signals of the applicable derivative with the conversion factor.
• 6. Forwarding of the converted data to the storage unit 4 for processing.
• 7. Parallel forwarding of the information about the assignment to a specific area of the topological model to the computing unit 6 .

The values in the table Top 2 and the order of processing and assignment of the leads to certain areas of the topological model according to the table Top 1 reflect the physiological peculiarities of the standardized ECG leads of a person. The described conversion leads to comparable results from EKG recordings, regardless of the position of the heart axes.

The desensitization of the topological model with regard to the position of the heart axis, that is to say the exclusive registration of the heart state and the type of deviation from the state of a healthy heart, is shown in FIG. 7. This is a representation of the same data as was used in FIG. 3, but the data were processed with the device described above and the corresponding method. The respective order of assignment of the respective derivative and the corresponding conversion factor is given above the projection. In the upper representation, a conversion was carried out in accordance with the first row of the tables Top 1 and Top 2 , in the lower representation, a conversion and assignment was carried out in accordance with the sixth row.

The similarity of the two representations in FIG. 7 is evident in spite of the different positions of the heart axis, that is to say the representation of the topological model is independent of the position of the heart axis and thus provides information which allows a comparison between two different hearts.

It is also possible to determine the processed and processed Link data with comparison data, e.g. B. with Herzda libraries where the ECGs of a variety of patients is stored together with the medical history. Because of the It is possible to compare with this data in addition to the topological model to issue a diagnosis. You can not just diagnoses for the respective examination but also developments between two or more investigations are shown and evaluated.  

It is also possible, in addition to the output of the topological To use various diagnostic methods and to carry this out alternatively or additionally, at for example using the Goldberger method.

Claims (21)

1. A method for displaying and monitoring function parameters of a physiological system, in particular electrocardiographic data derived from electronic measurement signals, the data being combined into a basic data model and converted into a graphical portrait, which is in the manner of a three-dimensional topological model is constructed,
characterized by
that several mutually independent sensors record the measurement signals,
that the measurement signals are assigned to certain areas of the topological model, and
that the assignment of the measurement signals to the areas takes place in dependence on the position of the physiological system in relation to the measurement sensors. 2. The method according to claim 1, characterized in that action potentials are determined in a cardiac examination with several standardized EKG leads,
that certain areas of the graphic portrait are assigned to the ECG leads, and
that the assignment of the ECG leads to the areas depends on the position of the heart axis. 3. The method according to claim 2, characterized in that the derivatives in different, fixed Sequences are assigned to the areas, with the Selection of the order depending on a signifi edge size of the action potentials. 4. The method according to claim 3, characterized in that the selection of the order based on the largest measured N amplitude of the R wave of a heartbeat occurs. 5. The method according to claim 3 or 4, characterized net that the order based on empirically determined Comparison data is set. 6. The method according to claim 5, characterized in that the comparison data taking into account the physiolo particularities of the standardized EKG lead are determined. 7. The method according to claim 5 or 6, characterized in net that the comparison data from an electronic Memory. 8. The method according to any one of claims 2 to 7, characterized ge indicates that the ECG leads each have a Conversion factor to be applied depending on the order of assignment to the areas is set.   9. The method according to claim 8, characterized in that by the conversion factor the sign of the EKG-Ab line is changed. 10. The method according to any one of the preceding claims, characterized in that with the graphic por a diagnosis is issued. 11. The method according to claim 10, characterized in that the diagnosis is based on a computer-based off evaluation of the determined ECG leads becomes. 12. The method according to claim 11, characterized in that that the diagnosis with different methods of Evaluation is created. 13. The method according to claim 12, characterized in that that the respective diagnosis is called up separately. 14. A device for performing the method according to claim 1, the devices ( 1 ) for data acquisition and conversion into electrical signals, a device ( 2 ) for determining an analysis cycle, an analog-digital converter ( 3 ) for digitizing the recorded signals and a storage unit ( 4 ), with an evaluation unit ( 5 , 6 , 7 ) with evaluation software for generating a three-dimensional, colored image with a closed surface on the basis of the recorded and evaluated signals, a control unit ( 8 ) for processing the pixels determined and an evaluation or output device ( 9 ),
characterized,
that several mutually independent devices ( 1 ) are provided for data acquisition and conversion into electrical signals and
that the devices ( 1 ) are connected to a switching device ( 50 ) which determines the order of processing of the determined signals as a function of a determined significant size. 15. The apparatus according to claim 14, characterized in that the devices ( 1 ) for data acquisition and conversion into electrical signals via devices ( 2 ) for determining an analysis cycle and analog-digital converter ( 3 ) for digitizing the recorded signals with the switching device ( 50 ) are connected. 16. The apparatus of claim 14 or 15, characterized in that the switching device ( 50 ) has a first evaluation device ( 51 ) for determining the significant size of the signal, a switch ( 53 ) for selecting the device ( 1 ) for data acquisition and one has a second evaluation device ( 52 ) for controlling the switch ( 53 ). 17. The device according to one of claims 14 to 16, characterized in that the devices ( 1 ) for Da tenaufnahme both with the first evaluation device ( 51 ) and with the switch ( 53 ) are connected. 18. The apparatus according to claim 17, characterized in that the second evaluation device ( 52 ) is connected both to the memory unit ( 4 ) and to the computing unit ( 6 ). 19. Device according to one of claims 16 to 18, characterized in that outputs ( 51-1 , 51-2 ) of the first evaluation device ( 51 ) are connected to inputs of the two th evaluation unit ( 52 ) and the second evaluation unit ( 52 ) controls the switch ( 53 ) on the basis of the size determined by the first evaluation unit ( 51 ) and determines the sequence of the further processing of the signals. 20. Device according to one of claims 16 to 19, characterized in that the evaluation units ( 51 , 52 ) are constructed from microprocessors in which empirically determined comparison data are stored. 21. The apparatus according to claim 20, characterized in that in the microprocessors conversion factors for Processing of the determined signal are stored.