DE102004052083A1 - Digital electronic diagnostic method and mobile device for non-invasive determination of lactate level, using two dimensional virtual scatter plot - Google Patents

Abstract

The mobile device for a non-invasive determination of lactate level comprises a micro controller including a micro controller ROM with preprogrammed algorithms. A non invasive sensorial detection, a micro controller supported completely electronic evaluation and control of the lactate level as well as the important individual threshold values under various conditions is performed. The heart pulse rate and the pulse pressure wave frequency of a person walking or running in the open air is taken into account.

Description

Purpose of invention

in the Field of medical prophylaxis, in sports practice, in physiotherapy and in the field of medical rehabilitation become constitutionally adapted physical exercises to the physiological capacity carried out under metrologically controllable conditions. There a insufficiently trained human body and increasing private and occupational stress through a modern lifestyle Increase in the corresponding diseases. Patients over thirty years be, depending on performance, very often also prophylactically, special individual physical exercises medical prescribed. To a complete Performance assessment of a test person must be in addition to the determination of mechanical muscle performance in successive stress levels, the maximum heart rate and its increase with the load, as well the increase in lactate concentration (concentration of salts and Esters of lactic acid from working skeletal muscle) depending on the load be recorded under metrologically controllable conditions. For Lactatwert determination blood samples from the earlobe am Taken at the end of the respective stress level. The stationary evaluation takes place later in the laboratory with the help of a special computer program. The determined individual lactate threshold above which acidification of the human body occurs lets you draw conclusions the efficiency of the subject and is a very important parameter for the creation an individual therapy and endurance training program. Of the Subject of the invention digital, electronic diagnostic procedure for bloodless lactate performance determination u. a mobile measuring device for electronic implementation "includes a digital electronic software supported Diagnosis method using a microcontroller and in a newly programmed specially programmed microcontroller ROM Algorithms for bloodless sensory acquisition and microcontroller-based fully electronic Evaluation and monitoring the lactate performance and the important lactate threshold (the hyperacidity point) in a multi-level physical stress (biomechanical muscle performance) taking into account the heart rate a student walking outside, walking or running.

 Under The lactate concentration is the concentration of the salts and esters of lactic acid the biomechanically working skeletal muscle. There are metrological Capture of lactate concentration basically two different technical Procedure: The stationary Laboratory test and the mobile field test.

Stationary lactate performance tests (Laboratory tests) are usually carried out with so-called bicycle ergometers. To the warm-up Muscles at low biomechanical load typically become the load levels are chosen so that the load every 3 minutes by 25 - 50 watts (depending on performance) is increased to the so-called load (about 4 - 6 stages). The pedaling frequency is kept constant and the pulse is constantly monitored. Blood samples from the earlobe become the end of the earlobe respective load level taken. In the lactate test, the lactic acid values are measured. The lactate threshold determined in the lactate test allows conclusions to be drawn capacity of the subject and is a very important parameter for the creation an individual training program.

Mobile lactate performance tests (running field tests) are usually carried out on suitable plastic sheets. After warming up at low tempo (walking for beginners), the load levels are typically chosen to increase the load by 7-10 beats to full load every 800 - 1200 m (depending on performance) (in total 4 - 6 levels). The pulse must be constantly monitored. To determine the lactate value, blood samples are taken from the earlobe at the end of the respective stress level. The stationary evaluation in the laboratory is done today with the help of a special computer program, which allows the determination of the individual lactate threshold. The previously customary 4 mmol threshold represents a very great simplification, since individual anaerobic thresholds are usually in the range of 3-5 mmol. The indication of a fixed 4 mmol threshold often means for volunteers an over- or underload. Therefore today the training hints are basically based on the individually determined anaerobic (aerobic = oxygen dependent) threshold. In aerobic endurance, sufficient oxygen is available for oxidative combustion of glycogen (animal starch) and fatty acids. Anaerobic endurance is present when the supply of oxygen for oxidative combustion is inadequate and the metabolic processes that take place without the participation of oxygen (anaerobic = anoxidative) play an essential role. Anaerobic glycolysis, the chem. Process of sugar degradation to lactic acid (lactate = salt of lactic acid). An increased uptake of oxygen after the stress takes place to refill the Kreatinphosphatspeicher (alaktazide oxygen debt) and the oxidative degradation of the lactate formed (lactazide oxygen fault). Lactic acid is the end product of anaerobic metabolism. This substance is created during intensive exercise above the endurance limit, when the muscles of the lungs and circulation no longer receive enough oxygen to meet their energy needs. By determining the lactate concentration, one can draw conclusions about the exercise intensity and the current performance of the subject. In performance tests, the lactate concentration z. B. during running at increasing speed. This test will help you to find the optimal running speed for different training areas. In emergency medicine, the determination of lactate is used as an indicator of so-called lactate acidosis, since during physical exertion lactate accumulates in the blood. The blood lactate value is used to assess the physical condition of the patient.

From Polar is a lactate measuring system called Lactate Pro known. It is based on the amperometric measuring principle and need to safe measurement only 5 μl Blood from the earlobe or the fingertip. When applying the blood drop into the analysis strip the blood hits the reaction pad and the lactate of the sample reacts specifically with the lactate oxidase present on the strip. At the same time the potassium iron cyanide becomes proportional to the lactate concentration reduced. Subsequent oxidation of the enriched potassium ferricyanide releases electrons, this electrical signal is combined with the corresponding one Equated lactate concentration. As an aid to the implementation of Lactate concentration measurement needed you have test strips, a lancet and alcohol swabs.

On Desire of some intensive care physicians, cardiologists and sports physicians has recently been a good market overview to measuring instruments with the possibility of the lactate determination: The company Arkray North America offers an electrochemical biosensor (lactate oxidase) on; the company EKF Industrie-Elektronik GmbH offers devices according to the enzymatic / amperometric principle work; the Eppendorf company offers devices based on enzymatic-amperometric (capillary blood method) work; the company Analox offers devices to the based on the photometric (490 nm) and the Clark-type amperometric oxygen electrode work; the company CMA / Microdialysis offers devices to the on the basis needs sterile microdialysis catheter for adults in resting skeletal muscle / adipose tissue / brain, work; the Fa. YSI offers devices on the basis of membrane with molecularly selective sensors work; Roche offers equipment based on enzymatic determination and reflectance photometry (wavelength 660 nm); from the company Boehringer is a handheld device in use in Germany currently out of distribution is, however, can the necessary test strips will be available for a few more years.

Of the Lactate is, so always invasive in the prior art over a Blood collection determined at the end of each measured exercise level. It follows that all disclosures and patents invasive "bloody" methods in theirs claims include. But it is for performance test outdoor definitely a noninvasive bloodless very simple physical Lactatwertbestimmung as possible based on a electro-physical sensors and electronic signal processing and evaluation desirable.

These Claims are made with the subject invention described below solved. It this is a very inexpensive, very light, calibratable, mobile electronic software-based measuring device with a Microcontroller, wherein in its ROM special new algorithms for lactate performance determination based on heart rate measurement or a pulse rate measurement and biomechanical power measurement are stored.

Technical construction and physical effect of the subject invention

With various subjects (age, gender, physical condition) computer-aided laboratory measurements are carried out as in a performance diagnostics with the help of an ergometer bike or ergometer treadmill. For a fixed predetermined number of discrete mechanical load levels (in watts) for each of these individual load levels in a dedicated appropriately defined time interval, the so-called RR values are measured, digitally compressed, then inverted by software (1 / RR) and then in dependence graphically represented by the mechanical stress levels in a so-called virtual scatter plot ( 1a ). This results in a two-dimensional number space, a stochastic geometric hyperbolic point structure with a very well-defined so-called vertex break point. Like now 1a For the virtual scatter plot, ie for the hyperbolic geometric point structure, two statistically determined so-called compensation straight lines can be calculated and displayed, which form an intersection point or a vertex inflection point due to their respective angles of inclination. Comparative measurements showed that the performance-dependent geometric point structure, ie the performance-dependent geometric position of the regression line and thus also the performance-dependent coordinates of the vertex buckling point significantly with the parallel laboratory correlate technically exactly determined proband-related lactate values. The vertical position of the vertex buckling point agrees well, as can be shown metrologically, with the proband specific current so-called physiological anaerobic Lactatwert threshold, from which always enters a so-called. Biochemical hyperacidity of the human body. The vertical position of the vertex break point (from now on called "hyperacidity point") varies individually from subject to subject and after a calibration is directly proportional to the individual anaerobic lactate value threshold.

Comparative measurements have shown that there is a very good correlation between the classical ECG signals and the arterial pulse wave pressure signals. It is from the measurements ( 1b ) to recognize that the time difference between the RR intervals of the ECG and the time difference between the blood pressure amplitudes of the pulse waves (PP intervals) match very exactly. Between the two signals there is only one anatomically caused constant transit time difference. Run-time differences are easily compensated electronically. Thus, analogous to the reciprocal RR intervals, a virtual scatter plot with the same mathematical properties can also be constructed with the reciprocal PP intervals.

In addition, the measurement data of the heart rate or the arterial pulse wave frequency of a Fourier analysis (FFT) are subjected, using a further special algorithm, the spectrum of the heart rate or the pulse waves is calculated and the highest occurring in the respective spectrum frequency f _high and the lowest In the calculated spectrum occurring frequency f _low can be determined in order to form the "cardiophysiological frequency quotient" f _high / f _low (thus named) healthy and diseased people gained "normalized cardiophysiological frequency quotient" to obtain a statement about the current physiological balance between the sympathetic and parasympathetic, ie about the current physical constitution.

In order to At a high load, a health-threatening excessive demand can be avoided should, should the cardiographic frequency quotient and the course the heart rate combined with the increase in lactate concentration gapless recorded, evaluated, documented and displayed.

The Description of the diagnosis procedure and the demand for a continuous and bloodless electronic Lacktat performance determination determine the physical structure mobile electronic battery powered calibratable measuring device.

In 2 the block diagram of the electronic measuring device is shown. Channel 1 is the electrical connection point for digital electronic cardiac pulse signals (obtained, for example, via ECG measuring devices), digital electronic pulse pressure signals (obtained, for example, via so-called heart rate monitors) and biomechanical power signals (obtained, for example, via an electronic ergometer ). Via the measuring and calibration interface 2.1 the digital signal reaches the pulse electronics block 2.2 consisting of a highly linear programmable measuring amplifier (MV) and a voltage-controlled pulse generator. Since in the transmission of digital signals, especially in radio transmissions, a change in the waveform may occur, the deformed signal is amplified by a programmable amplifier (MV) so far in its amplitude so that a subsequent voltage-controlled pulse generator can safely generate a technically accurate square-wave pulse signal. The then available digital signal can from the microcontroller of the digital stage 2.5 be further processed. Channel 2 is the electrical connection point for the analog electronic pulse signals obtained from the electronic measurement and evaluation of physiological pulse pressure waves. Via the measuring and calibration interface 2.1 Now the analog electronic pulse wave signal reaches the analog electronic block 2.3 consisting of a programmable measuring amplifier (MV), a multi-pole electronic filter, an analogue electronic differentiator, an analogue zero-point detector and a voltage-controlled pulse generator. The unipolar analogue electronic pulse signal is now amplified with a highly linear drift-poor programmable measuring amplifier (MV) so that when the voltage falls below a fixed voltage value the programmable measuring amplifier (MV) is asked via its control line to increase its gain so that all further measured values are safely processed can be. The unipolar electronic pulse signal is then sent using a Chebyshev low-pass filter 4 , Order (cut-off frequency 25 Hz) freed from high-frequency interference. The thus obtained pulse signal is differentiated electronically. The two inflection points of the individual pulses of the signal thereby become zero points with a positive or negative edge through the zero point. At each zero crossing with a positive edge, the pulse generator is driven and generates normalized positive unipolar pulses. These pulses are now in the microcontroller to a virtual Scatter plot further processed and evaluated. Channel 3 is the interface for the analog electronic cardiac pulse signal and the analog electronic biomechanical power signal. Via the measuring and calibration interface 2.1 the analogue signals reach the analog electronic block 2.4 consisting of a programmable amplifier, a multipolar filter, a sample & hold stage, an analog / digital converter. The unipolar analogue electronic pulse signal is amplified with a programmable high-linear broadband measuring amplifier so that when a preset voltage limit value is undershot the programmable measuring amplifier is asked via its control line to internally increase its gain in such a way that the electronics block functions properly 2.4 is possible. The electronic heart pulse signal is then using a Chebyshev low pass 4 , Order (cut-off frequency 25 Hz) to the suppression of high-frequency noise and to avoid antialiasing further processed. The analog electronic signal processed in this way is now converted into a digital signal via a Sample & Hold module (S & H) clocked by a microcontroller and an analog / digital converter (ADC). The bit-coded signals are then processed in the microcontroller, as described above, to a scatter plot and further evaluated. Channel 4 is the electrical connection point for special external calibrators for the electronic calibration of the three measuring channels (channels 1, 2 and 3) with the aid of the respective channel-specific programmable measuring amplifiers (MV).

The measuring and calibration interface 2.1 can from the microcontroller (block 2.5 ) can be switched to different operating modes via the control line for measurement and calibration: such as parallel or single measurements via different measuring channels, test mode with function checks or an internal or external calibration.

The internal electronic calibration is performed intermittently during normal measuring operation by the microcontroller (in block 2.5 ) interrupts the current measuring routine and performs the internal calibration. In the process, a signal is sent to the measuring and calibration interface via the control cable for measurement and calibration 2.1 to decouple sensors or external devices on channels 1 to 3 in order first to zero out the electrical zero points of channels 1 to 3 via the control lines with the programmable measuring amplifiers so that the calibration signal can be routed serially via the inputs of the programmable measuring amplifiers via the following Electronics back to the microcontroller (in the block 2.5 ), evaluated and compared with the stored signal. The amplification of the programmable measuring amplifier is then readjusted with the resulting difference signal in such a way that the difference signal becomes zero.

The digital block 2.5 consists of the microcontroller and an external memory (RAM). The bit-coded and rectangular earlier analog input signals (heart rate, pulse, power) can be stored in the external RAM of the digital block 2.5 stored and then digitally further processed according to their physical nature in the microcontroller so that new digital signals are generated, with the help of the pre-programmed in the microcontroller ROM, mentioned above, special evaluation algorithms generate a virtual proband specific scatter plot to from this the coordinates of Calculate Übersäuerungspunktes (vertex bend point) to then compare this with the fixed deposited coordinates of proband specific Übersäuerungspunktes, in turn, depending on the comparison result, using the signal block 2.6 to generate an appropriate indication on an alphanumeric display, an optical warning indicator and an audible warning indicator to uniquely identify the risk of possible or imminent or pre-existing acidification.

About the micro keypad 2.7 Different parameters and characteristic values can be entered in order to compare them with those in the external RAM (block 2.5 ), in order to obtain the desired performance diagnostic and medical statements and the control signals for various alphanumeric representations on a data display in order to generate further optoelectronic and electroacoustic operating and warning signals.

The electronic measuring device 2 can be beneficial in a watch case 3 can be attached, which can be attached via a clip mechanism to the clothing or on a belt or attached via an elastic skin-friendly upper arm band or a wrist band frictional on the upper arm or wrist. The electromagnetically susceptible components of the measuring device can individually or in groups z. B. shielded with Mumetall, so in the watch case 3 a transmission electronics with antenna and a receiving electronics with antenna can be integrated.

Next are an alphanumeric measurement data display 3.3 , as well as an alphanumeric clock data display 3.4 , different colored LEDs 3.5 , a piezoacoustic actuator 3.2 , a micro keypad 3 . 5 . 3.7 . 3.8 . 3.9 . 3.11 . 3.13 and the connections for different interfaces 3.10 . 3.12 . 3.15 . 3.16 on the front 3.1 housed in the watch case.

The watch case 3 But also can be particularly advantageous as usual on the wrist over a wrist band 3.14 As well as the diagnostic functions, there are also normal chronometric functions (date, calendar, time, start / stop, etc.) with the corresponding controls (micro-buttons for clock functions) and a clock data display 3.4 offers. The electrical connection between the electronics in the watch case and a heart signal or pulse signal measuring device and a biomechanical performance measuring device or to another evaluation for data transmission takes place in the simple embodiment, for technical and biological EMC reasons, with a well pluggable thin shielded highly flexible multi-core Cable over the plug connection 3.16 ,

Becomes for the RR signal acquisition uses a heart rate monitor, you can the subject invention, as already said above, beneficial to wear on the upper arm. Because the pulse watches In this case, in the case of. can usually have chronometric units Subject of the invention waived a chronometric device become.

In order to is the demand for technical simplicity, i. one very little effort of mechanical and electrical components As well as their fasteners and thus very low cost and a fail-safe low-maintenance function and a very easy operation over the entire operating period possible.

A further embodiment is that the diagnostic data in digital form, wirelessly using an FM / FM system or a PCM / PCM system transferred from and to the watch case become. For the FM / FM system is the RF oscillator with transmit antenna of the RF receiver with Receiving antenna integrated in the watch case. For the PCM / PCM system is the encoder with its transmit antenna and the decoder with its receive antenna in the watch case integrated. This technical embodiment is more complex and thus also more expensive, but offers the possibility of data redundancy.

In a further constructive embodiment of the subject invention, the high-frequency unit is located in an external plug-in module via a connector strip 3.15 can be electrically connected to the electronics inside the watch case. This embodiment offers the possibility that depending on the bioelectromagnetic sensitivity of the subject shielded cable or radio can be used.

The infrared interface (IR interface) 3.12 It is used for a wireless EMV-friendly transmission of all desired data to external devices with a corresponding IR interface or an external PC or laptop with a corresponding IR interface. The data can be read out privately, or by a medical laboratory or by a doctor, evaluated and, if necessary, further processed.

Claims (8)

Digital electronic software-based diagnostic method using a microcontroller and a special programmed in the microcontroller ROM special algorithm, characterized in that from a measured heart pulse signal or an arterial pulse signal, the time sequence of the successive stochastically scattering RR or PP intervals in software stochastically scattering Reciprocal RR or PP intervals are converted and digitally compressed to then be displayed and stored as a stochastic geometric hyperbolic point structure with a pronounced vertex breakpoint as a function of the measured and digitally processed associated biomechanical performance data in a two-dimensional virtual scatter plot such a proband-specific hyperbolic two-dimensional geometric point structure permanently stored in the ROM of a microcontroller and the individual position of the over-acid tion point, with the currently determined virtual scatter plot on the presence of a corresponding geometric point structure and the individual situation of the Übersäuerungspunktes software controlled can be that then depending on the test result, a corresponding display on an alphanumeric display, a visual warning and an audible warning A clear identification of the risk of a possible or imminent or existing overacidification can take place. Digital electronic software-based diagnostic method using a microcontroller and a special programmed in the microcontroller ROM special algorithm, characterized in that from a measured heart pulse signal or an arterial pulse signal, the time sequence of the successive stochastically scattering RR or PP intervals in software stochastically scattering Reciprocal RR or PP intervals are converted and digitally compressed, and then, depending on the measured and digitally processed associated biomechanical performance data in a two-dimensional virtual scatter plot as a stochastic geometric hyperbolic point structure with two distinct balancing straight lines with opposite Tilt angles can be displayed and stored, so that with a firmly stored in the ROM of a microcontroller proband specific hyperbolic two-dimensional geometric point structure and the individual geometric position of their straight line, with the currently determined virtual scatter plot on the presence of a corresponding geometric point structure with the individual position of their two equalization lines can be compared by software and depending on the test result using the already stored calibration curve can be converted to represent a corresponding display on an alphanumeric display on the respective current Lactatwert. A digital electronic software-based diagnostic method using a microcontroller and a special algorithm permanently programmed in the microcontroller ROM, characterized in that the heart rate or arterial pulse wave frequency measurement data are subjected to Fourier analysis (FFT) using the heart rate spectrum or the pulse wave frequency to determine the highest occurring in the corresponding spectrum frequency f _high or the lowest occurring frequency f _low , so as to form the "cardiophysiological frequency quotient" f _high / f _low that this with the already stored, by many comparative measurements healthy and diseased people can be compared "normalized cardiophysiological frequency quotient" can be compared in order to gain a statement about the current physiological balance between the sympathetic and parasympathetic, ie on the current physical constitution, to these au f to display an alphanumeric display. Electronic measuring device for carrying out the diagnostic method according to claim 1, 2 and 3, characterized in that the digital electronic pulse pressure signals and digital electronic heart pulse signals and the digital electronic biomechanical power signals of channel 1 via a controller-controlled measurement and calibration interface 2.1 on a pulse electronics block 2.2 consisting of a highly linear programmable measuring amplifier (MV) and a voltage-controlled pulse generator, which generates the digital signals generated by it to a microcontroller of the digital stage 2.5 for further processing, the analog-electronic pulse pressure signals from channel 2 via a controller-controlled measurement and calibration interface 2.1 continue on an analog electronics block 2.3 consisting of a highly linear programmable measuring amplifier (MV), a multi-pole filter (eg a Chebyshev low-pass filter) 4 , Order, cut-off frequency of 25 Hz), an electronic differentiator, a zero-point detector and a voltage-controlled pulse generator, which generates the digital signals generated by it to a microcontroller of the digital stage 2.5 for processing the analog-electronic pulse pressure signals and the analog-electronic heart signals from channel 3 via the controller-controlled measurement and calibration interface 2.1 on the analog electronics block 2.4 consisting of a linear programmable measuring amplifier (MV), an analog multi-pole filter (eg a Chebyshev low-pass filter) 4 , Order, cut-off frequency 25 Hz) and the controllergetakteten blocks, a sample & hold stage and an analog / digital converter, the digital bit sequences generated by it to a microcontroller of the digital stage 2.5 for further processing, to send a calibration signal via channel 4 via external calibrators to a controller-controlled measurement and calibration interface 2.1 to the channel-specific linear programmable measuring amplifiers (MV) for the electronic calibration of the analogue and digital electronic blocks ( 2.2 . 2.3 . 2.4 ), consisting of a micro keypad 2.7 with keylogic (T-logic) for the manual entry of physical, antrometric and chronological parameters, consisting of a signal unit 2.6 with an alphanumeric measurement data display, different colored LEDs 3.5 and a piezoacoustic actuator 3.2 , consisting of various different interfaces 2.8 for wired and infrared technology data transmission. Electronic measuring device for carrying out the diagnostic method according to claim 1, 2 and 3, characterized in that the electronic measuring device can be advantageously installed in a watch case, which via a clip mechanism on the clothing or on a belt or with an elastic upper arm band or hand Joint can be fastened non-positively on the upper arm or wrist, and the electromagnetic interference-sensitive components of the measuring device individually or in groups z. B. are well shielded with courage metal, so that a transmission electronics with antenna and a receiving electronics with antenna can be integrated directly into the watch case, provided with a front panel 3.1 on which an alphanumeric measurement data display 3.3 , an alphanumeric clock data display 3.4 , different colored LEDs 3.5 , a piezoacoustic actuator 3.2 , a micro keypad 3.5 , 3.7 , 3.8 . 3.9 . 3.11 . 3.13 and different ports for each interface 3.10 . 3.12 . 3.15 . 3.16 are arranged. Electronic measuring device for carrying out the diagnostic method according to claim 5, characterized in that the diagnostic data transmitted in digital form, using an FM / FM system wirelessly from and to the watch case who can, consisting of an RF oscillator with transmitting antenna and an RF receiver with receiving antenna housed in a watch case. Electronic measuring device for carrying out the Diagnostic method according to claim 5, characterized in that the diagnostic data in digital form, using a PCM / PCM system transmitted wirelessly from and to the watch case can be made up of an encoder with transmitting antenna as well a decoder with receiving antenna housed in a watch case. Electronic measuring device for carrying out the diagnostic method according to claim 5, characterized in that a high-frequency transmitting and receiving electronic unit, based on an FM / FM or PCM / PCM technology, is installed in an external plug-in module, and a connector strip 3.15 can be electrically connected to the electronics inside the watch case.