HU192718B - Connection arrangement for multiple-pole draining the bio potential of biological structures, living organism and measuring the potential difference being between the draining electrodes - Google Patents

Abstract

Field of the Invention The present invention relates to a switching arrangement for multipole removal of biological objects, biopotentials of living organisms, and for measuring the potential difference between drain electrodes with arbitrary but finite number of drain electrodes (Ej ... En) and associated electrode leads (Vj ... Vn) and pathway. with differential amplifiers, (Dj..On) arithmetic operation termination amplifiers (Mp.J ^). According to the invention, at least one of the active inputs of the differential amplifiers (Dj, D2, D3, ... Dn) is 0 - (/, M o - </ oo O- /, oo Figure 5 Ο- ΚΑ SZ HU 192 718 AA description : 10 pages (including Figure 5) -1-

Description

BACKGROUND OF THE INVENTION The present invention relates to a circuit arrangement for multipole drainage of biological objects, biopotentials of living organisms, and for measuring a potential difference between arbitrarily selected drainage electrodes. The present invention has any but a finite number of drainage electrodes and associated wires, as well as differential amplifiers and channel amplifiers for arithmetic operation. The circuit arrangement is implemented by providing high common mode interference suppression and input resistance, using low-cost electronic or electromechanical components. In addition, the present invention provides for the use of advanced microprocessor control and processing systems in the field of biological research and practical medical diagnostics.

The derivation and registration of electrical signals (biopotentials) occupies a very wide field of medicine and neurophysiology. Interpreting and analyzing biopotentials generated during nerve and muscle function is a very useful diagnostic tool and at the same time provides an opportunity to learn the basics of life phenomena. The devices most commonly used in practice, such as electroencephalographic (EEG) electrocardiographic (ECG), electromyographic (EMG) devices, are used to elicit 35 biopotential changes in the body's nerve and muscle function through an electrode system. In fact, it is a function of living space to generate, from an electrical point of view, a potential space whose spatial and temporal variations carry diagnostic information. A specific example is the electroencephalographic (EEG) examination, which can be used to diagnose structural (e.g., tumor) or functional (epilepsy) diseases of the brain using surface or implanted electrodes.

A similar example is the electrocardiographic (ECG) test, which can detect diseases of the heart muscle or pacing. It should be noted that modern medical diagnosis employs very different procedures for the determination of a particular disease, which examine a characteristic characteristic of the disease in question. Recently, surface mapping is also used in electrocardiographic examinations, where a large number of lead electrodes are placed on the body surface and the equipotential surfaces of the body surface are determined at designated times during the cardiac cycle.

The devices listed and similar are, in essence, capable of conducting, amplifying, recording, and sometimes computer analyzing, voltages between specific points in the biopotential space 60. It is inherent in the nature of the problem that (pL for spatial states) it is often necessary to record voltage changes between two electrodes of choice. The most typical example is electroencephalography (EEG), where biopotential differences between optional electrodes at specific points on the surface of the skull need to be determined, possibly several times during each study.

The known solutions are described with reference to Figures 1 and 2, wherein:

Figure 1 is a block diagram of an EEG device with input selector and differential amplifiers f,

Figure 2 is a block diagram of an EEG device with asymmetric preamplifiers.

3, 4 and 5, wherein: a

Fig. 3 illustrates a schematic embodiment of a circuit arrangement according to the invention in which the voltage between the arbitrarily selected drain electrodes is generated by summation;

Fig. 4 illustrates a schematic embodiment of a circuit arrangement according to the invention in which the voltage between the arbitrarily selected drain electrodes is obtained by subtraction;

Fig. 5 illustrates a practical embodiment of a circuit arrangement according to the invention in which the voltage between the arbitrarily selected drain electrodes is obtained by subtraction.

Figure 1 shows a known BS input sector and D 1, D ₂ ,

D ₃ , ... D _n contains block diagrams of EEG devices built with differential amplifiers.

For example, E j and the value of the difference between these _two biopotency elvezetőelektródák this particular case is between a few microvolts and a few hundred microvolts. At the same time, the ambient disturbance voltage U _z (same phase signal) can be several times ten millivolts, which occurs at the same phase at the discharge electrodes Ε ,, E ₂ , E ₃ , ... E _n . In such cases, it is common to use differential amplifiers Dj, D ₂ , D ₃ , ... D _n , which have three input connections55. One of these, the zero point, is connected to the patient's neutral discharge electrode, while the other two active inputs (+ and -) are connected to the BS input lead electrodes E _p Ej, E ₃ , ... E _n , respectively. through a selector.

A known feature of differential amplifiers is

EN 192718 That the gain of the same-phase signal connected to the input is much lower (e.g., fractional part) than the gain of the differential mode signal. Such amplifiers can achieve very high levels of interference suppression. The problem is that, for diagnosis, it must be ensured that the active input of any differential amplifier can be connected between any two drain electrodes. To this end, E j, 1¾. E ₃ , from the discharge electrodes Vj, V ₂ , V ₃ ,

... V _n , the electrode wires are routed to a switching system made up of a BS input selector, where they are connected via a routine program or individually to the inputs of the differential amplifiers.

The Ej, E 2, E _{3, n} .. £ elvezetőelektródák source impedance of a few ohms and a few tens of kilo ohm. Depending on the BS and V input selector switches between Ej, E 2, E _3, elvezetőelektródák _.Έ η j, V ₂ ... V _n, the length elektródavezetékek construct may be a few meters. This relatively high source resistance and long conductor pick up ambient electrical noise and disturbances so that differential mode interference voltages are generated that the differential amplifiers Dj, D ₂ , D ₃ , ... D _n placed after the BS input selector no longer provide useful differentiated from biopotentials,

Therefore, the EEG device or patient should be placed away from the source of interference or very careful static (possibly magnetic) shielding (Faraday cage) should be used. In addition, the BS input selector used must meet very stringent technical requirements after reliably switching very small signals.

To overcome these problems, the solution shown in Figure 2 is applied after the development of advanced integrated circuits.

Figure _{2 is a} block diagram of a known EEG device comprising asymmetric preamplifiers A 1, A ₂ , ... A 4. In this embodiment, in the Eh, E ^, elvezetőelektródák and BS input selector each Ej, following E _2,., £ _n elvezetőelektródát employ an impedance transformation, a possibly greater than one gain Ai, A _2, asymmetrical preamplifier signal having a control input NE neutral elvezetőelektróda and E j, E _2, E _3, .. £ "arises between elvezetőelektróda after independently szándékunktól between the patient and the body of the EEG device - a C _no stray capacitance is generated, which IU - regardless of insulant between two links the neutral lead electrode to common ground F.

These asymmetric preamplifiers A ₁ , A ₂ , A, j are placed close to the discharge electrodes E 1, E ₂ , E ₃ , ... JE _n , the advantage of which is that E ₁ , E 2, E ₃ , ... £ _n raises the biopotentials measured on the discharge electrodes to a higher level, while simultaneously reducing the source resistance measured on the VK device cable to the device. Therefore, the interference pick up on the VK device cable is reduced and the stringent technical requirements for the BS input selector are reduced. However, a new disadvantage arises.

As shown in Fig. ₂ , the impedance transformer A ₁ , A ₂ ..., Aj, asymmetric amplifiers amplify the potential difference between the NE neutral discharge electrode and the Ej, E ₂ , E "lead electrodes, i.e. the sum of the common mode interference signal and the useful biopotential. The impedance transformer Aj ...., A ₂ A "Asymmetric preamplifiers must have the same gain. The difference in their amplification and any change in their amplification (instability) generates a differential mode signal from a large interfering common mode signal relative to the useful signal. There was thus wasted good quality after the BS input selector Dj, D _2, D _3, ... D _n differential amplifiers, external disturbance noise inherently included in the AU _s CSJ CS ^ ... F _n channel amplifiers and RE registrants .

Another problem with both of the described solutions is the change of leads, because the advantageous suppression of high common mode interference signal, high input resistance of the differential amplifiers Dj, D ₂ , D ₃ , ... D _n can be utilized, thus allowing a relatively low value of discharge electrode resistance. therefore they need to be controlled separately and are not suitable for the development of so-called smart devices. Both the solution of FIG. 1 and FIG. 2 show another common drawback. They consist essentially of parallel channels, and each actuator (amplifier control, filter, etc.) is constructed in as many copies as the channel number. Consequently, the solution is expensive.

The known solutions for EEG devices detailed above are applicable, mutatis mutandis, to electromyography (EMG), electrocardiography (ECG), electrolytic model measurement systems, and electrophysiology, etc., wherever potential space or surface electrical measurement is performed.

It has now been found that the above deficiencies can be overcome by replacing the discharge electrode selector switch, which is usually a BS input selector in prior art solutions, with an electronic unit performing an analog or digital arithmetic operation (addition and / or subtraction), and between the unit and the discharge electrodes there is then placed a differential amplifier with an asymmetrical output having a symmetrical input which operates in the differential amplifier mode in the immediate vicinity of each discharge electrode. In this case, we can provide very high value interference suppression (CMRR) directly at the system input and the increased biopotentials by amplifying differential amplifiers, which already occur at low spinning resistances, can be easily deduced and enable the use of advanced semiconductor analog switching circuits and arithmetic units.

It is an object of the present invention that at least one of the + or - active inputs of the differential amplifiers Dj, D ₂ , D ₃ , ... D _{n is} directly via its associated electrode wire Vj, V ₂ , V ₃ , ... V _n .

EN 192 718 Connected to the various discharge electrodes E j, E2, E ₃ , .. E _n , and the zero points of the differential amplifiers D p D _{2 <} D ₃ , ... D _n are connected to each other and either to the neutral neutral electrode NE or they are connected to common ground F. The outputs k of the differential amplifiers D j, D ₂ , D ₃ , ... D _n are connected via gate circuits KA to the arithmetic operation channel amplifiers M j, M ₂ , M ₃ .... M _n , and the gate circuits KA and M j, M ₂ ". JvJjjj arithmetic operation channel amplifiers are connected to a SZ control unit.

In one embodiment of the circuit arrangement of the invention shown in Figure 3, the first differential amplifier Dj, e.g. + positive active input to the first discharge junction Ej, the second to eg. - negative input is connected to the last drain electrode E _n. The other D ₂ , D ₃ , „. D _n active input coupled differential amplifier consisting of one or more parts each chain switched in such a way that one example. D ₂ differential amplifier - negative active input to other eg. It is connected to the + positive active input of a differential amplifier D ₃ , and the differential negative amplifiers D ₂ , D ₃ , ... D _{n are} connected in series to each other - negative and + positive active inputs, E ₂ , E ₃ , E ₄ , respectively. . join elvezetőelektródákra, Dj, D _2,., "D _n differential amplifiers, k outputs a KA gate circuit are connected to input food, including analog and / or digital design, and the CF gate circuits, one or more outputs such Mj, M _2, M _3, ..Aí _n connected csatomaerősítőkre performing arithmetic operation comprising adder circuits.

In another embodiment of the circuit arrangement of the present invention shown in Figure 4, the + positive active inputs of the differential amplifiers Dj, D ₂ , D ₃ , D _n are connected to each other and directly or to a randomly selected pL E j They are connected via an AE unit amplifier, where the AE unit amplifier + positive active input is connected to the arbitrarily selected discharge electrode pL Ej and its zero point and - its negative active input is connected to the NE neutral discharge electrode and Dj, D ₂ , ... D _n differential amplifiers - the negative active inputs are connected to the other discharge electrodes E ^ E ₃ , .. JE _n , respectively, and the outputs of the differential amplifiers Dj, D ₂ , D ₃ "" D _n form the input of KA gate circuits which are analog and / or digital , and one or more outputs of the gate circuits KA are M _p M ₂ , .. M _{n are} connected to arithmetic operation channel amplifiers containing a subtraction circuit. In both the circuit arrangement of FIG. 3 and FIG. 4, a potential independent power supply output T, floating at the supply voltage points tj, t _{2 of the} differential amplifiers D j, D ₂ , D _3> ... D _n , is connected.

In the embodiment of the present invention shown in Figure 5, the zero points of the differential amplifiers Dj, D ₂ , D ₃ , ... D _n and the neutral amplifier NA are interconnected and connected to a common earth point F. Differential Amplifiers Dj, D ₂ , D ₃ , ... D _n - Negative Active Be4 Threads are connected to one end of a control resistor R ^ and a feedback resistor Ry.

RY feedback resistor the other end of the other end of the resistor Dj, D _2, ... D _n k output of differential amplifier, the other of R _Z R _z regulatory control resistor connected Ö összekötővezetékére. The connecting cable Ö is connected to the NA output of the neutral amplifier kn. The NA neutral amplifier + positive active input is connected to the NE neutral discharge electrode, the negative active input is connected to the common point P of the NA neutral amplifier R1, the feedback resistor and the NA neutral amplifier Rjj.2. The + positive active inputs of the differential amplifiers Dj, D ₂ , D ₃ , ... D _n are connected to the discharge electrodes Ej, E ₂ , E ₃ , .. E _{Q, respectively} . D j, D ₂ , D ₃ , "D _n differential amplifiers k outputs form an input to a KA gate circuit which is analog and / or digital and one or more outputs of the KA gate circuits M ₁ , M ₂ , M ₃ , .. al _n connected csatomaerősítőkre performing arithmetic operation comprising subtractor circuit. The supply points tj, t _{2 of} the circuit arrangement are connected to a common ground point F, which is potentially connected or independent of it.

There are embodiments in which a ground resistor Rj is inserted between the + positive active inputs of the differential amplifiers Dj, D ₂ , D ₃ , ... D _n and a common ground point F of the system.

For calibration, a NA calibration signal source is connected to the negative active input of the NA neutral amplifier via a RI coupling resistor or directly.

Between the output terminals of the differential amplifiers Dj, D ₂ , D _3> ... D _n and the input terminals of the gate circuits KA, an amplifier and / or a DC isolator circuit is inserted as needed.

Arithmetic operation amplifiers M j, M ₂ , Μ ₃ , .. Λ1 _η usually include a combination of summing and subtraction circuits. An advantage of the present invention is that it eliminates the costly (mechanical) selector system commonly used at the input point at the most critical point of the apparatus by continuously providing (using pL electronic switches) a potential difference between any two lead electrodes by simple arithmetic operation. It allows the device to be connected to an intelligent metering system and to control all channel parameters (gain, frequency range, etc.) simultaneously with the appropriate control unit.

The circuit arrangement according to the invention and its operation will be described in detail with reference to Figures 3, 4 and 5.

Figure 3 depicts a conceptual embodiment of a circuit arrangement according to the invention in which the potential difference between the arbitrary Ej, E _2, E _3, ... E _n elvezetőelektródák prepared using summation and floating to ensure the conditions for the differential operation, a potential T independent power supply.

Figure 3 schematically depicts a skull depicted on the left in Figure 41

GB 192718 The shield showing the discharge electrodes Ej, Ε ^, - Ε ,, showing the biopotentials Uj, U ₂ , U ₃ , ... respectively. The patient's body is connected to the electrical zero point of the device by means of an NE neutral discharge electrode. U illustrated in közösmódusú _your environmental interference voltage source, which is the resultant of ambient electrical noise interference. The discharge electrodes E _p E2 .. ~ E _{n are} connected to the active input of the differential amplifiers D _p D ₂ , ... D _n . Of course, D _p D ₂ , D ₃ , _. D _n differential amplifiers have inverting and non-inverting inputs, which are conventionally designated in the literature. AD j, D ₂ , _. D _n differential amplifiers have G gain.

Since the differential amplifiers D _p D ₂ , D ₃ ... D _{n have a} very high common mode interference suppression factor, their output points show the voltage differences between the active inputs multiplied by the gain G of the differential amplifier D, D ₂ , ... D _n , so that the voltages G (U jU ^, G (U ₂ -U ₃ ), G (U ₃ -U ₄ ) appear respectively. If these voltages are applied to the summing circuits of the channel amplifiers M j, M ₂ ..., any pair of discharge electrodes The resulting voltage U ₀ j, which appears at the output of the summing circuit of the M _t arithmetic operation amplifier, is as follows:

U ₀₁ = G (Uj-U ^ + G (U ₂ -U; j) = G (Uj-U ₃ ), i.e. the voltage between the discharge electrodes E 1 and E ₂ .

₀₂ resulting from the voltage U appearing summing circuit for performing arithmetic operation M ₂ csatornaerősítőhöz output terminal

U ₀₂ = G (Uj-U ^ + G (U ₂ -U ₃ ) + G (U ₃ -U ₄ ) = -GCUj-U ^, that is, the voltage between the discharge electrodes E j and E ₄ . method, any voltage between two drain electrodes can be generated, just be careful to sum up the output voltages of all the differential amplifiers between the two drain electrodes, but for a large number of leads this can be disadvantageous because the summing circuit is Dj, D _2> ... D _n it adds up its own noise so that the voltage between any discharge electrode is added with a noise voltage of D j, D ₂ , D ₃ , ... D y / S times _the differential voltage of _the differential amplifier's own F i,

S - is the sum of the voltages.

For this reason, it is advisable to choose the number of summaries as small as possible. Such intended purposes in Figure 3 include the elvezetőelektróda Ej and E _n elvezetőelektróda inserted Dj differential amplifier that supplies _(n U U j) voltage of G without summation. With careful design, additional differential amplifiers can be used to prevent noise from exceeding a predetermined level even with a large number of drainage electrodes.

It should be noted that the design of summing circuits is in practice very simple with circuit elements, e.g. can be realized by resistors.

The Dj, D _2> D ... _n differential amplifiers, differential mode ensures effective operation of independent power supply potential of T.

If a change of lead is required, this can be accomplished by means of KA gate circuits controlled by the SZ control unit.

Figure 4 illustrates a conceptual embodiment of a circuit arrangement according to the invention in which the voltage between the arbitrarily selected drain electrodes is obtained by subtraction.

As shown in Fig. 4, each of _the positive active inputs of _the differential amplifier Dj, D ₂ , ... D is connected and connected to the discharge electrode Ej via the short-circuit switch Z. The differential amplifiers Dj, D _2> ... D _n - negative active input are connected to the discharge electrode E ₂ , E ₃ , .. E ₅ , .. E _{q respectively} . The zero points of the differential amplifiers Dj, D ₂ , .. D _Q are connected to the NE neutral discharge electrode. At the output points of the differential amplifiers Dj, D ₂ , 0;}, ... D _n, the voltages G times U, GCUj-UjjGIUU-U ^, ..., applied to the discharge electrode Ej are displayed, ...

These output voltages are fed to Mj, M _2, .. _n Jví arithmetic operation performing csatomaerősítők subtractor's circuits, which are the following

G (Uj -U ₂ ) - G (U j -U ₃ ) = G (U ₃ -U ₂ ) • G u U j -U ^ -GCUj-U ^ -G ^ -U ^

G (Uj-U2) - G (Uj-U ₅ ) = G (U ₅ -U 2>

provide output voltage.

From the foregoing, it is directly apparent that the subtracting circuits directly derive a voltage difference between the two discharge electrodes from the voltages applied to the input pins. This switching arrangement has very favorable properties mainly in terms of noise. Figure 4 also shows a dashed line amplifier with an AE unit gain, which may be advantageous when a very large number of lead-in electrodes are used and the connected + positive active input of the differential amplifiers D j, D _2> ... D _n would be too heavy the source resistance of the discharge electrode Ej.

The connection of the discharge electrode and differential amplifier described so far is the so-called. provided bipolar drainage. However, when point x in Figure 4 is connected to the NE neutral discharge electrode, the entire system is converted to a unipolar drainage system. This type of lead-through provides an appropriate signal processing system for determining the voltage of any lead electrode relative to the weighted average of any selectable lead electrode group. Thus, local potential changes on the skull surface can also be determined

HU 192718 A

The switching arrangements shown in Figures 3 and 4 can also be used in combination. In this case, the addition and subtraction must also be used in combination.

The differential operation of the differential amplifiers D j, D ₂ , ... D _{n is} effectively provided by a potentially independent power supply T.

If a change in the lead-through is required, it can be done by the KA gate circuits controlled by the SZ control unit.

Figures 3 and 4 enable EEG leads of different systems to be implemented, such as: the voltage of all other lead electrodes for a particular lead electrode, the voltage difference between any two lead electrodes, forming a specific number of lead electrode groups, to determine the local EEG signal.

Figures 3 and 4 show the multipole detection and discharge of the circuit arrangement according to the invention.

Obtained by the new, U _2, ... biopotency, drained and amplified voltages develop the desired combination elvezetőelektróda like Figures 3 and 4 show arithmetic operations (addition and / or subtraction) must be performed.

The arithmetic operations can be performed in the present state of the art in analogue or digital form. The circuit arrangement of the present invention permits the use of any of the methods.

Fig. 5 illustrates a practical embodiment of a circuit arrangement according to the invention in which the potential difference between the arbitrarily selected drain electrodes is obtained by subtraction. All Dj, D _2, ... D _n differential amplifier is connected to the negative input of an active, and this common point is connected to a close to unity gain NA neutrálerősítő kj, output - preferably through control resistor R _{Z p} D D _2, .. JD _n differential amplifiers + positive active input directly connected to the discharge electrodes Ej, E ^. ^

The operation of the circuit is as follows: the amplification of the differential amplifiers Dj, D ₂ , D ₃ , ... D _{n is provided by} the feedback Rjj. consisting of regulating resistors, Dj, D ₂ , „. The output of D _n differential amplifiers is defined by the negative feedback to the negative active input. The differential amplifiers Dj, D ₂ , "D _{n from} the positive active input:

and the negative input:

rv

G ~ = ~ - have reinforcements Rjz

If we want the common mode U _{z for the} ambient interference voltage to be effectively suppressed, Dj, D ₂ , „. If the two active inputs of the differential amplifiers D _n have the same gain, then

NA Neutral Amplifier G _m greater than 1, that is

Must be R, z '.

This value can be set by the resistances of the NA neutral amplifier R ^ y feedback and Rjuj regulator. In practice, because Dj, D _2, .. _n differential amplifiers D G strengthening occurring EJ JE ,, elvezetőelektródáknál electronic potential and Dj, D _2, D _3,., "D _n differential amplifiers dynamic range

Between 10 ... 100-G being chosen so that the NA neutráliserősítő G _m Strengthening

G _m = l, ... 01 to be between 1.1, due to which can be easily set up using a micro-electronic or hybrid technology or discrete circuit elements can be provided in the R 'and R _v feedback resistors _RCV control sorting.

Can be seen in Figure 5. The coupling of ways to ensure the fulfillment of the above conditions, that Dj, _D2 ... common mode identical D _n differential amplifiers active control inputs of effect and phase U _z environmental interference voltage be, so this Dj, D _2, ..O _n differential amplifiers, due to high common mode interference suppression (CMRR), no interference voltage appears at their outputs. However, the Dj, D _2, .. JD _n due to differential amplifiers to strengthen and impedance transforming effect will be the biopotency manageable by existing microelectronic active components (analog gates etc) level of Dj, D ₂ '.D _n differential amplifier outputs KA gate circuits is an input which switches the outputs to the input of the amplifier subtraction circuit of the channel performing the arithmetic operations Mj, M ₂ , .. in the combinations determined by the SZ control unit. The common ground conductor can also be the input of the KA gate circuits.

The subtraction circuit generates the potential difference of the desired lead-off electrodes as described in FIG. 4 and supplies the resulting voltage of each EEG channel U ₀₁ , U ₀₂ , .... If one of the inputs of the subtraction circuit is connected by the gate circuit KA to the ground potential and the other input to the outputs k1 of the differential amplifiers D j, D ₂ , .. D _n , the potential voltages U _o j, U ₀₂ ".. are equal to the NE neutral lead electrode. U-U _n , U ₂ -U _n , ...). In this case, a potential distribution is available. This method can be successfully used in the more widespread use of the so-called. Surface mapping.

HU 192 718 A

5 shows a calibration voltage KJ calibration signal source is connected to the input of the active neutráliserősítő NA -negative via a coupling resistor R _cs. This connection ensures the simultaneous calibration of all measuring channels, either with DC voltage or with pulses.

Figure 5 shows a dashed line for the IC circuit which, due to its homogeneous structure, is well suited for microelectronic technology (semiconductor single crystal, thin layer hybrid, etc.). Between Dj, D ₂ , 'O _n differential amplifiers + positive active input and a common fold point F (potential 0), a single earthing resistance Rj can be connected. This grounding resistor R may be a large value (several Gohm), it provides inputs case outstanding electrical zero point of the system (not available in the D _{p 2} D, _D _n differential amplifiers saturate).

It is emphasized that the subtraction circuit is not necessarily an analog circuit, but may include, according to the present state of the art, sample circuits, counters, A / D converters, digital filters, etc., controlled by the SZ control unit.

The circuit arrangement of the present invention, which is exemplified by electroencephalograph devices, may, of course, also be used in the design of other systems with many leads. The advantage of the circuit arrangement is that by eliminating the switches normally used at the inputs by cheap electronic devices, high input resistances, high common mode interference suppression can be achieved without significantly increasing the electrical noise associated with the input.

In principle, since the present invention requires the use of at least two amplifiers at the input, the electrical noise is theoretically increased to 1/2 of its ideal value. However, noise, cables, switches, temporary connectors, etc. interfering effect, triboelectric effects, etc. in reality, this results in a significant reduction in noise and noise compared to the solutions used so far. In addition, the manufacturing costs are reduced - simple manufacturing technology, size reduction, and low cost labor. At the same time, the additional cost of user sites is reduced. There is no need for costly shielding, no hassle-free installation, and a lower-skilled user workforce can be employed.

Due to the very high input resistances of the differential amplifiers D _p D ₂ , Dj, ... D _n , stringent requirements for the installation of discharge electrodes (electrode resistance measurement) can be reduced, and even insulated (capacitive) discharge electrodes provide high quality discharge. For the same reason, chronically embedded deep microelectrodes, which previously required special amplification circuits, can be used directly with conventional equipment manufactured according to the invention.

The properties of the system can be changed during operation without touching the highly sensitive input points. The method and circuit arrangement of the present invention allow the use of state-of-the-art computer analyzers and e.g. to develop an optimized drainage system for cancer research - diagnosis.

Claims (9)

PATENT CLAIMS 1. A circuit arrangement for multipole derivation of biopotentials of biological objects, living organisms and for measuring the potential difference between the lead electrodes, which has any but a finite number of lead electrodes and associated electrode wires, as well as differential power amplifiers, D ₂ , D ₃ ,. "D _n ) has at least one active input (+ or -) directly through its associated electrode lead (Vp V ₂ , V ₃ , _. V _n ) to different enjoyment electrodes (Ej, E ₂ , E _3). connected, and the zero points (0) of the differential amplifiers (Dp D ₂ , D _3> ... D _n ) are connected to each other and connected to either the neutral discharge electrode (NE) or the common earth point (F), and the differential amplifiers ( D j, D _2, D ₃ '.. D _n) outputs (k) gate circuit are the arithmetic operation performing csatomaerősítőkkel through intermediaries (KA) (Mj, _M2, ._ M _{n) is} connected, and the gate circuits (KA) and the arithmetic operation performing csatomaerősítők are (Mj, M _2, .. J4, j) the control unit (S) connected, Circuit arrangement according to claim 1, characterized in that one active input (e.g. +) of the first differential amplifier (Dj) is applied to the first discharge electrode (Ej) and the other active input (eg -) to the last discharge electrode (Ej). ^) is switched on and the other differential amplifiers (D ₂ , D ₃ , .. J) _n ) active inputs are connected to each other in a one or more part chain such that one of the differential amplifiers (eg D2) has a negative active input (- ) is connected to the positive active input (+) of the other differential amplifier (eg D ₃ ), and thus the active inputs (- and +) of the differential amplifiers (D ₂ , D ₃ , .. D _n ) are connected in series to connected to discharge electrodes (E ^, E ₃ , E ₄ , ...), and the outputs (k) of the differential amplifiers (D1, D ₂ ". JD _n ) are connected to an input of a gate circuit (KA) which is analog and / or digital and the gate circuits (KA) are a va Several of its outputs are connected to arithmetic operation channel amplifiers (Mj, M ₂ , M ₃ , .. Jvl _n ) which include summing circuits (Fig. 3). figure). The circuit arrangement according to claim 1, characterized in that the differential amplifiers (Dj, D ₂ '. D _n ) are connected to each other by a positive active input (+) and are directly or one unit amplified on an optional discharge lead electrode (pL E1). connected via an amplifier (AE), wherein the positive active input (+) of the unit amplifier (AE) with the optional discharge lead (eg E j), and its zero (0) and negative active input (-) with the neutral lead (NE) there is EN 192 718 A connected, and the differential amplifiers (Dp D ₂ , .. -D _n ) are connected to the other lead electrodes (1¾. Ε ₃ , „Έ _η ), respectively, by the negative active input (-), and the differential amplifiers (Dp D2 ,. .D ( _n ) its outputs (k) are input to gate circuits (KA) which are of analogue and / or digital design and one or more outputs of gate circuits (KA) are connected to arithmetic operation channel amplifiers (Mp M ₂ "_M _n ) circuits (Figure 4). 4. Circuit arrangement according to any preceding claim, characterized in that the differential amplifiers (Dp D _2, .. J) power _n) points tp t ₂₎ floating potential independent power supply (T) output is turned on. 5. Circuit arrangement according to claim 1, characterized in that the differential amplifiers (Dp _D2, Dj, _. D _n) and the neutráliserősítő (NA), DATUM (0) are mutually connected, and the common ground point (F) are connected, one end of the differential amplifier (Dp D ₂ , D ₃ , _. D _n ) regulating resistor () - ₂ ) and feedback resistor (Ry) is connected to negative active input (-), the other end of feedback resistor (Ry) is to the output (k) of the differential amplifiers (DpD ₂ , .. JD _n ), and the other end of the control resistor (R ^) to a connecting lead (Ö) connecting the other control resistors (Rjj), which connecting lead (Ö) is the neutral amplifier (NA). is connected to its output (kn), and the positive active input (+) of the neutral amplifier (NA) to the neutral discharge electrode (NE), the negative active input (-) of the feedback resistance (R ^ y) of the neutral amplifier (NA) and is connected to the common point (P) of the resistor (NA) of the regulator (NA), the differential amplifiers (Dp D ₂ , _O _n ) positive active input (+) respectively connected to the discharge electrodes (Ep Ε ^ ,,, Εη), the outputs (k) of the differential amplifiers (Dp D ₂ , .. D _n ) are the input of a gate circuit (KA) consisting of analog and / or digital designs and one or more outputs of the gate circuits (KA) connected to an arithmetic operation hypothesis amplifier (Mp M ₂ , 1 ^ 3, .. 2 ^) containing a subtraction circuit, and the power connections of the circuit arrangement They are connected to a potentially connected or independent ground source (F) (Figure 5). 6. Circuit arrangement according to one of claims 1 to 3, characterized in that a differential resistor (Rj) is inserted between the positive active input (+) of the differential amplifiers (D 1, D ₂ , ..!) and the common ground point (F) of the system. . 7. Circuit arrangement according to one of the preceding claims, characterized in that the negative input of the active amplifier neutral (NA) - calibration signal source (KJ) is connected through a coupling resistor (R _cs) or directly (). 8. Circuit arrangement according to one of the preceding claims, characterized in that the differential amplifiers (Dp D _2, DJ, ... D _n) amplifier between the output (s) and gate circuits (CF) input terminals and / or DC voltage separator circuit element is switched on. 9. Circuit arrangement according to one of claims 1 to 3, characterized in that the arithmetic operation amplifier circuitry (Mp M ₂ , M ₃ , ... M _n ) comprises a combination of summing and subtracting circuits.