1

RESULTS OF EXPERIMENTAL RESEARCHES OF METROLOGICAL

CHARACTERISTICS NANOELECTRODES FOR MEASUREMENT OF ELECTRIC FIELDS

OF THE GROUND AND BIOPOTENTIALS OF THE PERSON

Avdeeva D.K., Klubovich I.A.

Tomsk Polytechnic University

Scientific Research and Development Institute of Introscopy

Tomsk, Russia

Measuring of constant electric fields of the Earth spend with the purpose of detection of

anomalies of an electric field of the Earth at geophysical measurements. In medicine measuring

of superficial biopotentials it is widely applied to functional diagnostics of various bodies and

fabrics of the person, however diagnostics on values of constants and lowfrequency potentials in

an organism of the person is absent in practical public health services.

The frequency range of investigated biopotentials reaches from 0,01Hz and above (up to

20000Hz at research of hearing of the person).

Not less important problem is also ecological monitoring of a condition of the Earth and

socially-hygienic monitoring in public health services.

The problem consists in improvement of quality of measurement of electric constant

fields of the Earth and biopotentials of the person.

Quality of measurements depends on stability of electrode potential on a direct current,

contact and polarizing properties of electrodes.

Now lead electrodes are applied to measurement of constant fields of the Earth and liquid

copper-zakisny. Lead electrodes are ecologically unsafe. In medicine electrodes are applied

metal, silver, chlorine-silver.

Developed nanoelectrodes are based on manufacturing techniques chlorine-silver of

electrodes on the basis of porous ceramics (manufacture of Tomsk Polytechnic University,

Scientific Research and Development Institute of Introscopy) and modern nanotehnologies and

nanomaterials.

The basic metrological parameters of the nanoelectrodes are: the drift of the difference of

electrode potentials at constant current, polarization voltage of the electrodes, the impedance of

the electrodes.

The two electrode cells EC and EC - "electrode-electrolyte-electrode" were investigated 1 2

during several days.

The measuring the drift electrode potential at the constant current were carried out using

device for the automated testing of medical electrodes DTE-2 (Certificate number 33700,

registered in the State register of measuring instruments under № 39325-08).

The dependences of electrode potential drift, obtained at the cell EC1 are presented on

the fig. 2a,b,c shows. The dependences of electrode potential drift, obtained at the cell EC2 are

presented on the fig. 2a,b,c.

The graphics also shows the average values M, the average square deviations σ, the

maximum deviations from the average values towards higher values (+ ∆Хmax) and the

maximum deviations from the average value toward lower values (-∆Хmax).

The maximum deviation in the direction of positive values is 0,0136 mV, the maximum

deviation in the direction of negative values is (-0,0140) mV, the maximum average square

deviation is 0,0112 mV.

Drift with the current of ≤ 1nA is equal (1-3) nV/sec.

0,0780,0980,1180,1380,1580,1780,198

12:30

13:30

14:30

15:30

16:30

0,0780,0980,1180,1380,1580,1780,198

20:30

21:30

22:30

V V

s

М = 0,1219 mV; σ = 0,0045 mV;

+∆Хmax = +0,0032 mV; -∆Хmax = -0,0098 mV

а) 1 day

М = 0,1253 mV; σ = 0,0112 mV;

+∆Хmax = +0,0136 mV; -∆Хmax = -0,0140 mV

V

s

+∆Х

М = 0,1056 mV; σ = 0,0064 mV;

max = +0,0098 mV; -∆Хmax = -0,0122 mV

∆E,m

b) 2 day

∆E,m

∆E,m

t, hour

t, hours

t, hour

2

0,090,0950,1

0,1050,110,1150,120,1250,13

12:20

12:30

12:40

12:50

13:00

13:10

13:20

13:30

13:40

13:50

14:00

14:10

∆E,mV

t, hours

М = 0,1100 mV; σ = 0,0044 mV;

+∆Хmax = +0,0054 mV; -∆Хmax = -0,0077 mV c) 3 day

Fig. 1а,b,c. Electrode potential from time of the electrode cell EC1

0,08

0,09

0,1

0,11

0,12

0,13

0,14

20:45

21:00

21:15

21:30

21:45

22:00

22:15

22:30

22:45

∆E,mV

t, hours

М = 0,1042 mV; σ = 0,0073 mV;

+∆Хmax = +0,0102 mV; -∆Хmax = -0,0086 mV а) 1 day

0,770,7750,780,7850,790,7950,8

0,8050,81

19:20

20:20

21:20

22:20

∆E,mV

t, hours

М = 0,7904 mV; σ = 0,0057 mV;

+∆Хmax = +0,0090 mV; -∆Хmax = -0,0069 mV b) 2 day

3

0,87

0,875

0,88

0,885

0,89

0,895

0,9

15:00

16:00

17:00

18:00

∆E,mV

t, hours

4

c) 3 day

М = 0,8823 mV; σ = 0,0040 mV; +∆Хmax = +0,0057 mV; -∆Хmax = -0,0064 mV

Fig. 2а,b,c. Electrode potential from time of the electrode cell EC2

The permissible value of the DC between two electrodes set on the human body is

equal 0,1 µA[1-3].

The dependences of the electrode potential drift, obtained at the cell EC1 at the current

0,1 µA, are presented on the Fig. 3a,b, the dependencies for EC2 are presented in Fig. 4a,b.

The drift of the electrode potential of EC1 is 0,005 mV / s; potential change – 0,25 mV,

the average value is 0,3188 mV, standard deviation – 0,0080 mV, the maximum deviation in the

direction of positive values is 0,0092 mV, the maximum deviation in the direction toward

negative values (- 0,0018) mV.

0,07

0,12

0,17

0,22

0,27

0,32

18:40

19:40

20:40

21:40

22:40

∆E,mV

t, hours

а)

0,290,2950,3

0,3050,310,3150,320,3250,33

19:00

20:00

21:00

22:00

23:00

∆E,mV

t, hours

М = 0,3188 mV; σ = 0,0080 mV;

+∆Хmax = +0,0093 mV; -∆Хmax = -0,0180 mV b)

Fig. 3а,b. The drift of the electrode potential difference EC1 from the time at the current 0,1 µA

0,59

0,69

0,79

0,89

0,99

1,09

13:30

14:30

15:30

16:30

17:30

18:30

19:30

20:30

21:30

22:30

∆E,mV

t, hours

a)

0,92

0,94

0,96

0,98

1

1,02

15:30

16:30

17:30

18:30

19:30

20:30

21:30

22:30

∆E,mV

t, hours

b)

Fig. 4а,b. The drift of the electrode potential difference EC2 in the time at the current of

0,1 µA

5

The drift of the electrode potential EC2 is equal 0,01 µV/s; the potential changing - 0,3

mV, the average value is 0,9655 mV, the average square deviation – 0,0295 mV, the maximum

deviation in the direction of positive values is 0,0484 mV, the maximum deviation in the

direction of negative values is (- 0,0425) mV.

The method is using in the medical and the geophysical equipmens based on the

constant current flowing through the system «electrode - object – electrode», the value of which

reaches a value 10 µA.

The studies of polarization voltage from the value of direct current were carrying out in

a range from 0,1 mA to 10 mA.

Polarization voltage ∆Uр is:

∆Uр=U2-U1,

where U1 - the difference in the electrode potentials under the influence of the constant

current ≤ 1nA;

U2 - the difference in the electrode potentials under the influence of the constant

current > 1nA.

Dependence of the polarization voltage ∆Uр electrode cell EC1 from the value of DC is

shown in Fig. 5.

0

1

2

3

4

5

6

7

0,1 0,5 1 5 10

Uр, м

В

кА

∆Up,

mV

A

Fi

I, мI, µ

6

g. 5

The measuring of the impedance of the electrode cells EC1 and EC2 were carrying out

using the device for the automated testing of medical electrodes DTE-2, the measuring currents -

0,1µA; 1 µA and 10µA; frequencies, Hz – 0,01; 0,05; 0,15; 1; 2; 75; 10000.

The results are shown in Fig. 6a,b.

m

current 1,0 µА current 0,1 µА current 10 µА

а) EC1

current 1,0 µА current 0current 10 µА

b) EC2

Fig. 6а,b. The dependences of the electrode impedance from the frequency at the

measuring currents

F, Hz

Z, O

,1 µА

diff

F, Hz

Z, Om

7

erent

The nanoelectrodes for the various purposes are presented on fig.7a-p for geophysical

and medical instrumentation.

Fig 7a. The geophysical nanoelectrodes

Fig 7b. Nanoeleсtrode ЭСК-01/н

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Fig 7c. Nanoeleсtrode ЭСК-03/н

Fig 7d. Nanoeleсtrode ЭСК-02/н1

9

Fig 7e. Nanoeleсtrode ЭСК-02/н2

Fig 7f. Nanoeleсtrod eЭСК-02/н1 in assembly

10

Fig 7g. Nanoeleсtrode ЭСЭГ-1/н2

Fig 7i. Nanoeleсtrode ЭСЭГ-1/н2 – top view

11

Fig 7k. Nanoelectrodes with button diverting

Fig 7l. Nanoeleсtrodes ЭСМГ-1/н1

12

Fig 7m. Nanoeleсtrodes ЭСМГ-1/н2

Fig 7n. Nanoeleсtrodes ЭСМГ-1/н3

13

Fig 7o. Nanoeleсtrodes ЭСМГ-1/н4

Fig 7p. Nanoeleсtrodes for ECG with limb

14

15

It is possible to do the following conclusions on the basis of nanoelectrodes

metrological researchings:

1. Nanoelectrodes have a high stability of the electrode potential in time at the current

≤ 1nA and at the current 0,1 µA.

The drift of the electrode potential at the current ≤ 1nA is equal (1-3) nV/sec.

The drift of the electrode potential at the current 0,1 µA is equal (5 ÷ 10) nV/sec.

2. Polarization voltage of the nanoelectrodes under the influence of a constant current

0.1 µA is equal (0,2 ÷ 0,3) mV and is not change with the prolonged force by the current.

3. Polarization voltage of the nanoelectrodes at the currents from 0,1 µA to 10 µA is

varies from 0,2 mV to 6,4 mV.

4. Nanoelectrode resistance is equal the tens and the hundreds ohm depending from

frequency and is not dependent from the value of the current at the frequencies < 1Hz.

Literature

1. GOST 19687-89. The devices for the measuring of the heart bioelectric potentials .

2. GOST R 50267.0-92 (IEC 601-1-88). The medical electrical devices. Part 1. The

general safety requirements.

3. GOST R IEC 60601-1-1-2007. The medical electrical devices. Part 1-1. The general

safety requirements. The safety requirements for the medical electrical systems.