Post on 21-Dec-2015
transcript
Diagnostic electromagnetic equipment. Physical
principles electrographic methods in the diagnosis of
diseases.
Plan of the lecture:
1. The main characteristics of the electric field.•The electric field;•The potential of the electric field;•An electric dipole. Dipole field;•Dipole moment;•Equivalent circuit current dipole;2. ELECTROGRAPHY;•Einthoven theory.•PD classification methods based on field research•Methods and devices for diagnostic studies of cardiovascular system.•Methods and devices for diagnostic studies of the nervous and muscular system
Basic descriptions of electric-field
The electric field arises up round any charged body, regardless of it moves or not. Power description of electric-field is a size of tension of electric-field, which equals the relation of force with which the field operates on a point charge, to the size of this charge:
q
FE
Potential of electric-field
q
W
Name the relation of potential energy of charge potential of electric-field in the field
W to the size of this charge q
Electric dipole. Weeds dipole
l
lqp
l
Name the system electric dipole from two even after a size and opposite after a sign point charges, located in the distance one from another. Description of dipol is a dipole moment – vector, even work of charge q on the sholder of dipole
Where is a vector, directed from negative to the positive charge (shoulder of dipole).
Potential of electric-field of point charge
r
r
q
04
0
Potential of electric-field of point charge is
in the distance
Where is a relative inductivity of environment, – the electric became.
law of Ohm for a complete circle
In obedience to the law of Ohm for a
complete circle
cã RR
EI
Power Line of the dipole and dipole moment of water.
Finding the potential difference between two points equidistant
from the dipole.
A B
O P
O
2
2
α2 α1
γ C
Finding the potential of a dipole in a remote point in
space
r2-r1
r2
r1
l
P
r1
α
O
+
-
Dipole at the center of an equilateral triangle
А В
С
РСА РВС
РАВ
ОЛ
The equivalent current dipole circuit
+
-
cR rR
витік
стік
Einthoven proposed to simulate the electrical activity of the heart dipoles with a dipole
moment
The theory of Einthoven
N
iiDcD
1
The theory of Einthoven
Einthoven, proportional to the projection of the electric vector in the appropriate direction
САВСАВСАВСАВ DDD ::::
Einthoven space curve.
Amplifier
1 2 3 4 5 6
A
B
C
D
654321
D
C
B
A
Title
Number RevisionSize
B
Date: 6-May-1999 Sheet of File: C:\BUTCH\П_ДСИЛ~1\МАЛ4.SCH Drawn By:
TV1
R
R2
R1
Cвх
Cвих
Uвх
Б Ек
+
Е
К
_
ReCe
Rвих
Electrocardiogram (EKG, ECG)
Electrocardiogram of a healthy person
0,9 с
Р
Q
PQ
R
S
T ST
The main blocks and Switches of modern electrocardiograph
The main blocks and Switches of modern electrocardiograph
Basic blocks and controls of modern electrocardiograph
The main blocks and Switches of modern
electroencephalograph.
Block diagram of the digital electroencephalograph.
Block diagram of the electroencephalograph.
1. Head of a patient with diverter electrodes (top view);
2. input box;
3. Patch Cables;
4. selector unit with switches for each channel;
5. power amplification with regulators filters high and low frequency (F) and rough or smooth gain control (Y);
6. Unit registration.
Block diagram of the electroencephalograph.
Rubber hat for attaching electrodes to the head.
A – bridge electrode, B – Needle, C – cup-shaped electrode: 1 – metal, 2 – sticky tape, 3 – electrode paste, 4 – skin. D – fixing the electrodes on the head by caps with rubber bands.
The main blocks and Switches of modern electromyogram
It functions as follows: biopotential muscles strengthened by amplifier (1)
through the switching device (2) and connection cable (3) goes to recording block and built-in controls
(4) Output signals from the interface block and
built-in control via connection cable coming in galvanometers oscilloscope (5).
Scheme of connection blocks that make up the unit to record
bioelectric potentials of muscles.
Surface electrodes andneedle electrode
Surface electrodes
Needl electrodes