BIOPOTENTIAL AMPLIFIERS - Design and Development of Medical Electronic Instrumentation - page 4

Vo lum e
Conductor
(Tissue )

Current
from
Sources

Output

Vin Rin

Biopotential
Source

Biopot ential
Amplifier

Current
to
Sources

Electrode

Electrode-Tissue
Interface

(a)

R

i

iinterf erfaace iin

Bio Biopote otentia tial

Sou Source

V OOuttpuut

R

iin iin

R

iinterrface ace

TTissuue

(b)

Tissue

i

Xce

in

Xin

Biopotential
Source

Rin

Electrode
Tissue
Interface

Re

Ve Vin

Output Vout

Rin

Xin

Xce

Biopotential
Amplifier

(c)

Figure 1.3 ( a ) Simplified view of the recording of biopotentials; ( b ) equivalent circuit; ( c ) generalized equivalent circuit.