Biomedical Engineering Reference
In-Depth Information
Ta b l e 7 . 4
Biometric
parameters of the healthy
subjects. Values are presented
as mean
Healthy
(80)
±
standard deviation
Female/male
31/49
Age (yrs)
27
±
5
Height (m)
1
.
73
±
0
.
17
Weight (kg)
69
±
9
.
6
performed in our laboratory, and Table
7.4
presents their biometric parameters. The
measurements were performed over the 2005-2009 time interval.
According to Pasker, the real (Re) and imaginary (Im) parts of the impedance
can be predicted from their biometric data as given below [
119
]:
Female
Re
0
=−
0
.
4300
·
h
+
0
.
00165
·
w
−
0
.
00070
·
a
+
0
.
9312
(RSD
=
0
.
0619
)
Re
1
=
0
.
01176
·
h
−
0
.
000106
·
w
−
0
.
000045
·
a
−
0
.
00817
(RSD
=
0
.
00256
)
Im
0
=
0
.
2487
·
h
−
0
.
001700
·
w
−
0
.
00053
·
a
−
0
.
2158
(RSD
=
0
.
0406
)
(7.12)
Male
Re
0
=−
0
.
2454
·
h
+
0
.
001564
·
w
−
0
.
00055
·
a
+
0
.
5919
(RSD
=
0
.
0493
)
Re
1
=
0
.
01176
·
h
−
0
.
000106
·
w
−
0
.
000045
·
a
−
0
.
00817
(RSD
=
0
.
00197
)
Im
0
=
0
.
2487
·
h
−
0
.
001700
·
w
−
0
.
00053
·
a
−
0
.
2158
(RSD
=
0
.
0306
)
where
h
denotes height in (m),
w
denotes weight in (kg),
a
denotes age in (yrs)
and
RSD
is the residual standard deviation. The real and imaginary parts of the
impedance are fitted by the polynomial:
R
rs
=
D
f
+
E
(7.13)
where
f
is the frequency. The coefficients calculated with (
7.12
) from their biomet-
ric parameters are then validated with the
E
and
D
coefficients resulting from the
curve fitting. For the real part of the impedance, the coefficient
E
is validated with
the coefficient Re
0
, respectively the coefficient
D
is validated with the coefficient
Re
1
. For the imaginary part of the impedance, the coefficient
E
is validated with the
coefficient Im
0
. Since the volunteers were presumed healthy (but not guaranteed),
the predicted values for terms in (
7.13
) were verified with the reference values from
[
119
,
121
]. Only in 56 (from the initial 80) subjects, the identified values from (
7.13
)
remained close to the predicted values of Re
0
,Re
1
and Im
0
, within the 95 % confi-
dence interval.
