OPTi CCA-TS2 - Page 283

Operator’s Manual – OPTI CCA-TS2 A-11
APPENDIX A - TECHNICAL SPECIFICATIONS
If measured O
2
Hb and tHb are not available and calculated SO
2
is enabled:
2
2
2
O00314.0tHb
100
O
39.1O P
S
t ⋅+⋅⋅=
[vol%]
7
NOTE:IfPO
2
isnotavailable,ctO
2
iscalculatedwithPO
2
=90mmHg.
P50
The oxygen partial pressure at half saturation, P50, is dened as the PO
2
value for a given blood
sample at which 50% of the hemoglobin is saturated with oxygen. While the actual P50 value can
only be determined by interpolation after measurement of oxygen saturation of a blood specimen
tonometered to levels of oxygen to provide an oxyhemoglobin slightly greater than and slightly
less than 50% with pH and PO
2
held constant at 7.4 and 40 mmHg respectively, the OPTI CCA-
TS2 allows for the estimation of P50 from measured SO
2
% ,PO
2
and pH. If a measured SO
2
% is
not available, the P50 value may be input via keypad.
For Adult hemoglobin:
( )
2
2
2
OlgOlg
50
O%100
O
9.2
)172.4(lg
Olg
:
107.26
22
S
S
Q
Q
where
k
k
−
=
+
=
⋅=
−
P
P
PP
[mmHg]
6
For Fetal hemoglobin:
( )
2
2
2
OlgOlg
50
O%100
O
9.2
)113.4(lg
lg
:
100.25
22
S
S
Q
Q
PO
where
P
k
k
−
=
+
=
⋅=
− PP
[mmHg]
6