Roche Diagnostics
Instructions for Use · Version 13.0 97
cobas b 123 POC system 4 Theoretical foundations
Parameters and calculations
Parameters and calculations
Conversion table for units
The system provides an array of useful parameters, which are calculated from the
measurement values of each sample. Refer to the following table for an explanation of
the symbols used in the equations. Unless stated otherwise, all measurement values
that are used in the equations were measured at 37 °C.
Temperature
Equation 4-1
Equation 4-2
Standard values and ranges
Parameter Unit 1
(Default)
Unit 2 Unit 3 Unit 4
ctO
2
, avDO
2
, ctCO
2
1 vol% = 1 mL/dL = 0.4464 mmol/L
Ca
2+
1 mmol/L = 4.008 mg/dL
tHb 1 g/dL = 10 g/L = 0.6202 mmol/L
Glucose 1 mmol/L = 18.02 mg/dL
Lactate 1 mmol/L = 9.008 mg/dL
Bilirubin 1 mg/dL = 17.1 mol/L
Osmolality 1 mOsm/kg = 1 mmol/kg
MCHC 1 g Hb/dL Ery = 0.155 mmol Hb/L Ery
Air pressure (PCO
2
, PO
2
) 1 mmHg = 1.3333 mbar = 0.1333 kPa
= 39.37x10
-3
inch Hg
Table 4-1 Conversion table for units
T F
9
5
--- T C32+=
T C
5
9
--- T F32–=
Parameter Standard value Possible range
tHb 15.0 g/dL 1.0–26.0 g/dL
150 g/L 1–260 g/L
9.0 mmol/L 1.0–16.0 mmol/L
FIO
2
0.21 0.10–1.00
R (Respiratory quotient) 0.84 0.70–2.00
Patient's temperature 37.0 °C 2.0–44.0 °C
98.6 °F 35.6–111.0 °F
Hb factor 3.0 2.7–3.3
Table 4-2 Standard values and ranges