ITC IRMA TruPoint Blood Analysis System - Manual (Page 145)

C.1
Appendix C
Principles of Operation
This appendix describes the measurement technology of the IRMA TruPoint
blood analysis system.
MEASUREMENT TECHNOLOGY
The IRMA TruPoint system utilizes potentiometric, amperometric, and
conductimetric measurement methodologies to measure the analyte concen-
tration in whole blood as described in the following table.
Sensor Measurement Technology
reference silver/silver chloride electrode
pH, pCO
2
, Na+,
K+, Cl
-
, iCa,
BUN/urea
potentiometric measurement utilizing ion specific
electrode (ISE) technology
14 ;
for the BUN/urea sensor, the NH
4
+
generated from the
reaction of urea with urease is detected
pO
2
amperometric measurement based on the principles of
the Clark electrode 13
hematocrit conductimetric measurement
glucose amperometric measurement; the H
2
O
2
generated from
the reaction of glucose with glucose oxidase is detected
creatinine amperometric measurement; the H2O2 generated from
the enzymatic reaction of sarcosine (as produced by
the enzymatic reaction of creatinine in the presence of
creatinine amidohydrolase and creatine in the presence
of creatine amidohydrolase) in the presence of
sarcosine oxidase is detected
Lactate amperometric measurement; the H
2
O
2
generated from
the reaction of lactate with lactate oxidase is detected