Mindray BA-88A - Calculating Nonlinear Calibration Parameters

6-2
This calibration method requires only one calibrator.
Two-point linear calibration
Calibration formula: baCR
+
= .
This calibration method adopts two calibration parameters:
a and b , where,
12
12
CC
RR
a
−
−
=
,
1
12
12
1
C
CC
RR
Rb ）（
−
−
−= .
This calibration method requires two calibrators.
C
1
and C
2
are respectively the
concentrations of calibrator 1 and calibrator 2.
R
1
and
R
2
are respectively the
responses of calibrator 1 and calibrator 2.
Multi-point linear calibration
Calibration formula: baCR
+
= .
This calibration method adopts two calibration parameters:
a and b .
This calibration method requires n (n≥3) calibrators.
i
C is the concentration of
calibrator
i .
i
R is the response of calibrator i . a and b can be obtained
through the method of least squares.
nCC
nRCRC
a
n
i
i
n
i
i
n
i
i
n
i
i
n
i
ii
/)(
/))((
2
11
2
111
∑∑
∑∑∑
==
===
−
−
=
6.2 Calculating Nonlinear Calibration
Parameters
Logistic-Log 4P
Calibration formula:
)]ln(exp[1
1
0
Cba
KRR
+−+
+=
This calibration method adopts four parameters:
0
R ,
K
, a and b .
This calibration method requires at least four calibrators. The concentration (or
activity) of calibrator 1 is 0, and the corresponding
R
is equal to
R
0
.This
calibration method is applied to the calibration curve that the response becomes
smaller and smaller with the concentration increase. See Figure 6-1.