Hemoglobin determination
Biotest Hemoglobin System
Accuracy and precision
Biotest Medizintechnik GmbH

Products
• Cuvette
– Biotest Hemoglobin
• Measuring device
– Biotest Hemoglobin Tester
2

Function
• Cuvette
• Blood capillary, reagent and measuring cuvette in one.
• Biotest Hemoglobin Tester
Photometer with integrated control and digital display
3

Function - Cuvette
• Chemical reaction
Haemolysis by sodium desoxycholat
Sodium nitrite
Methemo-
Free
Haemoglobin globin
Sodium azid
Azid-
Methaemo
-globin
Erythrocytes
4

Function - Cuvette
• Absorbance curve
5

Measurements n = 30
Mean g/dl
HiCN
SD g/dl
Sample 1
Sample 2
Sample 3
Sample 4
Sample 5
Sample 6
Sample 7
Sample 8
Sample 9
Sample 10
Sample 11
Sample 12
Sample 13
Sample 14
Sample 15
Sample 16
Sample 17
Sample 18
Sample 19
Sample 20
5,50 g/dl
7,42 g/dl
7,90 g/dl
9,82 g/dl
10,13 g/dl
11,70 g/dl
11,88 g/dl
12,77 g/dl
13,48 g/dl
13,51 g/dl
13,65 g/dl
14,10 g/dl
14,39 g/dl
14,76 g/dl
14,82 g/dl
15,21 g/dl
15,59 g/dl
15,83 g/dl
18,36 g/dl
19,37 g/dl
Mean value 13,01 g/dl 0,12 g/dl
0,09 g/dl
0,07 g/dl
0,12 g/dl
0,06 g/dl
0,10 g/dl
0,09 g/dl
0,24 g/dl
0,08 g/dl
0,11 g/dl
0,08 g/dl
0,13 g/dl
0,21 g/dl
0,08 g/dl
0,10 g/dl
0,17 g/dl
0,10 g/dl
0,13 g/dl
0,10 g/dl
0,18 g/dl
0,18 g/dl
CV &
0,59 %
0,94 %
1,50 %
0,56 %
0,65 %
1,15 %
0,66 %
0,82 %
0,64 %
0,95 %
0,95 %
1,61 %
0,93 %
1,46 %
0,61 %
1,02 %
0,77 %
2,04 %
0,63 %
0,84 %
0,97 %
Mean g/dl
5,46 g/dl
7,47 g/dl
7,97 g/dl
10,03 g/dl
10,05 g/dl
11,65 g/dl
11,75 g/dl
12,68 g/dl
13,47 g/dl
13,50 g/dl
13,51 g/dl
14,04 g/dl
14,41 g/dl
14,72 g/dl
14,82 g/dl
15,14 g/dl
15,66 g/dl
15,83 g/dl
18,57 g/dl
19,54 g/dl
Biotest
SD g/dl
0,08 g/dl
0,07 g/dl
0,09 g/dl
0,12 g/dl
0,12 g/dl
0,07 g/dl
0,10 g/dl
0,10 g/dl
0,10 g/dl
0,13 g/dl
0,08 g/dl
0,18 g/dl
0,10 g/dl
0,09 g/dl
0,10 g/dl
0,14 g/dl
0,13 g/dl
0,16 g/dl
0,10 g/dl
0,11 g/dl
13,01 g/dl 0,11 g/dl
CV &
0,93 %
0,60 %
1,29 %
0,69 %
0,62 %
0,69 %
0,94 %
0,82 %
0,99 %
0,54 %
0,59 %
1,47 %
0,91 %
1,12 %
1,23 %
1,17 %
0,58 %
0,81 %
0,81 %
0,76 %
0,88 % 6

Measurements
Linearity and precision, n = 20 measurements by each blood sample.
20,00 y = 1,0064x - 0,0773
R² = 0,9992
15,00
10,00
5,00
5,0 g/dl 10,0 g/dl 15,0 g/dl
Mean value HiCN, i g/dl
20,0 g/dl
7

Measurements
Vergleich venöses Blut
Biotest Hemoglobin Meßsystem mit HiCN-Methode
25,00
20,00
15,00
10,00
5,00
0,00
0,00 5,00 10,00 15,00
HiCN-Methode Hb [g/dl]
20,00 25,00 n = 300
Biotest
Linjär
(Biotest) y = 0,9965x + 0,0363
R
2
= 0,9981
8

Function - Tester
• Photometer; two wave lengths
• Evaluation and calculation
• Reading
Evaluation
9

Self calibration
• 100% green light, 100% red light and dark current
• Compared to moment of calibration
• If necessary automatic adjustment of LED current
Evaluation
10

Resolution
Absorption
Max deviation =
+/- 0,75 % or
+/- 30 steps
256 g/L
0 = 100 % light
470 – 880 nm
12 bits = 4000 ”steps”
Resolution
11

Calibration
Absorption
Two points of calibration for linearity; 80 and 220 g/L
0 = 100 % light
470 – 880 nm
256 g/L
Three control levels for linearity 120, 150, 180 g/L
12 bits = 4000 ”steps”
12

Function - Tester
• Calculation of Hb
Extinction
Turbidity
500 570 600 700 800 880
Wave length [nm]
Turbidity
13

Hb
Capillary blood
0 min 1 min 2 min 3 min
Time
14

Results - Introduction
• Accuracy
– How close to true value is the result
• Precision
– How close to each other are repeated measurements with the same sample
15

Results - Introduction
• Accuracy and precision
High accuracy
Low precision
Low accuracy
High precision
High accuracy
High precision
16

Results - Introduction
• Accuracy:
– Deviation (mean) in g/L
– Preferred; deviation in %
• Precision:
– Standard deviation SD
– Preferred; Coefficient of variation, CV %
17

Results
15
10
5
0
12,1
30
25
20
Precision with control blood (n=50)
Mean value 12,39 g/dl
SD
CV
0,084 g/dl
0,68 %
12,2 12,3 12,4
Result [g/dl]
12,5 12,6 12,7
18

Features
• Cuvette
– Aimed for Hb-measurement with Biotest-Hemoglobin-Tester and compatible instruments
– High accuracy and precision
– Can be used for venous, capillary and arterial blood
– Developed to be price worth due to latest production and control technique
19

Features
• Tester

Automatic calibration: no calibration or test cuvette needed

Cuvette holder minimizing the risk of contamination

Automatic monitoring of power supply with fast loading of batteries
(1 hour loading > 40 hours of measuring)

Automatic shut off with latest value saved

Measures only cuvettes with properly haemolysed blood
20

Summary
• High accuracy and precision
• Easy and reliable system
• Long time use on battery power
21

Results - Introduction
22