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Hemoglobin determination Biotest Hemoglobin SystemAccuracy and precision
Biotest Medizintechnik GmbH
2
Products
• Cuvette– Biotest Hemoglobin
• Measuring device– Biotest Hemoglobin Tester
3
Function
• Cuvette
• Blood capillary, reagent and measuring cuvette in one.
• Biotest Hemoglobin Tester
Photometer with integrated control and digital display
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Function - Cuvette
• Chemical reaction
Free Haemoglobin
Sodium nitrite Sodium azid
Erythrocytes
Haemolysis by sodium desoxycholat
Methemo-globin
Azid-Methaemo-globin
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Function - Cuvette
• Absorbance curve
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Measurementsn = 30
Mean g/dl SD g/dl CV & Mean g/dl SD g/dl CV &Sample 1 5,50 g/dl 0,09 g/dl 1,61 % 5,46 g/dl 0,08 g/dl 1,47 %Sample 2 7,42 g/dl 0,07 g/dl 0,93 % 7,47 g/dl 0,07 g/dl 0,91 %Sample 3 7,90 g/dl 0,12 g/dl 1,46 % 7,97 g/dl 0,09 g/dl 1,12 %Sample 4 9,82 g/dl 0,06 g/dl 0,61 % 10,03 g/dl 0,12 g/dl 1,23 %Sample 5 10,13 g/dl 0,10 g/dl 1,02 % 10,05 g/dl 0,12 g/dl 1,17 %Sample 6 11,70 g/dl 0,09 g/dl 0,77 % 11,65 g/dl 0,07 g/dl 0,58 %Sample 7 11,88 g/dl 0,24 g/dl 2,04 % 11,75 g/dl 0,10 g/dl 0,81 %Sample 8 12,77 g/dl 0,08 g/dl 0,63 % 12,68 g/dl 0,10 g/dl 0,81 %Sample 9 13,48 g/dl 0,11 g/dl 0,84 % 13,47 g/dl 0,10 g/dl 0,76 %Sample 10 13,51 g/dl 0,08 g/dl 0,59 % 13,50 g/dl 0,13 g/dl 0,93 %Sample 11 13,65 g/dl 0,13 g/dl 0,94 % 13,51 g/dl 0,08 g/dl 0,60 %Sample 12 14,10 g/dl 0,21 g/dl 1,50 % 14,04 g/dl 0,18 g/dl 1,29 %Sample 13 14,39 g/dl 0,08 g/dl 0,56 % 14,41 g/dl 0,10 g/dl 0,69 %Sample 14 14,76 g/dl 0,10 g/dl 0,65 % 14,72 g/dl 0,09 g/dl 0,62 %Sample 15 14,82 g/dl 0,17 g/dl 1,15 % 14,82 g/dl 0,10 g/dl 0,69 %Sample 16 15,21 g/dl 0,10 g/dl 0,66 % 15,14 g/dl 0,14 g/dl 0,94 %Sample 17 15,59 g/dl 0,13 g/dl 0,82 % 15,66 g/dl 0,13 g/dl 0,82 %Sample 18 15,83 g/dl 0,10 g/dl 0,64 % 15,83 g/dl 0,16 g/dl 0,99 %Sample 19 18,36 g/dl 0,18 g/dl 0,95 % 18,57 g/dl 0,10 g/dl 0,54 %Sample 20 19,37 g/dl 0,18 g/dl 0,95 % 19,54 g/dl 0,11 g/dl 0,59 %Mean value 13,01 g/dl 0,12 g/dl 0,97 % 13,01 g/dl 0,11 g/dl 0,88 %
HiCN Biotest
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Measurements
Linearity and precision, n = 20 measurements by each blood sample.
y = 1,0064x - 0,0773R² = 0,9992
5,00
10,00
15,00
20,00
5,0 g/dl 10,0 g/dl 15,0 g/dl 20,0 g/dl
Mean value HiCN, i g/dl
Bio
tes
t H
em
og
lob
in S
ys
tem
, g
/dl
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MeasurementsVergleich venöses Blut
Biotest Hemoglobin Meßsystem mit HiCN-Methode
y = 0,9965x + 0,0363
R2 = 0,9981
0,00
5,00
10,00
15,00
20,00
25,00
0,00 5,00 10,00 15,00 20,00 25,00
HiCN-Methode Hb [g/dl]
Bio
tes
t S
yste
m H
b [
g/d
l]
Biotest
Linjär(Biotest)
n = 300
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Function - Tester
• Photometer; two wave lengths
• Evaluation and calculation
• Reading
Evaluation
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Self calibration • 100% green light, 100% red light and dark current• Compared to moment of calibration• If necessary automatic adjustment of LED current
Evaluation
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Absorption 256 g/L
12 bits = 4000 ”steps”
Resolution
0 = 100 % light 470 – 880 nm
Resolution
Max deviation = +/- 0,75 % or +/- 30 steps
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Calibration
Absorption 256 g/L
12 bits = 4000 ”steps”0 = 100 % light 470 – 880 nm
Two points of calibration for linearity; 80 and 220 g/L
Three control levels for linearity 120, 150, 180 g/L
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Function - Tester
• Calculation of HbE
xtin
ctio
n
500 570 600 700 800 880Wave length [nm]
Turbidity
Turbidity
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Hb
Time
0 min 1 min 2 min 3 min
Capillary blood
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Results - Introduction
• Accuracy– How close to true value is the result
• Precision– How close to each other are repeated
measurements with the same sample
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Results - Introduction
• Accuracy and precision
High accuracyLow precision
Low accuracyHigh precision
High accuracyHigh precision
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Results - Introduction• Accuracy:
– Deviation (mean) in g/L
– Preferred; deviation in %
• Precision:– Standard deviation SD
– Preferred; Coefficient of variation, CV %
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Results
Precision with control blood (n=50)
0
5
10
15
20
25
30
12,1 12,2 12,3 12,4 12,5 12,6 12,7
Result [g/dl]
Nu
mb
ers
Mean value 12,39 g/dlSD 0,084 g/dlCV 0,68 %
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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
20
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
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Summary
• High accuracy and precision• Easy and reliable system• Long time use on battery power
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Results - Introduction