The analysis of the blood cell components is one of the important interests in medicine and clinical research. By analyzing the blood cells in whole blood, many kinds of disease can be diagnosed, such as AIDS, leukemia, malaria, nephritic syndrome, chronic liver disease, hyperlipidemia, and anemia. ...
The analysis of the blood cell components is one of the important interests in medicine and clinical research. By analyzing the blood cells in whole blood, many kinds of disease can be diagnosed, such as AIDS, leukemia, malaria, nephritic syndrome, chronic liver disease, hyperlipidemia, and anemia. However, most of the conventional blood analysis methods (e.g. flow cytometer) are still expensive, heavy, and bulky. Even if they show a good performance to analyze the blood cell, it is quite difficult to use them in point-of-care applications, particularly in resource-poor countries or rural area. Recently, the blood analysis technique based on CMOS image sensor has been studied to provide a cost effective, comfortable, and versatile analysis system. Furthermore, CMOS image sensor is widely used in mobile phones, so this system is effectively applicable for the point-of-care system with mobile phone. This thesis describes an LED and CMOS image sensor based hemoglobin concentration measurement system. To characterize the effect of the wavelength of LED light source to hemoglobin concentration measurement, wavelength of 625 nm, 525 nm, and 470 nm were illuminated on hemolyzed blood sample, respectively. A uniform light illumination was designed with a combination of LED and 300 μm diameter pinhole film mask. Aluminum foil covered black box was designed to eliminate the unnecessary external light noise signal. Internally generated scattered light noise was effectively absorbed by covering with black flock paper on the internal surface of the black box. Hemolyzed blood sample, 50 μL of whole blood with 4950 μL of lysing buffer solutions, was prepared to measure the hemoglobin concentration. In order to minimize the influence from Brownian motion of particles in aqueous sample, CMOS image sensor collected 100 images consecutively. Then these images were averaged by Image J software program. The illuminated light intensity through hemolyzed 10 different patients' blood samples decreased exponentially with the hemoglobin concentration, which is consistent with Beer-Lambert law. After the measurement, background image calibration process was additionally performed in order to decrease the unexpected light intensity variation from the environmental effect. From the measurement result, it was found out that the light from a blue LED with the wavelength of 470 nm, among red/green/blue LEDs, is the most effective light to analyze the hemoglobin concentration. Fitting curve was induced by using Origin program from the blue light based measurement result. Based on this fitting curve, a blind test was performed by using 33 unlabeled different patients' blood samples. Compared to results of a commercially available, expensive, hematology analyzer(XE-2100), the measurement results of the fabricated analysis system from the blind test showed a very close output with a mean error rate of ∼1.36%. Furthermore, the repeatability test was performed by performing an testing the identical sample after storing the sample for different time duration and the results showed that the repeatability was very good up to 48 hours. This LED and CMOS image sensor based hemoglobin measurement system was successfully realized and the hemoglobin concentration of real patients’ blood samples were accurately measured by using this system.. By combining this blood analysis system with cell phones which are used by more than 4 billion people in the world, a very convenient and affordable telemedicine or point-of-care health monitoring system can be realized, especially in developing countries or resource-poor environments.
The analysis of the blood cell components is one of the important interests in medicine and clinical research. By analyzing the blood cells in whole blood, many kinds of disease can be diagnosed, such as AIDS, leukemia, malaria, nephritic syndrome, chronic liver disease, hyperlipidemia, and anemia. However, most of the conventional blood analysis methods (e.g. flow cytometer) are still expensive, heavy, and bulky. Even if they show a good performance to analyze the blood cell, it is quite difficult to use them in point-of-care applications, particularly in resource-poor countries or rural area. Recently, the blood analysis technique based on CMOS image sensor has been studied to provide a cost effective, comfortable, and versatile analysis system. Furthermore, CMOS image sensor is widely used in mobile phones, so this system is effectively applicable for the point-of-care system with mobile phone. This thesis describes an LED and CMOS image sensor based hemoglobin concentration measurement system. To characterize the effect of the wavelength of LED light source to hemoglobin concentration measurement, wavelength of 625 nm, 525 nm, and 470 nm were illuminated on hemolyzed blood sample, respectively. A uniform light illumination was designed with a combination of LED and 300 μm diameter pinhole film mask. Aluminum foil covered black box was designed to eliminate the unnecessary external light noise signal. Internally generated scattered light noise was effectively absorbed by covering with black flock paper on the internal surface of the black box. Hemolyzed blood sample, 50 μL of whole blood with 4950 μL of lysing buffer solutions, was prepared to measure the hemoglobin concentration. In order to minimize the influence from Brownian motion of particles in aqueous sample, CMOS image sensor collected 100 images consecutively. Then these images were averaged by Image J software program. The illuminated light intensity through hemolyzed 10 different patients' blood samples decreased exponentially with the hemoglobin concentration, which is consistent with Beer-Lambert law. After the measurement, background image calibration process was additionally performed in order to decrease the unexpected light intensity variation from the environmental effect. From the measurement result, it was found out that the light from a blue LED with the wavelength of 470 nm, among red/green/blue LEDs, is the most effective light to analyze the hemoglobin concentration. Fitting curve was induced by using Origin program from the blue light based measurement result. Based on this fitting curve, a blind test was performed by using 33 unlabeled different patients' blood samples. Compared to results of a commercially available, expensive, hematology analyzer(XE-2100), the measurement results of the fabricated analysis system from the blind test showed a very close output with a mean error rate of ∼1.36%. Furthermore, the repeatability test was performed by performing an testing the identical sample after storing the sample for different time duration and the results showed that the repeatability was very good up to 48 hours. This LED and CMOS image sensor based hemoglobin measurement system was successfully realized and the hemoglobin concentration of real patients’ blood samples were accurately measured by using this system.. By combining this blood analysis system with cell phones which are used by more than 4 billion people in the world, a very convenient and affordable telemedicine or point-of-care health monitoring system can be realized, especially in developing countries or resource-poor environments.
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#LED CMOS 이미지 센서 혈색소
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