Determination of the Suitability of 650 Nm Laser Wavelength for Rapid Detection of Sickle Cell Aneamia (SCA): Photo Diagnostic Approach
N.A. Jadah and I.A. Shamkhi
Sickle cell anaemia (SCA) is a type of inherited haemoglobin disease. It is resulting from point mutation in the β-haemoglobin gene, producing a phenotype of sickle haemoglobin HbS. There are many different clinical and chemical methods of SCA diagnosis which depend on the chemical structure of HbS and its electro potential. In this work we use the optical properties of blood samples for highly specific detection of heamopathological disorder with respect to their blood group type using a 650 nm wavelength diode laser. We then investigate if there any relationships between blood group type and haemoglobin disorder. We have here a first attempt to assemble an integrated photo-bio detector for such disorders using laser wavelength that is absorbed by normal blood so that any change in transmittance value interprets as pathological disorders of haemoglobin according to blood group and anaemia type. We designed the proposed photo-bio detector according to Beer-Lamberts law using a diode laser of 650 nm wavelength as a source of illumination. The laser beam passed through a cuvette of blood sample, and then transmitted light directed to a focusing lens that reduces laser beam diameter to 2 mm. An optical sensor window of laser power meter receives and measures the volts of the transmitted laser beam. The readings that displayed on the laser power meter were taken and analysed statistically using compare means values and analysis of variance (ANOVA). The main findings of our research were that the photo-bio detector is capable of distinguishing between different blood groups, with different cases of haemoglobin disorder, SCA and iron deficiency anaemia from normal blood of the same blood type. The differences in readings of the photo-bio detector resulted from differences in the amino acids of the red blood cells (RBCs), plasma membrane that responsible of blood group types and the haemoglobin concentration either normal, sickled deficient or iron deficiency anaemia and oxygen content. According to haemoglobin concentration as well as construction RBCs corpuscles, the reading on biosensor was affected in the form of rise or fall in transmittance values of laser light. Also, iron dissociation blood sample that results from compound anaemia (βThalassemia βThal + SCD) drops the readings to the lowest values because of increasing in absorbance of 650 nm by haemolyzed blood samples.
Keywords: Diode laser, photo-bio detector, biosensor, blood, sickle cell anaemia (SCA), iron deficiency anaemia