A Mazuina Mohamad creator author. text my 2023 2023 monographic eng xiv, 115 pages : 1 CD ROM Illustration ; 30 cm.+ This thesis describes the development of an optical fibre sensor for the detection of bilirubin (BR) molecules and measurement of its concentration in the visible (Vis) wavelength region. The concentration which exceeds the normal rate of BR in the human body that can lead to jaundice, and severe of hyperbilirunemia to newborns. Current practices have drawbacks which take longer of time to produce results. Some of the existence techniques are based on the consumption of other element for measuring the BR concentration in the sample. So that, BR molecules is mixed with a particular substance which can give effects to the identification and concentration measurement of BR. This research is carried out to identify the optimum absorption of BR molecules and analyses a cross sensitivity issue which is arise as a BR concentration measurement system based on spectroscopy study. It was developed using an open-path technique where the analytical sample is tested through the transmitting UV-Visible light beam. The experimental setup consists of halogen light source, cuvette holder, cuvette (cell), optical fibre cables and computer to display results. The Spectrasuite software was used in initial set up to display the optimum absorbance of BR. This software was irrelevant to measure the BR concentration in real-time. Therefore, LabVIEW can be used for this purpose. The developed optical sensor was successfully optimized. It is able to measure the various concentration of the four samples which are 50 μmol/L, 100 μmol/L, 150 μmol/L and 200 μmol/L at the particular visible absorption peak at 440 nm with low noise signal. Ratio technique was implemented to solve the cross-sensitivity issue between the BR molecules and Hemoglobin (Hb). Otherwise, the cross-sensitivity issue between carbon dioxide and oxygen can be ignored due to the very low absorption in the visible region. The developed BR concentration measurement system was also compared with the commercial set up system. It is associated with each concentration. It is also defined as a correlation between the measured absorbance produced by both instruments. The error percentage showed less than 3% which is considered as a laboratory standard for the instrument with good precision. By the advantage of LabVIEW, the optical sensor has an ability to measure the BR concentrations in real-time. This is a good potential that the optical sensor can identify the BR molecules and measure its concentration in a fast time response which is around 3s. specialized Mazuina Mohamad Faculty of Electrical & Electronics Engineering Technology Thesis (Doctor of Philosophy) -- Universiti Malaysia Pahang – 2023 Includes bibliographical reference Faculty of Electrical & Electronics Engineering Technology Dissertations Universities and colleges Dissertations Thesis Dissertations THE0009474 (Local) UMP 230614 20251125110741.0 eng