In the present study, Infrared (IR) thermal camera is used to measures the temperature map of the target skin surface and the resulting thermal image is used to evaluate the carotid artery stenosis (CAS). A novel parametric thermal feature extraction method is used, of which, statistical features, viz., mean, standard deviation (SD), variance, smoothness, and kurtosis, are calculated and the two groups of patients (control and diseased: total of 80 samples) are classified. Using cut-off value-based binary classification model, the control group (C: 0% stenosis) is classified against four diseased groups, namely, D1 (10%-29%), D2 (30%-49%), D3 (≥50%), and D (≥10%), respectively. Further, extended control (C’: 0-29%) and diseased (D’: ≥30%) groups are made, for which, in addition to cut-off value, support vector machine (SVM)-based classification models are tested. For group (C and D1), (C and D2), (C and D3), and (C and D), the maximum accuracy, using cut-off value-based classification model, is found to be in the range of 97.7% to 100%. Between group C’ and D’, the maximum accuracy, using cut-off value and SVM-based classification model, is found to be 75.7% and 84.4%, respectively. These results prove the potential of IR thermography as a CAS screening tool.
Ng obtained a B. Eng (CL I) from Uni. of Newcastle upon Tyne; Ph.D. at Cambridge Univ. with a Cambridge Commonwealth Scholarship; PG Diploma in Teaching Higher Edu., NIE-NTU. He is a Fellow of the American Society of Mechanical Engineers (FASME) and member for Academy of Pedagogy and Learning, USA. His expertise is in commercial and in-house developed software to perform numerical simulation in the biomedical engineering (BME), thermal-fluid and health-related diagnosis fields. He has been an editorial board member for 10 journals and reviewer for 30 journals. He was Editor-in-Chief for 2 ISI-journals which were captured by the JCR within 2-years of their inauguration. He is an expert research funding reviewer for many funding agencies worldwide. He has been recognized internationally for academic excellence. He received numerous best papers, service awards and has directly supervised 5 RFs, graduated 23 PhD and 26 Master students. He was awarded the SPRING-Singapore Merit Award for his work in thermal imagers to screen SARS fever as well as contributions to the Singapore Standardization Program. Being a co-inventor of 3 US patents on software classifiers to identify the different stages of breast cancer development in iTBra-system, he was accoladed with equity in a listed company. His ongoing work on non-contact screening for carotid artery stenosis and superficial vein-finder has resulted in 3 filing patents. He has notable citations in the field of infrared physics & technology in BME research.