| Raman scattering originates from the inelastic collisions between molecules and incident photons while producing energy exchange.Raman spectroscopy contains abundant information about molecular vibration and can be used as a"fingerprint"spectrum for molecular recognition.Raman spectroscopy is considered to be one of the most promising techniques for non-invasive detection of human blood glucose because of its advantages such as clear and sharp peaks,poor overlap and weak Raman signals of water.However,conventional laboratory Raman systems,with large size,cumbersome nature,high cost and poor accuracy,are limited in clinical application.In this thesis,a miniature wearable Raman spectroscopy system which successfully achieved noninvasive detection of human blood glucose level was developed.A novel method of spectrum collection was proposed.A thallium-doped grin lens was employed as the collection lens.A specially designed wearable fiber optic probe was employed to achieve the stable and convenient collection of Raman spectrum.In addition,a novel method of quantitative analysis of Raman spectrum was proposed.In this method,the peak area was used as the main reference factor while the peak intensity as the auxiliary reference factors to calculate the target concentration.A non-linearized multivariate dominant factor-based partial least squares(PLS)model was employed for different samples to predict the glucose level.Glucose solution,11 rats,and 10 healthy human were studied as subjects.The mean R~2 values were 98.1%,89.3%,and 86.3%for glucose solution,rats,and human subjects respectively.The system has the advantages of more compact structure,lower cost,better testing stability and convenient for human body to wear.The testing results demonstrate that miniature wearable Raman spectroscopy system is feasible and repeatable to achieve the noninvasive detection of human blood glucose accurately and has important clinical application value in disease diagnosis. |
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