Volume 2 Issue 1
Authors: E. Dermatas; M. Vlachos
Abstract: In this paper a method for finger vein pattern extraction from infrared images of human finger is proposed. The finger vein pattern is extracted by the execution of a two step region growing procedure, based on statistical properties of derivatives of the acquired infrared images. Initially, original image is filtered by four different Gaussian kernels (in order to take into account the different orientations of veins). Afterwards, the second partial derivatives of the obtained images are computed. Sequentially, the Hessian matrix of these images is constructed and its eigenvalues are computed in a pixel by pixel basis. The minimum eigenvalue and the absolute value of its gradient comprise the two characteristics (features) used in the two step region growing procedure which follows. The region growing procedure is restricted by statistical attributes such as the mean value and the standard deviation of the segmented regions (vein and tissue) and the mean value and the standard deviation of the gradient of the minimum eigenvalue image. Due to the occurrence of some misclassifications a final post processing step, based on morphological operations, is performed. The developed method achieves to efficiently segment the image despite of intensity variations which are evident in the original image. Moreover, an improved version of the proposed method, which uses the multidirectional response of a specially designed matched filter and its gradient as the two features used in the two stage region growing procedure, is also presented. The modified version, as experimental results show, outperforms the classic version and leads to more robust finger vein pattern extraction.
Keywords: Vein Pattern; Region Growing; Hessian Matrix; Eigenvalue; Gradient; Matched Filter; Morphological Postprocessing
Authors: Tsu-Wei Nee; Arthur Chiou; De-Ming Yang; Soe-Mie F. Nee; Stewart H. Wu
Abstract: Polarimetric imaging of Stokes vector (I, Q, U, V) can provide independent signatures of polarization and depolarization of biological tissues and cells. Using a Stokes digital imaging system, we measured the Stokes vector images of tissue samples from sections of rat livers. The derived Mueller matrix elements can quantitatively provide five-signature (m01, m11, m22, m23 and m33) imaging data for the bio-sample. The images of four independent optical properties: linear-dichroic polarization, depolarization, cross-polarized depolarization and phase retardation of the test sample are then derived. The probability distribution for these parameters can also be obtained from the imaging data. Based upon the anisotropic orientation distribution of ellipsoid model bio-molecules, five matrix elements, m01, m11, m22, m23 and m33 were simulated to obtain the estimated optical properties to compare with those measured properties of the sample. This polarimetric multi-signature optical technology is a new option of biosensing technology to inspect the structures of tissue samples and is useful for critical disease discrimination and medical diagnostics applications.
Keywords: Polarimetric Mueller Matrix Imaging; Bio-Medical Tissues; Anisotropic and Photon-Scattering Signatures
Authors: Fangnian Lang; Guiqun Cao; Changtao He
Abstract: The fusion of multimodal brain images for a given clinical application is importance. Generally speaking, a PET image indicates brain function and has low spatial resolution, while an MRI image shows brain tissue anatomy and contains no functional information. Hence, a perfect fused image should contain both functional information and spatial characteristics with no spatial and color distortions. The intensity-hue-saturation (IHS) transform and retina-inspired model (RIM) fusion technique can preserve more spatial feature and more spectral information content, respectively. Moreover, principal component analysis (PCA) algorithm can extract main feature to minimize redundancy. The proposed algorithm integrates their advantages to improve fused image quality. The experiment demonstrates that the proposed algorithm outperforms conventional fusion methods such as PCA, Brovey, RIM, discrete wavelet transform (DWT) in light of visual effect and quantitative evaluation.
Keywords: SF; PCA; RIM Model; IHS Transformation; Image Fusion
Authors: Priti Kumar Roy; Amar Nath Chatterjee; Sutapa Biswas Majee
Abstract: Alteration in host-virus interaction dynamics during long-term infection by HIV necessitates consideration of inverse relationship between high viral load and density of CTL response leading to dysregulation of host immunity system. Mathematical modeling introducing negative feedback control mechanism helps in establishment of threshold condition for disease eradication as well as necessary conditions for existence of different equilibria depending on values of basic reproduction ratio. Moreover, IL-2 adjuvenated HAART therapy has been found to be highly cost-effective in recovery of the immunity status in the present mathematical model using negative feedback effect.
Keywords: HIV, CD4+T Cells, CTL, Negative Feed Back Control, HAART, IL-2
Authors: Bo-Han Wei; Chi-Wen Chu; Chia-Hung Huang; Shyh-Jiun Liu; Hao-Yu Chu
Abstract: Silver and copper are commonly used as antibacterial elements in most of biomedical apparatus. Because silver (Ag) is relatively expensive and has some tissue-toxicity as the concentration of ionized silver reaches a critical value, it is necessary to find an alternative element for treating some kinds of bacterial or fungal infection. Copper-based antibacterial material can be a good candidate because of its lower cost, better antifungal ability, and higher chemical stability than those of silver. A series of ZrCuNiAl thin films are coated on 304 stainless steel by a DC sputtering method with different sputtering power. The amorphous feature of these ZrCuNiAl thin films is confirmed by glancing incident x-ray diffraction (GIXRD). The porosity and surface roughness are observed by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM), respectively. The adhesion capability and hardness of these amorphous thin films are conducted by scratch test and nano indentation, respectively. In addition, the organisms such as Staphylococcus aureus , Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii and Candida albicans are used in this study to evaluate the antimicrobial effects for ZrCuNiAl thin films which coating on 304 stainless steel substrate
Keywords: Biomedical, Antibacterial Material, Amorphous Material, Microstructure, Thin Films, Physical Vapor Deposition (PVD)
Authors: David Brenner; Guy Garty; Helen C. Turner; Yanping Xu
Abstract: We have developed a Quantitative Light Absorption Analysis (QLAA) method to rapidly estimate human lymphocyte concentrations isolated from small volumes of whole blood. Measurements of the light absorption analysis were calibrated for lymphocyte concentration levels using a hemocytometer. To validate the QLAA system, blood samples were collected from 17 healthy donors and lymphocyte absorption measurements were directly compared with the manual microscope counting. The results showed that lymphocyte measurements obtained using the QLAA system were comparable with the manually scored lymphocyte counts but with measurements taken in seconds.
Keywords: QLAA; lymphocyte; radiation RABiT