International Conference on Photonics and Imaging in Biology and Medicine最新文献

{"title":"Sensitivities of reflectance to scattering variations in a diffusive medium","authors":"Xiaojuan Zhang, Y. Liu","doi":"10.1117/12.741351","DOIUrl":"https://doi.org/10.1117/12.741351","url":null,"abstract":"The sensitivity expression of spatial-resolved diffuse reflectance to scattering parameter is deduced in the P3 approximation model, and the influence of scattering parameter on the reflectance is analyzed using this expression. The results show that the sensitivity is distinct with that of the diffusion approximation in the region of about one transport mean free path, and optimum source-detector distance where the sensitivity to scattering parameter equals zero differs from the diffusion approximation's too.This optimum source-detector distance is found shortened when a medium has bigger scattering coefficient or bigger absorption coefficient. The research is very valuable for in vivo measurement based on the spatial-resolved diffuse reflectance.","PeriodicalId":110373,"journal":{"name":"International Conference on Photonics and Imaging in Biology and Medicine","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133609336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coherent backscattering diagnostics of tissue-like media and tissues","authors":"L. V. Kuznetsova, D. Zimnyakov","doi":"10.1117/12.741464","DOIUrl":"https://doi.org/10.1117/12.741464","url":null,"abstract":"The transport properties of highly scattering media including biotissues with expressed fibrillar structure are studied by measuring coherent backscattering. Fitting of the experimental data with the coated coherent potential approximation led to evaluation of the transport parameters without a-priori knowledge of the optical properties of scattering particles for strongly scattering dense media. The peculiarities of light diffusion in multiple scattering media characterized by macroscopic anisotropy of scattering properties (such as, the collagen-containing biological tissue with partially oriented fibrillar structure) are introduced. The experimentally obtained ratio of the reduced scattering coefficients in the directions of parallel and perpendicular to the fibers is equal to 0.37 which is in a good agreement with the same value obtained with laser videoreflectometry method.","PeriodicalId":110373,"journal":{"name":"International Conference on Photonics and Imaging in Biology and Medicine","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133691865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of temperature on optical properties of rat skin in vivo","authors":"Q. Ouyang, D. Zhu, Qihuan Luo, Hui Gong, Qingming Luo","doi":"10.1117/12.741499","DOIUrl":"https://doi.org/10.1117/12.741499","url":null,"abstract":"Local optical properties of tissue measurement system combined with a temperature control setup were used to investigate temperature-induced changes in optical properties of rat skin in vivo. The temperature of skin was maintained at 32°C, 35°C, 38°C and 41°C for more ten minutes, respectively. And the system composed a single wavelength (1310nm), multi-arrays optical probe with the separations of source-detector less than 1.25mm, was introduced to measure the reflectance of skin. The results showed that the reflectance at higher temperature was less than that at lower temperature. Further more, the optical properties were calculated. The higher temperature, the more both reduced scattering coefficient and absorption coefficient decreased. It means that temperature rise will induces a decrease in attenuation coefficient, and increase the penetrability of light. Research on temperature effect of skin may be helpful to optical clearing technique.","PeriodicalId":110373,"journal":{"name":"International Conference on Photonics and Imaging in Biology and Medicine","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132710434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Full-field optical coherence tomography by achromatic phase shifter with a rotating half-wave plate","authors":"Yaliang Yang, Z. Ding","doi":"10.1117/12.741363","DOIUrl":"https://doi.org/10.1117/12.741363","url":null,"abstract":"In optical coherence tomography (OCT), broad-bandwidth optical sources are required to achieve high axial resolution. Introducing a variable phase shift achromatically between the probe and reference beams is required for phase-shifting algorithms implemented to extract the coherence signal. We propose a full-field OCT using an achromatic phase shifter based on wave plates. The phase shifter that is almost independent of the wavelength over a range of 240 nm, can provide a phase shift of eight times the rotating angle of the half-wave plate. The system is based on a Michelson interferometer, illuminated by a white light source, and has several advantages compared with previous implementation of full-field OCT based an achromatic phase shifter. Numerical simulation on phase shift error and amplitude ratio between orthogonal polarization components at nominal phase shifts required for two typical phase-stepping algorithms is conducted. Approach for extracting OCT signal by the revised Carre algorithm is presented.","PeriodicalId":110373,"journal":{"name":"International Conference on Photonics and Imaging in Biology and Medicine","volume":"6534 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128883310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microscopic fluorescence spectral analysis of basal cell carcinomas","authors":"Qingli He, H. Lui, D. Zloty, B. Cowan, L. Warshawski, D. McLean, H. Zeng","doi":"10.1117/12.741593","DOIUrl":"https://doi.org/10.1117/12.741593","url":null,"abstract":"Background and Objectives. Laser-induced autofluorescence (LIAF) is a promising tool for cancer diagnosis. This method is based on the differences in autofluorescence spectra between normal and cancerous tissues, but the underlined mechanisms are not well understood. The objective of this research is to study the microscopic origins and intrinsic fluorescence properties of basal cell carcinoma (BCC) for better understanding of the mechanism of in vivo fluorescence detection and margin delineation of BCCs on skin patients. A home-made micro- spectrophotometer (MSP) system was used to image the fluorophore distribution and to measure the fluorescence spectra of various microscopic structures and regions on frozen tissue sections. Materials and Methods. BCC tissue samples were obtained from 14 patients undergoing surgical resections. After surgical removal, each tissue sample was immediately embedded in OCT medium and snap-frozen in liquid nitrogen. The frozen tissue block was then cut into 16-&mgr;m thickness sections using a cryostat microtome and placed on microscopic glass slides. The sections for fluorescence study were kept unstained and unfixed, and then analyzed by the MSP system. The adjacent tissue sections were H&E stained for histopathological examination and also served to help identify various microstructures on the adjacent unstained sections. The MSP system has all the functions of a conventional microscope, plus the ability of performing spectral analysis on selected micro-areas of a microscopic sample. For tissue fluorescence analysis, 442nm He-Cd laser light is used to illuminate and excite the unstained tissue sections. A 473-nm long pass filter was inserted behind the microscope objective to block the transmitted laser light while passing longer wavelength fluorescence signal. The fluorescence image of the sample can be viewed through the eyepieces and also recorded by a CCD camera. An optical fiber is mounted onto the image plane of the photograph port of the microscope to collect light from a specific micro area of the sample. The collected light is transmitted via the fiber to a disperserve type CCD spectrometer for spectral analysis. Results. The measurement results showed significant spectral differences between normal and cancerous tissues. For normal tissue regions, the spectral results agreed with our previous findings on autofluorescence of normal skin sections. For the cancerous regions, the epidermis showed very weak fluorescence signal, while the stratum corneum exhibited fluorescence emissions peaking at about 510 nm. In the dermis, the basal cell island and a band of surrounding areas showed very weak fluorescence signal, while distal dermis above and below the basal cell island showed greater fluorescence signal but with different spectral shapes. The very weak autofluorescence from the basal cell island and its surrounding area may be attributed to their degenerative properties that limited the production of coll","PeriodicalId":110373,"journal":{"name":"International Conference on Photonics and Imaging in Biology and Medicine","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114759390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurements of refractive index and near infrared absorbance of hemoglobin solutions incubated with glucose","authors":"O. Zhernovaya, V. Tuchin, I. Meglinski, L. Ritchie","doi":"10.1117/12.741455","DOIUrl":"https://doi.org/10.1117/12.741455","url":null,"abstract":"The purpose of this study is to investigate the effect of presence of glucose and glycation of hemoglobin on refractive index and absorbance of aqueous hemoglobin solutions with different glucose concentrations. It is shown that the changes of refractive index caused by glycation of hemoglobin may be observed using refractive index measurements.","PeriodicalId":110373,"journal":{"name":"International Conference on Photonics and Imaging in Biology and Medicine","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129709081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"1310nm high-power, broad-band superluminenscent laser diode for OCT application","authors":"Lisa T. Li, Xiangjun Zhao, Jingyi Wang, Jinyan Jin, Zhenghua Wu, Weiming Zhu, Wenchao Xu","doi":"10.1117/12.741096","DOIUrl":"https://doi.org/10.1117/12.741096","url":null,"abstract":"Super-luminescent laser diodes (SLD) in 800 to 1300 nm wavelength windows have been widely used in optical coherence tomography (OCT) systems. The imaging resolution of OCT systems is proportional to the bandwidth of the SLD light source. Here we present a new design to achieve broad bandwidth (>100nm at 1310nm) in one chip by using two types of quantum wells. The bandwidth of an SLD with a single active region is determined by the material bandwidth, confinement factor, and the length of the active region. Neglecting spatial hole burning (SHB), the spectral density of amplified spontaneous emission (ASE) can be the function of cavity length and spectral density of spontaneous emission and net gain. The main factor that limits the ASE bandwidth is the net gain. The bandwidth of net gain has to be larger than 200 nm to obtain a 100 nm wide ASE spectrum if the ASE power is larger than several mW. SLDs usually work at very high pump current (>400mA) to achieve high output power. From simulations, we found the level of electron injection mainly determines the material gain. At the high injection level, large bandgap quantum wells can get high gain and dominate the spectrum if the improper design is used. So in our design, we put the small bandgap quantum wells at the N side to make the electron distribution in favor of long-wavelength material. Thus, and will be balanced at high current injection level (>550mA). Figure 7 shows the measured spectrum of such structure. The achieved spectral width is larger than 100nm and out put power is larger than 5 mW.","PeriodicalId":110373,"journal":{"name":"International Conference on Photonics and Imaging in Biology and Medicine","volume":"6534 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129594517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on animal laser varicose treatment in CIOMP, CAS","authors":"Lai-ming Zhang, Dian-jun Li, Q. Lu, Guilong Yang, Jin Guo","doi":"10.1117/12.741105","DOIUrl":"https://doi.org/10.1117/12.741105","url":null,"abstract":"The work on laser varicose treatment carried out in CIOMP, CAS cooperating with The First Clinical Hospital, Jilin University is summarized. Dozens of animal experiments adopting dog and rabbit samples are made in a long time of several years. Different lasers are used, including long pulse frequency-doubled Nd:YAG(532nm) and semiconductor laser(808nm). Dozens of animal experiments show that laser has good efficacy to occlude the vein vessels. It has precise adjustability and relatively short treatment time only needing outpatient office setting with high cost and effect rate; It provides minimal invasion, often under local anesthesia and intravenous sedation thereby eliminating the need for general anesthesia, greatly shortens postoperative recovery term, and it is highly safe with no side effects and no serious complications.","PeriodicalId":110373,"journal":{"name":"International Conference on Photonics and Imaging in Biology and Medicine","volume":"59 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127383118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of density features surrounding mammographic abnormalities","authors":"Jiang Luan, E. Song, Meng Bo, Renchao Jin, Xiangyang Xu","doi":"10.1117/12.741326","DOIUrl":"https://doi.org/10.1117/12.741326","url":null,"abstract":"In clinic, surrounding density of breast abnormalities is an important cue for radiologists to distinguish between benign and malignant abnormalities on mammogram. It may also be an important feature to be used in computer-aided diagnosis (CAD) system. The purpose of our work is to analyze the density distribution surrounding benign or malignant mass. The cases used in this study are selected from the Digital Database for Screening Mammography (DDSM) provided by the University of South Florida. For each case, the mass boundaries marked by experienced radiologists are used and 30 3-pixel-wide bands, one outside another, surrounding each mass are considered. A few density features including the average gray level and the distribution skewness of the gray levels on every surrounding band were calculated. For every feature in each corresponding band, average values were calculated for 10 benign cases and 10 malignant cases, respectively. The preliminary analysis results show that the intensities surrounding benign masses tend to be higher than those surrounding malignant masses. They also show that the standard deviation of intensities surrounding benign masses tend to be larger than those surrounding malignant masses. Similar analysis was also carried out with mass boundaries automatically identified by computer and the results corroborate the analysis with mass boundaries marked by radiologists.","PeriodicalId":110373,"journal":{"name":"International Conference on Photonics and Imaging in Biology and Medicine","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127336750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of endogenous flurophores in the layered retina","authors":"Gaixia Xu, Danni Chen, Yiwen Sun, J. Qu, Zi-yang Lin, Z. Ding, H. Niu","doi":"10.1117/12.741574","DOIUrl":"https://doi.org/10.1117/12.741574","url":null,"abstract":"In this paper, we measured and analyzed the characteristic of endogenous fluorophores in porcine layered retina by using advanced fluorescence spectroscopy and microscopy imaging technology. It was found that there were obvious contrasts corresponding to the different layers of retina, which may be important for fundus disease diagnosis. The retinal pigment epithelium cells exhibited strong autofluorescence with as emission peak of 600±10nm when excited with 860-nm light. The emission peak of photoreceptors was at 652±5nm, and the emission peak of retinal vessels layer was weak and at 640~700nm, when excited with 488-nm light. Autofluorescence images of three layers of retina were obtained using the same setup. We concluded that the main endogenous fluorophore in PRE was lipofuscin and that in retinal vessels was porphyrin. What's more, the FMHW (full width at half. maximum) of retinal fluorescence spectrum was broad, which suggested that there wasn't only one endogenous fluorophores of tissues excited.","PeriodicalId":110373,"journal":{"name":"International Conference on Photonics and Imaging in Biology and Medicine","volume":"6534 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130902371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}