For a favorable treatment result, early diagnosis of pathological cancerous micro-areas with their subsequent removal is highly important and can be achieved by the development of new modeling techniques and conducting relevant experiments. Various models of the bladder can be developed and applied to provide a platform for studying, processing and improving the signals received from various video systems. Here, in order to study visualization properties at fluorescence endoscopy, 3D optical phantoms of urinary bladder have been developed. The phantoms simulated optical properties of the bladder wall, including localized areas that represent tumor tissues and contained PpIX photosensitizer at various concentrations for fluorescence "diagnostics". To perform bimodal fluorescence imaging, a two-channel video fluorescence system was used. First, intraoperative images of the bladder wall were obtained in a patient with bladder cancer. A video system was used to reveal and image pathological areas with increased fluorescence intensity. Fluorescence indices in tumor tissue were recorded and corresponded to different concentrations of PpIX photosensitizer. Then, a bimodal fluorescence imaging was performed on 3D phantoms. The obtained images and fluorescence intensity measurements showed the ability of the video fluorescence system to register bladder wall structures and accumulated in them photosensitizers in concentrations from 0.25 to 20 mg/kg. The developed models can serve as a useful instrument for test measurements for constructing multimodal mosaic panoramic images of the bladder surface. This will help to advance in solving problems of endoscopic image processing using bimodal imaging, which uses diagnostic (fluorescence) and color channels.
The new approach to intraoperative navigation during glial brain tumors removal is presented. A combined method is proposed for simultaneous spectroscopic and video fluorescence analysis of the state of tissues in the destruction zone using the applied part performed in the form of a neurosurgical aspirator cannula. In the walls of the applied part there are tubular channels into which lighting and receiving optical fibers are integrated. At the end of the cannula, the channels for optical fibers are arranged so as to perform spectroscopic analysis in contact with the surface of the biological tissue, as well as video fluorescence analysis at the working distance to the surface of the tissue. The joint use of fiber-optic systems for recording the video stream and spectral dependences allows real-time assessment of the degree of pathological tissue changes in the field of view of the video system, which are also located in the aspiration zone, with the simultaneous quantification of diagnostically significant spectroscopic criteria. System testing was carried out on samples of human intracranial tumors obtained during neurosurgical operations. During the removal of a tumor from different sites (tumor center, perifocal area), the degree of in vivo fluorescence signal from the tumor site was determined intraoperatively using a Zeiss Opmi Pentero intraoperative microscope in Blue 400 mode. From the selected area of the tumor, biopsy material was taken (presumably homogeneous in its properties) with subsequent measurement of spectra and combined images using the developed device. A high correlation was shown between the level of the fluorescence signal recorded spectroscopically and the brightness of the fluorescence image in the endoscopic channel of the device. The level of the fluorescent signal showed a high correlation with the degree of malignancy of tissues according to the results of pathomorphological examination.
A 5-ALA-induced fluorescence-based imaging device for guidance during surgery of malignant and non-malignant preliminary photosensitized tumors is presented. The setup fits existing clinical optical rigid and flexible endoscopes and operation microscopes. It consists of three light sources including white light, red light fluorescence excitation and blue light fluorescence excitation sources. The light from any combination of the latter sources is delivered to tissue using specially designed fiber optic light guide. Two cameras are used to acquire fluorescence and back reflected white light images: a gray-level camera for fluorescence in the far red range and a color camera for white light images. A dichroic mirror is implemented to spectrally split the light coming from tissue. Images from both cameras are processed into a computer with specially developed software where it can be displayed in different modes including overlaying or been used for image mosaicing which allows for increasing the intrinsic reduced field of view of endoscopes by providing highly resolved extended cartography. Experiments were carried out on phantoms and on patients in clinical conditions during surgery of brain and other tissues. Blue light excitation was more sensitive for thin tumors but red light excitation was more beneficial for solid tumors and for navigation in presence of slight bleeding.
Background: In excess of 60% of all cancers are detected in low and middle-income countries, with breast cancer (BC) the dominant malignancy for women. Incidence rates continue to climb, most noticeably in the less than 50-year-old population. Expansion of mammography infrastructure and resources is lacking, resulting in over 60% of women diagnosed with stage III/IV BC in the majority of these countries. Optical Breast Spectroscopy (OBS) was shown to correlate well with mammographic breast density (MBD). OBS could aid breast screening programs in low- and middle-income countries by lowering the number of mammographs required for complete population coverage. However, its performance needs to be tested in large population trails to ensure high sensitivity and acceptable specificity. Methods: For the planned studies in low- and middle-income countries in different continents, online methods need to be implemented to monitor the performance and data collection by these devices, operated by trained nurses. Based on existing datasets, procedures were developed to validate an individual woman's data integrity and to identify operator errors versus system malfunctions. Results: Using a dataset comprising spectra from 360 women collected by 2 instruments in different locations and with 3 different trained operators, automated methods were developed to identify 100% of the source or photodetector malfunctions as well as incorrect calibrations and 96% of instances of insufficient tissue contact. Conclusions: Implementing the dataset validation locally in each instrument and tethered to a cloud database will allow the planned clinical trials to proceed.
A new method for spectral data formalization was developed. Spectral coordinates allows extracting specific properties of spectral components in order to convert physical experimental data into diagnostic data. Also visualization method is presented which allows placing spectral coordinates as a point onto orthogonal coordinates in order to perform statistical data accumulation, data clustering, and making following diagnostic assumptions. As experimental test data spectra collected in-vivo in patients were used.
Development of minimal invasive diagnostics methods is of great importance in today's healthcare. The present work deals with the measurements of glucose concentration in small drops, its volume being in the range of 1 (mu) L and its glucose concentration being in the range of 1-10 mM. The aim of the work was to develop robust quantitative method of glucose measurement in small volumes of interstitial fluid obtained after laser shot or by other low invasive procedures. The commercially available Amlex Red glucose assay kit was used in the present work. The glucose is detected by enzyme-coupling reactions resulting in formation of fluorescence dye resorufin. The diagnostic paper was used as a reaction medium. The fluorescence of dye in diagnostic paper was measured with the use of fiber optics spectrometer. It was shown that dye fluorescence correlates fairly well with glucose concentration. The method may be modified to involve cholesterol concentration measurement as well.
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