1.A Combined Optical Positioning Method Based on 1-D and 2-D Cameras.
Journal of Biomedical Engineering 2015;32(6):1310-1316
Optical positioning system has a wide range of application in many fields. This paper presents an optical positioning method which combines linear and plane cameras. 1-D image signal of linear camera is used to get 1-D coordinates of the targets, which can be processed quickly. We can use it to assist processing the 2-D image signals of plane camera under some constraints. Linear camera can reduce the amount of position searching and calculation in coordinates extracting of targets in 2D image, and it can also help identify multiple targets. The results showed that our method could reach an accuracy of 1.608 mm, which was about one thousandth of the measurable range, and the reconstruction time for 4 targets without geometric constraints is 23.87 ms, namely 41.9 fps.
Equipment Design
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Imaging, Three-Dimensional
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instrumentation
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Optical Devices
2.Long-term Fiber Photometry for Neuroscience Studies.
Yi LI ; Zhixiang LIU ; Qingchun GUO ; Minmin LUO
Neuroscience Bulletin 2019;35(3):425-433
Fiber photometry is a sensitive and easy way to detect changes in fluorescent signals. The combination of fiber photometry with various fluorescent biomarkers has substantially advanced neuroscience research over the last decade. Despite the wide use of fiber photometry in biomedical fields, the lack of a detailed and comprehensive protocol has limited progress and sometimes complicated the interpretation of data. Here, we describe detailed procedures of fiber photometry for the long-term monitoring of neuronal activity in freely-behaving animals, including surgery, apparatus setup, data collection, and analysis.
Animals
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Brain
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metabolism
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Calcium Signaling
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Female
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Male
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Mice
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Neurons
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metabolism
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Neurosurgical Procedures
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Optical Fibers
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Optical Imaging
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instrumentation
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methods
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Photometry
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instrumentation
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methods
4.Evaluation of neointimal proliferation in stented canine coronary artery with optical coherence tomography.
Jin-da WANG ; Jun GUO ; Feng TIAN ; Ting-shu YANG ; Yun-dai CHEN
Journal of Southern Medical University 2011;31(11):1855-1857
OBJECTIVETo evaluate the accuracy of optical coherence tomography (OCT) in evaluating neointimal proliferation in canine coronary artery following stenting.
METHODSIn 15 domestic dogs, a single bare-metal stent was implanted in the anterior descending or the circumflex branch of the left coronary artery. Ninety days after stenting, the dogs underwent coronary angiography and OCT, followed by quantitative histological assessment of neointimal proliferation in the target arterial segments. The parameters of OCT and the histological findings were analyzed comparatively.
RESULTSA total of 15 OCT-histology matched frames acquired at the point with the most severe stenosis in every stent, and 60 pathological sections from all the stents were analyzed. The difference of the stent area assessed by OCT was comparable to that defined histologically (5.01∓0.79 mm(2) vs 4.99∓0.81 mm(2), P>0.05). Neointimal thickness and area were smaller with OCT assessment than with histological assessment (0.19∓0.08 mm vs 0.22∓0.10 mm, and 1.52∓0.49 mm(2) vs 1.85∓0.78 mm(2), respectively, P<0.05). The lumen area was larger by OCT assessment than by histological assessment (3.50∓0.66 mm(2) vs 3.15 ∓ 0.43 mm(2), P<0.05). Close correlations were found between OCT and histological evaluations of the neointimal thickness (R(2)=0.5280.767), neointimal area (R(2)=0.5280.537) and stent area (R(2)=0.528), but the correlation was poor for lumen area (R(2)=0.5280.307). All the stents showed full endothelialization without thrombus or aneurysm in the stents.
CONCLUSIONOCT allows precise and reproducible assessment of neointimal proliferation in the coronary artery following stenting, but for measurement of the lumen area, OCT shows a poor correlation to histological evaluation.
Angioplasty, Balloon ; adverse effects ; instrumentation ; Animals ; Coronary Angiography ; Coronary Vessels ; diagnostic imaging ; pathology ; Dogs ; Male ; Models, Animal ; Neointima ; pathology ; Stents ; adverse effects ; Tomography, Optical Coherence ; Tunica Intima ; pathology
5.Real-time in situ three-dimensional integral videography and surgical navigation using augmented reality: a pilot study.
Hideyuki SUENAGA ; Huy Hoang TRAN ; Hongen LIAO ; Ken MASAMUNE ; Takeyoshi DOHI ; Kazuto HOSHI ; Yoshiyuki MORI ; Tsuyoshi TAKATO
International Journal of Oral Science 2013;5(2):98-102
To evaluate the feasibility and accuracy of a three-dimensional augmented reality system incorporating integral videography for imaging oral and maxillofacial regions, based on preoperative computed tomography data. Three-dimensional surface models of the jawbones, based on the computed tomography data, were used to create the integral videography images of a subject's maxillofacial area. The three-dimensional augmented reality system (integral videography display, computed tomography, a position tracker and a computer) was used to generate a three-dimensional overlay that was projected on the surgical site via a half-silvered mirror. Thereafter, a feasibility study was performed on a volunteer. The accuracy of this system was verified on a solid model while simulating bone resection. Positional registration was attained by identifying and tracking the patient/surgical instrument's position. Thus, integral videography images of jawbones, teeth and the surgical tool were superimposed in the correct position. Stereoscopic images viewed from various angles were accurately displayed. Change in the viewing angle did not negatively affect the surgeon's ability to simultaneously observe the three-dimensional images and the patient, without special glasses. The difference in three-dimensional position of each measuring point on the solid model and augmented reality navigation was almost negligible (<1 mm); this indicates that the system was highly accurate. This augmented reality system was highly accurate and effective for surgical navigation and for overlaying a three-dimensional computed tomography image on a patient's surgical area, enabling the surgeon to understand the positional relationship between the preoperative image and the actual surgical site, with the naked eye.
Calibration
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Data Display
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Feasibility Studies
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Humans
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Image Processing, Computer-Assisted
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instrumentation
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methods
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Imaging, Three-Dimensional
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methods
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Mandible
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anatomy & histology
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Maxilla
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anatomy & histology
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Models, Anatomic
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Optical Devices
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Oral Surgical Procedures
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instrumentation
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methods
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Pilot Projects
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Stereotaxic Techniques
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instrumentation
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Surgery, Computer-Assisted
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instrumentation
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methods
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Tomography, X-Ray Computed
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methods
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Tooth
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anatomy & histology
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User-Computer Interface
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Video Recording
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instrumentation
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methods
6.Enhancement of image used in optical imaging of intrinsic signal.
Journal of Biomedical Engineering 2012;29(1):137-142
Optical imaging of intrinsic signals is a secondary image of the cerebral cortex. The weak optical signal is decided by anatomical structure of brain. The spatial filter is a powerful technology for de-noising and image enhancement. We used different linear and nonlinear filters to deal with optical imaging. Furthermore, we compared the degree of noise suppression and discussed the image details. Our result showed that nonlinear median filter can keep more image details with effective noise reduction. It is useful for image enhancement of optical imaging.
Animals
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Artifacts
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Blood Vessels
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anatomy & histology
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Cats
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Cerebral Cortex
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anatomy & histology
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physiology
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Cerebrovascular Circulation
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physiology
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Female
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Image Enhancement
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methods
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Image Processing, Computer-Assisted
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instrumentation
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methods
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Male
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Optical Imaging
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methods
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Photic Stimulation
7.Performance of a low cost magnifying device, magnivisualizer, versus colposcope for detection of pre-cancer and cancerous lesions of uterine cervix.
Veena SINGH ; Aditya PARASHARI ; Sanjay GUPTA ; Pushpa SODHANI ; Ashok SEHGAL
Journal of Gynecologic Oncology 2014;25(4):282-286
OBJECTIVE: To assess the performance of a low cost magnifying device (Magnivisualizer) compared to a standard optical colposcope for detection of precancerous and cancerous lesions of the uterine cervix. METHODS: A total of 659 consecutive symptomatic women attending a gynecologic outpatient clinic underwent unaided visual inspection followed by cytology, visual inspection of the cervix using 5% acetic acid (VIA), and VIA under magnification (VIAM) with the Magnivisualizer. All women, independently of test results, were referred for colposcopic examination. Colposcopic-directed biopsies were obtained from all positive lesions and compared to positive VIAM cases. RESULTS: The detection rate for VIA positive lesions was 12% (134/659), while it was 29% for VIAM positive lesions (191/659). The sensitivities of detection of cervical intraepithelial neoplasia (CIN) 2 and higher lesions were 61.7% for VIA, 88.3% for VIAM, and 86.7% for colposcopy, with a specificity of 58.5% for VIA, 55.8% for VIAM, and 90.4% for colposcopy. The performance of colposcopy and VIAM was moderate (kappa, 0.48; 95% confidence interval [CI], 0.41 to 0.54) for detection of CIN 1 and higher lesions and excellent (kappa, 0.87; 95% CI, 0.82 to 0.94) for detection of CIN 2 and higher lesions. CONCLUSION: In low resource settings, where colposcopic facilities are not available at the community level, a simple low-cost, handheld Magnivisualizer can be considered a valid option for detection of cervical precancerous and cancerous lesions. However, it cannot replace traditional colposcopy because it has a low specificity that results in many unnecessary biopsies.
Acetic Acid/diagnostic use
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Adult
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Aged
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Biopsy/methods
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*Colposcopes
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Colposcopy
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Early Detection of Cancer/*instrumentation/methods
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Equipment Design
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Female
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Humans
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Middle Aged
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Neoplasm Grading
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Optical Imaging/*instrumentation/methods
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Outpatient Clinics, Hospital
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Reproducibility of Results
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Uterine Cervical Dysplasia/*diagnosis/pathology
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Uterine Cervical Neoplasms/*diagnosis/pathology