排序方式: 共有45条查询结果,搜索用时 46 毫秒
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Kaicheng Liang Giovanni Traverso Hsiang-Chieh Lee Osman Oguz Ahsen Zhao Wang Benjamin Potsaid Michael Giacomelli Vijaysekhar Jayaraman Ross Barman Alex Cable Hiroshi Mashimo Robert Langer James G. Fujimoto 《Biomedical optics express》2015,6(4):1146-1163
Depth resolved and en face OCT visualization in vivo may have important clinical applications in endoscopy. We demonstrate a high speed, two-dimensional (2D) distal scanning capsule with a micromotor for fast rotary scanning and a pneumatic actuator for precision longitudinal scanning. Longitudinal position measurement and image registration were performed by optical tracking of the pneumatic scanner. The 2D scanning device enables high resolution imaging over a small field of view and is suitable for OCT as well as other scanning microscopies. Large field of view imaging for screening or surveillance applications can also be achieved by proximally pulling back or advancing the capsule while scanning the distal high-speed micromotor. Circumferential en face OCT was demonstrated in living swine at 250 Hz frame rate and 1 MHz A-scan rate using a MEMS tunable VCSEL light source at 1300 nm. Cross-sectional and en face OCT views of the upper and lower gastrointestinal tract were generated with precision distal pneumatic longitudinal actuation as well as proximal manual longitudinal actuation. These devices could enable clinical studies either as an adjunct to endoscopy, attached to an endoscope, or as a swallowed tethered capsule for non-endoscopic imaging without sedation. The combination of ultrahigh speed imaging and distal scanning capsule technology could enable both screening and surveillance applications.OCIS codes: (170.4500) Optical coherence tomography, (170.3880) Medical and biological imaging, (170.2150) Endoscopic imaging, (170.2680) Gastrointestinal 相似文献
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J D Osmond H P Pendergrass M S Potsaid 《The American journal of roentgenology, radium therapy, and nuclear medicine》1975,125(4):972-977
A technetium 99m diphosphonate scan is a sensitive detector of bony metastases of breast, prostate, and lung cancer. For these particular neoplasms, a negative bone scan in an asymptomatic patient is adequate evidence for absence of bony metastases and a correlative roentgenographic examination may not be necessary. Positive studies demonstrating multiple characteristic discrete areas of increased activity should be considered strong evidence for metastases. Single equivocal lesions require roentgenographic and occasionally biopsy correlation. If roentgenography fails to reveal the source of increased uptake, (e.g., degenerative disease) the scan lesion should remain suspicious for metastases. 相似文献
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Tsung-Han Tsai Benjamin Potsaid Yuankai K. Tao Vijaysekhar Jayaraman James Jiang Peter J. S. Heim Martin F. Kraus Chao Zhou Joachim Hornegger Hiroshi Mashimo Alex E. Cable James G. Fujimoto 《Biomedical optics express》2013,4(7):1119-1132
We developed a micromotor based miniature catheter with an outer diameter of 3.2 mm for ultrahigh speed endoscopic swept source optical coherence tomography (OCT) using a vertical cavity surface-emitting laser (VCSEL) at a 1 MHz axial scan rate. The micromotor can rotate a micro-prism at several hundred frames per second with less than 5 V drive voltage to provide fast and stable scanning, which is not sensitive to the bending of the catheter. The side-viewing probe can be pulled back to acquire a three-dimensional (3D) data set covering a large area on the specimen. The VCSEL provides a high axial scan rate to support dense sampling under high frame rate operation. Using a high speed data acquisition system, in vivo 3D-OCT imaging in the rabbit GI tract and ex vivo imaging of a human colon specimen with 8 μm axial resolution, 8 μm lateral resolution and 1.2 mm depth range in tissue at a frame rate of 400 fps was demonstrated.OCIS codes: (170.4500) Optical coherence tomography, (170.3880) Medical and biological imaging, (170.2150) Endoscopic imaging, (170.2680) Gastrointestinal, (140.3600) Three-dimensional image acquisition, (110.2350) Fiber optics imaging, (120.5800) Scanners, (120.3890) Medical optics instrumentation 相似文献
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Tsai TH Potsaid B Kraus MF Zhou C Tao YK Hornegger J Fujimoto JG 《Biomedical optics express》2011,2(8):2438-2448
We developed a piezoelectric-transducer- (PZT) based miniature catheter with an outer diameter of 3.5 mm for ultrahigh-speed endoscopic optical coherence tomography (OCT). A miniaturized PZT bender actuates a fiber and the beam is scanned through a GRIN lens and micro-prism to provide high-speed, side-viewing capability. The probe optics can be pulled back over a long distance to acquire three-dimensional (3D) data sets covering a large area. Imaging is performed with 11 μm axial resolution in air (8 μm in tissue) and 20 μm transverse resolution, at 960 frames per second with a Fourier domain mode-locked laser operating at 480 kHz axial scan rate. Using a high-speed data acquisition system, endoscopic OCT imaging of the rabbit esophagus and colon in vivo and human colon specimens ex vivo is demonstrated. 相似文献
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