超声内镜联合CT门静脉成像技术对肝硬化GOV程度及疗效的评价

本研究探讨了超声内镜联合CT门静脉成像技术对肝硬化食管胃静脉曲张(GOV)程度及治疗效果的评价价值。选取72例肝硬化GOV患者为研究对象,根据食管静脉曲张套扎术(EVL)治疗效果分为良好组与不良组。结果发现,不良组总横断面表面积、胃左静脉、门静脉、脾静脉、肠系膜上静脉直径及门静脉长度均大于良好组,曲张静脉壁厚度小于良好组(P<0.05);总横断面表面积、胃左静脉、门静脉、脾静脉、肠系膜上静脉直径及门静脉长度与肝功能Child-Pugh分级、静脉曲张程度呈正相关,曲张静脉壁厚度与肝功能Child-Pugh分级、静脉曲张程度呈负相关(P<0.05);总横断面表面积、曲张静脉壁厚度/胃左静脉、门静脉、脾静脉、肠系膜上静脉直径及门静脉长度均为肝硬化GOV患者治疗效果的影响因素(P<0.05);超声内镜、CT门静脉成像参数联合预测肝硬化GOV患者治疗效果的AUC为0.857。可见,超声内镜、CT门静脉成像参数与肝硬化GOV程度、肝功能分级及EVL治疗效果密切相关,可为临床预测EVL治疗效果提供一定参考。     

基于拉锥结构的全光纤型内窥OCT探针研究

本文报道了一种基于拉锥结构的全光纤型内窥光学相干层析成像探针. 基于大纤芯多模光纤的低光束发散特性, 使用大纤芯多模光纤代替透镜作为成像元件, 并在单模光纤与大纤芯多模光纤之间引入过渡拉锥段以减少插入损耗. 首先利用光学仿真软件(Rsoft)确定探针的最佳结构, 然后通过拉锥、切割以及熔接工艺实现探针制作, 并对探针的出射光束特性与插入损耗进行测量, 最后将该探针与扫频光学相干层析成像主系统联机, 对人体指尖皮肤及鸡气管壁组织进行成像. 该探针直径为250 μm, 不锈钢保护管外径为325 μm, 硬端长度1 cm, 插入损耗约为0.3 dB, 空气中有效成像范围达800 μm. 该探针为内窥光学相干层析成像技术在心血管疾病的应用提供了高紧凑度、高传输效率与高灵活性的选择.     

In Vivo Endoscopic Tissue Identification by Rapid Evaporative Ionization Mass Spectrometry (REIMS)

Gastrointestinal cancers are a leading cause of mortality, accounting for 23 % of cancer‐related deaths worldwide. In order to improve outcomes from these cancers, novel tissue characterization methods are needed to facilitate accurate diagnosis. Rapid evaporative ionization mass spectrometry (REIMS) is a technique developed for the in vivo classification of human tissue through mass spectrometric analysis of aerosols released during electrosurgical dissection. This ionization technique was further developed by utilizing surface induced dissociation and was integrated with an endoscopic polypectomy snare to allow in vivo analysis of the gastrointestinal tract. We tested the classification performance of this novel endoscopic REIMS method in vivo. It was shown to be capable of differentiating between healthy layers of the intestinal wall, cancer, and adenomatous polyps based on the REIMS fingerprint of each tissue type in vivo.     

Pitfalls and problems in flexible fiberoptic videolaryngoscopy

The flexible fiberoptic laryngoscope is a valuable tool in the examination of laryngeal and supraglottic structure and function. Nevertheless, persistent questions remain about the validity of the perceived image, and a variety of concerns arise relative to the equipment used, the difficult to examine patient, and the difficulty in obtaining measurable objective data. All of these areas are discussed. Distortions of the video image that result from the wideangle lens effect are described. Given an awareness of the distortions that may be present in the fiberoptic video image, it is clear that it is necessary to exercise caution in making judgments of anatomic or physiologic integrity based on fiberoptic information alone.     

光声内窥镜系统在人体直肠癌离体组织中的实验研究

研制了基于4阵列传感器的光声内窥镜探头,并基于此搭建了光声内窥镜成像系统,开展了仿体实验成像研究,通过内窥镜探头4个阵元位置激光吸收强度的变化情况来分析仿体中吸收体的位置,论证了其定位能力,利用光声内窥镜系统对人体离体的正常组织、直肠癌早期组织进行成像研究;通过对不同阵元位置的光吸收强度分布进行统计分析,证明了光声内窥镜对早期直肠癌组织和正常组织的辨别能力,此项技术有望提高直肠癌早期诊断的准确率,具有潜在的临床应用前景。     

高清医用电子内窥镜微型CMOS摄像模组

研发并报道一个全新的130万像素电子内窥镜微型摄像模组.该模组采用低压差分信号技术实现图像数据的长距离高保真传输,它包括一个1/5.5英寸、分辨率为1 280×1 024像素的CMOS图像传感器,一个视场角为140°的小型镜头以及2个电路板.小型镜头座直接粘合到图像传感器的非光学窗口部分,两块印刷电路板垂直装配,使模组的尺寸缩小到长宽高分别为15.0 mm、5.5 mm、5.2 mm的空间.编码芯片将并行数字信号编码成低压差分信号经双绞线传出模组.搭建了实验系统并对摄像模组的实践性能进行评价.实验表明:模组分辨率达到136 lp·mm-1,图像传输距离达到2 m以上.紧凑的结构、高清分辨率图像、大视场和长传输距离使其适用于内窥镜诊治,特别是高清胃镜和结肠镜.     

Biomedical Applications of Translational Optical Imaging: From Molecules to Humans

Light is a powerful investigational tool in biomedicine, at all levels of structural organization. Its multitude of features (intensity, wavelength, polarization, interference, coherence, timing, non-linear absorption, and even interactions with itself) able to create contrast, and thus images that detail the makeup and functioning of the living state can and should be combined for maximum effect, especially if one seeks simultaneously high spatiotemporal resolution and discrimination ability within a living organism. The resulting high relevance should be directed towards a better understanding, detection of abnormalities, and ultimately cogent, precise, and effective intervention. The new optical methods and their combinations needed to address modern surgery in the operating room of the future, and major diseases such as cancer and neurodegeneration are reviewed here, with emphasis on our own work and highlighting selected applications focusing on quantitation, early detection, treatment assessment, and clinical relevance, and more generally matching the quality of the optical detection approach to the complexity of the disease. This should provide guidance for future advanced theranostics, emphasizing a tighter coupling—spatially and temporally—between detection, diagnosis, and treatment, in the hope that technologic sophistication such as that of a Mars rover can be translationally deployed in the clinic, for saving and improving lives.     

Frequency-domain fluorescence lifetime imaging for endoscopic clinical cancer photodetection: Apparatus design and preliminary results

We describe a new fluorescence imaging device for clinical cancer photodetection in hollow organs in which the tumor/normal tissue contrast is derived from the fluorescence lifetime of endogenous or exogenous fluorochromes. This fluorescence lifetime contrast gives information about the physicochemical properties of the environment which are different between normal and certain diseased tissues. The excitation light from a CW laser is modulated in amplitude at a radio frequency by an electrooptical modulator and delivered by an optical fiber through an endoscope to the hollow organ. The image of the tissue collected by the endoscope is separated in two spectral windows, one being the backscattered excitation light and the other the fluorescence of the fluorochrome. Each image is then focused on the photocathode of image intensifiers (II) whose optical gain is modulated at the same frequency as the excitation intensity, resulting in homodyne phase-sensitive images. By acquiring stationary phase-sensitive frames at different phases between the excitation and the detection, it is possible to calculate in quasi-real time the apparent fluorescence lifetime of the corresponding tissue region for each pixel. A result obtained by investigating the endogenous fluorochromes present in the mucous membrane of an excised human bladder is presented to illustrate this method and most of the optical parameters which are of major importance for this photodetection modality have been evaluated.     

Symplectic supercuspidal representations and related problems

In this paper, we summarize the basic structures and properties of irreducible symplectic supercuspidal representations of GLn(F) over a p-adic local field F with characteristic zero, and explore possible topics for further investigation.     

Fiber optic probes for linear and nonlinear Raman applications – Current trends and future development

This review focuses on fiber optic probes for linear and nonlinear Raman spectroscopy, especially for medical applications. It aims at providing an overview over contemporary technology, recent first clinical trials, and helps identifying future developments necessary to bring the emerging technology to clinical end users. After a short introduction to linear and nonlinear Raman spectroscopic modalities, general design considerations will be discussed and compared to common fiber probe setups. Subsequently, examples for medical applications of fiber optic Raman probes will be given concentrating on probes for linear Raman spectroscopy as these devices are technologically more mature compared to their counterparts based on nonlinear Raman spectroscopy. The review also includes a brief summary of first multimodal fiber optic probes and highlights their benefits for clinical applications. Finally, probes are introduced which employ either nonlinear Raman spectroscopy or surface enhanced spectroscopy.