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No description available.

No description available.

by Chung Sheung Chee, Sydney. / Thesis (M.D.)--Chinese University of Hong Kong, 1988. / Includes bibliographical references.

Thesis (PhD) - Swinburne University of Technology, Faculty of Engineering and Industrial Sciences, Centre for Micro-Photonics, 2007. / A thesis submitted for the degree of Doctor of Philosophy, Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, 2007. Typescript. Bibliography: p. 146-162.

The utilization of intranasal local anesthetic agents has become a prevalent approach in nasal endoscopy procedures, aimed at enhancing patient comfort and optimizing procedural outcomes. This comprehensive literature review seeks to evaluate the benefits and risks associated with the use of intranasal anesthetics prior to nasal endoscopy. A total of twenty-eight studies published within the last three decades were meticulously examined and incorporated in this literature review. The majority of the reviewed studies overwhelmingly demonstrated no significant reduction in patient discomfort or pain during nasal endoscopy with the use of intranasal anesthetics. However, it is noteworthy that two of the included studies highlighted the potential benefits of masking agents to mitigate the bitter taste associated with anesthetic agents, leading to increased analgesic properties during the endoscopic procedure. Conversely, three of the reviewed studies indicated that intranasal anesthetic usage positively impacted the ease of the procedure for the endoscopist, resulting in improved visualization of the nasal cavity and higher-quality images. Interestingly, the choice of specific anesthetic agents, such as cocaine, tetracaine, lidocaine, or co-phenylcaine, did not appear to play a substantial role in the reported outcomes across the studies. In contrast, the method, timing, and decision-making process regarding the application of intranasal anesthetics emerged as crucial factors that influenced the observed outcomes and potential side effects. The variations in these factors yielded diverse results among the studies, emphasizing the significance of careful consideration and standardized protocols in the administration of intranasal anesthetics. Overall, while the reviewed studies generally did not demonstrate significant benefits in terms of reducing patient discomfort or pain, there were notable improvements in the ease of procedure for the endoscopist with intranasal anesthetic usage. Furthermore, the choice of anesthetic agent alone did not significantly impact the outcomes. However, the methodology, timing, and decision-making were shown to be important factors in achieving desirable results. Further research is warranted to explore optimal approaches for intranasal anesthetic administration, including the development of effective masking agents and standardized protocols. It is crucial for further research to assess the utilization of intranasal anesthetics to ensure patient comfort, procedural efficacy, and safety during nasal endoscopy procedures.

Wireless capsule endoscopy (WCE) offers a patient-friendly, non-invasive and painless investigation of the entire small intestine, where other conventional wired endoscopic instruments can barely reach. As a critical component of the capsule endoscopic examination, physicians need to know the precise position of the endoscopic capsule in order to identify the position of intestinal disease after it is detected by the video source. To define the position of the endoscopic capsule, we need to have a map of inside the human body. However, since the shape of the small intestine is extremely complex and the RF signal propagates differently in the non-homogeneous body tissues, accurate mapping and localization inside small intestine is very challenging. In this dissertation, we present an in-body simultaneous localization and mapping technique (Body-SLAM) to enhance the positioning accuracy of the WCE inside the small intestine and reconstruct the trajectory the capsule has traveled. In this way, the positions of the intestinal diseases can be accurately located on the map of inside human body, therefore, facilitates the following up therapeutic operations. The proposed approach takes advantage of data fusion from two sources that come with the WCE: image sequences captured by the WCE's embedded camera and the RF signal emitted by the capsule. This approach estimates the speed and orientation of the endoscopic capsule by analyzing displacements of feature points between consecutive images. Then, it integrates this motion information with the RF measurements by employing a Kalman filter to smooth the localization results and generate the route that the WCE has traveled. The performance of the proposed motion tracking algorithm is validated using empirical data from the patients and this motion model is later imported into a virtual testbed to test the performance of the alternative Body-SLAM algorithms. Experimental results show that the proposed Body-SLAM technique is able to provide accurate tracking of the WCE with average error of less than 2.3cm.

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Femtosecond laser microsurgery has emerged as a remarkable technique for precise ablation of biological systems with minimal damage to their surrounding tissues. The combination of this technique with nonlinear optical imaging provides a means of microscopic visualization to guide such surgery in situ. A clinical endoscope capable of image-guided femtosecond laser microsurgery will provide physicians a means for cellular-level microsurgery with the highest precision. This dissertation focuses the development of a miniaturized fiber-coupled probe for image-guided microsurgery, towards future realization as a clinical endoscope. The first part of the dissertation describes the development of an 18-mm diameter probe. This development includes delivery of femtosecond laser pulses with pulse energy in excess of 1 µJ through air-core photonic bandgap fiber, laser beam scanning by a microelectromechanical system scanning mirror, and development of a new image reconstruction methodology for extracting increased temporal information during Lissajous beam scanning. During testing, the 18-mm probe compares favorably with the state-of-the-art as a microscopic imaging tool and we present the first known demonstration of cellular femtosecond laser microsurgery through an optical fiber. The second part of the dissertation explores further refinement of the design into a streamlined package with 9.6 mm diameter and improved imaging resolution. Study of the optical performance through analytical and computer-aided optical design indicates that simple custom lenses can be designed that require only commercial-grade manufacturing tolerances while still producing a fully aberration-corrected microsurgical endoscope. With the 9.6-mm probe, we demonstrate nonlinear optical imaging, including tissue imaging of intrinsic signals from collagen, using average laser powers 2-3× lower than the current state-of-the-art. We also demonstrate the use of the 9.6-mm probe in conjunction with gold nanoparticles for enhanced imaging and microsurgery through plasmonics. Finally, in the third part of this dissertation, we detail bench-top development of a new clinical application for combined femtosecond laser microsurgery and nonlinear optical imaging: the treatment of scarred vocal folds. We show the utility of femtosecond laser microsurgery for creating sub-epithelial voids in vocal fold tissue that can be useful for enhancing localization of injectable biomaterial treatments. We demonstrate that a single compact fiber laser system can be utilized for both microsurgery and imaging. Furthermore, the proposed clinical technique is shown to be achievable with parameters (e.g., pulse energy, focused spot size) that were found to be attainable with fiber-coupled probes while still achieving ablation speeds practical for clinical use. / text

Diss. (sammanfattning)--Göteborg : Göteborgs universitet, 2007. / Härtill 3 uppsatser.