Browsing by Author "Sheu, Ming-Jen"

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Design of a bi-directional illumination system for a dual view capsule endoscope
(2019-02-06)
Sheu, Ming-Jen
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Liu, Ying-Lan
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Wang, Jhi-Joung
;
Pan, Jui-Wen
;
光電系統研究所
The capsule endoscope is an important tool for the intestinal examination. But the main disadvantage of the traditional capsule endoscope is the limited field of view. In order to solve this problem, the dual view capsule endoscope (DVCE) was developed. In this work, a dual view illumination system is designed for a DVCE. The dual view illumination system is divided into two sub-systems with a front view illumination lens and a back view illumination lens. The Bezier curves for the front view and back view illumination lenses are used for optimization, based on which we change the radiation pattern of the LED so that the dual view illumination design can support energy for the front view and back view simultaneously while achieving low power consumption and high efficiency. Moreover, a non-uniform illumination process is used to compensate for the problem of uniformity and relative illumination for the DVCE lens. Through this design, we can obtain a uniformity of 91% and an efficiency of 25.2% for front view illumination and uniformity of 91% and an efficiency of 23.5% for back view illumination. Finally, tolerance analysis can also be completed for mass production.
Dual view capsule endoscopic lens design
(2015-04-06)
Sheu, Ming-Jen
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Chiang, Che-Wen
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Sun, Wen-Shing
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Wang, Jhi-Joung
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Pan, Jui-Wen
A dual view capsule endoscopic (DVCE) lens is proposed with front view and back view functions. This is a hybrid lens with a catadioptric mirror and an aspherical surface to support both view functions. The field of view (FOV) for the front view function is 90 degrees. The FOV for the back view function is 260 to 290 degrees. The TV distortion for the front view and back view function is under 30% and 25%. The corner relative illuminations for the two view functions are above 0.53. The Modulation Transfer Function (MTF) performance at the Nyquist Frequency for the two view functions can be kept above 0.35, even under tolerance they can remain above 0.2. Moreover, the telecentric conditions at the image plane of the DVCE system can support constant magnification through focusing. This condition can reduce the measurement error by slightly defocusing of the lens. Thus, the two view functions can offer physicians a wide viewing angle to deal with lesions over the fold. (C)2014 Optical Society of America
Enhancing Bowel Sounds by Using a Higher Order Statistics-Based Radial Basis Function Network
(2013-05-01)
Lin, Bor-Shyh
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Sheu, Ming-Jen
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Chuang, Ching-Chin
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Tseng, Kuan-Chih
;
Chen, Jen-Yin
Auscultation of bowel sounds provides a noninvasive method to the diagnosis of gastrointestinal motility diseases. However, bowel sounds can be easily contaminated by background noises, and the frequency band of bowel sounds is easily overlapped with background noise. Therefore, it is difficult to enhance the noisy bowel sounds by using precise digital filters. In this study, a higher order statistics (HOS)-based radial basis function (RBF) network was proposed to enhance noisy bowel sounds. An HOS technique provides the ability of suppressing Gaussian noises and symmetrically distributed non-Gaussian noises due to their natural tolerance. Therefore, the influence of additional noises on the HOS-based learning algorithm can be reduced effectively. The simulated and experimental results show that the HOS-based RBF can exactly provide better performance for enhancing bowel sounds under stationary and nonstationary Gaussian noises. Therefore, the HOS-based RBF can be considered as a good approach for enhancing noisy bowel sounds.
Higher-Order-Statistics-Based Fractal Dimension for Noisy Bowel Sound Detection
(2015-07-01)
Sheu, Ming-Jen
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Lin, Ping-Yi
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Chen, Jen-Yin
;
Lee, Chien-Ching
;
Lin, Bor-Shyh
Bowel sounds is an important physiological parameter of distinguishing the gastrointestinal motility dysfunction. Auscultation of bowel sounds provides a noninvasive way for clinical diagnosis, but it is also easily affected by environmental noise. In this study, a novel higher-order-statistics (HOS)-based fractal dimension algorithm was proposed for detecting noisy bowel sounds. By using the nature of preserving non-Gaussianity for higher order statistics technique, the proposed method can effectively detect bowel sounds under different noise conditions, and its performance is insensitive to the change of noise type and noise level.
Microprism for a capsule endoscope with wafer level optics
(2019-08-01)
Chen, Luan-Ying
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Pan, Jui-Wen
;
Sheu, Ming-Jen
;
Chang, Kao-Der
;
光電系統研究所
Capsule endoscopes are pill-sized devices that physicians can utilize for diagnosis of a patient's small intestine. For diagnostic requirements, excellent image quality, large field of view (FOV) and compact size are crucial. In this paper, a multi-camera capsule endoscope (MCCE) composed of two wafer level optic modules and microprism elements which can offer both a large FOV and clear image quality within limited space conditions is described. The properties of the microprism needed to ensure the necessary image quality are further discussed, including working efficiency, the ability to increase the FOV, and the inhibition of chromatic aberration. Finally, the functioning of the MCCE is verified through an optical simulation and preliminary experiments. The results show that the max half FOV of the MCCE could be increased from 28 degrees to 37 degrees, and the relative illumination could be kept at 80% without a dark corner effect.