Browsing by Author "Jeng, Wei-De"

Now showing 1 - 11 of 11

A 3D photographic capsule endoscope system with full field of view
(2013)
Ou-Yang, Mang
;
Jeng, Wei-De
;
Lai, Chien-Cheng
;
Kung, Yi-Chinn
;
Tao, Kuan-Heng
Current capsule endoscope uses one camera to capture the surface image in the intestine. It can only observe the abnormal point, but cannot know the exact information of this abnormal point. Using two cameras can generate 3D images, but the visual plane changes while capsule endoscope rotates. It causes that two cameras can't capture the images information completely. To solve this question, this research provides a new kind of capsule endoscope to capture 3D images, which is "A 3D photographic capsule endoscope system ". The system uses three cameras to capture images in real time. The advantage is increasing the viewing range up to 2.99 times respect to the two camera system. The system can accompany 3D monitor provides the exact information of symptom points, helping doctors diagnose the disease.
Color calibration of swine gastrointestinal tract images acquired by radial imaging capsule endoscope
(2016-01-01)
Mang Ou-Yang
;
Jeng, Wei-De
;
Lai, Chien-Cheng
;
Wu, Hsien-Ming
;
Lin, Jyh-Hung
The type of illumination systems and color filters used typically generate varying levels of color difference in capsule endoscopes, which influence medical diagnoses. In order to calibrate the color difference caused by the optical system, this study applied a radial imaging capsule endoscope (RICE) to photograph standard color charts, which were then employed to calculate the color gamut of RICE. Color gamut was also measured using a spectrometer in order to get a high-precision color information, and the results obtained using both methods were compared. Subsequently, color-correction methods, namely polynomial transform and conformal mapping, were used to improve the color difference. Before color calibration, the color difference value caused by the influences of optical systems in RICE was 21.45 +/- 1.09. Through the proposed polynomial transformation, the color difference could be reduced effectively to 1.53 +/- 0.07. Compared to another proposed conformal mapping, the color difference value was substantially reduced to 1.32 +/- 0.11, and the color difference is imperceptible for human eye because it is <1.5. Then, real-time color correction was achieved using this algorithm combined with a field-programmable gate array, and the results of the color correction can be viewed from real-time images. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)
Design and analysis of radial imaging capsule endoscope (RICE) system
(2011-02-28)
Ou-Yang, Mang
;
Jeng, Wei-De
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this study, a radial imaging capsule endoscope (RICE) system is designed, which differs from a conventional front imaging capsule endoscope (FICE) system. To observe the wrinkled intima of the intestine, which spreads without folding around the circumference of the capsule when a capsule endoscope with a diameter that slightly exceeds that of the intestine passes through it, the RICE uses a cone mirror, a radial window shell, and a focus optical module that comprise the radial imaging system. This concept was demonstrated in a packaged optical simulator. The RICE optical model also has been established and verified by many simulations and experiments. In minimizing the sagittal and tangential aberrations, the optical module of the RICE has achieved an F-number of 4.2, a viewing angle of 65.08 degrees, and an RMS radius of the 4th to 6th fields of less than 17 um. A comparison of these characteristics with those of the focus optical module that is used in FICE lenses reveals that the spot size is 50% larger for each field, and the modulation transfer function (MTF) is remarkably improved from 7% to 36% at 100 lp/mm on the 5th field of the sagittal plane. (C) 2011 Optical Society of America
Design and analysis of wearable pupillometer for autonomic neuropathy of diabetic patients
(2014-10-10)
Ko, Mei-Lan
;
Chen, Yin-Yuan
;
Ouyang, Yuan
;
Huang, Ting-Wei
;
Tsuen, Bi-Shiou
Diabetes is a familiar disease in modern society. In the early stage of diabetes, symptoms are unobvious, but they usually induce diabetic autonomic neuropathy or, worse, cardiovascular autonomic neuropathy. Pupillometers are effective instruments for observing human pupils. This article presents a novel wearable pupillometer design, without external light artifacts, and an embedded algorithm with blinking elimination, which investigates autonomic neuropathy through recording pupil dynamics triggered by an external sensitive invisible light source. The pupillometer is experimented on 36 healthy subjects and 10 diabetic patients under four different colors (white, red, green, and blue) as well as two different light intensities: 50 and 500 mcd. Ten parameters derived from pupil diameter, pupil response time, and pupil response speed will be evaluated for the healthy subjects and diabetic patients. The results show that three in four parameters related to pupil diameters, one in four related to light intensities, and one in two related to pupil response speed could have significant differences (p < 0.05) between healthy subjects and diabetic patients. These parameters obtain over 85% sensitivity, 83% specificity, and 88% accuracy. The pupillometer is proven reliable, effective, portable, and inexpensive for diagnosing diabetes in an early stage. (C) 2014 Optical Society of America
Design of illumination system in ring field capsule endoscope
(2011)
Jeng, Wei-De
;
Mang Ou-Yang
;
Chen, Yu-Ta
;
Wu, Ying-Yi
;
電控工程研究所
This paper is researching about the illumination system in ring field capsule endoscope. It is difficult to obtain the uniform illumination on the observed object because the light intensity of LED will be changed along its angular displacement and same as luminous intensity distribution curve. So we use the optical design software which is Advanced Systems Analysis Program (ASAP) to build a photometric model for the optimal design of LED illumination system in ring field capsule endoscope. In this paper, the optimal design of illumination uniformity in the ring field capsule endoscope is from origin 0.128 up to optimum 0.603 and it would advance the image quality of ring field capsule endoscope greatly.
Image stitching and image reconstruction of intestines captured using radial imaging capsule endoscope
(2012-05-01)
Mang Ou-Yang
;
Jeng, Wei-De
;
Wu, Yin-Yi
;
Dung, Lan-Rong
;
Wu, Hsien-Ming
This study investigates image processing using the radial imaging capsule endoscope (RICE) system. First, an experimental environment is established in which a simulated object has a shape that is similar to a cylinder, such that a triaxial platform can be used to push the RICE into the sample and capture radial images. Then four algorithms (mean absolute error, mean square error, Pearson correlation coefficient, and deformation processing) are used to stitch the images together. The Pearson correlation coefficient method is the most effective algorithm because it yields the highest peak signal-to-noise ratio, higher than 80.69 compared to the original image. Furthermore, a living animal experiment is carried out. Finally, the Pearson correlation coefficient method and vector deformation processing are used to stitch the images that were captured in the living animal experiment. This method is very attractive because unlike the other methods, in which two lenses are required to reconstruct the geometrical image, RICE uses only one lens and one mirror. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.5.057004]
Improve the image discontinuous problem by using color temperature mapping method
(2011)
Jeng, Wei-De
;
Ou-Yang, Mang
;
Lai, Chien-Cheng
;
Wu, Hsien-Ming
;
電控工程研究所
This article mainly focuses on image processing of radial imaging capsule endoscope (RICE). First, it used the radial imaging capsule endoscope (RICE) to take the images, the experimental used a piggy to get the intestines and captured the images, but the images captured by RICE were blurred due to the RICE has aberration problems in the image center and lower light uniformity affect the image quality. To solve the problems, image processing can use to improve it. Therefore, the images captured by different time can use Person correlation coefficient algorithm to connect all the images, and using the color temperature mapping way to improve the discontinuous problem in the connection region.
Improving the uniformity of luminous system in radial imaging capsule endoscope system
(2013-02-01)
Mang Ou-Yang
;
Jeng, Wei-De
;
資訊工程學系
;
電機資訊學士班
;
Department of Computer Science
This study concerns the illumination system in a radial imaging capsule endoscope (RICE). Uniformly illuminating the object is difficult because the intensity of the light from the light emitting diodes (LEDs) varies with angular displacement. When light is emitted from the surface of the LED, it first encounters the cone mirror, from which it is reflected, before directly passing through the lenses and complementary metal oxide semiconductor (CMOS) sensor. The light that is strongly reflected from the transparent view window (TVW) propagates again to the cone mirror, to be reflected and to pass through the lenses and CMOS sensor. The above two phenomena cause overblooming on the image plane. Overblooming causes nonuniform illumination on the image plane and consequently reduced image quality. In this work, optical design software was utilized to construct a photometric model for the optimal design of the LED illumination system. Based on the original RICE model, this paper proposes an optimal design to improve the uniformity of the illumination. The illumination uniformity in the RICE is increased from its original value of 0.128 to 0.69, greatly improving light uniformity. (C) The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI. [DOI: 10.1117/1.OE.52.2.023003]
Research of accommodative microfluctuations caused by visual fatigue based on liquid crystal and laser displays
(2014-10-10)
Jeng, Wei-De
;
Ouyang, Yuan
;
Huang, Ting-Wei
;
Duann, Jeng-Ren
;
Chiou, Jin-Chern
Different levels of visual fatigue in the human eye depend on different color-formation methods and image quality. This paper uses the high-frequency component of the spectral power of accommodative microfluctuations as a major objective indicator for analyzing the effects of visual fatigue based on various displays, such as color-formation displays and 3D displays. Also, a questionnaire is used as a subjective indicator. The results are that 3D videos cause greater visual fatigue than 2D videos (p < 0.001), the shutter-type 3D display causes visual fatigue more than the polarized type (p = 0.012), the display of the time-sharing method causes greater visual fatigue than the spatial-formation method (p = 0.008), and there is no significance between various light source modules of displays (p = 0.162). In general, people with normal color discrimination have more visual fatigue than those with good color discrimination (p < 0.001). Therefore, this paper uses the high-frequency component of accommodative microfluctuations to evaluate the physiological stress or strain by overexerting the visual system, and can compare the level of visual fatigue between various displays. (C) 2014 Optical Society of America
Research of Color Distribution Index in CIEL*a*b* Color Space
(2010)
Jeng, Wei-De
;
Huang, Ting-Wei
;
Mang Ou-Yang
;
Lee, Tsang-Hsing
;
Hsieh, Yao-Fang
The index for evaluating the ability of color reproduction is required. The color distribution index (CDI) was proposed to comment the display ability of color distribution of reproduction in CIE Lu'v' color space. A cell of Just Noticeable Difference (JND) for luminance and chromaticity (u'v') was proposed to qualify whether the reproduced colors are in some region of color volume of display. Human eye can perceive fewer colors at low luminance, however, the scalar of chromaticity (u'v') JND at low luminance was the same with the one at other luminance. CDI will be distorted at low luminance. In this paper, regarding perceptible vision at low luminance, we try to use chromaticity (a*b*) JND to replace chromaticity (u'v') JND. The color distribution will be discussed in CIE La*b* color space. We find that CDI at low luminance in CIE L*a*b* color space is higher than in CIE Lu'v' color space, as well as different gamma curves and different bit depths affect CDI. The displays are going to keep approaching 100% true color reproduction; hence the index for evaluating the ability of color reproduction is required.
The Novel research of Intraocular Pressure Tonometer by Using Inductance sensor
(2012)
Tang, Yu-Shun
;
Jeng, Wei-De
;
Huang, Ting-Wei
;
Ou-Yang, Mang
;
Chiou, Jin-Chern
This article mainly discusses the theoretical derivation and the estimate of the intraocular pressure (IOP) sensor by using inductance. The inductance changes associate with the variation of anterior corneal curvature radius due to the differences of IOP. The value of inductance is transformed by the LC oscillator, and the signal is transmitted by antenna, and finally read by the exterior readout circuit to achieve IOP measuring. The result show that the estimative values of inductance is close to the measured values, and the percentage of inductance variation is about 0.08% per 1 mmHg. Because of the low percentage, it makes much harder to realize readout circuit. In the future, the alteration of structure and material are considered to increase the percentage of varying inductance.