Oral cancer is a serious and growing problem in many developing and developed countries. To improve the cancer screening procedure, we developed a portable light-emitting-diode (LED)-induced autofluorescence (LIAF) imager that contains two wavelength LED excitation light sources and multiple filters to capture ex vivo oral tissue autofluorescence images. Compared with conventional means of oral cancer diagnosis, the LIAF imager is a handier, faster, and more highly reliable solution. The compact design with a tiny probe allows clinicians to easily observe autofluorescence images of hidden areas located in concave deep oral cavities. The ex vivo trials conducted in Taiwan present the design and prototype of the portable LIAF imager used for analyzing 31 patients with 221 measurement points. Using the normalized factor of normal tissues under the excitation source with 365 nm of the central wavelength and without the bandpass filter, the results revealed that the sensitivity was larger than 84%, the specificity was not smaller than over 76%, the accuracy was about 80%, and the area under curve of the receiver operating characteristic (ROC) was achieved at about 87%, respectively. The fact shows the LIAF spectroscopy has the possibilities of ex vivo diagnosis and noninvasive examinations for oral cancer.
This study presents the portable multispectral imaging system that can acquire the image of specific spectrum in vivo for oral cancer diagnosis. According to the research literature, the autofluorescence of cells and tissue have been widely applied to diagnose oral cancer. The spectral distribution is difference for lesions of epithelial cells and normal cells after excited fluorescence. We have been developed the hyperspectral and multispectral techniques for oral cancer diagnosis in three generations. This research is the third generation. The excited and emission spectrum for the diagnosis are acquired from the research of first generation. The portable system for detection of oral cancer is modified for existing handheld microscope. The UV LED is used to illuminate the surface of oral cavity and excite the cells to produce fluorescent. The image passes through the central channel and filters out unwanted spectrum by the selection of filter, and focused by the focus lens on the image sensor. Therefore, we can achieve the specific wavelength image via fluorescence reaction. The specificity and sensitivity of the system are 85% and 90%, respectively.
Glaucoma was diagnosed or tracked by the intraocular pressure (IOP) generally because it is one of the physiology
parameters that are associated with glaucoma. But measurement of IOP is not easy and consistence under different
measure conditions. An infrared videopupillography is apparatus to monitor the pupil size in an attempt to bypass the
direct IOP measurement. This paper propose an infrared videopupillography to monitoring the pupil size of different
light stimulus in dark room. The portable infrared videopupillography contains a camera, a beam splitter, the visible-light
LEDs for stimulating the eyes, and the infrared LEDs for lighting the eyes. It is lighter and smaller than the present
product. It can modulate for different locations of different eyes, and can be mounted on any eyeglass frame. An analysis
program of pupil size can evaluate the pupil diameter by image correlation. In our experiments, the eye diameter curves
were not smooth and jagged. It caused by the light spots, lone eyelashes, and blink. In the future, we will improve the
analysis program of pupil size and seek the approach to solve the LED light spots. And we hope this infrared
videopupillography proposed in this paper can be a measuring platform to explore the relations between the different
diseases and pupil response.
Currently, the cancer was examined by diagnosing the pathological changes of tumor. If the examination of cancer can diagnose the tumor before the cell occur the pathological changes, the cure rate of cancer will increase. This research develops a human-machine interface for hyper-spectral microscope. The hyper-spectral microscope can scan the specific area of cell and records the data of spectrum and intensity. These data is helpful to diagnose tumor. This study finds the hyper-spectral imaging have two higher intensity points at 550nm and 700nm, and one lower point at 640nm between the two higher points. For analyzing the hyper-spectral imaging, the intensity at the 550nm peak divided by the intensity at 700nm peak. Finally, we determine the accuracy of detection by Gaussian distribution. The accuracy of detecting normal cells achieves 89%, and the accuracy of cancer cells achieves 81%.
Until now, the cancer was examined by diagnosing the pathological changes of tumor. If the examination of cancer can
diagnose the tumor before the cell occur the pathological changes, the cure rate of cancer will increase. This research
develops a human-machine interface for hyper-spectral microscope. The hyper-spectral microscope can scan the specific
area of cell and records the data of spectrum and intensity. These data is helpful to diagnose tumor.
This research aims to develop a new system and a human-machine interface to control the hyper-spectral microscope.
The interface can control the moving speed of motor, the
exposure-time of hyper-spectrum, real-time focus, image of
fluorescence, and record the data of spectral intensity and position.
KEYWORDS: Color reproduction, Eye, Image quality, Electrical engineering, Medicine, Visual system, Visualization, Digital image processing, Current controlled current source, 3D image processing
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.
Generally, the instrument of color measurement can be divided into spectrophotometer and color
meter. The former instrument use prism or grating to separate the light, it can achieve high
accuracy but a higher price. The latter instrument use color filter, however there is no spectrum
information with it. This article establishes a color measuring system and uses eigen-spectrum
method in double light sources to calibrate the spectrum. The measuring system includes
tri-stimulus sensors which were made by color filter. The tungsten lamp and Xenon lamp are used
to be light source. The advantage of this measuring system is the higher accuracy and the lower
cost. The eigen-spectrum method can calibrate the spectrum in less eigenvector. This method used
singular value deposition to obtain basis function of spectrum set, which can be obtained by
measuring. Because the range of the spectrum set was 380nm to 780nm, the eigenvector per
nanometer from 380nm to 780nm can be obtained. In general, the color spectrum can be obtained
with less eigenvector. The color difference in L*a*b* color space from 31.2398 down to 2.48841,
and reconstructs the spectrum information.
The purpose of color measuring instrument is judging the color information by scientific method, which may
instead of the human's eyes. Generally, the instruments of color measuring have two kinds, spectrophotometer
and color meter. The former measures spectrum by usage of prism or grating to separate the light, this could
achieve high accuracy but with a higher price. The latter obtains tristimulus from color filter; however there is no
spectrum information with it. This article establishes a color measuring system and uses eigenspectrum method
to correct the average inaccuracy. The measuring system includes tristimulus sensors which were made by color
filter, and Xenon lamp as light source. The advantage of this measuring system is the higher accuracy and the
lower cost. The eigenspectrum method can correct the average inaccuracy in less eigenvector, which can save
the time. This method used singular value deposition to obtain basis function of spectrum set, which can be
obtained by measuring. Because the range of the spectrum set was 380nm to 780nm, the eigenvector per
nanometer from 380nm to 780nm can be obtained. In general, the color spectrum can be obtained with less
eigenvector. This article establishes a color measuring system, which has three sensors and uses Xenon lamp as
light source, to acquire the color spectral reflectance. This article also uses the eigenspectrum methods to
correct the average color difference in L*a*b* color space,which from 31.2398 down to 4.8401, and reconstructs
the spectrum information.
KEYWORDS: Black bodies, Light sources, Color difference, CIE 1931 color space, Light sources and illumination, Body temperature, Curium, RGB color model, LCDs, Manufacturing
Color temperature(CT) conversion of triprimary color display from one white point to another on the Planckian's locus
with the maximal brightness has been proposed. However, whether converting an original white point to another white
point on the isotemperature line will enlarge maximal brightness more than converting an original white point to another
white point on the Planckian's locus needs to be determined. This paper proposes a new algorithm to enlarge maximal
brightness by calling the center of gravity method of color mixing in the acceptable color difference range while the CT
is converted. From the prior study, we find that the apexes of color gamut boundary move along the line of center gravity
of primaries while the total brightness varies, where the line of center gravity of primaries is linked by the color points
mixed by two or more full primary colors and one partial primary color. And in CIE 1931 color space, the color gamut
boundary expanding from white point as total brightness decreasing will touch the isotemperature line with its apexes.
Therefore, the best point of CT conversion of tri-primary color display with more maximal brightness is determined by
the isotemperature line and the line of center gravity of primaries. Further, the theory extends to multi-primary color
displays. Lastly, the simulations prove that converting a white point to another on the isotemperature line enlarges
maximal brightness more than converting a white point to another on Planck's locus.
A new feedback readout circuit of microbolometers for sensing radiant power is proposed in this paper. Due to excellent
thermal characteristics of microstructure on infrared application recently, the readout circuits of the microsensors would
not concern the responsivity only, but should also take offset voltage cancellation, digitalization, and signal-to-noise ratio
under considerations. Although Wheatstone bridge readout circuit has been widely used in resistive thermal sensor
readout for several decades, its nonlinear output voltage acting as the offset voltage still perplex us, as well as its
digitalization and signal-to-noise ratio could be unsatisfied for microbolometer applications. Hence, we present the
feedback readout which could optimize the key factors simultaneously and increase the responsivity without any layout
modification of the bridge structure on Infrared Focal Plane Array (IRFPA) microbolometer chip. The results revealed
that the balanced parameter, frequency, equal to 0.5 would be the best condition for these requirements instead of the
balanced parameter equal to unity by intuition traditionally. Compared to traditional Wheatstone bridge readout circuit,
the feedback readout circuit would improve the responsivity of 2.86 times, immunize the offset voltage exactly, obtain a
very large OVRR, and reduce the noise of the readout circuit of 5.6 dB. These significantly important results will
improve significantly the performance of the readout circuit, and speed up the commercialization of infrared focal plane
array of microbolometers.
Recently, color reproduction stages are developed greatly, such as liquid-crystal displays, LCD TV, LCD
projectors, DLP projectors, and etc. Wide-color-gamut displays are distinguishing feature of many display
manufacturers. Many researches about multi-primary color displays are proposed, but there are still some
problems which are not solved. This study proposed a novel multi-primary projection display system using
two projectors. One of the two projectors is modified by changing two dichroic mirrors inside. The modified
projector is combined with the other to a new six-primary color display. This study applies equal-luminance
boundary theorem to construct gamut volume and evaluates the merit between gamut volume and brightness.
By this method, the cut-off wavelength of dichroic mirrors can be found out. In the past, to align the images
of the two projectors is pre-distorted to compensate the trapezoidal distortion. This study proposes to
eliminate trapezoidal distortion by using the offset of the projector. This study directly changes dichroic
mirrors to maintain the brightness and contrast, and solves lower brightness and contrast resulted from adding
filters before. Additionally, this study uses a reflection mirror to twist projection path and also constructs a
stage to align projection images more accurately.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.