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.
The pupil response to light can reflect various kinds of diseases which are related to physiological health. Pupillary abnormalities may be influenced on people by autonomic neuropathy, glaucoma, diabetes, genetic diseases, and high myopia. In the early stage of neuropathy, it is often asymptomatic and difficulty detectable by ophthalmologists. In addition, the position of injured nerve can lead to unsynchronized pupil response for human eyes. In our study, we design the pupilometer to measure the binocular pupil response simultaneously. It uses the different wavelength of LEDs such as white, red, green and blue light to stimulate the pupil and record the process. Therefore, the pupilometer mainly contains two systems. One is the image acquisition system, it use the two cameras modules with the same external triggered signal to capture the images of the pupil simultaneously. The other one is the illumination system. It use the boost converter ICs and LED driver ICs to supply the constant current for LED to maintain the consistent luminance in each experiments for reduced experimental error. Furthermore, the four infrared LEDs are arranged nearby the stimulating LEDs to illuminate eyes and increase contrast of image for image processing. In our design, we success to implement the function of synchronized image acquisition with the sample speed in 30 fps and the stable illumination system for precise measurement of experiment.
Oral cancer is one of the serious and growing problem in many developing and developed countries. The simple oral visual screening by clinician can reduce 37,000 oral cancer deaths annually worldwide. However, the conventional oral examination with the visual inspection and the palpation of oral lesions is not an objective and reliable approach for oral cancer diagnosis, and it may cause the delayed hospital treatment for the patients of oral cancer or leads to the oral cancer out of control in the late stage. Therefore, a device for oral cancer detection are developed for early diagnosis and treatment. A portable LED Induced autofluorescence (LIAF) imager is developed by our group. It contained the multiple wavelength of LED excitation light and the rotary filter ring of eight channels to capture ex-vivo oral tissue autofluorescence images. The advantages of LIAF imager compared to other devices for oral cancer diagnosis are that LIAF imager has a probe of L shape for fixing the object distance, protecting the effect of ambient light, and observing the blind spot in the deep port between the gumsgingiva and the lining of the mouth. Besides, the multiple excitation of LED light source can induce multiple autofluorescence, and LIAF imager with the rotary filter ring of eight channels can detect the spectral images of multiple narrow bands. The prototype of a portable LIAF imager is applied in the clinical trials for some cases in Taiwan, and the images of the clinical trial with the specific excitation show the significant differences between normal tissue and oral tissue under these cases.
The difference of spectral distribution between lesions of epithelial cells and normal cells after excited fluorescence is one of methods for the cancer diagnosis. In our previous work, we developed a portable LED Induced autofluorescence (LIAF) imager contained the multiple wavelength of LED excitation light and multiple filters to capture ex-vivo oral tissue autofluorescence images. Our portable system for detection of oral cancer has a probe in front of the lens for fixing the object distance. The shape of the probe is cone, and it is not convenient for doctor to capture the oral image under an appropriate view angle in front of the probe. Therefore, a probe of L shape containing a mirror is proposed for doctors to capture the images with the right angles, and the subjects do not need to open their mouse constrainedly. Besides, a glass plate is placed in probe to prevent the liquid entering in the body, but the light reflected from the glass plate directly causes the light spots inside the images. We set the glass plate in front of LED to avoiding the light spots. When the distance between the glasses plate and the LED model plane is less than the critical value, then we can prevent the light spots caused from the glasses plate. The experiments show that the image captured with the new probe that the glasses plate placed in the back-end of the probe has no light spots inside the image.
The intraocular pressure (IOP) that can diagnose or track glaucoma generally because it is one of the physiology parameters that are associated with glaucoma. But IOP is not easy and consistence to be measured under different measure conditions. Besides, diabetes is associated with diabetic autonomic neuropathy (DAN). Pupil size response might provide an indirect means about neuronal pathways, so the abnormal pupil size may relate with DAN. Hence an infrared videopupillography is needed for tracking glaucoma and exploring the relation between pupil size and DAN. Our previous research proposed an infrared videopupillography to monitoring the pupil size of different light stimulus in dark room. And this 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 can be mounted on any eyeglass frame. But it can modulate only two dimensions, we cannot zoom in/out the eyes. Moreover, the eye diameter curves were not smooth and jagged because of the light spots, lone eyelashes, and blink. Therefore, we redesign the optical path of our device to have three dimension modulation. Then we can zoom in the eye to increase the eye resolution and to avoid the LED light spots. The light spot could be solved by defining the distance between IR LED and CCD. This device smaller volume and less prices of our previous videopupillography. We hope this new infrared videopupillography proposed in this paper can achieving early detection about autonomic neuropathy in the future.
Recently, hyperspectral imaging (HSI) systems, which can provide 100 or more wavelengths of emission autofluorescence measures, have been used to delineate more complete spectral patterns associated with certain molecules relevant to cancerization. Such a spectral fingerprint may reliably correspond to a certain type of molecule and thus can be treated as a biomarker for the presence of that molecule. However, the outcomes of HSI systems can be a complex mixture of characteristic spectra of a variety of molecules as well as optical interferences due to reflection, scattering, and refraction. As a result, the mixed nature of raw HSI data might obscure the extraction of consistent spectral fingerprints. Here we present the extraction of the characteristic spectra associated with keratinized tissues from the HSI data of tissue sections from 30 oral cancer patients (31 tissue samples in total), excited at two different wavelength ranges (330 to 385 and 470 to 490 nm), using independent and principal component analysis (ICA and PCA) methods. The results showed that for both excitation wavelength ranges, ICA was able to resolve much more reliable spectral fingerprints associated with the keratinized tissues for all the oral cancer tissue sections with significantly higher mean correlation coefficients as compared to PCA (p<0.001 ).
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.
This paper focuses on implementing two novel CMOS-MEMS type switches: buckling type and thermal type, by
using commercially available TSMC 0.35 μm two-poly four-metal (2P4M) CMOS process. There are two novel designs in these
two type switches: first, the soft contact structure with post-processing fabrication; second, using residual stress to achieve
large structural deformation in buckling type and thermal type switches. To create the soft contact structure, residual
gradient stress effect has been utilized to make bending-down curvatures. According to the experiments, the layer Metal1 has
the largest negative residual gradient stress effect that can achieve the largest negative deflection in z-axis. Because the
structure will bend down after post-processing release, larger lateral contact area are set up to gain the lower contact miss
ability. In the post-processing fabrication, 0.3μm thickness gold will be deposited on the contact tips. Due to the essence of gold,
comparing with aluminum, has no oxidation issue, gold also has the advantage of higher conductivity to reduce the electrical
power loss. In the buckling type design, the switch uses residual stress to achieve lateral buckling effect to solve long distance
problem. In the thermal type design, this paper design a folded-flexure with the electro-thermal excitation to turn the
switch on or off. In the prototype, the device size is 500 μm x 400 μm and the gap between two contact pads is 9 μm in off-state.
on the experimental results, the switch can work stably at 3 volts, and the displacement of the thermal type switch can
achieve 2.7μm, which is sufficient for the mechanism of switching-on or switching-off.
We present a 3×3 micro-optoelectromechanical systems (MOEMS) phase shifter array that achieves a /4 vertical displacement with peak-to-valley deformation within /10 (514-nm light source). The mirror reflective surface is made of an aluminum layer with a high optical reflectivity exceeding 90%. Each individual micromirror pixel is controlled and driven by comb drive actuators. The phase shifter array is fabricated using the Taiwan Semiconductor Manufacturing Company 0.35-µm 2P4M complementary metal-oxide semiconductor process. In-house post-processing is utilized to reserve a 40-µm-thick bulk-silicon under the 200 µm×200 µm mirror. This eliminates mirror deformation from residual stress after the device is released. The micromirror demonstrates a vertical displacement of /4 at 38 V. The device resonant frequency is 3.71 kHz, and the fill factor is 0.65. This MOEMS phase shifter array can be used as a spatial light modulator in holographic data storage systems.
This work presents a power-efficient wireless sensor implemented using microelectromechanical system (MEMS)-based dry electrodes (MDE) and a ZigBee protocol chip for physiological signal acquisition. To improve signal quality with low electrode-skin interface impedance, a silicon-based MDE is fabricated via micromachining technology. The proposed wireless sensor can provide four different channels for up to 10 kHz bandwidth, 10-bit resolution biomedical signal transmissions. Different from other systems, the proposed wireless sensor employs a novel power management method for physiological signals to reduce power consumption. The proposed wireless sensor successfully transmits electrocardiogram (ECG) signals and four-channel electroencephalogram (EEG) signals with power consumptions of 92.7 and 56.8 mW respectively. It consumes 46% less power than the original sensor without power management (173 mW) in ECG acquisition and 67% less power in EEG acquisition. The circuit printed-circuit-band area in the proposed wireless sensor is 3.5×4.5 cm, suitable for various portable biomedical applications.
In this paper, a tilting micromirror device that can achieve designed angle is proposed. A lever structure, driven by electrostatic actuators, was used to enlarge tilting angle. To obtain precise deflecting angle, the lever structure is constrained by the substrate. By applying a voltage, the electrostatic actuators drive the lever down to the substrate such that the micromirror device on the opposite side of the lever structure could be lifted. PolyMUMPs process was used to fabricate proposed micromirror devices. The actuators are simulated to investigate characteristics of the micromirror devices. Experimental results had indicated that the micromirror device could reach 10-degree tilting angle with 80V driving signal with 6.4% relative error compared to designed model.
In this paper, a back-to-back micromirror device fabricated through surface-micromachining and flip chip packaging technologies is developed for optical add/drop multiplexer applications. Pre-stressed beams were designed to elevate micromirror devices after the release and thermal heat-treatment processes. Torsion flexure structure design provides a reliable rotation degree of freedom for micromirror devices. A mechanical stopper was bonded using flip chip packaging on the top of micromirror devices to constrain the popped-up micromirror to obtain precise deflecting angle. Preliminary experiments had demonstrated the feasibility of the micromirror devices.
An efficient spiral-type magnetic microactuator design, composed of an enclosed core and a magnetic plate, is presented to produce a high magnetic flux density, a large force, and a large displacement. The design allows a large variation in area of the Permalloy plate and then the area of the poles can optimally enlarge with the fixed area of the Permalloy plate. Verification by the magnetic path analysis and the finite element method yields a theoretical actuator design for the magnetic microactuator. An integrated magnetic microactuator is fabricated and tested to demonstrate the capability of the improved design. The microactuator consists of an electromagnet and a four-suspended-beam structure, bound together with a 28-μm-thick spacer between them. A series of experiments determines that the measured stiffness of the four-beam structure is approximately 45 μN/μm. Notably, the Permalloy plate on the four-suspended-beam structure is moved by 27.6 μm at a current and voltage of 292 mA and 4.5 V, respectively. The estimated force produced by the microactuator is around 1240 μN. These results show the microactuator with an enclosed core is efficient in producing magnetic force and has flexibility in application.
In this paper, the configuration of combining holographic gratings and micromirror devices for optical add/drop functions is proposed for constructing OADM. Based on this architecture, a MEMS based vibrating micromirror device that is driven by electrostatic force in executing add/drop functions is designed and fabricated. Preliminary experiments had demonstrated the feasibility of the proposed system.
This paper describes the development of a novel, flexible, with appropriate accuracy dynamic characteristics measurement system for optical scanning micromirror. With the system, we can measure dynamic behavior such as transient response, scan speed, scan angle, scan repeatability, and scan non-linearity of the canning micromirror devices. Moreover, the optical system performances such as scan spot size and even scan spot intensity can also be obtained.
In this paper, a parametrical method is developed to design a magnetic microactuator. The method is based on modeling the magnetic microactuator using the finite element analysis software that can be used to calculate the energy density and magnetic force. Here, the concept of design on experiments (DOE) is used to identify critical parameters that affect the performances of the electromagnetic microactuator. Numerical simulation results from a series of DOE have indicated that the dimension of core and the magnetic material block have the influence on planar electromagnetic actuators. When the length of the magnetic components is equal to that of outer diameter of coil circuit, we obtain the best efficiency in magnetic force. Furthermore, when we increase the thickness of the magnetic materials block or shorten the distance between the coils and magnetic materials block, the magnetic force will increase dramatically. In addition, we can achieve a great magnetic force when the combination ratio of the length of the core is half of the magnetic material block. Simulation results have shown that electromagnetic actuators with high aspect ratio planar cold could sustain higher electrical current that consequently increases the magnetic force. During the realistic fabrication, the thick resist patterning and electroplating technologies is used to fabricate the above-mentioned electromagnetic microactuator. Experimental results indicated that the magnetic force follows closely to the simulation results.
KEYWORDS: Micromirrors, Actuators, Mirrors, Microelectromechanical systems, Surface micromachining, Oxides, Signal processing, Digital micromirror devices, Lithium, Control systems
A newly developed micromirror device that possesses two rotational and one displacement degrees of freedom has been designed and fabricated by using surface micromachining technology. The device consists of a micromirror, four vertical thermal-actuator arrays and four torsion bars that connect the mirror and the actuator. The vertical thermal actuator has the capability to elevate from its origin position. To demonstrate the feasibility of the vertical thermal actuator, various layouts and sizes has been designed. The present device was fabricated through the Multi-User MEMS process. When the controlled signal is applied to any two adjacent thermal-actuator arrays of the device, the remaining two thermal actuator arrays and torsion bars will act as the supporting beams that allow the micromirror to experience rolling or pitching motion. On the other hand, by applying controlled signals to all four thermal-actuator arrays synchronously , the micromirror would elevate vertically. Note that different rolling or pitching angle of the micromirror can be archived by designing the locations of the torsion bars with vertical thermal actuators. Through the process, a compact, extremely light in weight, potentially low cost, and operating in very low voltage micromirror device with various applications can be obtained.
By using a modular maltibody dynamics code, dynamical behavior of space structure elements is investigated to get an effective construction scenario for large space systems in orbit. Deployment construction of a triangular key structure for a solar power satellite in low earth orbit is treated, and the dynamical responses through the deployment in orbit plane, orbit normal or parallel plane are simulated. Illustrative examples clearly show the large variety of resulting dynamical behavior during and after deployment construction.
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