bluuebunny/crossref_metadata_2025 huggingface dataset:
RAPID PROTOTYPING OF WIRELESS AUGMENTATIVE AND ALTERNATIVE COMMUNICATION SYSTEM FOR SPEECH IMPAIRED SUBJECTS
Authors: LEE HSIAO-YU , WU CHAO-MIN
Published: December 2008

Wireless telecommunications holds particular promise for people with speech impairment because it can provide convenience for communication and enhance user's mobility. However, people with speech impairments are likely to also have varied movement disorders which result in the inability to use the existing voice telephone facility. The aim of this research is to extend the current augmentative and alternative communication (AAC) system to wireless telecommunication service for speech-impaired subjects. A pocket personal computer (PPC) with wireless modules is adopted herein, that can be functioned as a portable AAC device, voice pager within a range, and mobile phone. The touch screen of PPC with designed graphics icon can be served as large buttons to activate the high-fidelity sound that is in turns sent to the wireless modules for "talking" through the phone. An AAC layout editor is used to link the pre-recorded sound to the graphics icon and to compile the icon-based graphics for each individual. In addition, levels of dynamic linkages, including script-based, category of use, semantic linkage, and frequency of use are implemented for assisting the speech impairment user to retrieve these pre-stored conversational items which can speed up the communication rate.
THERMAL LESION FORMATION AND DETERMINATION FOR EXTERNAL ULTRASOUND THERMAL THERAPY
Authors: LIU HAO-LI , CHEN YUNG-YAW , YEN JIA-YUSH , LIN WIN-LI
Published: December 2008

The purpose of this paper is to investigate the relationship between the formation of the thermal lesion and the major parameters of the external ultrasound heating systems, and to propose a useful thermal lesion determination procedure, which is capable of specifying the range of a thermal lesion by temperature feedback in external ultrasound thermal therapy. This work is based on an ideal ultrasound power deposition formed by an external ultrasound heating system and the temperature distribution is calculated by the transient bioheat transfer equation. A simplified model was employed to determine the heating pattern for four most important parameters. Through the simplified power expression, the property of a new parameter, T300, which is defined as the maximal temperature corresponding to the thermal dose of 300 minutes, is also investigated. When the target volume is large enough such that the thermal conduction effect becomes negligible, the T300 value is almost independent of the system parameters and the heating strategies, and is dominated by the blood perfusion rate with a monotonic correlation. The method enables us to use feedback information in the ultrasound heating process and to pre-determine the heating range of the thermal lesion, which will be very useful in ultrasound treatment planning.
PERFORMANCE EVALUATION OF THE HIGH RESOLUTION SMALL ANIMAL PET SCANNER
Authors: MOK SENG-PENG , WANG CHAO-HSING , CHEN JYH-CHENG , LIU REN-SHYAN
Published: December 2008

Molecular imaging is an important technology to clarify biological and medical uncertainties in the 21th century. This is best realized via in vivo imaging of biological processes in small animals. Thus, a special high resolution imager dedicated for small animals is required. We recently installed a high resolution animal positron emission tomography (PET) scanner (microPET R4) for doing in vivo molecular imaging of gene expression. This paper describes the performance evaluation of our microPET R4 scanner. The microPET R4 scanner is a dedicated PET for studies of rodents. The system is composed of 96 detector modules, each with an 8 × 8 array of 2.1 × 2.1 × 10 mm3 lutetium oxyorthosilicate (LSO) crystals, arranged as 32 crystal rings and 14.8 cm in diameter. The detector crystals are coupled to a Hamamatsu R5900-C8 position sensitive photomultiplier tube (PS-PMT) via a 10 cm long optical fiber bundle. The system operates in 3D mode without inter-plane septa, acquiring data in list mode. A number of scanner parameters such as sensitivity, spatial resolution and energy resolution were determined in this work. In the center of field of view (FOV) a maximal sensitivity of 21.04 cps/kBq was calculated from a measurement with a germanium-68 point source with an energy window of 250-750 keV. Spatial resolution of 2.03 mm (FORB+2D-FBPJ/1.61 mm (FORB + 2D-OSEM) full width at half maximum (FWHM) in the tangential direction and 2.07 mm (2D-FBP)/1.65 mm (2D-OSEM) FWHM in the radial direction were measured in the center with a 0.28 mm diameter 18F-FDG line source. The energy resolution of the scanner was measured across all crystals ranging from 13.9% to around 34.6% with a mean of 18.45%. The results show that the microPET R4 is a suitable PET scanner for imaging small animals like mice and rats.
STATISTICAL-BASED SUB-BAND FILTERING TECHNIQUE FOR DIGITAL MAMMOGRAM ENHANCEMENT
Authors: LIN HONG-DUN , LIN KANG-PING , CHUNG BEING-TAU
Published: December 2008

Early detection and diagnosis of breast cancer markedly increases survival rate. Digital mammography is believed to help breast image experts to detect breast cancer early. Accurate diagnosis also depends on the quality of the image presented to the experts. This study addresses the quality improvement of the image. A statistically based sub-band filtering method is applied to enhance the mass and calcification shown in the digital mammograms by inhibiting noise. The method is based on sub-band transformation due to its decomposition characteristic and includes two steps: noise inhibition and boundary enhancement. Contrast ratios and frequency responses are measured to evaluate the enhancement performance and the distortion affect, respectively, to validate the effectiveness of the proposed technique. By comparing the enhancement performance of proposed and conventional methods, a phantom mammogram image that consists of similar mammographic microcalcifications, breast gland and well-circumscribed mass is designed for simulation experiment. Moreover, the real mammograms with microcalcifications are also applied on representing the efficient enhancement ability by the proposed method in this paper. Results in this study demonstrate that the proposed method improves the quality of the image more than other enhancement methods, according to these two criteria. The comparison results show that not only the image quality is improved but also within less image distortion.
NORMAL GAIT OF CHILDREN
Authors: CHOU PEI-HSI , CHOU YOU-LI , SU FONG-CHING , HUANG WEI-KENG , LIN TING-SHENG
Published: December 2008

The rapid development of gait analysis and its increasing application to pathological gait in children has created an urgent need for normative data. However, research on maturation of gait in children is just in the beginning stage in Taiwan. In order to care for the welfare of children, more data and knowledge in the field are mandatory. The first goal of this study is to offer some background data and basic studies to any other researchers who are interested in this topic. The second goal was to investigate the corresponding factors to gait parameters, such as body weight, height, angular deformities (genu varum and valgum) and torsional deformities (toe in and out). In this study, twenty-three children (five years old in average) were included and motion analysis and force plate system were applied to investigate the kinematics and kinetics of lower limbs. The results showed that body height and weight are both corresponding factors to gait development. Gait analyses revealed that there were no differences between boys and girls. Children with genu valgum attend to more gait stability using compensatory mechanism.
PULSATILE FLOW FIELDS IN A MODEL OF ABDOMINAL AORTA WITH ITS PERIPHERAL BRANCHES
Authors: LEE D. , CHEN J. Y.
Published: December 2008

In a previous study by the authors, steady flow fields in a model of abdominal aorta with its seven peripheral branches were reported. In the present study, the some aorta model was simulated numerically with a pulsatile inlet waves for both the resting and exercise conditions. The baseline pulsatile flow field was presented in terms of velocity vectors and iso-velocity contours as well as the wall shear stress (WSS) distribution and the recirculation zones. The time-averaged behavior of the flow field represented by the fluid dynamic factors was discussed. The results were consistent with those obtained experimentally and numerically by other investigators. It was also found that under the present conditions, the steady flow behavior could adequately describe the time-averaged behavior of its corresponding pulsatile case, particularly in the regions where convective flow dominated. The present computer code may provide a platform for clinical simulations.
USING TEXTURE AND SHAPE FEATURES TO RETRIEVE SETS OF SIMILAR MEDICAL IMAGES
Authors: LEE JIANN-DER , LOU LI-PENG
Published: December 2008

In this paper, a novel scheme has been proposed for image retrieval task using the feature extracted directly from a compressed or uncompressed image. The texture information is first extracted by exploiting the multiresolution nature of wavelet decomposition, which represent the horizontal, vertical and diagonal frequency distribution of an image. We then calculate the mean and standard deviation of wavelet coefficients of each sub-band as texture features. In additions, we also extract shape feature by using the fixed-resolution block representation, which divides the image into isometric blocks and calculate the overlapped degree of each block with binary codes. The experimental results show that the retrieval efficiency is considerably improved by the proposed approach.
DEVELOPMENT OF A M3S PROTOTYPE SYSTEM USING DIGITAL SIGNAL PROCESSOR
Authors: CHIEN JEN-CHIEN , HSUEH MENG-LUN , CHEN CHIEN-CHI , LUH JER-JUNN , LAI JIN-SHIN , CHONG FOK-CHING
Published: December 2008

Acute disabilities always need different types of assistive devices in their daily life. Usually, each of these devices is designed for only one particular usage. Because of this, an acute disable may have to use a joystick to manipulate his wheelchair, used a mouse to control computer, or used a keyboard to control movement of mechanical arm. Thus no consideration of interrelations among these tools was discussed.

In 1990, the technical working committee 173 (TC-173/sc-1/wg-7) of ISO (International Organization for Standardization) using serial interface protocol (ISO 7176-7) to integrate all types of assistive tools for the disabilities. At the same time, the European Common Commission funded the research for M3S interface (Multiple Masters Multiple Slave). It provides the disable a concrete integral control for his movement, working, environment control and communication. This is an integrated intelligent real time control capability protocol. It is a plug and play device interface.

We design and develop a M3S protocol using TMS320F243 DSP chip. The system was tested for I/O control and it meets the equipments supported by the M3S working group. Thus, it would bring lots of comforts for the disable.
WAVELET-BASED LOSSY-TO-LOSSLESS MEDICAL IMAGE COMPRESSION USING DYNAMIC VQ AND SPIHT CODING
Authors: MIAOU SHAOU-GANG , CHEN SHIH-TSE , CHAO SHU-NIEN
Published: December 2008

As the coming era of digitized medical information, a close-at-hand challenge to deal with is the storage and transmission requirement of enormous data, including medical images. Compression is one of the indispensable techniques to solve this problem. In this work, we propose a dynamic vector quantization (DVQ) scheme with distortion-constrained codebook replenishment (DCCR) mechanism in wavelet domain. In the DVQ-DCCR mechanism, a novel tree-structure vector and the well-known SPIHT technique are combined to provide excellent coding performance in terms of compression ratio and peak signal-to-noise ratio for lossy compression. For the lossless compression in similar scheme, we replace traditional 9/7 wavelet filters by 5/3 filters and implement the wavelet transform in the lifting structure. Furthermore, a detection strategy is proposed to stop the SPIHT coding for less significant bit planes, where SPIHT begins to lose its coding efficiency. Experimental results show that the proposed algorithm is superior to SPIHT with the arithmetic coding in both lossy and lossless compression for all tested images.
ESTABLISHING BIOMECHANICAL MODEL OF HUMAN BODY FOR RESTORING STANDING FUNCTIONS
Authors: LIU CHENG-LIANG , YU CHUNG-HUANG , CHEN SHIH-CHING , WU WEN-SHAN
Published: December 2008

This work presents a five-segment biomechanical model of the human body for paraplegics of spinal cord injury (SCI) with thoracic nerve injury. When the functional electrical stimulation (FES) system is used to restore sit-to-stand function, the biomechanical model can be used to analyze the position, force, and moment of the human body at every joint through inverse dynamics. A series of data taking from SCI patient under FES of restoring sit-to-stand function are implemented on the model. The results help realize the role of each joint and muscle in the sit-to-stand process so as to improve the rehabilitation in the future plan.
DETERMINING INTRA-ANEURYSMAL FLOW FOR COILED CEREBRAL ANEURYSMS WITH DIGITAL FLUOROSCOPY
Authors: JOU LIANG-DER , SALONER DAVID , HIGASHIDA RANDALL
Published: December 2008

Background and Purpose. Aneurysm geometry often dictates the success of coil embolization. A strong hemodynamic force or high intra-aneurysmal flow may indicate a high probability of recanalization. It is necessary to develop a tool that can predict and estimate the level of hemodynamic forces that coils are subject to during the procedure. Methods. A compartment model is developed to estimate the intra-aneurysmal flow after coil embolization from digital fluoroscopy. The model is based on the measured signal intensity curves for the aneurysm and adjacent artery and derives the amount of intra-aneurysmal flow reduction. A clinical case of a carotid aneurysm was used for demonstration of its ability. Results. Intra-aneurysmal flow was reduced by 70% after coil embolization, and the estimated porosity was 60%. Flow reduction was confirmed by computational fluid dynamics simulations that modeled the coiled aneurysm as a porous medium. Conclusion. Intra-aneurysmal flow reduction may be used to predict the outcome of coil embolization or possible aneurysm recurrence. A sustained high intra-aneurysmal flow prohibits complete embolization and allows recanalization of the aneurysm. The compartment model provides a reasonable estimate of intra-aneurysmal flow and hemodynamic forces on the coils.
A STUDY OF ULTRASONIC LIVER IMAGES CLASSIFICATION WITH ARTIFICIAL NEURAL NETWORKS BASED ON FRACTAL GEOMETRY AND MULTIRESOLUTION ANALYSIS
Authors: LEE WEN-LI , HSIEH KAI-SHENG , CHEN YUNG-CHANG , CHEN YING-CHENG
Published: December 2008

In this study, we evaluate the accuracy of classifiers for classification of ultrasonic liver tissues. Two different statistic classifiers and three various artificial neural networks are included: Bayes classifier, k-nearest neighbor classifier, Back-propagation neural networks, probabilistic neural network and modified probabilistic neural network. These five different classifiers were investigated to determine their ability to classify various categories of ultrasonic liver images. The investigation was performed on the basis of the same feature vector. For statistic classifiers the classification accuracy is at most 90.7% and with artificial neural networks the accuracy is at least 92%. The experimental results illustrated that artificial neural networks are an attractive alternative to conventional statistic techniques when dealing with classification task. Moreover, the feature vector based on fractal geometry and wavelet transform can provide good discriminant ability for ultrasonic liver images under study.
ENDOPROSTHESIS-RELATED COMPLICATIONS AFTER LIMB-SALVAGE OPERATION OF MALIGNANT BONE TUMORS AROUND THE KNEE
Authors: YANG RONG-SEN
Published: December 2008

Endoprosthetic reconstruction using a custom-made metallic megaendoprosthesis is one of the common modalities for the limb salvage operation. The new promising advance of material science, design and fabrication of the endoprosthesis enable an immediate rehabilitation program and provide a durable and functional limb. Thus a successful limb reconstruction is possible in the well-selected patients. In addition to the endoprosthesis-related increased stress, a limited soft tissue support and constraint after limb salvage procedure usually results in an increased incidence of complications, especially in the long term survivors. Some patients may even need revision of the endoprosthesis and, at times, amputation.

The complications after oncological endoprosthectic reconstructions usually occur more frequent than the conventional primary total joint arthroplasty. Considering the characteristics of the surgical procedure and the high demands on the implants, such a relatively high frequency of complications is not unexpected. The common complications include wound necrosis, aseptic loosening, fatigue fracture, local osteolysis, joint contracture, dislodgement/dislocation, nerve or vascular injury, rotational deformity, leg length discrepancy, infection, periprosthectic fracture, etc. Some complications are encountered with other modality of limb salvage procedure, whereas the other endoprosthesis-related complications are endoprosthetic-unique and not uncommon. The major causes of such a relatively high endoprosthesis-related complications include (1) extensive excision of soft tissue, leading to change of biomechanical ergonomics, little soft tissue constraints or support for a long replacement segments, and decreased local defense to infection, (2) increased stress on the implants due to higher activity level in the youthful active individuals, relatively narrower medullary canals with less cancellous bone for fixation, (3) special needs for the stability resulting an increased mechanical constraints placed directly within the endoprosthesis, thus raising the local stress transferred to the prosthesis, and to the prosthesis-bone interface, (4) poor immunological, hematological, or nutritional status resulting from chronic oncologic diseases or chemotherapy. It in turn accelerates the wear processes of the components, induces the wear particulate disease and local osteolysis, as well as to cause the aseptic loosening eventually. Early detection and early correction of minor complications has an important role of preventing the major complications, thus reduces the necessity of reoperation, and at times, amputation. We will review these complications in this article.
NUMERICAL PREDICTION OF SHEAR STRESS DISTRIBUTIONS FOR A DISSECTED AORTA
Authors: NIU YANG-YAO , CHU WEI-KUANG , YU HSI-YU , WANG YAO-HUNG
Published: December 2008

In this study, the formation of the shear stress on the three-dimensional realistic health and dissected aortic dissection models is investigated under the laminar Newtonian flow assumption with Reynolds numbers 100 to 600. Numerical simulation shows that strong oscillating positive-negative wall stress distributions are found along both the lower and upper aortic vessels during the whole pulsatile cycle. Especially, the location of maximum wall shear stress is always found around the beginning of dissected aortic vessel. However, due to three ascending branch effects, the location of the wall stress extreme on upper arch is moved upward from the dissected vessel surface to the location behind the third ascending branch.
THE ARCHITECTURAL DESIGN FOR DYNAMIC ARTERIAL COMPLIANCE-MEASURING INSTRUMENT
Authors: LIN ALBERT CHIN-YUH , HUANG HUANG-NAN , CHEN TSUNG-HUNG , TUNG HUNG , HUANG YU-WEN
Published: December 2008

Arterial compliance is defined as the variation of arterial vessel diameter under the blood pressure. This paper introduces the architecture of a brand-new compliance measurement. Two techniques are used: one is to use pressure feedback control and then obtain the variation of arterial vessel diameter at wrist; the other is to detect the delay time between two adjacent pressures and then calculate the downstream blood pressure according to the upstream blood pressure and delay time. The above information can easily compute the dynamic nonlinear arterial compliance. Therefore, the instrument comprises of two pressure sensors: one is fixed and the other is sliding upward and downward by a peizo-actuator. The piezo-actuator is imposed a strain gauge which senses the displacement of the actuator, or the variation of arterial vessel diameter. The design philosophy and fabrication of this instrument are present.
THE DESIGN AND FABRICATION OF PRESSURE DETECTION HEAD
Authors: LIN ALBERT CHIN-YUH , HUANG HUANG-NAN , CHANG SU-CHI , TUNG HUNG , HUANG YU-WEN
Published: December 2008

In this research, a tiny size non-invasive pressure detection head is designed and fabricated. It serves as an essential component of the multi-functional sphygmus detection system. When the pressure detection head places upon the correct position at wrist, it transmits the pulse pressure from the touch membrance through the silicon oil, and then to the pressure die. This kind of structure will provide a stable data acquisition for pulse pressure sensing. To verify the performances of the pressure detection head, a pressure test bench together with standard testing procedure is developed to gather information on the tested signals. The test results indicate that the designed pressure detection head is feasible and can be used for sphygmic diagnosis in medicine.
FABRICATION AND EVALUATION OF CHITOSAN MEMBRANES FOR GUIDED TISSUE REGENERATION
Authors: CHEN TA WEI , KUO SHYH MING , CHANG SHWU JEN , KUAN TANG CHING
Published: December 2008

Chitosan membranes were prepared by a thermal induced phase separation method, following treatment with nontoxic NaOH gelating and Na5P3O10, Na5SO3 crosslinking agents. Effects of these reaction agents on chitosan membranes were evaluated to survey the feasibility of using these membranes in guided tissue regeneration (GTR) application. The preliminary results showed chitosan membranes crosslinked with Na5P3O10 and Na2SO3 had gel content of 53.5% and 52.2%r, respectively. Contrarily, the chitosan matrix gelated with NaOH dissolved completely during gel content measurement. Chitosan membrane treated with Na5P3O10 had lowest elastic modulus of 12.9 Mpa as compared with other membranes treated with Na2SO3 (17.9Mpa) and NaOH(23.6Mpa). From SEM observations, NaOH gelated chitosan membrane had the smoothest surface morphology than others. However, Na5P3O10 crosslinked chitosan membrane had better cell adhesion and proliferation results in cell culture test. All three chitosan membranes degraded by about 23%∼28% of initial weight after a 90-day in vitro shaking test.
DEVELOPMENT OF AN ARTERIAL APPLANATION TONOMETER FOR DETECTING ARTERIAL BLOOD PRESSURE AND VOLUME
Authors: WANG JIA-JUNG , LIU SHING-HONG , CHERN CHING-IUAN , HSIEH JUI-HSAING
Published: December 2008

Traditional arterial tonometry permits noninvasive and continuous recording of the arterial pressure waveform, by applanating a superficial artery supported by a bone. In the paper, we present an arterial tonometer to simultaneously register the blood pressure waveform and the arterial time-varying volume. The tonometer consisted mainly of a chamber filled with a conductive fluid, a flexible diphragm in touch with an artery, and a pressure sensor used to detect the underlying arterial pressure. In addition, four electrodes were in parallel diposed in the chamber, two of them were triggered with a constant-current source, and the voltage difference between the other two inner electrodes was assocated with the amount of change in the arterial volume. The pressure calibration curve performed with a mercury sphygmomanometer showed a fairly linear relationship (r = 0.998) between the tonometer's chamber pressure and the voltage output of the pressure-sensing circuit. The volume calibration was carried out with vessel-like cylinders of various diameters and a linear relationship (r = 0.884) of the change in vessel volume to the voltage output of the volume-sensing circuit was obtained. Clinical testing results revealed that the noninvasive blood pressure measurement with the tonometer was appreciably consistent with the invasive measurement with the catheter-tipped pressure transducer. In summary, the arterial applanation tonometer developed may be used to reliably determine the full arterial blood pressure waveform and the change in the arterial volume, and to make the wall compliance assessment of a superficial artery possible.
OPTIMAL DOSE OF MR CONTRAST AGENT IN T1-WEIGHTED MRI
Authors: HSIAO C-C , JAO J-C , TING Y-N , PAN H-B , CHEN P-C
Published: December 2008

Nowadays magnetic resonance imaging (MRI) has been commonly used in many indications. Concurrent development of MRI contrast agents has aided the rapid expansion and increased clinical efficacy. The use of contrast agents can improve lesion detection and characterization. With the contrast enhancement, lesion conspicuity is dramatically increased. Therefore, contrast enhanced MRI could provide more accurate diagnosis and be helpful for further therapy. The routinely used dose of contrast agents suggested by the documents only relies on the body weight of the subject. However, the relationship between the signal enhancement and the dose of contrast agents needs to be further investigated in order to achieve the maximum enhancement from optimal dose of the contrast agents. The aim of this study is to obtain the optimal dose of two contrast agents (Magnivist and Omniscan) for various T1-weighted pulse sequences (SE, SPGR, 2D TOF and 3D TOF) and various coils (body coil, NV array coil and head coil). The optimal dose is defined as achieving the MR images with the highest enhancement. The results show that there are significant differences in optimal dose among various pulse sequences. However, there are no significant differences in optimal dose among various coils and these two contrast agents. The advantage of finding optimal dose is to minimize dose and potential toxicity, and furthermore to decrease the cost of contrast agents. This study was done on a phantom, and it is expected to provide useful information to the contrast enhanced MRI in the routine clinical diagnosis and research in the future.
TEMPORAL ANALYSIS OF THE ACCELERATION AND DECELERATION PHASES FOR VISUAL SACCADES
Authors: LIN HSUAN-HUNG , CHEN YUNG-FU , CHEN TAINSONG , TSAI TZU-TUNG , HUANG KUO-HSIEN
Published: December 2008

Previous studies showed that the relation for product of peak velocity and duration against saccadic amplitude was highly linear correlated. The velocity profile was related as a triangular profile and referred to the saccadic amplitude as an integration of the profile, so that the amplitude is proportional to the product of peak velocity and duration. The saccadic amplitude can be described as a function of peak velocity and duration.

In this study, in addition to the triangular profile, the rational power function was applied to explain the above linear relation. The acceleration and deceleration phases can be described, respectively, with the different shape parameters (n1 and n2).

Finally, we described the product of peak velocity and acceleration time relating to the acceleration amplitude, and the product of peak velocity and deceleration time relating to the deceleration amplitude. The results show that the acceleration and deceleration phase parameters could be used to accurately delineate the saccadic characteristics.
INTEGRATING EDGE DETECTION AND THRESHOLDING APPROACHES TO SEGMENTING FEMORA AND PATELLAE FROM MAGNETIC RESONANCE IMAGES
Authors: LEE JIANN-SHU , CHUNG YI-NUNG
Published: December 2008

Anterior knee pain (AKP) is a common pathological condition. The most obvious problem causing knee pain is the abnormal patellar tracking mechanism. For computerized knee joint analysis, how to successfully segment the knee bones is an import issue. This paper presents a simple while effective algorithm for fully automatic femur and patella segmentation for magnetic resonance (MR) knee images through integrating edge detection and thresholding approaches. Based on consideration of computational complexity and accuracy, we develop a compound approach to segment the MR knee images. The moment preserving thresholding is first utilized to gather the bone-outline information employed to estimate the region of interest (ROI). An ROI based wavelet enhancement is proposed to restrict the contrast improvement only around the bone edges. The restriction makes both the adhesion separation of bone and surrounding tissues and the bone contour conservation become possible and avoid harsh thresholding resulting from the global based wavelet enhancement. Cooperating with the morphology operation, stable initial guess of the bone regions can be achieved. To overwhelm the main drawback of the existing edge based segmentation methods, i.e. the necessity of complicated post-processing, a new approach - FLoG is proposed to provide a feasible solution. It converts the edge detection results using LoG into a region-based format through the flow fill operation. The developed onion-growing algorithm can properly combine the initial guess of bone regions with the FLoG outputs in an efficient way. The experimental study shows our method is superior to the conventional ones in meeting the requirement of physicians. This is because our method can perform well in dealing with the tougher conditions, i.e. the partial volume and the soft tissue adhesion conditions. Because of the integration of the thresholding approach with the FLoG edge detector, our algorithm is even robust to unsatisfactory imaging conditions. Hence, our method lends itself to assisting the clinical diagnosis of knee functions.
EVALUATION OF CLOSED-LOOP CONTROL SYSTEM FOR RESTORING STANDING AND SITTING FUNCTIONS BY FUNCTIONAL ELECTRICAL STIMULATION
Authors: LIU CHENG-LIANG , YU CHUNG-HUANG , CHEN SHIH-CHING , CHEN CHANG-HUNG
Published: December 2008

Functional electrical stimulation (FES) is a method for restoring the functional movements of paraplegic or patients with spinal cord injuries. However, the selection of parameters that control the restoration of standing up and sitting functions has not been extensively investigated.

This work provides a method for choosing the four main items involved in evaluating the strategies for sit-stand-sit movements with the aid of a modified walker. The control method uses the arm-supported force and the angles of the legs as feedback signals to change the intensity of the electrical stimulation of the leg muscles. The control parameters, Ki and Kp, are vary for different control strategies. Four items are collected through questionnaires and used for evaluation. They are the maximum reactions of the two hands, the average reaction of the two hands, largest absolute angular velocity of the knee joints, and the sit-stand-sit duration time. The experimental data are normalized to facilitate comparison. Weighting factors are obtained and analyzed from questionnaires answered by experts and are added to evaluation process for manipulation. The results show that the best strategy is the closed-loop control with parameters Ki=0.5 and Kp=0.
EFFECTS OF DENTAL IMPLANT LENGTH AND BONE QUALITY ON BIOMECHANICAL RESPONSES IN BONE AROUND IMPLANTS: A 3-D NON-LINEAR FINITE ELEMENT ANALYSIS
Authors: LIN CHUN-LI , KUO YU-CHAN , LIN TING-SHENG
Published: December 2008

The aim of this study was to evaluate the influence of implant length and bone quality on the biomechanical aspects in alveolar bone and dental implant using non-linear finite element analysis. Two fixture lengths (8 and 13mm) of Frialit-2 root-form titanium implants were buried in 4 types of bone modeled by varying the elastic modulus for cancellous bone. Contact elements were used to simulate the realistic interface fixation within the implant system. Axial and lateral (buccolingual) loadings were applied at the top of the abutment to simulate the occlusal forces. The simulated results indicated that the maximum strain values of cortical and cancellous bone increased with lower bone density. In addition, the variations of cortical bony strains between 13mm and 8mm long implants were not significantly as a results of the same contact areas between implant fixture and cortical bone were found for different implant lengths. Lateral occlusal forces significantly increased the bone strain values when compared with axial occlusal forces regardless of the implant lengths and bone qualities. Loading conditions were found as the most important factor than bone qualities and implant lengths affecting the biomechanical aspects for alveolar bone and implant systems. The simulated results implied that further understanding of the role of occlusal adjustment influencing the loading directions are needed and might affect the long-term success of an implant system.
A NEONATAL FACIAL IMAGE SCORING SYSTEM (NFISS) FOR PAIN RESPONSE STUDIES
Authors: CHEN KEE-HSIN , CHANG SUSANNA , HSIAO TZU-CHIEN , CHEN YUEH-CHIH , LIN CHII-WANN
Published: December 2008

The aim of this study was to establish a scoring system, Neonatal Facial Image Scoring System (NFISS), for investigating the pain responses in neonates during routine venipuncture. We collected 1998 facial images from 19 infants during the first phase of this study and identified twelve features of the facial image: normalized scale for NFISS (scale from 0-15), including brow bulge (0-2), vertical brow furrowing (0-1) and short distance (0-1), brow lowering (0-1), eyes close (0-1), bulging eyes (0-2), eye-eye furrowing (0-1), cheek bulge (0-1), nasal-labial furrowing (0-2), mouth open and stretch (0-1), lip purse (0-1) and taut tongue (0-1). During the second evaluation phase, with 2770 images from 31 newborn infants (average age: 2.85°”.027 days), the pain responses were graded on the NFISS scale. Two peak score values during a time course of baseline-venipuncture-recovery (3-3-10 min) were found with needle piercing and needle withdrawal. The reliability of the score analysis was evaluated using 492 randomly selected images out of the 2770 images. The results for intra-scorer (author, one week interval) and inter-scorer (author and one experienced nurse) has correlation coefficients of 0.916 and 0.826, respectively.
IN VITRO RELEASE OF HYDROCORTISONE BY GLYCINE-IMMOBILIZED EVAL MEMBRANE
Authors: LAI PING-SHAN , YOUNG TAI-HORNG , WANG CHENG-YI , SHIEH MING-JIUM
Published: December 2008

A pH-sensitive membrane for colon-specific drug delivery was prepared by glycine-immobilization on poly (ethylene-co-vinyl alcohol) (Gly-EVAL) that can enhance the permeability of hydrocortisone at pH 7.4 and resist drug permeation at pH 2.0 or in gastric juice. As the results of drug releasing profile, it is proposed that the electrical repulsion occurring between adjacent carboxylate ions at pH 7.4 on Gly-EVAL causes the higher permeation rate of hydrocortisone. Consequently, the hydrocortisone coated by Gly-EVAL can escape from degradation in acid environment and release significantly in neutral or weak basic pH values, which is ideally suitable for local treatment of ulcerative colitis.
THE HIP STRESS LEVEL ANALYSIS FOR HUMAN ROUTINE ACTIVITIES
Authors: WANG XISHI , WANG TIANYING , JIANG FUCHUAN , DUAN YIXIANG
Published: December 2008

Since 1980's, Bergmann and his research group have been pursuing the instrumented hip implants with telemetric data transmission [1-6]. Their collected gait data were recorded in HIP98[7], and it was updated in 2001. So far it is unique gait data base of the human hip contact force simultaneously measured in vivo. It is well recognized, however, that intrinsic pathomechanical changes in articulator cartilage depends upon local stress levels rather than upon global joint loading, and the abnormal mechanical stress upon hip joint cartilage is one of the main causes of osteoarthritis. In this paper, therefore, based on the gait data of HIP98 (2001 version) and Hertzian elasticity contact theory, a realistic stress level and peak stress analysis at hip joint for the human routine activities are presented.
DEVELOPMENT OF A PORTABLE DEVICE FOR HOME MONITORING OF SNORING
Authors: HSU YEH-LIANG , CHEN MING-CHOU , CHENG CHIH-MING , WU CHANG-HUEI
Published: December 2008

Snoring analysis is important for the diagnosis and treatment of sleep-related breathing disorders (SRBD). Snoring has traditionally been assessed in clinical practice from subjective accounts by the snorer and his/her partner. The use of polysomnographic recording is a standard evaluation procedure for SRBD patients. However, it is expensive and is not suitable for long term monitoring. This paper describes the development of a portable microcontroller based device for long-term, home monitoring of snoring. By analyzing the temporal feature of the snoring sound, this device can output the total snoring count, average number of snores per hour, and the number of intermittent snoring. In our tests, the average success rate in identifying snores is over 85% in a lab environment and around 70% in a home.
DESIGNING LOW POWER OF SIGMA DELTA MODULATOR FOR BIOMEDICAL APPLICATION
Authors: LEE HO-YIN , HSU CHEN-MING , HUANG SHENG-CHIA , SHIH YI-WEI , LUO CHING-HSING
Published: December 2008

This paper discusses the design of micro power Sigma-delta modulator with oversampling technology. This Sigma-delta modulator design is paid special attention to its low power application of portable electronic system in digitizing biomedical signals such as Electro-cardiogram (ECG), Electroencephalogram (EEG) etc. [1]. A high performance, low power second order Sigma-delta modulator is more useful in analog signal acquisition system. Using Sigma-delta modulator can reduce the power consumption and cost in the whole system. The original biomedical signal can be reconstructed by simply applying the digital bit stream from the modulator output through a low-pass filter. The loop filter of this modulator has been implemented by using switch capacitor (SC) integrators and using simple circuitry consists of OpAmps, Comparator and DAC. In general, the resolution of modulator is about 10 bits for biomedical application. In this two order Sigma-delta modulator simulation results of the 1.8V sigma delta modulator show a 68 dB signal-to-noise-and-distortion ratio (SNDR) in 4 kHz biomedical signal bandwidth and a sampling frequency equal to 1 MHz in the 0.18 μ m CMOS technology. The power consumption is 400 μ W. It is very suitable for low power application of biomedical instrument design.
A NEW WIRELESS-TYPE PHYSIOLOGICAL SIGNAL MEASURING SYSTEM USING A PDA AND THE BLUETOOTH TECHNOLOGY
Authors: CHIEN JIA-REN CHANG , TAI CHENG-CHI
Published: December 2008

A light and portable-type wireless physiological signal retrieving system has always been a medical personnel's dream. To fulfill this dream, this paper investigates a feasible method to create a wireless-type physiological signal measuring system using a PDA and the bluetooth technology. The proposed system will reduce the service costs and raise the service efficiency for current medical care systems. The waveforms and data of physiological signals, such as electrocardiograms (ECGs), phonocardiograms (PCGs), electroencephalograms (EEGs), body temperatures, and so forth, are always the vital references for medical doctors to diagnose the patients' body condition. The traditional physiological signal measuring instruments or devices possess some shortcomings, such as high prices, bulky dimensions, ill-portability and excessive connection cables. In contrast, the proposed wireless-type physiological signal measuring system, being able to get rid of said shortcomings, holds apparent advantages in service costs and service efficiency and, hence, shall be the trend for the future. This study has completed some tests in ECG, PCG, and body temperature measurements. The proposed prototype system has successfully using the bluetooth technology to invisibly transmit and receive physical signals through the air.
REPAIR OF ARTICULAR CARTILAGE INJURY
Authors: CHIANG HONGSEN , HUANG YI-YOU , JIANG CHING-CHUAN
Published: December 2008

Articular cartilage defects heal poorly and lead to consequences as osteoarthritis. Clinical experience has indicated that no existing medication would substantially promote the healing process, and the cartilage defect requires surgical replacement. Allograft decays quickly for multiple reasons including the preparation process and immune reaction, and the outcome is disappointing. The extreme shortage of sparing in articular cartilage has much discouraged the use of autograft, which requires modification. The concept that constructs a chondral or osteochondral construct for the replacement of injured native tissue introduces that of tissue engineering. Limited number of cells are expanded either in vitro or in vivo, and resided temporally on a scaffold of biomaterial, which also acts as a vehicle to transfer the cells to the recipient site. Three core elements constitute this technique: the cell, a biodegradable scaffold, and an environment suitable for cells to present their proposed activity. Modern researches have kept updating those elements for a better performance of such cultivation of living tissue.
A NOVEL QRS DETECTION ALGORITHM APPLIED TO THE ANALYSIS FOR HEART RATE VARIABILITY OF PATIENTS WITH SLEEP APNEA
Authors: LEE REN-GUEY , CHOU I-CHI , LAI CHIEN-CHIH , LIU MING-HSIU , CHIU MING-JANG
Published: December 2008

Sleep-related breathing disorders can cause heart rate changes known as cyclical variation. The heart rate variation of patients with obstructive sleep apnea syndrome (OSAS) is more prominent in sleep. For this reason, to analyze heart rate variability (HRV) of patients with sleep apnea is a very important issue that can assist physicians to diagnose and give suitable treatment for patients. In this paper, a novel QRS detection algorithm is developed and applied to the analysis for HRV of patients with sleep apnea. The advantageous of the proposed algorithm is the combination of digital filtering and reverse R wave detection techniques to enhance the accuracy of R wave detection and easily implement into portable ECG monitoring system with light complexities of computation. The proposed algorithm is verified by simulation and experimental results.
EVALUATION OF A PC-BASED DATA ACQUISITION SYSTEM FOR LONG-TERM RECORDING OF ACTION POTENTIALS WITH MINIMAL DEDICATED CIRCUITS
Authors: LI JEN-YU , JANG JIN-KAE , KUO TE-SON , JAW FU-SHAN
Published: December 2008

Owing to the improvement of computing power, computer-aided multi-unit acquisition and separation rapidly proliferated during the last two decades. To utilize this technology is, however, not easy since task-specific designs are usually mandatory. To overcome this obstacle, a commercial data acquisition system was used to evaluate whether it is possible to accomplish the task of multi-unit acquisition without the aid of these devices. As the results shown that the technique of spike-trigger acquisition can provide the capability to reduce the data amount to 2% while compared with that sampled by continuous acquisition. However, the interval between two consecutive spikes cannot be shorter than 5 ms. This suggests that special designed devices are still necessary.
A LOW-COST VISION-BASED HUMAN-COMPUTER INTERFACE FOR PEOPLE WITH SEVERE DISABILITIES
Authors: SU MU-CHUN , SU SHI-YONG , CHEN GWO-DONG
Published: December 2008

The object of this paper is to present a low-lost vision-based computer interface which allows people with disabilities to use their head movements to manipulate computers. Our system requires only one low-cost web camera and a personal computer. Several experiments were conducted to test the performance of the proposed human-computer interface.
BLOOD FLOW ANALYSIS OF POLYURETHANE HEART VALVES AT PEAK SYSTOLE
Authors: HSU CHEUNG-HWA
Published: December 2008

Polyurethane (PU) heart valves provide central flow at peak systole and the associated hemodynamic characteristics are superior to that of mechanical valves with almost no anticoagulation therapy for patients. Durability performances, on the other hand, are also superior to those of biological valves. This paper analyzes blood flow characteristics of the PU heart valves at fully open position with computational fluid dynamics. These data provide information for the improvement of leaflets and leaflet support geometry to minimize the scale of recirculation zone of the flow field. To simulate the hemodynamic characteristics of the blood flow, CFX-4.3 software with the finite volume method is utilized to analyze the three-dimensional Reynolds-averaged Navier-Stokes equations. By modifying the geometry of leaflets along with the supports, the scale of vortex flow and blood velocity are reduced obviously. Maximum flow velocity reduces 33% compared to that of original model at peak systole.
EFFECTS OF HEMATOCRIT LEVEL ON THE BLOOD FLOW IN THE CORRUGATED VESSEL DUE TO THE IMPLANTATION OF INTRAVASCULAR STENTS
Authors: TING TA-WEI DAVID , WU BING-SHIUN
Published: December 2008

The vascular stenting has been accepted as a very effective treatment of occlusive vascular disease. But the implantation of vascular stent will change the geometric shape of stenosed vessel to be corrugated and create some local hemodynamic features characterized by the flow separation, recirculation in the area close to the stent. Under the physiological conditions of left coronary artery and specific geometric shapes created by the implantation of stent, the numerical method has been used to solve the blood flow and the shear stress distribution patterns in the vicinity of the stent. The non-Newtonian fluids with different levels of hematocrit (H), 25%, 45%, 65% are employed for the numerical simulation and compared with the numerical results of the Newtonian fluid in which the blood viscosity is assumed to be constant. The simulations have revealed that the surface of stent and atheroma bumps experience lower time-averaged wall shear stress by the non-Newtonian fluid with lower level of hematocrit. The value of wall shear stress on the peak of atheroma bumps has also been studied because it may associate with the cause the rupture of atheroma plaque.

The numerical results of Newtonian fluid were compared with those of non-Newtonian fluid with hematocrit level of 45%, the average hematocrit value inherent in normal person. It is noted that non-Newtonian effect on the time-averaged wall shear stress distribution along the stent surface is not significant. The outline of bulged atheroma experiences almost same time-averaged shear stress distribution acting by the fluid with or without the non-Newtonian property. It means that for the non-Newtonian fluid with hematocrit level of 45% the property of changing viscosity in the flow field didn't affect the results of wall shear stress distribution on the surfaces of stent and atheroma bump resulted from the simulation of Newtonian fluid flow.

These results will provide insight into the effects of different levels of hematocrit on the blood flow in the corrugated vessel due to the implantation of stent. Our findings suggest that the level of hematocrit is closely associated with the value of wall shear stress distribution. It is particularly significant to acute stage of atherogenesis, intimal hyperplasia, platelet deposition, thrombosis, endothelial cell orientation and the rupture of atheroma plaque after the implantation of stent. Some of the results presented can be used to explain the clinical performance of vascular stenting.