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This paper describes new methods for determining lung density and air volume from an indirect measurement of the electrical resistivity of the lungs. Resistivity, in Ωm, was found by fitting measured Electrical Impedance Tomography (EIT) data to a Finite Difference model of the thorax. This part of the technique has already been described in the literature for neonatal lungs. Using the method now described lung density can also be determined by comparison of the resistivity of the lungs, measured at a relatively high frequency, with values predicted from a published model of lung structure. Lung air volume can also be calculated from a knowledge of total lung weight and density. The new method was implemented on EIT data collected from eleven normal adult subjects, using eight electrodes placed in a single plane around the thorax. A mean lung density of 292 kg m−3 (SD 36 kg m−3) was obtained. Sources of error are discussed. It is concluded that absolute differences in lung water of more than 25% and changes over time of 10% or more should be detected using the current technology. [ABSTRACT FROM AUTHOR]

In an FPGA-based medical EIT system, the necessary sinusoidal signals are generated using DDS inside an FPGA. Similarly, the phase and amplitude of the acquired signal are measured by using an I/Q demodulator inside the FPGA. In a multi-channel EIT system, signal generation and measurement are required for every channel. To design a high performance multi-channel EIT system, signal generation and demodulation with a high SNR are required. These require a large number of logic gates in the FPGA. In this paper, optimizing the use of the FPGA to design a more efficient multi-channel EIT system in terms of cost, power consumption and size is discussed. The sinusoidal signal is generated with a high sampling frequency using the DDS technique, and has a 102dB SNR and a 50Hz frequency resolution. The result of frequency resolution is a trade-off to minimize the space consumption in the FPGA. In the design of the I/Q demodulation, the down-sampling technique is used which decreases the size of the multipliers. Moreover, it reduces the number of coefficients in the dual-channel low-pass filtering. The Optimal FIR filtering technique is used to design the low-pass filters. The resulting filters have 150dB SNR and 0.001 dB equirriple in the pass-band. [ABSTRACT FROM AUTHOR]

This paper describes a proposed methodology for the development of adaptive sites for use in training, collaborative learning, distance education and, mainly, continuing education, applicable to the operation of hospital equipment by healthcare professionals. The mechanism of adaptation of the site, that employs neural networks of the Multi-layer Perceptron and Interactive Activation and Competition types, is focused on the interface through the use of different media in the presentation of the content. The characteristics of the user are based on the cognitive theory of Multiple Intelligences. The system automatically modifies the form of content presentation using text, flow chart, drawing and animation as well as offering the possibility for the user to explicitly alter the medium through which defined content is presented with the aim of matching this to their current needs. For the evaluation of the proposed method a case study was carried out, based on a multiparametric monitor. The operating manual for the equipment was implemented in two sites: one "adaptive" and one "static" that provide the same content, enabling the carrying out of a motivational evaluation between the different approaches. The results clearly indicate that the benefits to the user are greater using the site with the proposed methodology. [ABSTRACT FROM AUTHOR]

SENTINEL is a Coordinated Action funded by the European Commission under the specific program (EURATOM) for research and training in the nuclear energy field as part of the 6th Framework Program. The project deals with radiation protection, safety and related issues that arise as a result of new developments in equipment, digital imaging, medical devices and information technology industries, paralleled by novel practices and modalities. In practice, this project deals with almost all-radiological digital imaging, outside of Computed Tomography. This project is important as at present developments are entirely driven by combined and essential global forces of the industry on one hand and the clinical users on the other hand. There has been no parallel action in research on the protection, safety, efficacy, optimization, justification or ethical issues, despite a certain amount of regulatory development. This deficit is now evident, as day-to-day practice has outpaced the available statutory safety and standards framework. The undertakings of the project covers: Functional and Objective Equipment Performance and International StandardsDosimetry, Constancy Testing and QAJustification, Ethics, and EfficacyGuidelines, Good Practice, and Training Materials. The project underwrites the safety, efficacy and ethical aspects of clinical practice while protecting and adding value to the products and of the associated knowledge based equipment, information technology and service industries. The Coordination Action is divided into eight distinct but interrelated Work Packages: Functional Performance and Standards; Efficacy and Safety in Digital Radiology, Dentistry and Nuclear Medicine; Efficacy and Safety in Cardiology; Efficacy and Safety in Interventional Radiology; Efficacy and Safety in Population Screening/Sensitive Groups; Good Practice Guidance and Training. The intention of the present paper is to present the efforts of this Coordinated Action in the area of education and training. [ABSTRACT FROM AUTHOR]

We studied the prototypal developments of Plastic Cortex Stimulator (PCS) for stroke recovery. The PCS implanted in damaged cortex of rat brain can increase the plasticity of nearby cortical area, so that the motor sensation can be improved. For future implantation, an wireless technology is necessary. In this paper, the ZigBee technology was used. ZigBee is a proprietary set of high level communication protocols designed to use small, low power digital radios for wireless personal area networking (WPAN). The stimulation module receives the waveform parameters through ZigBee and generates the electric stimulation current. The result shows that it is possible to use Zigbee technology on the PCS. The wireless control of PCS based on ZigBee can help the tele-rehabilitation of the stroke patients. [ABSTRACT FROM AUTHOR]

This paper presents the KAIST-Ewha colonoscopy simulator II with increased haptic fidelity as well as visual feedback. The colonoscopy simulator includes a specially developed haptic interface and optimized colon models constructed from CT data of actual patients. The colonoscopy simulator provides with enhanced haptic realism, which is made possible by employing a haptic device with decoupled translational and roll force-feedback mechanisms. Manipulation of the colonoscope tip is monitored by four deflection sensors, and triggers computation to render accurate graphic images corresponding to the knob rotation. A photo-sensors unit is developed to simulate jiggling motion which is one of the important colonoscopy skills to fold and straighten the colon. Friction in the haptic device is compensated by using force-torque sensors, and the force-torque profile during simulation is also logged by these sensors. The colonoscopy simulator employs a centerline-based parametric modeling of the colon for fast and accurate collision detection and haptic response between the colon and the colonoscope. The developed Colon Modeler provides with patient-customized colon models, and various training scenarios including rare cases. [ABSTRACT FROM AUTHOR]

Japan's population is aging faster than that of any other country. The rate of elderly people ages 65 and over has exceeded 19% and the rate with continue to increase to reach 28.7% in 2020 according to the official estimation. The number of the demented elderly is expected to increase with the rate. It's difficult to treat moderate or severe dementia but the possibility is suggesting in the case of mild dementia or MCI. Therefore it is urgent to find people with dementia as early as possible and make them change their lifestyle and rehabilitate intellectually. The Stroop effect is a delay occurs in the processing of the word's color when a word such as blue, green, red, etc. is printed in a color differing from the color expressed by the word's semantic meaning. It has suggested that the Stroop task performance correlates with higher function and our study showed that there is a strong correlation between the Stroop effect and dementia severity. In this paper we show a cognitive function self-training system by Stroop effect task for mild demented or MCI. This system consists of a notebook-size personal computer and a liquid crystal display with a touch screen. Sixteen words printed in congruent or incongruent color are shown in random order on the display and subjects touch the words that are incongruent color via touch screen. The subject's brain called anterior cingulated, involved in a wide range of thought processes, are stimulated by performing the Stroop effect task. An answer time measurement and the determination of answer are made. These date are saved and fed back to next words display time. [ABSTRACT FROM AUTHOR]

Tracheal intubation is the standard method of airway management in artificial respiration for medical treatments such as anesthesia, intensive care, and emergency care. However the intubations frequently cause fractures to the teeth. Japan's residency program and law concerning emergency life guards were amended in 2004 for trainees to be trained for a given period. The training to get licenses expands rapidly throughout Japan and an objective evaluation method of it will be required. The importance of education system in tracheal intubation is increasing from the legal amendments. In this system, a commercially available force sensor, Flexi-Force (Nitta Cooperation, Japan), and two-axes gyroscope sensor (MicroStone Cooperation, Japan) were attached to the laryngoscope for monitoring its motion. The sensors' outputs are incorporated in H8 microcomputer with a LCD display (SUNLIKE Cooperation, Taiwan) to evaluate operators' skill. If the laryngoscope is operated incorrectly, alarm buzzers beep according to wrong actions. The laryngoscope system is also designed to be able to send data on a connected computer to be analyzed later. Main points of positive evaluations of medical doctors are as follows: (1) By using the thin force sensor, the usability is very close to that of a normal laryngoscope; (2) The acquisition and display of the data in response to the sensor is sufficiently fast; (3) Because the buzzer is changeable, one can use according to the training objectives. This paper suggests a training system with sensors for safer treatments. [ABSTRACT FROM AUTHOR]

The Artificial Intelligence Applied in the Modeling and Implementation of a Virtual Medical Office Project (IACVIRTUAL) proposes an intelligent system to simulate a Web-based Medical Office conceived to support (i) patients who are interested in following their medical reports, (ii) professionals interested in decisions support systems for diagnosis and treatment, and (iii) students interested in learning by following available medical cases. IACVIRTUAL has several modules and among them are the Decision Support Module (DSM) and the Educational Module (EM). The Intelligent Tutor System (ITS), a sub-module of EM, is based on the MATHEMA architecture, which was conceived to provide a space for promoting cooperative interactions between an apprentice and a society of artificial tutor agents, having a human expert's society as a backup assistance for such interactions. DSM supports medical diagnosis and subsidies EM with problem resolution using Case-Based Reasoning (CBR). CBR is an Artificial Intelligence technique that solves a new problem using adaptations of solutions of already known similar problems. The CBR model proposed for IACVIRTUAL is based on the Cross-industry Standard Process for Data Mining (CRISP-DM) and follows the 4R (Recuperation, Reutilization, Revision and Retention) cycle. Using (i) this model as fundament, (ii) a base with 1052 clinical records referring to the disease Ischemic Cardiopathy, (iii) the support of a medical expert, (iv) methods of Data Mining, and (v) the IACVIRTUAL environment; a system was developed to support medical diagnosis in the field of Cardiology. This paper intends to describe this system as well to present a case study where it was used in the context of IACVIRTUAL project. [ABSTRACT FROM AUTHOR]

This paper extends our previous work on Competitive Fuzzy Cognitive Maps for Medical Decision Support Systems by enhancing them with Case Based Reasoning Methods. The synergy of these methodologies is accomplished with a novel algorithm that leads to more dependable Advanced Medical Decision Support Systems for situations where the decisions are not clearly distinct. The model proposed and developed here is applied successfully for two paradigms of decision support. The first one is a differential diagnosis example from the speech pathology area for the diagnosis of language impairments and the second one is a treatment planning example from external beam radiation therapy. [ABSTRACT FROM AUTHOR]

For medical decision making processes (diagnosing, classification, etc.) all decisions must be made effectively and reliably. Conceptual decision making models with the potential of learning capabilities are more appropriate and suitable for performing such hard tasks. Decision trees are a well known technique, which has been applied in many medical systems to support decisions based on a set of instances. On the other hand, the soft computing technique of Fuzzy Cognitive Maps (FCMs) is an effective decision making technique, which provides high performance with a conceptual representation of gathered knowledge and existing experience. FCMs have been used for medical decision making with emphasis in radiotherapy and classification tasks for bladder tumour grading. This paper proposes and presents an hybrid model derived from the combination and the synergistic application of the above mentioned techniques. The proposed Decision Tree-Fuzzy Cognitive Map model has enhanced operation and effectiveness based on both methods giving better accuracy results in medical decision tasks. [ABSTRACT FROM AUTHOR]

Chronic glomerulonephritis (CGN), which is caused by an inflammation of the kidney, can be diagnosed via urine, X-ray and biopsy. The objective of this paper was to present an method for the automatic discrimination of clinical test data of CGN patients via a urine analyzer, independently of an inspector's visual inspection, using both statistical methods and a neural network. 10 parameters on a urine strip pad were utilized in order to diagnose disease during the urine test. The indicators of strip pads explain the meanings of the reacted color levels of urobilinogen, glucose, ketones, bilirubin, protein, nitrite, pH, occult blood, specific gravity and leukocytes. In order to detect CGN using the neural network, 4 parameters which are without statistic significance regarding CGN are removed via chi-square and t-tests. The input layer of the neural network consists of a reduced number of 6 parameters and the output layer is used to determine whether or not the given sample is dispositive for CGN. The learning process involved training with the data from 73 normal and 66 CGN patients. The validation set consisted of 50 normals and 50 patients, and was not used in the training set. The neural network was able to discriminate correctly in 96 percent of the normal patients and 94 percent of the CGN patients. Tests of statistic significance and the application of such a neural network appear to be quite effective with regard to the discrimination of CGN. [ABSTRACT FROM AUTHOR]

In this paper, we applied a hot water-induced thermotherapy system to the foot, based on the oriental medicine principle of Dongeuibogam, which is concerned with the notion that the head should be kept cool and the feet warm. The objective of this study was to determine the influence on the cardiovascular system effected by physiological parameters inherent to thermal stimulation at a temperature of 43°C. Therefore, the relevant physiological parameters, blood flow, heart rate, blood pressure, oxygen saturation, and leg temperature, associated with the cardiovascular system, were selected for analysis. The experimental equipment used in this study included a hot water system designed for the feet. Pre and post experimental conditions, at a temperature of 43°C, were assessed for 10 healthy volunteers over 10 days. Pre and post measurements were obtained at 5, 10, 15, and 20 minutes. The biosignal transition results of the experiments were as follows; Blood Flow(ml/min): 1.18 ± 0.50 inc, Heart Rate(bpm): 6.97 ± 0.72 inc, Blood Pressure(mmHg): (max) −1.49 ± 2.81 dec, (min) −0.06 ± 0.13 dec, Oxygen Saturation(%): 1.34 ± 0.28 inc, (dec: decrease, inc: increase). According to our results, hot-water thermotherapy applied to the foot does appear to exert an influence on the cardiovascular system, and also appears to generally improve human metabolism. [ABSTRACT FROM AUTHOR]

This paper describes a computational model of the interaction between a cantilevered flexible plate and unsteady channel flow serving as a mechanical analogue for the vibration of the soft palate driven by respiration. Such vibrations are associated with snoring and/or sleep apnea. Previous work on this analogue system has assumed a constant inlet air velocity whereas, in reality, a pressure drop drives the airflow through the upper airway from oral and nasal inlets to the lungs. Here we develop a model wherein the inlet flows are variables that are determined on the basis of time-varying resistances through the nasal and oral passages, caused by the motion of the soft palate that separates them. This approach permits us to model asymmetry in the positioning of the flexible plate (soft palate) within the channel; previous studies have, perforce, had the flexible plate located along the channel centerline. The new model then provides a muchimproved representation of the configuration found in the upper airway. The pressure drop is imposed for each time step by computing appropriate inlet velocities. The Navier-Stokes equations are solved using an explicit finite-element method written specifically for the channel geometry within which the plate moves fully coupled to the flow. The motion of the plate, driven by the pressure field, is modeled using classical thin-plate mechanics with the addition of a shear-stress induced tension term We find that imposing constant inlet velocity generates over-predictions of energy transfer between flow and flexible plate and hence a lower critical velocity for the onset of unstable flutter motions of the plate. We show that offsetting the flexible plate within the channel leads to a significant displacement of the plate towards the narrower channel and find modifications to its energy interaction with the fluid flow. These effects are used to propose a new dysfunction mechanism, initiating the collapse of the pharynx, based on the first-mode motion of the flexible plate, that is a direct result of asymmetry. [ABSTRACT FROM AUTHOR]

Establishing a visual perception for patient who bear a disability on the retinal cells, a strategy of acquisition the external image information from an image sensor and transmitting of its information to implanted electrodes have studied in many papers. Although a construction of a CMOS (complementary metal oxide semiconductor) image sensor as an image acquisition device has been improved, the images taking from an image sensor still include several noises (e.g. thermal noise, random noise, dark current). Moreover, noise can be generated on the occasion of data transmission from an image sensor to electrodes. In this study, we proposed a fundamental method and a condition for functional electrical stimulation on the retinal ganglion cell based on the CMOS image sensor with higher frame rate, and we studied the influence of noise element on the reaction of retinal ganglion cell. [ABSTRACT FROM AUTHOR]

The advances reported herein form part of a larger project that has as its objective the development of a full flow-structure-interaction model of the human upper airway. Here we first briefly report on a two-dimensional (saggital section) model built using published CT-scan geometric data. For the development of our three-dimensional capability, we use the unique data captured in vivo by an endoscopic optical technique that we have developed. This measurement system, described as anatomical optical coherence tomography (aOCT), allows quantitative real-time imaging of the internal anatomy of the human upper airway with minimal invasiveness. Moreover, the system permits motions of the internal geometry at a fixed location to be recorded. The aOCT data set is insufficient by itself to construct a complete geometry because only the polar coordinates are obtained in a local reference frame. Accordingly, the locus described by the endoscope, in which the aOCT is housed, is obtained by orthogonal CT scans. The combination of CT scans and aOCT measurements then provides the required geometric information for the construction of the computational model. Results of a two-dimensional model show how the soft palate responds to the mean-flow variations of the breathing cycle. For the three-dimensional work, the key results of this paper rest in the reconstruction of the time-dependent geometry of the upper airway, the first time that this has been accomplished using direct internally-based measurement. [ABSTRACT FROM AUTHOR]

In this paper, survival estimate under ventricular fibrillation, cardiopulmonary resuscitation, administration of drug (epinephrine), measurement of coronary perfusion pressure and ECG signal is investigated. In 360 segments derived from ECG signal and coronary perfusion pressure data of 18 test dogs with experimental cardiac arrest of cardiac cause, several features are inspected for classification of a group of a return of spontaneous circulation (ROSC). Feature vectors, such as spectral moment, median and peak frequency, level-crossing spectrum, average segment amplitude, extracted from the time and frequency domain analysis are initially tested for the use of statistical analysis, and then Support Vector Machine finds the best boundary line discriminating between ROSC and Non-ROSC. Consequently, determination of the experimental period leading the best performance of Support Vector Machine results in a high sensitivity and specificity of ROSC estimate. [ABSTRACT FROM AUTHOR]

Ventricular fusion beats are the result if the depolarizing wavefronts of excitations that originate from different sites collide within the ventricular functional syncitium. Fusions have been a matter of concern since 1944 [1]. The region of collision functions like a barrier that prevents the further spreading of the depolarizing wavefronts. As a consequence of the change in the spatio-temporal excitation spreading fusions have a complex signal morphology. Hence, fusions can cause problems for proper signal analysis. Erroneous signal analysis and pattern recognition, however, may be a major problem for the timing control of cardiac pacemakers and implantable defibrillators. Furthermore, fusions have also an impact on the spatio-temporal process of contraction since the contraction waves follow the depolarizing wavefronts and collide in the same region. As a consequence, ventricular fusions affect the hemodynamic efficiency of the cardiac pump mechanism. The occurrence of fusion beats has been used for diagnostic purposes, e.g. for the diagnosis of disturbances of the regular excitation spreading like the Wolff-Parkinson-White syndrome or bundle branch blocks. More recently interest is growing in the therapeutic employment of provoked fusions, e.g. for treatment in certain forms of cardiomyopathy and for reversed cardiac remodeling by multisite pacing. Fusions can be detected in records both of surface electrocardiograms and intramyocardial electrograms. Until now, however, the basic understanding of the signal morphology of intramyocardial electrograms is rather poor. For that reason, the analysis and interpretation of the signal morphology of intramyocardially recorded fusion beats needs further examination. This paper presents some results of the analysis of intramyocardial electrograms. [ABSTRACT FROM AUTHOR]

Mathematical model of craniocaudal forces developed by a mechanical activity of heart and blood flow through great arteries has been described in the paper. The model was used to generate oscillations corresponding to seismocardiographic signals. [ABSTRACT FROM AUTHOR]

We are interested in developing novel multifunctional biomaterials applied for dental surgery and the fabrication of artificial bone scaffolds with a controlled pore structure. Hydroxyapatite (noted HAp) is a useful biomaterial due to its good biocompatibility. Small amount of iron has been known to influence the crystallinity and solubility of HAp. In this study, various kinds of trace iron containing HAp (noted FeHAp) were synthesized by adding an aqueous solution of iron nitrate into a modified pseudo-body solution with an excess of phosphate ion concentration. The crystal structures of FeHAp were refined by the Rietveld analysis. The optical properties of FeHAp were measured by UV-vis spectroscopy. The results indicate that the cell parameters become longer and the photo-absorption become stronger with increasing iron within the studied composition range. This implies that FeHAp is possible to have additional functions comparing with plain HAp when is used as a biomaterial. In this paper, syntheses and characterization of the novel FeHAp are reported. [ABSTRACT FROM AUTHOR]

Atherosclerosis is a major contributing factor to death and disability worldwide. It is implicated in coronary heart disease, stroke, peripheral arterial disease and bowel infarction. Catheter angiography is widely used in patients who suffer from this disease. Apart from the various risk factors and side effects associated with such a technique are the obvious high costs involved. This paper explores the concept of using acoustic waves as a cost effective and accurate method to detect the location and condition of diseased segments of blood vessels. The propagation and reflections of arterial pulse waves (generated by the contraction of the left ventricle) in the systemic arteries are simulated using a linearised acoustic model. The original wave travel to the brachial artery, iliac bifurcation and aorta is traced. The reflected wave that travels back up the aorta and into the brachial artery through the subclavian artery is also determined. By observing the time lag between the original and the reflected waves, the effects of arterial stiffness, geometry are studied by simulating the model at various stiffness, geometries. An algorithm to non-invasively identify the arterial stiffness variation is described. [ABSTRACT FROM AUTHOR]

One of the important characteristics of biological soft tissues is they can convert their mechanical deformations into electrical signals and vice versa. That means the endogenous electric fields in soft tissues can be altered by external forces. This paper reports the results of our recent research on the mechanical-electric properties of frog Sartorius and Gastrocnemius muscles by oscillatory tensile tests. The muscle samples were obtained from living bull frogs. A modified Ringer's solution with high concentration of potassium was used for depolarizing frog muscles to avoid the bioelectric affect. Both dried and fresh muscles were tested to investigate water involvement on piezoelectricity behaviour of the samples. Oscillatory tensile tests were conducted on the muscles by a force-controlled mechanical device. Different loading forces and rates were ranged in order to monitor the electric signal generated in the muscle sample by the deformation alternation. Meanwhile, the loading forces and the generated electric signals were recorded with the same time scale. The experimental results demonstrated that skeletal muscles have good mechanical-electric behaviour. When the muscle is deformed, it gives off small but measurable electrical voltages. The electric voltage in the muscle can be varied, depending on the external forces under sinusoidal or square waveform loading path. For frog Sartorius and Gastrocnemius muscles, those electric signals varied within 0.15V to 0.8V under loading forces ranged from 10N to 18N. The mechanical-electric behaviour of dried samples was more stable and reliable than fresh samples. It is because the mechanical-electric behaviour of fresh sample varies with percentage of their water content sensitively. This investigation is an essential step for understanding the mechanical-electric behaviour of biological soft tissues. [ABSTRACT FROM AUTHOR]

This paper describes design of the dexterous manipulator for laparoscopic surgery that performs like a human whole arm and the FEM simulation result to measure the force of its tool-tip for including force-feedback loop. Though a human whole arm has 7 degrees of freedom, we have designed overall 8 degrees of freedom because of considering one dof translation motion that corresponds with human body movement. Some researchers reported that if we could develop either mechanical or electromechanical tele-operators which enable surgeons to move a MIS system in a manner analogous to an open instrument, we could potentially reduce the time of current laparoscopic procedures by at least 15% and we could perhaps also enable surgeons to perform procedures which are currently too difficult. Accordingly, we are expecting that the suggested design provides surgeon with improved dexterity during minimally invasive surgery. [ABSTRACT FROM AUTHOR]

As the standard of living rises, people are more interested in their health and desire well-being life. However they cannot make sufficient effort regarding their health and life style due to the fast moving working environment. In order to attain their sound life, it is necessary for people to have support from user customized life management service. This paper proposes lifestyle recommendation system using Framingham Heart Study based Clinical Decision Support System (CDSS). The most prominent features of this system are rule based clinical decision supporting, life style recommendation based on user's vital signs, existence of chronic disease, life pattern and family history, as well as life style enhancement promoting service that induces user to accomplish their mental and physical healthiness based on the recommendations. The prototype system is designed and implemented using smart objects such as smart mirror and Kiosk. The doctor side application is also built to enable medical doctors to examine systems' appropriateness of clinical use. [ABSTRACT FROM AUTHOR]

A key challenge of distributed surgical simulation is to maintain a high level of state consistency among the distributed users under the limitation of network transmission capacity. In this paper, a framework integrating a scalable deformable model and an extensible communication protocol is proposed to meet this challenge. A prototype has been developed by using the client-server network architecture. Experimental results demonstrate that this framework can support collaborative surgical simulation with acceptable network latencies. [ABSTRACT FROM AUTHOR]

Three dimensional (3D) reconstruction is applied to medicine, especially in robotic surgery assistant systems. By a conventional ultrasonic machine and a position tracker sensor, serial 2D images are produced and used in 3D reconstruction. This paper describes important ultrasonic image processing and a VTK based software used for 3D surface reconstruction. Details of VTK classes are explained. From its application in biological samples, it seems the 3D shapes are suitable on ultrasound-based robotics assisted surgery system (HIT-RAUS). [ABSTRACT FROM AUTHOR]

This paper proposes multi-functionalization of the previously reported laparoscopic forceps manipulator with multi-slider linkage mechanism which enables 2-DOFs horizontal and vertical bending of ±90 degrees and 1-DOF grasping manipulation. Specifically we added a bipolar electric scalpel function on the forceps blades for more safe, speedy and efficient surgical operation with coagulation of tissues and occlusion of blood vessels from various directions in abdominal cavity. This functionalization can lead cutting down the number of surgical instruments and insert ports, and saving troubles of changing tools. For the scalpel function, we mounted a pair of electrodes measuring 1.0 × 5.0 × 0.1 mm × 2 lines aligned with a 0.5-mm space, to generate high current density between two forceps blades. In animal experiment using swine (39 kg, male), we evaluated the ability of occluding blood vessels on mesenteric surface tissues through various directional approach paths using 2-DOFs bending manipulation effectively. We coagulated blood vessels 2-3 times with setting of 20 W and 2-3 seconds energization. And in order to confirm whether the blood vessels were completely occluded or not, we attempted a cut of ablated parts with scissors and checked blood leak. In this experiment we tried to occlude 6 vessels. Four vessels were occluded successfully, while other two vessel occlusions were incomplete. A little leak was shown in these vessels, however, some repeated coagulation made complete seals. These incomplete coagulations resulted from ablated tissues on the electrodes surface for something of a shield to interrupt effective energization. For the solution of this trouble, it can be effective to improve the electrode and forceps blade shapes. In conclusion, we are sure of feasibility of the bipolar electrode scalpel function with multi-DOFs bending manipulator to ablate tissues and seal blood vessels for laparoscopic clinical applications. [ABSTRACT FROM AUTHOR]

A master slave dexterous manipulator allows dexterity to be increased. Moreover, with capability of remote surgery, it is possible to realize participations of highly capable doctors to a surgery, which takes place in a distant place. And also, it is possible to facilitate a team work medical treatment between doctors from all around the world. We have conducted Japan inland remote surgery experiments between Tokyo and Shizuoka (150km of direct distance) for 4 times at the writing time. ISDN(2B+D) and ISDN(23B+D) have been used in the experiments. Laparoscopic cholecystectomies have been successfully carried out on pigs within 50 msec of control signal time-delay and 400 msec of image time-delay, approximately. The completion time of whole surgical procedure was approximately 90 min, which is roughly equal to a conventional laparoscopic cholecystectomy. In this paper, a remote surgery experiment, which was conducted between Japan and Korea is described. Research & Development (R & D) Internet testbet APII (Asia-Pacific Information Infrastructure), which consists of an optical submarine cable network KJCN (Korea-Japan Cable Network), was used. In the experiment, a laparoscopic cholecystectomy was successfully carried out on a pig. The network time-delays of control signal and images were 6.5 msec and 435.5 msec respectively. A comparison of remote surgery experiments using ISDN and the Internet was studied. [ABSTRACT FROM AUTHOR]

In prostate brachytherapy, radioactive seeds are permanently implanted in the prostate for delivering a tumorocidal dose to the cancerous tissues. These seeds provide a significant radiation dose to a relatively small volume, requiring that the seeds be placed accurately to ensure complete treatment. Sensitivity of the urethra and rectal mucosa to radiation are other factors that heighten the need for careful placement of the seeds. In currently practiced manual procedures, the needles are inserted into the patient through fixed holes of a physical template where the maneuverability of the needle is extremely difficult. In contrast, a robotic system can not only provide flexibility in positioning and orientating along with improved consistency and accuracy of needle insertion and seed deposition but may also assist less skillful/inexperienced clinicians to treat patients with higher quality. Thus, it is important to develop an automated (or a semiautomated) seed delivery device which can provide enhanced consistency, accuracy and efficiency. In this paper, we present the design and development of a 8DOF motorized semi-automated ultrasound image-guided robotic system for performing prostate brachytherapy. In this system, we have incorporated various important data and methods gleaned from in-vivo measurements in the operating room. Techniques, proven by in-vitro experiments, to reduce needle insertion force and tissue deformation have been implemented into this design. Three force-torque sensors have been incorporated to track the forces on the needle for detecting pubic arch interference and to improve robot control. Rigidity and factor of safety of the device has been analyzed using the finite element method. Provisions for position, velocity and force feedback incorporated in this device are useful in improving needle insertion accuracy, consistency and efficiency. We also present preliminary experimental results regarding the performance of the prototype system. [ABSTRACT FROM AUTHOR]

Previous bone fusion surgery by surgeon has three major difficulties: lack of operation accuracy, surgeon's overexposure to radioactive contamination, and need of surgeon's intensive labor during operation. This paper proposes a bilateral teleoperation system for spine bone fusion surgery, BiTESS-II, to overcome those problems. In order to determine design specification of the system, we estimated human bone properties during gimleting and screwing process using the developed data acquisition systems. Based on the spine bone properties, we designed an end effecter, a slave robot and 2 master devices. The slave robot can perform surgical operation to gimlet cortical bone and to insert screws into human spine. Master devices are used to control the pose of the slave robot and to generate haptic information identical to the slave side. We also developed novel force reflection methods without force sensor so that the end effecter can be designed simple and light. The performance of the developed system was verified by experiments. [ABSTRACT FROM AUTHOR]

This paper proposes a surgical task model for developing an intelligent control method for a laparoscopic assistant robot. The proposed model makes the use of surgical knowledge composed of surgical procedure, tool information, desired view and preferred control method at different phases of surgery. For establishing the surgical task model, procedures in human cholecystectomy are analyzed. It was found that there are specific task and action associated with a specific tool and certain views are preferred by the surgeon. It was also found that the surgeon prefers the assistant to stay steady while manipulating the tissues or organs whose motions are constrained by anatomical features while they prefer the assistant to track the tool tip when there are relatively limited constraints. The interaction scheme based on this surgery task model is implemented using a compact laparoscopic assistant robot and its performance was compared to the in vivo porcine cholecystectomy using voice commands alone. [ABSTRACT FROM AUTHOR]

The paper deals with calculation of the parameters of ceramic material from a set of destruction tests of ceramic heads of total hip joint endoprosthesis. The standard way of calculation of the material parameters consists in carrying out a set of 3 or 4 point bending tests of specimens cut out from parts of the ceramic material to be analysed. In case of ceramic heads, it is not possible to cut out specimens of required dimensions because the heads are too small (if the cut out specimens were smaller than the normalised ones, the material parameters derived from them would exhibit higher strength values than those which the given ceramic material really has). On that score, a special testing jig was made, in which 40 heads were destructed. From the measured values of circumferential strains of the head's external spherical surface under destruction, the state of stress in the head under destruction was established using the final elements method (FEM). From the values obtained, the sought for parameters of the ceramic material were calculated using Weibull's weakest-link theory [ABSTRACT FROM AUTHOR]

Recently, transparent-resinous-ultravioletcuring- type (TRUCT) Braille signs are becoming more and more popular in Japan, especially when they are printed together with visual characters. These signs are made by screen printing whose technique can be applied to various base materials, such as paper, metal, and plastic. TRUCT Braille signs have begun to be used in public facilities, such as on tactile maps and on handrails. Naturally, it is expected that Braille beginners will utilize these signs. However, it has been pointed out that the friction between the forefinger and the base material may affect TRUCT Braille reading. In this study, we invented soft and thin material finger cover to reduce friction during Braille reading. And also we have carried out a study to investigate the effect of using a finger cover. The subjects were 12 Braille learners with acquired visual impairment, who were asked to read randomly selected characters with and without wearing the finger cover. The results show that most participants could read TRUCT Braille significantly faster and more correctly with a finger cover than without it regardless of dot height. This result suggests that wearing finger cover enables the Braille learners to read TRUCT Braille more efficiently. The finger cover can be used as a Braille reading assistance tool for Braille learners. Effectiveness of finger cover may include the safety factor that forefinger remains clean. In other words, with the finger cover, forefinger will not become dirty. After one or two years, we will put into practical use finger cover in Japan. [ABSTRACT FROM AUTHOR]

One of the most crucial aspects of closed-loop control of upright mobility using functional electrical stimulation (FES)-evoked muscle contractions is the development of a robust control algorithm. The need for compliance with certain safety requirements when FES-evoked movements are deployed to neurological patients is essential, and the computational tools employed play a fundamental role in this task. This paper reports on some new developments regarding closed-loop control of upright mobility and discusses some important issues concerning FES control design. Our laboratory has focused on the restoration of mobility in spinal cord-injured individuals by means of FES-evoked muscle contractions, and currently we deploy a Pocket PC to control an ambulatory neuromuscular stimulator, while movement feedback data is collected from portable motion sensors. Programmed in Matlab Simulink, the control algorithm is structured with sensor feedback (thighs and shanks kinematic data) acting as the model input and the stimulator channels (gluteus, quadriceps and common peroneal nerve) as the model output. In both input and output components, properties such as sampling rate and stimulation parameters are handled. The functions of standing up, sitting down and stepping are designed as finite-state models and grouped into different subsystems, thereby assuring that conditions of ‘worst-case' system behavior can be identified and treated independently. The operator initiates the changes between states via button presses. The two major control actions of the model's algorithm are the modulation of quadriceps stimulation to avert knee buckle during stance and the stimulation of the common peroneal nerve to refine swing leg motion during stepping. This control algorithm has proven to meet the differing requirements of both the clinical and research environments, by achieving flexible programming with a fast algorithm development, real-time operation, reliable processing of heavy mathematical calculations and the ability to counteract external disturbances or unexpected behavior. [ABSTRACT FROM AUTHOR]

Stroke is a debilitating condition with major costs for patients and their care-givers. Here we present a novel virtual reality (VR) based cognitive neurorehabilitation system for improving the rehabilitation of stroke patients with arm and hand paresis. Using a custom, low-cost kinematic tracking system designed for clinical or home use, patients engage in task-oriented interactions with objects in a virtual environment. Our paradigm is based on the hypothesis that observed actions correlated with self-generated or intended actions activate the motor pathways by means of the so-called "mirror-system". This cognitive approach engages cortical motor observation, planning and execution areas. Combined with intensive, task-oriented acute-phase training (1-6 weeks after stroke) when the factors for facilitating recovery are at their highest levels, we postulate that our approach will facilitate cortical plasticity and improve recovery of upper limb function. The tasks range from simple (hitting moving virtual objects) to complex (grasping and moving virtual objects). In the first-person VR environment the patient controls a displayed pair of upper limbs that follow the position and movements of his/her own arms and hands while performing the tasks. The therapist can adjust the contribution of the non-paretic hand in "assisting" the representation of the paretic hand to varying degrees in performing the tasks, simultaneously stimulating the action recognition systems and increasing patient motivation through graded task success. In this paper we present the neuroscientific background of the system, a technical description of its components, and results from testing on healthy subjects and stroke patients. [ABSTRACT FROM AUTHOR]

For patients requiring temporary cardiac pacing or in occasions when a rapid and precise control of the heart rate is needed, electrical stimulation of the heart from the esophagus can be used. Determination of the pacing threshold for transesophageal atrial or ventricular pacing remains largely an empirical process. In this paper we present a novel approach in quantifying transesophageal electrostimulation of the heart. The goal of this study is to investigate the capacity of computational models for the analysis of current density distribution during transesophageal pacing. We constructed the finite-element model from segmented images of transversal cross-sections of the thorax. Electrical conductivity of the segmented regions (esophagus, heart, aorta, lungs, etc.) was assumed to be homogenous and isotropic. We obtained solutions for the current density distribution in the thorax for two types of pacing leads: (i) a conventional lead having cylinder shape electrodes and (ii) a selective lead where electrodes comprise only a part of cylinder's side surface. We estimated stimulation regions and compared numerical results for the current density with previous studies in which these two types of pacing leads were analyzed without taking into account inhomogeneous conductivity of the thorax. Advantages of selective lead over conventional one were demonstrated. Numerical experiments indicate that analysis of current density distribution using the finite-element model is useful for the optimization of the pacing lead geometry, optimization of the insertion depth of the lead, and optimization of the stimulus amplitude. [ABSTRACT FROM AUTHOR]

This paper is a report on an investigation of the relationship between the condition number of a leadfield matrix of magnetoencephalography (MEG) and source reconstruction accuracy. We suggest the use of the condition number as a promising a priori accuracy estimator of neuromagnetic inverse problem (NIP) since various simulation studies demonstrated that the reconstructed source distribution has the wider region and contains the more spurious sources if a leadfield matrix has the higher condition number. The simulation results also verified that the accuracy estimator based upon the condition number can explain well-known phenomena of NIP, which suggests a potential application of the proposed concept. [ABSTRACT FROM AUTHOR]

This paper investigates the induced electric fields and currents in a human body tissues and organs of a live-line worker standing right under the maximum sag-point (mid span) of a double circuit 132 kV transmission line located in Riyadh, Saudi Arabia. The main purpose of this study is to determine, if the electric fields and current densities induced inside the critical tissues of a human body such as brain and heart are within the exposure limits of the IEEE Standards C95.6 - 2002. The double circuit 132-kV, 60 Hz transmission line has a power rating of 293 MVA, a maximum recorded peak load current of 603 A. Charge simulation method and the Biot-Savart law have been adopted for computation of external electric and magnetic fields. Finite Difference Time Difference (FTDT) technique and anatomical human body model with more than 40 different tissues with 3 mm voxel sizes have been utilized to calculate organs internal induced electric field and circulating currents. Simulation indicates that, at 1.75 meter above the ground level and under the maximum sag-point of the 132 kV transmission line, the computed external electric field is 1689 V/m and the external magnetic field is 92 mG. These values are below the limits set by the IEEE Standards for external exposure for the live-line workers. The maximum induced electric fields in the brain and heart are 29.5 and 6.3 mV/m respectively. These values are below the IEEE Standard recommended limits of 53 mV/m for the brain and 943 mV/m for the heart. The maximum induced electric fields for all human tissues, excluding the skin, was at the bone marrow of the feet and is 1.86 V/m. This value is lower than the IEEE Standard limit of 2.1 V/m for extremities. Consequently, a worker standing under the maximum sagpoint of a 132 kV transmission line during the peak loading condition is safe from the short term effects of EMF exposure on human body tissues. [ABSTRACT FROM AUTHOR]

Maximum Intensity Projection (MIP) is a volume rendering technique which is used to extract high-intensity value along the corresponding viewing ray. It identifies patients' anatomical structures from MR or CT data sets. Recently, it becomes possible to generate MIP images with interactive speed by using Graphic Processing Unit (GPU) even in large volume data sets. As we can observe volume data sets in many arbitrary directions, usually, volume boundary plane is obliquely crossed with view-aligned texture plane. There is no data value in the outer of volume data boundary therefore the Nyquist frequency at the boundary becomes high. Since the sampling distance is not increased at volume data boundary in volume rendering, the aliasing problem due to data loss exists. If numbers of slices are increased to solve the aliasing problem for reducing sampling distance, it will decrease the rendering speed, too. In this paper, we propose a new method to re-render volume boundary planes. Our method improves image quality to reduce sampling distance near volume boundary which is high frequency area. On the other hand, MIP is independent of sampling order and increasing numbers of slices do not degrade image quality by using our method. Image quality is improved without increasing rendering time since it is only 6 clipping planes are needed for re-rendering. In addition, our method can be successfully used to apply to Volume of Interest (VOI) or clip-plane. [ABSTRACT FROM AUTHOR]

This paper presents an efficient graphics hardware- based method to segment and visualize level-set surfaces as interactive rates. Our method is composed of CPU page manager, GPU level set solver, and GPU volume renderer. The CPU page manager generates page table, inverse page table and available page stack as well as process the activation and inactivation of pages. Our GPU level set solver computes only voxels near the iso-surface. To run efficiently on GPUs, volume is decomposed into a set of small pages. Only those pages with non-zero derivatives are stored on GPU. These active pages are packed into a large 2D texture. The 3D level set partial differential equation (PDE) is computed directly on this packed format. The CPU page manager is used to help manage the packing of the active data. Our GPU volume renderer performs volume rendering of the original data simultaneously with the evolving level set. Our efficient GPU-based method relies on packing the level set surface data into a dynamic, sparse texture format. As the level set moves, this sparse data structure is updated via a novel GPU to CPU message passing scheme. Our method is applied to two chest CT datasets for evaluating computation time. Experimental results show that our solution is much faster than previous optimized solutions based on software technique. [ABSTRACT FROM AUTHOR]

The three-dimensional viewing aids experts by providing a better comprehension about the shape and composition of an organ or structure from the analyzed human body. As three-dimensional ultrasound equipments are still an expensive resource, the main goal of this work is to develop a three-dimensional visualization system, which obtains ultrasound images from two-dimensional equipment. The images should be acquired in B-Mode and they are the source for providing the volume rendering by this system. In this paper initial results using images corresponding to computational phantoms are shown. The main idea of the visualization system is to provide to the physician not only the surfaces visualization but also to display the fetal internal structures. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy is one of the main sources of blindness throughout the world. Retina microaneurisms are good clues to an early diagnosis of diabetic rethinopathy. Their size is from 10 to 100 micrometers and they appears on retina photographs like a small dot (from 2×2 to 20×20 pixels on images depending on the captor resolution). Classification of these photographs by a human operator is time consuming. But it is necessary to adequately guide medical therapy. Our goal is to automate this task in order to make early detection for every diabetic people, with saving a considerable amount of ophtalmolgists' time. The algorithm presented in this paper uses wavelet image decomposition. Our method compares a small part of the decomposed images (typically 15×15 pixels) with a theoretical microaneurism. It is modeled by the use of a generalized Gaussian curve. The comparison lays in performing the squared errors sum between coefficients of each subband and the theoretical microaneurism corresponding coefficients. Thresholds are adjusted by using a genetic algorithm (grid search) to separate microneurisms from other structures. This algorithm is tested on 651 retinopathy lesions. Each image has been manually segmented by an ophthalmologist to compare our results to theirs. Result of specificity and sensitivity scores are shown for different kinds of wavelets and levels of decomposition. The best combination is obtained with the Haar wavelet and 2 levels of decomposition. In this case results are: 96.18% of specificity and 87.94% of sensitivity. [ABSTRACT FROM AUTHOR]

Medical imaging systems such as computed tomography, magnetic resonance imaging provided a high resolution image for powerful diagnostic tool in visual inspection fields by physician. Especially MDCT image can be used to obtain detailed images of the pulmonary anatomy, including pulmonary diseases such as the pulmonary nodules, the pulmonary vein, etc. Image segmentation is an important problem in medical image processing and computer vision. In X-ray CT images, several approaches have been reported for segmenting lung cancer area. However, manual segmentation of the lung area may require several hours for analysis. Furthermore, MDCT images contain more than 300 slices. Therefore, manual segmentation method cannot apply for clinical application in the MDCT images. Ground-Glass Opacity (GGO) is defined as increased attenuation of lung parenchyma without obscuration of the pulmonary vascular markings on CT images. It is one of the important features in lung cancer diagnosis of computer aided diagnosis. If the area, occupied by GGO is large on the CT image, medical doctor can extract the GGO comparatively easily. However, the possibility to overlook the light gray shadow becomes higher when GGO exists as a small area. In this paper, we propose a new technique for automatic detection of GGO shadows by three characteristics on the thorax MDCT image. In the first step, we extract the region of interests in order to segment the lung area. To segment the lung area, we start preprocessing the CT slices by employing binarization, labeling, shrinking and expansion processing. In the second step, we calculate characteristics of GGO shadows such as mean value, standard deviation, and semi interquartile range. In the final step, the GGO shadow's regions are extracted by linear discriminant function. The proposed technique was applied to 5 lung MDCT image sets (each case containing 210 to 250 CT slices) and all of the GGO shadows are detected correctly on the image sets. [ABSTRACT FROM AUTHOR]

This paper presents deformable templates as a tool for segmentation and localization of biological structures in medical images. Structures are represented by a prototype template, combined with a parametric warp mapping used to deform the original shape. The localization procedure is achieved using a multi-stage, multi-resolution algorithm designed to reduce computational complexity and time. The algorithm initially identifies regions in the image most likely to contain the desired objects and then examines these regions at progressively increasing resolutions. The final stage of the algorithm involves warping the prototype template to match the localized objects. The algorithm is presented along with the results of four example applications using MRI, x-ray and ultrasound images. [ABSTRACT FROM AUTHOR]

Traditional endoscopes penetrate the human body in order to provide high-resolution internal views of cavities and hollow organs. Even though such examinations are mostly considered non-invasive, the procedure causes pain, or at least discomforts the patient, who consequently needs some kind of sedation or anesthesia. Virtual endoscopes provide internal views of the human body without penetrating it, based on a set of parallel cross-sections produced with any computer tomography method. This paper presents the design and implementation of a software system, which acts like a virtual endoscope. It takes into account the general requirements of the system, gives a solution that uses a multi-step algorithm, and finally shows the resulting 3-D images. Most of the algorithmic steps have several possible solutions. Some comparisons are made among them where appropriate. Our virtual endoscope establishes 3-D internal views based on sets of 2-D slices, which originate from magnetic resonance imaging devices. The chain of the applied image processing methods consists of the followings: (1) Adaptive filtering to eliminate the low-frequency intensity non-uniformity (INU) artifact, and high-frequency "salt-and-pepper" disturbances; (2) Segmentation of the stack of MRI slices using an enhanced fuzzy C-means algorithm; (3) 3-D surface recovery algorithm based on level set methods and fast marching methods, a comparison is made between their performances; (4) Interactive visualization using modern computer graphics technologies, providing the possibility to measure distances, areas, volumes as well. The quality of service provided by the chosen method mainly depends on the resolution of the input images. [ABSTRACT FROM AUTHOR]

In this paper, a non-linear registration method is used to interpolate and reconstruct (3D+t) CT data sets from multislice CT scans, which are collected simultaneously with digital spirometry. The non-linear registration approach applied is an optical flow based method. It estimates a velocity field between successive scans, which is used to reconstruct a 4D CT data set by interpolating data at user-defined tidal volumes. A qualitative and quantitative evaluation showed that artifacts can be reduced significantly by this technique. The comparison between slice changes inside a data segment and slice changes at segment borders enables a quantitative evaluation. For four patient data sets the artifacts could be reduced by 31.8 %, 29.9 %, 30.7% and 41.6% (mean over all data segments). Furthermore, the reconstructed 4D CT data sets are used for studying the motion of lung tumors and inner organs during the respiratory cycle. The reconstructed 4D data sets of 4 patients with lung tumors were used to quantify the individual tumor and organ movements during a breathing cycle. Based on the determined velocity field, trajectories of landmarks and surface points are analyzed. The motion of the lung tumor center in three orthogonal directions can be displayed and probabilities of lung tumor appearance are computed in 3D. [ABSTRACT FROM AUTHOR]

Detection of subtle lesions on CT images is a difficult task for radiologists, because subtle shadows tend to have low contrast, and a large number of CT images must be interpreted in a limited time. A temporal subtraction image, which is obtained by subtraction of a previous image from a current one, can be used for enhancing interval changes (such as difference in the size of a tumor) on medical images by removing most of the normal structures. For detection of lesions in chest radiographs, the temporal subtraction technique has been applied successfully to clinical cases. Although the overall performance of the temporal subtraction technique was relatively good, registration errors still remained. In this paper, we propose a new nonlinear image-warping technique for accurate registration and subtraction of two thoracic MDCT images with particular emphasis on reducing the artifacts caused by blood vessels and ribs. Our new method was examined on 10 sets of MDCT images. Preliminary results indicated that interval changes on the subtraction images were enhanced considerably with reduction of misregistration artifacts. [ABSTRACT FROM AUTHOR]

The general solution to the cluster validity problems is that one selects or defines a cluster validity index and performs a traditional clustering algorithm for all possible numbers of clusters in sequence to find the clustering structure with the best cluster validity. This is a time-consuming work. To effectively determine the optimal number of clusters in a given data set and at the same time construct the clusters with good validity, this paper presents an automatic clustering algorithm that do not require users to give each possible number of clusters. The automatic clustering algorithm treats the number of clusters as a variable and evolves it to an optimal number. In this study, in addition to the general solutions using four different traditional clustering algorithms, the proposed algorithm is employed to solve the problem of classifying the excited hearing neurons of rats. Experimental results show that the proposed clustering algorithm provides the best clustering results and the best number of classes of the excited hearing neurons is three. [ABSTRACT FROM AUTHOR]

Addressing the rising interest in biomedical and pharmacological high-content screening assays, a concept has been developed, which integrates automated imaging, multi-parametric sensor readout and probe handling into a single embedded platform (IMR). This paper describes the real-time automated microscopy capabilities of the IMR: Utilizing a topology of distributed intelligences and hardware-based synchronization, the platform concept allows precisely timed and synchronized operation of all integrated platform components. Hardware level synchronization is achieved by means of a newly developed, highly modular digital signal processor based "Integration Control Unit", which runs a real time environment and provides standard electrical interfaces to connect to other platform components. Being suitable for high-content and high-throughput analytical screening, the automated platform may thus develop into an enabling technology for future screening assays, especially in the field of pharmacological drug screening. [ABSTRACT FROM AUTHOR]

The use of coded apertures in gamma imaging has theoretical advantages over collimators. The near-field conditions of nuclear medicine, however, result in images that are corrupted by near-field artifacts. Work that was limited to ideal coded apertures has shown that near-field artifacts and ghosting can be reduced geometrically. This is achieved by placing multiple identical limited-field-of-view coded apertures side by side, in the form of a matrix. In this paper, a basic analysis extends the work towards useful coded apertures viz. apertures that are realistic in terms of thickness, transmission of the aperture material, and pinhole width. Realistic coded apertures tighten the constraints on the imaging system. Computer simulation results for a two-dimensional digital Shepp-Logan phantom are presented. The results show that realistic coded apertures introduce a new ‘tartan' artifact, but that the technique of limiting the field-of-view controls the ‘tartan'. Near-field artifacts and ghosting are also reduced. The image is enhanced visually and in terms of a root-mean-square error measurement, which decreases from 74 to 17. [ABSTRACT FROM AUTHOR]