畑 豊

Precise measurement of cerebral surface area will explores a new method for evaluating cerebral disorders because the cerebrum will be deformed by the cerebral disorders. Conventional methods for segmenting the cerebral region from MR images give coarse area by counting the number of the surface voxels of the segmented region. In contrast, this paper proposes a novel method for extracting cerebral contour with sub-voxel accuracy. The new method is based on particle method, and introduces three kinds of particles that are correspond to cerebrospinal fluid, gray matter and white matter. The proposed method was applied to neonatal MR images, and the experimental results validated that the cerebral contour was extracted with a root-mean-squared-error of 0.45 mm in comparison with the ground truth contour given by a physician.

The aim of this study was to clarify how the introduction of a 24-hour unconscious and unrestrained monitoring system in a nursing home affected the physical and mental functions of care staffs. This system was composed of an air pressure sensor system and an ultrasonic oscillosensor system. The intervened participants were ten care staffs (age 37.4+/-14.2) and nineteen elderly persons (age 85.6+/-8.9) in a nursing home, Osaka, Japan. We carried out a baseline survey at the end of September 2008, and the follow-up study was done at the end of October 2008. From the comparisons of the average scores of measurements between pre- and post-intervention using generalized linear model, the scores of "energy expenditure during diaper changing", "frequency of diaper changing", and "decreased work incentives"; (P<0.01, P<0.05). These results suggest that the introduction of the 24-hour monitoring system in the nursing home could decrease care burden of the care staffs. © 2010 TSI Press.

In this paper, we propose a personal identification by sole pressure change. We obtain sole pressure change of multiple steps by using two pressure sensor sheets. Each pressure sensor sheet is inserted into each shoe as an inner sock. Then, we extract characteristics of sole pressure change from the obtained data. We make template data of both feet from the extracted characteristics. We propose a Euclidean distance based method for personal identification. As the experimental result, we have recognized one of ten volunteers with over 90% accuracy.

In functional test of hip joint, anatomical coordinate system is used. Anatomical coordinate systems are defined by inputting landmarks manually. Therefore decision of anatomical coordinate systems includes inter- and intra-operator variability. In addition, variability of anatomical coordinate systems will affect results of diagnosis and/or cause critical error of total hip arthroplasty (THA) is operation that replaces damaged hip joint by implants. This paper proposes automated definition of anatomical coordinate systems and evaluation method for clinical study. As a result of having applied proposed method, anatomical coordinate system was decided automatically. A result of comparing with pelvic coordinate systems was decided by orthopaedic doctors, an angle mean error ± standard deviation (SD) was 0.78 ± 0.34 deg and an position mean error ± SD was 2.6 ± 1.6 mm. As a result of having calculated pelvic tilt and symmetry of pelvis, the proposed method obtained useful data. © 2010 TSI Press.

The estimation system of the knee joint angle that decreases the variability caused by the subjective diagnosis of the knee joint disorders has been attracting a considerable attention. This paper proposes an unconstraint knee joint angle measurement system using inertial and magnetic composite MEMS sensor. The proposed system estimated the posture difference between the thigh and shank region from the difference of the measurement vector between the compound sensors attached on the shank and the thigh, respectively, and 3-D knee joint angles can be calculated by applying Grood's definition. Through experimented results, the knee flexion angle was obtained compared with the true value due to the measurement error of 1.3 deg in average. © 2010 IEEE.

Voxel based morphometry (VBM) is an approach which detects voxels whose brain tissue density is statistically different from control groups in magnetic resonance (MR) images. It has been applied to diagnose cerebral disorders, cognitive dementias, etc. However, VBM is not applied to neonatal brains because of large differences between the adult brain and the neonatal brain. This article proposes a modified VBM for neonatal brain. The modified VBM segments the brain region by using skull stripping method for neonates, and normalizes the segmented brain into the standard neonatal brain. The standard neonatal brain is constructed by using non-rigid image registration. The proposed method was applied to 14 neonates whose age was between -1 month and 1 month. For any neonates, the method normalized the brain shape successfully.

Anterior cruciate ligament (ACL) injury and knee osteoarthritis are well-known injuries of the knee joint, and pivot shift is a symptom of the ACL injury. Today, to diagnose the pivot shift phenomenon, the manual testing is examined for the early diagnosis, however, it should be affected by inter- and intra observer variability. This article proposes a novel system for detecting and quantifying the pivot shift phenomenon during pivot-shift testing using inertial and magnetic composite micro electro mechanical systems (MEMS) sensor. The system estimated 3-D acceleration vector caused by the pivot shift phenomenon using wavelet transform. The experimental results indicated that the pivot shift phenomenon was detected and quantified. And, there are correlation between the maximum acceleration of the knee movement at the pivot shift and the conventional evaluation by assessors. © 2010 IEEE.

Brain shape is deformed regionally by kinds of cerebral diseases and the degree of progress. Therefore quantitative evaluation of the deformation using MR images is effective for diagnosis of cerebral diseases. We proposed a homologous brain shape modeling deformation for quantitative evaluation of the brain shape using sulcal-distribution index (SDI) in MR images. So in this paper, we propose the homologous brain shape modeling. And we find the availability of the homologous brain shape modeling by investigating relationship between the movement distance with the homologous brain shape modeling and gray matter (GM) density of voxel based morphometry (VBM). This study employed nine male and two female and investigate a difference between male group and female group. The experimental results showed that the relationship between the homologous brain shape modeling and VBM was found from the same detection significant difference. © 2010 TSI Press.

Cortical dysplasia is a congenital anomaly of cerebral cortex. It accompanies considerable number of pediatric intractable epilepsy patients. Therefore, it is very effective to detect cortical dysplasia lesions and to estimate dysplasia degree quantitatively in pediatric brain MR images for planning treatment. However, image features on the pediatric brain MR images of cortical dysplasia aren't clarified. This paper proposed the estimation method using intensity profile by detecting cortical dysplasia in pediatric brain MR images. The experimental results for three subjects with cortical dysplasia showed that the proposed method detected cortical dysplasia lesions with a mean sensitivity of 90.9%, a mean specificity of 93.1%, and a mean efficiency of 92.0%. © 2010 TSI Press.

First, we describe an automated procedure for segmenting an MR image of a human brain based on fuzzy logic for diagnosing Alzheimer's disease. The intensity thresholds for segmenting the whole brain of a subject are automatically determined by finding the peaks of the intensity histogram. After these thresholds are evaluated in a region growing, the whole brain can be identified. Next, we describe a procedure for decomposing the obtained whole brain into the left and right cerebral hemispheres, the cerebellum and the brain stem. Our method then identified the whole brain, the left cerebral hemisphere, the right cerebral hemisphere, the cerebellum and the brain stem. Secondly, we describe a transskull sonography system that can visualize the shape of the skull and brain surface from any point to examine skull fracture and some brain diseases. We employ fuzzy signal processing to determine the skull and brain surface. The phantom model, the animal model with soft tissue, the animal model with brain tissue, and a human subjects' forehead is applied in our system. The all shapes of the skin surface, skull surface, skull bottom, and brain tissue surface are successfully determined. © 2010 Copyright SPIE - The International Society for Optical Engineering.

It is effective to evaluate magnetic resonance (MR) images for diagnosing neonatal cerebral disorders because they often accompany the deformation of the brain shape. However, there are many difficulties when radiologists manually extract cerebral surface from the MR images. Therefore, it requires to extract the cerebral surface from neonatal MR images automatically. There are many methods to extract cerebral surface from adult MR images, but there are few methods for neonatal MR images. This paper proposes a new extraction method based on particle method. The proposed method introduces three kinds of particles corresponding to cerebrospinal fluid, gray matter and white matter. First, particles are assigned according to the cerebral shape. Second, particles are moved to form the homogeneous particles, and are transited to the other particles with respect to MR signal. The proposed method was applied to neonatal MR images. The results showed that the proposed method extracted cerebral surface with high accuracy. ©2010 IEEE.

In this paper, we analyze human gait pattern and estimate her/his foot age. We acquire foot pressure distribution change as gait pattern by a mat type load distribution sensor. From the foot pressure distribution data, duration of gait cycle and center of foot pressure (CFP) changes are determined for each stride. We employ four estimation indexes such as step length, step CFP width, the time of double supporting period and distance of step CFP changes. We employ 87 volunteers, and divided them to young, middle age and elderly groups. By comparing of three groups, we found that elderly had shorter step length and larger step CFP width than young and middle age people. Besides, the double supporting time of the elderly was longer, and distance of step CFP changes was longer than those of young and middle age people. From these facts, sixteen fuzzy IF-THEN rules are made. We determine a fuzzy degree for her/his foot age by fuzzy MIN-MAX center-of-gravity method. In our experiment on 87 volunteers, we compared these results with regression method. ©2010 IEEE.

This paper describes a trans-skull ultrasonic system that measures the blood flow velocity through the brain's blood vessel under skull. In this system, we use an ultrasonic array probe with the center frequency of 1.0MHz. The system determines the blood flow by Doppler effect. This Doppler effect is examined by the center of gravity shift in the frequency domain. We test the system in the condition of the water flow in silicon tube under the cow scapula. The experimental result shows that the system detects the flow velocity by Doppler effect and confirms the usefulness of the method under skull. ©2010 IEEE.

This paper describes a data synthesis method of two ultrasonic waves for visualizing brain image under skull. In it, we employ 0.5MHz and 1.0MHz ultrasonic array probes. We synthesize the waves of 0.5MHz and 1.0MHz and visualize the sulcus and skull. We perform the experiment with a cow scapula as a skull and a steel sulcus as a cerebral sulcus. We calculate the thickness of the bone from the synthesized waves. The thickness is determined from the surface and bottom points determined from the wave. The surface point is easily determined from the wave. The bottom point is determined by fuzzy inference. The sulcus surface was extracted from a B-mode image made from the synthesized waves. As the result, we successfully determined the skull depth and visualized the sulcus from the synthesized waves in comparison to the results obtained from each waves of 0.5MHz or 1.0MHz. ©2010 IEEE.

Quantitative diagnosis of the knee joint dynamics is required to decrease the inner- and intra-observer variability. This paper proposes a noninvasive, unconstrained and free field of measurement system of 3 degree-of-freedom knee joint angles. The proposed system employs a compound sensor of inertial and magnetic sensors. Based on a rigid-body link model, the proposed method enables a measurement system. The experimental results showed that the proposed method estimated the flexion of knee joint angle with a mean displacement of 1.3 deg. ©2010 IEEE.

This paper proposes a sensing system for a behavior detection system using an ultrasonic oscillosensor and an air pressure sensor. The ultrasonic oscillosensor sensor has a cylindrical tank filled with water. It detects the vibration of the target object from the signal reflected from the water surface. This sensor can detect a biological vibration by setting to the bottom bed frame. The air pressure sensor consists of a polypropylene sheet and an air pressure sensor, and detects the pressure information by setting under the bed's mattress. An increase (decrease) in the load placed on the bed is detected by the increase (decrease) in the pressure of the air held in the tube attached to the sheet. We propose a behavior detection system using both sensors, complementally. The system recognizes three states (nobody in bed, keeping quiet in bed, moving in bed) using both sensors, and we detect the behavior before getting out of bed by recognized these states. Fuzzy logic plays a primary role in the system. As the fundamental experiment, we applied the system to five healthy volunteers, the system successfully recognized three states, and detected the behavior before getting out of bed. As the clinical experiment, we applied the system to four elderly patients with dementia, the system exactly detected the behavior before getting out of the bed with enough time for medical care support. Copyright © 2010 The Institute of Electronics, Information and Communication Engineers.

This paper describes a fuzzy segmentation approach and the rendering technique called fuzzy maximum intensity projection (FMIP) for the endorrhachis in magnetic resonance images. First, we propose a fuzzy segmentation procedure, which assigns the high fuzzy degree for the high possibility to the endorrhachis. Second, we describe FMIP, which projects higher fuzzy membership degrees to brighter values in the 2D plane for every voxel in the volume dataset. This enables us to visualize regions of interest with higher accuracy after the fuzzy segmentation is done in the dataset. The applicability of them is tested in the visualization of the endorrhachis in magnetic resonance images. A comparison between FMIP and MIP shows that FMIP visualizes it more effectively. © 2009 Elsevier B.V. All rights reserved.

This paper proposes an ultrasonic system to determine thickness and wave speed of an object. In it, the authors newly develop a triangle probe system composed of three probes: a central probe and two side probes. The central probe straight transmits/receives ultrasonic waves and the right probe receives ultrasonic waves transmitted from the left one. In the authors' method, the triangle probe is moved to the depth direction of an object. Then, two peak intensities are revealed at the focal points of the surface and at the bottom of the object. The authors show a method to calculate the wave speed and the thickness of the objects from two focal points. In the experiment, the authors extract the two focal points aided by fuzzy logic. Then, they determine the wave speed and thickness of the object from these focal points. The experimental results on two hard phantoms show that the method can successfully determine the wave speed and the thickness of the object with high accuracy. Copyright © 2009 inderscience enterprises Ltd.

Because most of refractory patients with focal cortical dysplasia are candidate for epilepsy surgery, it is important to detect cortical dysplasia of epileptic children. This paper proposes an automated method for detecting cortical dysplasia using magnetic resonance (MR) images. To evaluate the cerebral cortex layer, the proposed method extracts texture features of a region which is perpendicular to the cerebral surface. Cortical dysplasia degree (C.D.D.) is estimated by using support vector machine (SVM). The experimental results for two subjects showed that the proposed method detected cortical dysplasia lesions with a mean sensitivity of 68.6%, a mean specificity of 67.0%, and a mean efficiency of 68.1%.

皮質形成異常に起因する難治てんかんの外科的治療には，小児頭部MR画像からの皮質形成異常領域の検出は非常に有効である．しかし，皮質形成異常のMR画像上での画像特徴は明らかでなく，またその自動検出手法も未だ確立されていない．本文では，脳の皮質構造を評価するため，脳表に直交する評価単位領域を構築し，各領域のテクスチャ特徴量を算出し，Support Vector Machine (SVM) を用いて皮質形成異常度推定法を提案する．同提案法において，識別精度が最大となる特徴量の組み合わせを求めることで，皮質形成異常のMR画像上での画像特徴を調査する．また，本手法を適用した結果，皮質形成異常を有する小児頭部MR画像から，平均感度68％で皮質形成異常領域を検出できた．

近年，様々なシステムの自動化に伴い利便性の高い個人認証技術が必要とされている．本論文では利用者の行動的な特徴を用いる生体認証の一つとして歩行時の足裏荷重分布を用いた生体認証手法を提案する．本手法では連続した歩行中より一歩分の荷重分布を抽出し認証に用いる．歩行行動の特徴として体重移動に基づく特徴および足形に基づく特徴を算出し，それぞれの特徴量において特徴量に関する二つの知識より導出されたファジィIF-THENルールに基づく分類器を作成する．これらの分類器を人工免疫システムを利用し学習させ個人認証を行う．男女30名の被験者よりそれぞれ6回分の荷重分布データを取得し本手法による認証性能の評価実験を行った．その結果，1対1照合である検証では15.0%のEER(Equal Error Rate)，1対N照合である識別では7.0%のFAR(False Rejection Rate)の誤認証率により個人認証が行えた．

人工膝関節置換術（Total Knee Arthroplasty, TKA）は損傷した膝関節の治療を行う手術である．現在，生体内における人工膝関節の動作機能には未だ不明な点が多い．そのため，手術法や人工膝関節形状の評価などの診断において膝関節の動作機能の解析を行うことは非常に重要である．現在，X線透視画像と3次元形状データを用いた2D/3Dイメージマッチングによる解析手法が多く提案されている．しかし，これらの方法は静止画像の解析手法であり，動画像を用いて膝の連続動作を考慮する研究はほとんど行われていない．本研究ではカルマンフィルタを用いたDigital Radiography（DR）画像からの人工膝関節の3次元動態解析システムを提案する．カルマンフィルタを用いることで，膝の連続動作を考慮した解析を行い，解析精度を向上させる．実験の結果，人工膝関節の運動角度を解析誤差0.31度の精度で示した．

睡眠時無呼吸症候群(SAS: Sleep Apnea Syndrome)などの睡眠障害により良質な睡眠をとれない人が近年増加している．現在，睡眠状態のモニタリングにはポリグラフ検査が一般的であるが，センサを体表につけて計測を行うため拘束性が高い．そこで本研究では非拘束に生体情報を取得する空気圧センサを用いて心拍と呼吸活動の検出を行う．空気圧センサはベッド上にいる人の生体情報を非拘束に取得することができる．提案法では取得したデータよりファジィ推論を用いて心拍・呼吸活動の検出を行う．本手法を成人男性に適用した結果，心拍は1.71%の誤差率，呼吸は2.08％の誤差率でそれぞれ検出することができた．

This paper describes a human health monitoring system by an ultrasonic sensor and an mat sensor systems. The system is realized with constrain-free, low cost and bed-side usage applicable. In it the ultrasonic sensor system obtains the state of a patient in bed by placing it under a bed frame. The mat sensor system detects heart beats and respiration signals by placing it to the mattress on the bed. This means that we can measure autonomic nerve system by using the heart rate and contribute the diagnosis of sleep apnea. This system employs fuzzy logic techniques to detect them. Thus, the system of systems with fuzzy logic can noninvasively and unconsciously provide human health information with high accuracy. © 2009 IEEE.

Wearable joint kinematics monitoring is effective for analyzing daily human behavior, for evaluating the knee functionality in the daily life, etc. This study proposes a new wearable joint kinematics monitoring system using a composite sensor which is composed of inertial and magnetic sensors. For each segment of the joint, the composite sensor is attached. By indentifying the two sets of acceleration and magnetic vector at the center of knee joint, difference of pose between the sensors are estimated. And, all of three joint angles; flexion/extension (f/e) angle, internal/external (i/e) rotation angle and varus/valgus (v/v) angle, are calculated. The proposed system was applied to knee joint kinematic analysis. The measurement accuracy was evaluated by comparing with optical sensor system. The mean error of measuring f/e angle was -1.61 ± 3.09 deg; of measuring i/e angle was 0.93 ± 1.75 deg; and of measuring v/v angle was 1.83 ± 1.79 deg. To demonstrate the applicability of wearable monitoring, the proposed method was applied to measure knee joint angles during walking and during stair-climbing. © 2009 IEEE.

Knee kinematics in the every daily life or during the sports activities attracts the considerable attentions. Recent advances in micro electro mechanical system technologies produce many types of mobile sensors. This article introduces a system-of-systems (SoS) which estimates the knee kinematics by integrating MARG sensor and pressure sensor. Each sensor is with miniature size, low power consumption and wireless data transmission. The sensors measure the different signals simultaneously, and the intelligent data analysis system derives 3-degree-of- freedom knee joint angles and the knee joint moment by integrating the different kinds of signals. And, the present SoS can be applied to almost all activities in the daily life. ©2008 IEEE.

This paper describes a system of systems for heath care of elderly. The system consists of three systems: one is the system that detects heart rate and it provides the condition of autonomous nerve system. The second one is the system detecting respiration. Third one is the system detecting cough with phlegm to suction. In them we emply non-contacted three senors such as an ultrasonic oscillosensor touched to bed frame, an air pressure with an air tube in matress in bed and PCM Recorder with microphone. The system of systems can detect fundamental biosiganls of heart rate, respiration and cough with phlegm to suction, and it provides the condition of primary biosignal of heart and respiration as well as autonomous nerve system. © 2009 IEEE.

The brain shape is deformed regionally by kinds of cerebral diseases and the degree of progress. Therefore quantitative evaluation of the deformation using MR images is effective for diagnosis of cerebral diseases. To evaluate the cerebral deformation, almost conventional methods are based on normalization of the brain shape which deforms the evaluating brain into the standardized brain. Because the normalization process does not take into account anatomical features such as the cerebral sulci and gyri, in some cases the normalization process produces that one sulcus of the evaluating brain miss-corresponds to the other sulcus of the standardized brain. This paper proposes a homologous brain shape modeling method for quantitative evaluation of the brain shape in MR images. We define a new image feature called sulcal-distribution index (SDI) to represent the 3-D distribution of sulci, and the proposed method deforms a template brain model so that SDI of the deformed brain model calculated from the evaluating brain MR images is similar to SDI of the template brain model. By using SDI, the proposed method can take into account anatomical features of the cerebral sulci. The experimental results showed that the proposed method homologically modeled the brain shape with a mean displacement of 1.3 mm. ©2009 IEEE.

Cerebral surface extraction plays a fundamental role of computer aided diagnosis (CAD) for neonatal brain magnetic resonance (MR) images. However, cerebral sulci of the neonatal brains is complexity folded, and it is difficult to extract complete cerebral contour from MR images due to the limitation of spatial resolution and partial volume effect (PVE). This paper proposes a novel method to extract the cerebral contour based on fuzzy thick rubber model (TRM). The TRM is deformed by using fuzzy control schemes so that the digitally synthesized MR images from the deforming TRM are identical to the given MR images. By synthesizing the MR images with respect to PVE, the proposed method is able to extract the cerebral contour with sub-voxel accuracy. The proposed method was applied to 7 subjects whose revised ages were from -17 days to 34 days. The root-mean-squared-error between the extracted contour and the manually delineated contour by two physicians was 1.09 ± 0.48 mm from the truth contour. And, to demonstrate the clinical effective, gyral index was calculated using the extracted cerebral contour. ©2009 IEEE.

Recently, the increase of care burden due to the increase of number of the elderly dementia patients is a matter of concern in Japan. However, dementia of the elderly tends to be wrongly recognized as the effect of aging, and there are many cases in which early detection are difficult. In this paper, we focus on the cognitive impairment as one of the core symptoms of dementia, and propose the fuzzy estimation system to detect the level of dementia through monitoring the participants' sleep using air pressure and ultrasonic sensor systems which were developed by our laboratory. As a result of applying this method to twenty-three women in a nursing home, we could confirm the high correlation between the degree of dementia and the truth value, the score of Revised Hasegawa's dementia scale. ©2009 IEEE.

This paper proposes a biometric personal authentication based on the pressure distribution while one step walking. We extract one step from a walk on a mat type load distribution sensor and use it to personal authentication. With this method, features which are based on weight movement and foot shape during walking are calculated, then a classifier is developed on the basis of fuzzy inference. We employed 30 volunteers. All volunteers are ranged from 20 to 85 years old. For each volunteer, we took walk data six times. Then, we evaluated this method by five training data and one test data. We obtained 6.1% EER (Equal Error Rate) and 13.9% FRR (False Rejection Rate) in verification (1:1 collation) and identification (1:N collation), respectively. ©2009 IEEE.

This paper describes a method for a respiratory rate monitoring system by an air pressure sensor. By using this sensor, we propose a detection method of a respiratory rate for human in bed by fuzzy logic. Our method was examined on four healthy volunteers. We successfully detected the respiratory rate and the time of apnea state. In our method, fuzzy logic plays a primary role in the detection of respiratory points. The experimental results showed that the error ratio of respiratory rate was 1.3 % and the error of time of apnea state was 1.1 seconds. Consequently, this system can noninvasively detect the respiratory rate and the time of apnea state by using an unconstrained device. ©2009 IEEE.

In this paper, we describe a human health management system scheme and its practical applications. Specifically, it focuses on health management, medical diagnosis, and surgical support system of systems engineering (SoSE). The application domains discussed here are broad and essential in health management and clinical practice. Firstly, we describe a system of systems (SoS) in human health management. Within it, a notion of health management is introduced and discussed from the viewpoint of SoS. Human health management is the first level of daily monitoring for a healthy human. Sensing and control technology during sleep are espectially focused on because the quality and quantity of sleep has considerable impact on health. Secondly, an SoS in medical diagnostic imaging is discussed. This section introduces a clinical usage of a magnetic resonance imaging (MRI) scanner for the diagnosis of certain diseases. In it, there is a new system that consists of image processing system and expert medical knowledge system described by fuzzy logic. To demonstrate the effectiveness of the new system, applications to human brain magnetic resonance images and orthopedic kinematic analyses are introduced. Thirdly, we describe an SoS in medical ultrasonic surgery support device. This section introduces a novel ultrasonic support system for supporting crash bone orthopedic surgery. © 2009 IEEE.

In this paper, we propose a trans-skull imaging system of the human brain using an ultrasonic array probe. In it, we employ a cow scapula imitated to human skull and a steel with ditches imitated to cerebral sulci. We scan the phantom consisting of the bone and steel ditches by a 32channel array probe and obtain the B-mode image. From the B-mode image, we extracted the bone thickness by fuzzy inference, and visualize the ditches by filtering techniques. Experimental result shows that the mean error of bone thickness is less than 1mm and that the mean errors of the ditch width and depth are 6.9mm and 2.8mm, respectively. ©2009 IEEE.

This paper proposes functional assessment system of autonomic nervous system by the heart rate variability using an air cushion sensor. The air cushion sensor can unconstraintly detect vital information by sitting down on the sensor. We perform functional assessment of autonomic nervous system by heart rate variability obtained by the system. We built the real time display system for visualizing the autonomic nervous system functions. In this system, we employ fuzzy membership functions with dynamic parameter to detect RR intervals. The experimental results show that we detect RR intervals with the correlation coefficient of 0.846 with comparison to that of electrocardiograph. Then, the errors of the HF (index of parasympathetic system) and the LF/HF (index of sympathetic system) are 18.34% and 16.99%, respectively. ©2009 IEEE.

Total knee arthroplasty (TKA) is an orthopedic surgery which replaces the damaged knee joint with the artificial one. To diagnose the function of the implanted knee joint, it is effective to estimate 3-D knee kinematics in vivo. There are some conventional methods for estimating kinematics of the implanted knee using 2-D/3-D image registration for X-ray fluoroscopic images and 3-D geometrical models of the knee implant. However, these methods are based on static image analysis although the knee joint continuously moves. This paper proposes an analysis method of the knee kinematics using digital radiography images with Kalman filter. Use of Kalman filter enables us to take into account the continuous knee movement. The experimental results showed that the proposed method estimated the knee joint angles within a mean error of 0.31 deg. ©2009 IEEE.

本論文では，手術後に発生する褥瘡予防を目的とした看護ファジィエキスパートシステムを提案する．まず，手術後の褥瘡発生要因に関するエキスパート看護師の経験的知識を述べた．次に，その内容からファジィメンバーシップ関数を決定し，看護ファジィエキスパートシステムを構築した．構築したエキスパートシステムは，これらのメンバーシップ関数を用いて計算した値の平均値によって各患者の褥瘡発生に関するファジィメンバーシップ値を決定した．本システムの評価には，10名の実際の手術患者のデータを用いて，Leave-one-out cross validation法を適用した．提案したファジィエキスパートシステムによって得られた結果は，統計的分析による先行研究結果と比べて，その精度において優れていた．

Measurement of cortical thickness using human brain magnetic resonance (MR) imaging can assist physicians in quantifying cerebral atrophy. Most of the conventional measurement methods assign the same class to all pixels with a similar MR signal independent of their locations, and are therefore unsuitable for MR images that have strong intensity nonuniformity (INU) artifact. We propose an automated method that locally segments the cerebral cortex using an adapted fuzzy spatial model representing the transit of MR signals from the cerebral cortex to the white matter. This method assigns fuzzy degrees belonging to brain tissues using the adaptive fuzzy spatial model for local intensity transition from the cerebral cortex to inside the cerebrum. We also introduce an evaluation method of cortex segmentation algorithms that consists of reproducibility, quantitative, and qualitative tests; we use this method to evaluate and discuss the proposed segmentation method in comparison with the conventional method.

Diagnostic imaging system is a necessity for brain diagnosis. Transcranial Ultrasonography can noninvasively image the intracranial blood flow and brain tissue in real time from only temple area of human head. However, the ultrasonic wave causes attenuation, decentration, and refraction in the skull, so the ultrasonography can not provide the transcranial brain surface image from arbitrary place. In this paper, we propose an imaging system of brain surface and skull from arbitrary places by considering the ultrasonic refraction of the skull. We do an experiment by using a cow scapula to imitate the skull bone and a biological phantom to imitate the cerebral sulcus. We first visualize the shape of scapula, and grasp the shape of scapula surface. We second remove the delay and the multi echoes of refracted wave. We third calculate the thickness of the scapula by using fuzzy inference. In the inference, we employ amplitude, correlation coefficient and the elapsed time. Finally, we calculate the refractive angle of ultrasonic wave and visualize the image referring to the refraction of ultrasonic wave. In the result of applying our method, we can estimate the thickness of scapula at all points, and successfully visualize the phantom surface image.