Syoji Kobashi

Publications (180) View all

• Conference Proceeding: Neonatal brain MR image segmentation based on system-of-systems in engineering technology

  A. Hashioka, K. Yamaguchi, S. Kobashi, Y. Wakata, K. Ando, R. Ishikura, K. Kuramoto, T. Ishikawa, S. Hirota, Y. Hata
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  ABSTRACT: Measurement of cerebral volume and surface area using magnetic resonance (MR) image is effective for quantitative diagnosis of cerebral diseases. The measurement should require a brain segmentation process. Although many approaches for adult brain have been studied, there are few studies for neonatal brain. This study proposes a brain segmentation method for neonatal brain. Based on system of systems engineering technology, the proposed approach is composed from two systems; automated fuzzy logic based skull striping (AFSS) system and contour shape based modeling (CSM) system. AFSS segments the cerebral region based on Bayesian classification with Gaussian mixture model. CSM evaluates the skull stripping result of AFSS, and updates AFSS system parameters. Experimental results in 34 neonates (revised age between -2 weeks 1 day and 2 years 5 months) showed that the proposed approach segmented the brain region with sensitivity of 98.1% and false-positive rate of 27.9%.
  System of Systems Engineering (SoSE), 2011 6th International Conference on; 07/2011
• Conference Proceeding: A testicular tubule evaluation method by ultrasonic array probe

  Y. Takashima, K. Kuramoto, S. Kobashi, Y. Hata, T. Ishikawa
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  ABSTRACT: This paper describes a testicular tubules evaluation using 1.0MHz ultrasonic array probe. In this system, we evaluate a diameter of testicular tubules. We employ an ultrasonic array probe with the center frequency of 1.0MHz. We employ evaluation index that cumulative relative frequency of amplitude values. In the experiment, we employ 24 nylon lines as the testicular tubules. Amplitude of large nylon line echo is larger than that of small nylon echo. For the evaluation, we calculate cumulative relative frequency amplitude of acquisition data. Fuzzy if-then rules are made by the cumulative relative frequency of large and small lines. We evaluate a rate of large lines among all lines by using the fuzzy MIN-MAX center-of gravity method. In this experiment, the proposed method successfully evaluated the rate of the large lines. We changed the rate of large lines in 24 nylon lines, and tested our method 20 times for each rate. We evaluated the rate with 5.77% in mean absolute error.
  Fuzzy Systems (FUZZ), 2011 IEEE International Conference on; 07/2011
• Conference Proceeding: Wavelet Transform Based Quantification of Pivot-Shift Testing Using Inertial and Magnetic Composite MEMS Sensor

  S. Kobashi, A. Tomaru, Y. Tsumori, S. Yoshiya, K. Kuramoto, S. Imawaki, Y. Hata
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  ABSTRACT: 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.
  Emerging Trends in Engineering and Technology (ICETET), 2010 3rd International Conference on; 12/2010
• Conference Proceeding: Free placement trans-skull Doppler system with 1.0MHz array ultrasonic probe

  M. Nakamura, Y.T. Kitamura, T. Yanagida, S. Kobashi, K. Kuramoto, Y. Hata
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  ABSTRACT: 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.
  Systems Man and Cybernetics (SMC), 2010 IEEE International Conference on; 11/2010
• Conference Proceeding: A 3-DOF knee joint angle measurement system with inertial and magnetic sensors

  A. Tomaru, S. Kobashi, Y. Tsumori, S. Yoshiya, K. Kuramoto, S. Imawaki, Y. Hata
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  ABSTRACT: 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.
  Systems Man and Cybernetics (SMC), 2010 IEEE International Conference on; 11/2010