| Co-Investigator(Kenkyū-buntansha) |
KONDO Katsuya University of Hyogo, Graduate School of Engineering, Associate Professor, 助教授 (00295750)
KOBASHI Syoji University of Hyogo, Graduate School of Engineering, Research Associate, 助教授 (00332966)
YANAGIDA Toshio Osaka University, Graduate School of Frontier Bioscience, Professor, 大学院・生命機能研究科, 教授 (30089883)
KITAMURA Yuri T. Osaka University, Graduate School of Medicine, Research Associate, 大学院・医学系研究科, 助手 (90294074)
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| Budget Amount *help |
¥10,200,000 (Direct Cost: ¥10,200,000)
Fiscal Year 2004: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2003: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2002: ¥5,300,000 (Direct Cost: ¥5,300,000)
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| Research Abstract |
Conventional transcranial sonography system can imago real-time intracranial blood flow and brain tissue non-invasively. However, skull prevents ultrasound and keeps us from disclosing a brain anatomy. The main factor is the acoustical mismatch between soft skin and the skull. The acoustic velocity in the skull is about 2800-3500 m/s whereas about 1600 m/s in soft skin. Additionally, porous layer of the skull prevents ultrasound from penetrating to intracranial tissue. Due to this, conventional sonography system is used only for neonates whose skull is not complete. However, in adults, available window of skull is restricted to the temporal bone. This limited size of the window keeps us from disclosing brain information. Any transcranial sonography system with placement free has not been developed.
This research attempts to develop a intracranial tissue visualization system with placement free. By visualizing shape of an intracranial tissue from all angles, it supports to diagnose the d
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isease with high accuracy. First, we confirmed that ultrasonic wave penetrated the human frontal bone (3-6 mm) or artificial bone (12 mm). We describe our developed ultrasonography system. Ultrasound probe acquires data of an intracranial tissue in human head. The ultrasonic pulsar receiver transmits and receives ultrasonic waves via the probe. The data of ultrasonic waveform is acquired by the personal computer. The aim of this study is to divide our wave into echo of skull surface, echo of skull bottom, and the surface of brain. To solve this problem, our experiment is done on the flat region of human skull, i.e., frontal region of head. We make an anatomical model consisting of skull surface, skull bottom, and brain surface by the anatomical knowledge. In our system, after we sequentially compares a triangle fuzzy membership function with full wave of raw echo waves, we extract every target echo with maximal matching score referring to the model. We thus identify every echo by the model and the fuzzy pattern matching. Finally, we visualize the surface and bottom of the skull and the brain surface. As the result of applying it to two human heads, we could identify all echoes of skin, skull surface, skull bottom and brain surface. The shape of skull and the soft tissue in all data was obtained. Average error of the skin thickness was 0.88 mm, and the average error of distance between skin and brain surface was 2.44 mm, these values are obtained by comparing with MRI data. Less
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