著者

小澤 哲也 馬渡 宏 薮上 信 石山 和志 荒井 賢一

出版者

公益社団法人 日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:02850192)

巻号頁・発行日

vol.29, no.8, pp.831-837, 2005 (Released:2007-05-10)

参考文献数

5

被引用文献数

2 2

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The impedance and phase characteristic of a magnetic thin film changes when a magnetic field is applied. The high-frequency-carrier magnetic field sensor, also called a GMI sensor, employs this phenomenon as its principle. We directed our attention to the change in the phase characteristic, and measured the dc magnetic field by measuring the phase as a phase difference, using the dual-mixer time-difference method. We optimized the method and the continuous sampling condition to measure the phase difference, and developed an efficient system for measuring the continuous sampling phase difference with low noise. The system was successfully used to measure the ac magnetic field by continuous sampling of the phase difference of a high-frequency-carrier magnetic field sensor.

著者

仙道 雅彦 島崎 克彦 石山 和志 井上 光輝 荒井 賢一

出版者

公益社団法人日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:18804004)

巻号頁・発行日

vol.23, no.4, pp.1657-1660, 1999-04-15

被引用文献数

24

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The fundamental swimming properties of spiral-type magnetic micro-machines were investigated in detail by constructing four micro-machines with differnt structures. These micro-machines are able to swim in various liquids with kinematic viscosities ranging from 1.37 to 1000mm^2/s. This result suggests that the micro-machines have potential medical uses. In particular, they can swim against the stream in a liquid whose the velocity is comparable to the that of venous blood.

著者

石山 和志 千葉 淳

出版者

公益社団法人日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:18804004)

巻号頁・発行日

vol.28, no.11, pp.1067-1073, 2004-11-01

被引用文献数

1

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Recently, medical actuators of various kinds have been reported. We have particularly reported actuators for colon endoscope navigation. Magnetic actuators have the unique feature that they can be moved wirelessly, using external magnetic fields. The magnetic actuator consists of a permanent magnet and a spiral structure. When a rotational magnetic field is applied, the actuator rotates and moves without wired connection. The actuator therefore has a potential use for colon endoscope navigation. In this paper, we show some results compared with other navigation systems.

著者

千葉 淳 仙道 雅彦 石山 和志 荒井 賢一

出版者

社団法人日本生体医工学会

雑誌

生体医工学 : 日本エム・イー学会誌 (ISSN:1347443X)

巻号頁・発行日

vol.42, no.4, pp.313-317, 2004-12-10

被引用文献数

1

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In this paper, the authors propose applying a magnetic actuator to a capsule endoscope. We fabricated a capsule-type magnetic actuator and investigated its moving properties in a silicone tube and in pig intestines. The device consists of a dummy capsule measuring 11 mm in diameter and 40 mm in length, a magnetic actuator composed of a permanent magnet inside the dummy capsule and a 1-mmφ spiral structure outside the capsule. The permanent magnet is magnetized in the direction of the diameter. When a rotational magnetic field is applied, the magnetic actuator rotates and moves wirelessly. In this study, we measured the effect of the spiral shape on the velocity and thrust properties. According to our experimental results using the silicone tube, the optimal actuator was formed with 4 spirals set at a spiral angle of 45 degrees. In the subsequent moving test performed in pig intestines, the actuator traveled a distance of 450 mm to its destination in the large intestine in 150 s, and a distance of 400 mm to its destination in the small intestine in 110s. This result confirms the potential applicability of the actuator as a guidance system for capsule endoscopes.

著者

千葉 淳 仙道 雅彦 石山 和志 荒井 賢一

出版者

公益社団法人日本磁気学会

雑誌

日本応用磁気学会誌 (ISSN:18804004)

巻号頁・発行日

vol.29, no.3, pp.343-346, 2005-03-01

被引用文献数

2 12

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Application of a magnetic actuator to a capsule endoscope is proposed. Capsule-type magnetic actuators were fabricated and their motion properties were investigated in a silicone tube and in the intestine of a pig. The dummy capsule is 11mm in diameter and 40mm in length. This magnetic actuator is composed of a permanent magnet inside the dummy capsule and spiral structures outside it. The permanent magnet is magnetized in the direction of the diameter. When a rotational magnetic field is applied, the magnetic actuator rotates and moves wirelessly. The velocity of capsules with top spirals was examined in a silicone tube. In addition, a motion test was conducted in the intestine of a pig. The actuator can pass through the small and the large intestines over distances of 450mm and 400mm, respectively, in less than 150s. The capsule can pass out of the bag-shaped section of the large intestine. This result shows that the actuator has the potential to be used in the guidance system of a capsule endoscope.