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Online ISSN : 1884-5827
Print ISSN : 1341-9455
ISSN-L : 1341-9455
10 巻, 3 号
選択された号の論文の4件中1~4を表示しています
  • 三田村 好矩, 川原 幸洋, 鈴木 慶, 岡本 英治, 四津 良平, 川田 志明, 田中 隆
    1998 年 10 巻 3 号 p. 96-101
    発行日: 1998/09/30
    公開日: 2010/07/21
    ジャーナル フリー
    The intra-cardiac axial flow pump has been developed. This device has several advantages; it fits well anatomically, its blood-contacting surface is small, and it is implanted as easily as an artificial heart valve replacement. The axial flow pump consists of an impeller and a motor, both of which are encased in a housing. The four-vane impeller is used. Sealing of the motor shaft is achieved by means of a ferrofluidic seal. A flow of 5 L/min was obtained at a differential pressure of 100 mmHg(13.3kPa)with a motor speed of 7000 rpm. Sealing was kept against a pressure of 188 mmHg(25kPa)at 8000 rpm. The index of hemolysis(NTH)was 0.031. The intra-cardiac axial flow pump is a very promising circulatory support.
  • 増澤 徹, 築谷 朋典, 遠藤 誠子, 巽 英介, 妙中 義之, 山根 隆志, 西田 正浩, アスタロシュ バラージュ, 宮副 雄貴, 伊藤 ...
    1998 年 10 巻 3 号 p. 102-105
    発行日: 1998/09/30
    公開日: 2010/07/21
    ジャーナル フリー
    The purpose of this study is to examine the relationship between the flow condition and hemolysis level by integrating hemolysis test, flow visualization and computational fluid dynamics(CFD)to establish design criteria for the good hemocompatible centrifugal pump. Axial and radial gaps between the impeller tip and casing wall of Nikkiso centrifugal blood pump were modified independently and flow condition and hemolytic property of these pumps were examined. Examined gaps were 1.5, 1.0, and 0.5 mm for axial gap and 3.0, 2.0, 1.0, and 0.5 mm for radial gap, respectively. The pumps with the axial gap of 0.5 mm and the radial gap of 0.5 mm showed higher hemolysis level than the other pumps showed. Maximum shear stress in the pump, estimated by CFD, were increased by decreasing the radial gap from 3.0 to 0.5 mm. Regional flow pattern change at the tongue region by decreasing radial gap was observed by flow visualization. Gaps between impeller tip and casing wall are dominant factors to determine hemolytic property of the centrifugal pump. Relationship between regional flow pattern and blood trauma should be investigated in the future.
  • 張 斌, 舟久保 昭夫, 福井 康裕
    1998 年 10 巻 3 号 p. 106-110
    発行日: 1998/09/30
    公開日: 2010/07/21
    ジャーナル フリー
    It is well known that acoustic language signals depend on the movement of the visible facial articulators to such an extent that a great amount of phonetic information can be extracted from lip-reading alone. An automated speech recognition system, for voice-impaired people, based on data from lip movement, is both desirable and feasible for sentence recognition. Unlike the usual lip-reading experiment, in this paper we researched a minimized auto-lipreading system, which can be used to help voice-impaired people under certain circumstances. In our system, a video camera is set up in front of the subject to continuously monitor the subject's facial images and pass them to image processing equipment. We decode discourse based only on the movements of three points in the mouth area, which are traced through image processing. The data for a whole sentence is correlated with predefined sentences through a back propagation neural network. The system attained a 86% correct recognition rate in a 20-sentence recognition task.
  • 尾田 雅文, 関口 行雄, 原 利昭
    1998 年 10 巻 3 号 p. 111-118
    発行日: 1998/09/30
    公開日: 2010/07/21
    ジャーナル フリー
    An ultrasonic technique was developed to study the characteristics for contact mechanics of an artificial hip joint. Total Hip Replacement model was used to determine contact pressure distribution on an artificial aceptabular cup subjected to compressive load ranged from196N to 588N in four femur positions. The contact pressure was found to be nonuniform and less than 6MPa. It was shown that the tendency of the pressure distribution is in agreement with that obtained by the computer simulation.Some preliminary results were also presented to illustrate the effect of the direction and the magnitude of the load applied to a stem on the contact pressure distribution on the aceptabular cup and to evaluate the contact mechanism of the artificial hip joint.
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