著者

坪子 侑佑 渡辺 祥太 白石 泰之 三浦 英和 山田 昭博 鈴木 拓志 平 恭紀 山家 智之

出版者

一般社団法人 日本生体医工学会

雑誌

生体医工学

巻号頁・発行日

vol.53, pp.S200_01-S200_01, 2015

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The authors have been developing a pulmonary mechanical simulator in order to establish a design parameters of a novel artificial cardiovascular devices. In pulmonary circulation, interactive pressure-flow changes are regulated by pulmonary impedance characteristics. We focused on the native impedance characteristics variation in the pulmonary circulation. To examine the effect of respiratory control on pulmonary resistance, we measured pulmonary arterial pressure and flow in adult goat under the different respiratory settings with open/closed-chest condition. Pulmonary input impedance in two respiratory conditions under the anesthetized open-chest positive pressure ventilation (PPV) and the awake spontaneous respiration (SR) were calculated. Longitudinal impedance at 0 Hz in SR showed lower than in PPV, and at high harmonic area in SR was bigger than in PPV. In order to examine the hemodynamic response for newly designed artificial internal organs, pulmonary impedance variation caused by respiratory control should be considered. For sophisticated pulmonary resistance model, reproducing the negative pressure condition in the thoracic cavity, and pulmonic vascular resistance regulation might be required.

著者

笹木 悠一郎 鈴木 拓志 岩上 卓磨 谷 卓治 長沼 秀樹 木野 久志 HYTTINEN JARI KELLOMAKI MINNA 田中 徹

出版者

公益社団法人 日本生体医工学会

雑誌

生体医工学 (ISSN:1347443X)

巻号頁・発行日

vol.52, no.Supplement, pp.O-253-O-254, 2014 (Released:2014-10-04)

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In this study, we have developed a chip-surface stimulus electrode array for fully-implantable subretinal prosthesis chip. To realize visual restoration with high resolution, stimulus electrodes should be miniaturized and arrayed with high density. When we miniaturize them, however, their electrochemical impedances become higher and their amount of charge injection become smaller. Additionally, as the number of electrodes increases, it becomes difficult to make electrical connection to each pixel of the retinal prosthesis chip and each electrode by electrical wiring. To overcome these problems, we have developed the stimulus electrodes that have low electrochemical impedances and large charge injection capacities, and established a fabrication process of chip-surface stimulus electrode array. We fabricated the stimulus electrodes made of extremely porous platinum which had large-surface-area compared with conventional Pt. We also fabricated the chip-surface stimulus electrodes array on the subretinal prosthesis chip which surface was rough and covered with insulator film.