| Japanese |
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| Title | カテーテルを用いた圧導出系の周波数特性とその評価法 |
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| Subtitle | 原著 |
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| Authors | 杵淵嘉夫*, 鈴木利保*, 山崎陽之介*, 山本道雄* |
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| Organization | *東海大学医学部麻酔科 |
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| Journal | 循環制御 |
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| Volume | 12 |
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| Number | 1 |
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| Page | 111-119 |
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| Year/Month | 1991/ |
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| Article | 原著 |
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| Publisher | 日本循環制御医学会 |
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| Abstract | 「要旨」カテーテルの先端に加えられた力はカテーテル内の液体を媒体として受端に配置されたトランスデュサに伝わる. この過程で圧波形は様々な変形を受ける. 波形歪を振幅の歪と位相の歪に分け, 2次系の運動方程式を用いて, それぞれの歪が5%の許容誤差となる周波数特性の範囲を計算した. その結果を固有周波数と制動係数からなる2つのパラメータで記述し, 系の特性を評価する目安とした. 75cmと110cmの長さの異なる7F Swan-Ganzカテーテル系の周波数特性を実測し, それぞれ固有周波数は12.7, 9.1Hz, 制動係数は0.24, 0.35となり, 許容誤差内で導出できる理論的な最高周波数は2.9, 2.3Hzと推定された. また, 制動係数を最適値に調整すれば最高周波数はそれぞれ6.6, 4.7Hzと推定された. 直接導出した肺動脈圧波形の周波数成分は心拍数を基本波とし, その5倍程度の周波数成分まで分布しており, 198bpm(3.3Hz)と80bpm(1.3Hz)のとき, それぞれ16.5, 6.7Hzに相当した. これらの値は使用したSwan-Ganzカテーテルの許容できる周波数帯域を超えており, 波形の歪ないしは鈍り減少が存在すると推定された. |
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| Practice | 基礎医学・関連科学 |
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| English |
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| Title | An Assesment of frequency Characteristics of the Fluid-Filled Catheter-Manometer system |
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| Authors | Yoshio Kinefuchi, Toshiyasu Suzuki, Yonosuke Yamasaki, Michio Yamamoto |
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| Organization | Department of Anesthesiology Tokai University School of Medicine |
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| Journal | Circulation Control |
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| Volume | 12 |
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| Number | 1 |
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| Page | 111-119 |
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| Year/Month | 1991/ |
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| Article | Original article |
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| Publisher | Japan Society of Circulation Control |
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| Abstract | Various distortions in wave forms are inevitable in a catheter-transducer hydraulic system. The amplitude may be exaggerated or damped and the wave may lag behind producing phase distortions, that is, delayed zero-crossing points. Solving the second-order kinetic equation to which these distortions are known to obey, we calculated the ranges of frequencies compatible with erros limitted withi n a 5% band. These data were then rearranged to construct a two-parameter chart, namely natural frequencies and damping coefficients, so that accepatable ranges in these parameters of any catheter-manometer systems may be mapped out. As an example, we measured the frequency characteristics of two Swan-Ganz pulmonary artery catheters of the same size (Fr 7) with different length, 75 and 110 cm respectilvely, and determined the natural frequencies (12.7 and 9.1 Hz) and damping coefficients (0.24 and 0.35). Referring to this chart, the maximal high frequency these catheters would be able to reproduce without excessive distrtions can be predicted to be 2.9 and 2.3 Hz. Further improvement in high frequency response can be expected on the chart, with adjustment of damping coefficient to the optimal value, to stretch to 6.6, 4.7 Hz. Pulmonary artery wave forms obtained in the laboratory or at bedside consist of frequency components up to 5 times the heart rates and the maximal frequencies were found to be 16.5 Hz with HR 198 bpm (3.3 Hz) and 6.7 Hz with HR 189 bpm (1.3 Hz) respectively. These values were outside of the ranges of frequencies these catheters were capable of reproducing wave forms with acceptable distortions. |
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| Practice | Basic medicine |
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