著者

酒井 直隆 嶋脇 聡

出版者

宇都宮大学

雑誌

基盤研究(B)

巻号頁・発行日

2008

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ラットの坐骨神経を大腿二頭筋枝、脛骨神経、総腓骨神経の3つの神経束に分割し、各々の神経束にフック電極もしくは埋設電極を取り付け、ラットの下肢動作時の神経活動電位を計測した。その結果、各々の神経束から個別に活動電位を得ることができ、いずれも活動電位は2相性で、活動時間、最高電位、最低電位、電位差といったパラメータの値や周波数分布の特徴は類似していた。フック電極と埋設電極によって計測される活動電位を比較すると、計測される最高電位、最低電位、電位差の値に相違があるものの、活動時間や周波数分布の特徴から同様の活動電位を検出できた。活動電位は、大腿二頭筋枝、脛骨神経、総腓骨神経ともに類似の波形であり、足関節の屈伸はこれらの神経活動電位の位相差によって、拮抗筋の収縮・弛緩による協調運動が実現するものと考えられた。そのため坐骨神経を神経束に分離後、同一平面上に配置して各神経束に電極を装着することで、電位束ごとに異なる神経電位を感知することが可能であり、この方法で神経束電位による多チャンネル化が実現するものと考えられた。

著者

嶋脇 聡 酒井 直隆

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集C編 (ISSN:18848354)

巻号頁・発行日

vol.78, no.787, pp.883-891, 2012 (Released:2012-03-25)

参考文献数

27

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Finger deformities refer to the symptoms where a flexed or extended joint becomes fixed in one direction and is prevented from returning to a normal state due to muscle or tendon abnormalities around the joint as a result of trauma or a pathological abnormality. The deformities exist in numerous forms, and their causes are known to be either a muscle imbalance or tendon rupture. We focused on the finger deformity forms of the boutonnière and swan-neck deformity. To clarify the formation mechanisms of these deformities, conventional studies have used cadaveric fingers whereas in this study we used the finite element method to model the mechanism of human finger flexion and extension (extensor tendons, flexor tendons, phalanges, tendon pulleys, and ligaments). Using this model, flexion angles of the distal interphalangeal (DIP) and the proximal interphalangeal (PIP) joint were calculated with conditions for a tendon (central band, lateral band, flexor digitorum superficialis tendon) rupture and tendon tension abnormalities. The results have shown that the conditions which most resembled the boutonnière deformity were those of the central band removal model, and the conditions which most resembled the swan-neck deformity were those of the flexor digitorum superficialis tendon removal model and the tendon tension abnormalities. These results are in agreement with those from clinical observations and cadaveric finger experiments, and demonstrated that the finite element method was effective for clarifying the mechanisms for finger deformity formations.

著者

嶋脇 聡 酒井 直隆

出版者

Japan Ergonomics Society

雑誌

人間工学 = The Japanese journal of ergonomics (ISSN:05494974)

巻号頁・発行日

vol.47, no.1, pp.31-35, 2011-02-15

被引用文献数

1

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ヒトが物体を把持する直前に,物体の形状や大きさに依存した手の形を準備するプリシェイピング動作を実行する.本研究の目的は,三次元動作解析システムを用いて指関節角度を計測することによって,プリシェイピングに及ぼす視覚条件の影響を調査することである.9人の健常者が4つの視覚条件(通常,閉眼,仮想,仮想閉眼)で円柱の把持を実施した.円柱は高さ120 mm,直径30 mmであった.関節の初期角度と最終角度の間である中間値までの中間時間が計測された.結果として,仮想条件におけるDIPとPIP関節の中間時間は通常および閉眼条件におけるそれらより有意に低値であった.4つの視覚条件におけるMP関節の中間時間の間で有意差は無かった.これは,通常および閉眼条件で,近位関節より順番に屈曲する「なじみ機構」が作用しているが,仮想条件では,3関節とも同時に屈曲したことを示した.

著者

中山 敦 嶋脇 聡 酒井 直隆 中林 正隆

出版者

一般社団法人 日本機械学会

雑誌

茨城講演会講演論文集 2013.21 (ISSN:24242683)

巻号頁・発行日

pp.219-220, 2013-09-06 (Released:2017-06-19)

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When human hand grasping an object, nail will support and restrain the deformation of finger pulp. Object is able to be grasped firmly due to the adaptation of finger pulp to the shape of grasped object. So, the nail is considered to be playing an important role in every motion of the fingertip. But the study case regarding the nail structure and it's mechanical properties are very rare. We used guitar string and applied to ways of doing experiment, such as pressing and flipping on the string.

著者

嶋脇 聡 須田 拓也 中林 正隆 杉本 英治

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.84, no.862, pp.18-00131, 2018 (Released:2018-06-25)

参考文献数

37

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The neck is an important body part that links the head and chest sections. However, very few analyses of cervical movement derived from muscle contractions have been conducted with numerical simulation. This study aimed to construct a multi-body model of the neck comprising the bones, muscles, and ligaments (including the intervertebral disc) and to apply flexion and extension movements to analyze the behavior of each cervical segment. We created bone models (including cervical vertebrae C1-C7) from X-ray computed tomography (CT) images of the upper half of the human body. Each bone model was bound by 17 types of ligaments constructed as 51 wire models. We set six types of muscles as the protagonists for neck flexion and 12 types for the neck extension. Muscle strength was defined with a parallel contraction element model and an elastic element model. The intervertebral discs represented five spring models with repulsion characteristics on compression and attraction characteristics on extension. The neck section could flex up to 38.1° and extend up to 61.0° with contraction in the flexor and extensor models. The maximum cervical segment angles on flexion and extension were measured at C0-C1 and C4-C5, and their contribution rates were 20.7% and 19.3%, respectively. Each cervical segment angle when flexing and extending closely matched the experimental results measured by other studies. The centers of rotation for cervical segments from C2-C3 to C4-C5 on maximum flexion were different from those in previous experimental result. This may be because of the settings pertaining to the interspinous ligament, nuchal ligament and supraspinous ligament. On the other hand, our results for maximum extension were consistent with past experimental result. An improved neck model will allow the analysis of cervical segment movement through the joint restrictions based on damage to the ligaments and muscles or arthrodesis when flexing and extending.

著者

嶋脇 聡 吉田 和樹 中林 正隆

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.856, pp.17-00063-17-00063, 2017 (Released:2017-12-25)

参考文献数

36

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Arterial endothelial function is known as a factor that correlates with progression of arteriosclerosis. This is measured by flowmediated dilatation (FMD) testing. This test is performed by measuring the brachial artery diameter with an ultrasound system or by measuring digital pulse volumes. Technical and cost-related problems have been pointed out for both methods. We came up with an idea to apply the near-infrared light-based vascular visualization to the measurement of changes in vessel diameter. So, at first, we investigated whether the FMD reaction can be detected with near-infrared transmission images. Next, we derived the estimated values that is considered to correspond to the FMD reaction from the vascular image change. We aimed to determine if these estimated values correlate with brachial-ankle pulse wave velocity (baPWV), which is related to arteriosclerosis. In 50 adult males varying in age, the right upper arm was compressed with a cuff at 200 mmHg for 5 min to cause the FMD reaction after the cuff release. In a 11-min period including time points before and after the cuff compression, near-infrared (wavelength: 850 nm) transmission images near the bilateral finger joints were taken with a CCD camera. The mean brightness was calculated from the images. While no major temporal changes in mean brightness were observed before cuff release, the mean brightness of the hyperemic finger sharply decreased after cuff release. This result suggested that the FMD reaction can be detected with near-infrared transmission images. When the brightness decrease ratio (BDR1) before and after cuff release were compared among age groups, BDR1 at age 50 over years group was significantly smaller than that at age 20-29 years group (p<0.05). BDR1 showed a significant negative correlation with baPWV (R=0.34). This measurement method is considered to have a possibility of estimating FMD reaction and arterial endothelial function.

著者

嶋脇 聡 龍前 三郎 清水 優史

出版者

社団法人 日本流体力学会

雑誌

日本流体力学会誌「ながれ」 (ISSN:02863154)

巻号頁・発行日

vol.19, no.4, pp.280-281, 2000-08-30 (Released:2011-03-07)

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The flow downstream to a contraction in a tube with bleeding flow was investigated by numerical analysis. The bleeding flow was orthogonally induced with tube axis from circumferential entrance. In the analysis, axisymmetrical and laminar flow was assumed.The calculated results were analyzed with respect to the following three parameters.· ratio Qb/Q of bleeding flow rate Qb to that of flow from contraction Q. · relative position of reattachment point of stream from the contraction and bleeding point.· ratio d/D of diameter of the contraction d to that of down stream tube D. From the results, it was clarified that all these parameters had the influence on the flow downstream to the contraction and pressure loss caused by bleeding flow. The pressure loss by bleeding flow could be lowered by decreasing of Qb/Q, setting the bleeding point far downstream to the contraction, and by increasing of d/D. Moreover, by normalizing the dimension of settings by Reynolds number in the contraction, the similarities of flow and of pressure distribution alone the tube wall were shown.