著者

横田 和幸 船瀬 新王 藤原 清悦 内匠 逸

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.57, no.2-3, pp.58-67, 2019-06-10 (Released:2019-08-20)

参考文献数

19

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Several studies have reported on maze tasks for humans. From the results of these maze tasks, human brain function has been elucidated. However, few studies have verified the level of difficulty of maze tasks. Therefore, the validity of these studies is questionable. The purpose of this study was to investigate factors influencing the level of difficulty of maze task for humans. We conducted an experiment in which subjects search for a goal in mazes generated on a computer. Subjects explore the mazes on two different days. In making the mazes, we set the number of steps required to reach the goal position and the number of T-junctions from the start position to the goal position. We called such mazes “continuous-T mazes.” When a subject reached the goal position three consecutive times without extra steps, the subject moved on to the next maze. The number of trials before moving on to the next maze was recorded as the score. We established new parameters;“maze cost” and “weighted maze cost,” to estimate the level of difficulty of mazes, and compared the score with these parameters. The score correlated with both the “maze cost” and the “number of T-junctions from the start position to the goal position.” These results suggest that both parameters indicate factors influencing the difficulty of mazes.

著者

戸川 達男

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.58, no.2, pp.81-83, 2020

著者

戸川 達男

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.49, no.2, pp.310-312, 2011

著者

戸川 達男

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.58, no.2-3, pp.81-83, 2020-06-10 (Released:2020-09-10)

著者

鈴木 恭宜 大下 浩二郎 垂澤 芳明 野島 俊雄 豊島 健 藤本 裕

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.46, no.2, pp.189-201, 2008-04-10 (Released:2008-10-06)

参考文献数

23

被引用文献数

1

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This paper presents a probabilistic evaluation of electromagnetic interference caused by portable telephones in implantable cardiac pacemakers. Based on experimental results of electromagnetic interference in the 900 MHz and 1.5 GHz band PDC(Personal Digital Cellular)system in Japan, a distribution is extracted of the maximum distances between the affected pacemaker and a portable telephone. This paper shows that the distribution is approximated as a Rayleigh distribution using statistical analysis. The interfering probability for which the maximum distance of X cm is exceeded is defined based on the product of the cumulative distribution of the Rayleigh distribution and the ratio of the affected pacemaker types to the measured ones. The interfering probabilities that exceeded the maximum distance of 15 cm for the 900 MHz and 1.5 GHz band portable telephones are 5.0×10-4and 6.0×10-4, respectively. The expected values, which are a product of the interfering probability and the number of measured pacemaker types for the 900 MHz and 1.5 GHz band portable telephones, are 0.210 and 0.248, respectively. The continued surge in the number of pacemaker types indicates that the expected values will continue to increase. If the immunity of the new pacemaker types in the future maintains the same level as that in the present, this paper indicates that the maximum distance of the new pacemaker types must continue to be confirmed using the electromagnetic interference test.

著者

杉町 勝 木村 裕一

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.53, no.Supplement, pp.S285-S286, 2015 (Released:2016-06-18)

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原稿を投稿して論文を出版することは,世界中に研究成果を発信する最も強力な方法のひとつである.その一方で,著者は投稿に際しガイドラインやルールに緻密に従う必要がある.これらのルールは,投稿原稿が科学的なものでなければならないことから生じる満たすべき構成条件,すなわち新規性・重要性・信頼性と密接に関係している.本講演では引用,著作権,多重投稿,研究・出版倫理,動物やヒトを用いた研究についての倫理,利益相反開示などについて情報を提供し,会員の皆様の投稿や査読応答の際に役立てていただくことを目的とする.

著者

島谷 哲史 渡邉 英一 鈴木 康之 野村 泰伸 清野 健

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.53, pp.S175_01, 2015

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A pacemaker (PM) and an implantable cardioverter defibrillator (ICD) are devices that are inserted into the body to maintain regular heart rhythm in patients with serious heart rhythm problems. Among Japan's aging population, the number of patients requiring PM and ICD implantation has gradually and steadily increased. Therefore, a quantitative assessment of the future number of those patients is not only clinically, but also medical-economically and politically important. In this study, to develop a forecasting model for the number of patients requiring PM or ICD implantation, we analyzed past records of the number of PM and ICD implantation from 2006 to 2013 in Japan. Using a multiple regression analysis, we show the age and gender dependence of the number of PM and ICD implantation in each year, and propose a forecasting model based on age and gender composition rates of population. Moreover, as an application of our model, we estimate the future demand of PM and ICD devices in Japan.

著者

小谷 潔 斉藤 毅 立花 誠 高増 潔

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.43, no.2, pp.252-260, 2005 (Released:2007-01-19)

参考文献数

26

被引用文献数

3

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Respiratory sinus arrhythmia (RSA) is well known as a noninvasive index of cardiac vagal activity, which has an important role in maintaining homeostasis. In this study, we improved the signal processing of RSA in the respiratory phase domain for real-time analysis and used results of this signal processing to control the mental arithmetic workloads of subjects. Four healthy subjects performed two experiments : a self-speeded workload and a real-time task controlled workload. In these experiments, we obtained R—R intervals from electrocardiograms with a sampling frequency of 1 kHz, and respiratory information from elastic chest band with a sampling frequency of 100 Hz. Further, we placed an accelerometer on the larynx and sampled at the rate of 100 Hz. First, we conducted the self-speeded task experiment for 10 minutes. Subjects were required to do mental arithmetic at their best pace and to take two rest periods, approximately 1-minute each. The amplitude of RSA after averaging 24 respirations was lower when the subjects were working than when they were resting (P <0.001); we found that the amplitude of RSA reflects even short-term working or resting. This suggests the possibility of controlling the mental workload by using RSA amplitude data. Second, the average of rest and working RSA amplitudes was set as a threshold. If the average RSA amplitude for a subject's last 24 respirations was higher than the threshold, we assigned a mental arithmetic task at a pace of 20 questions per minute; if the average was lower, we stopped the task. Results of the experiment showed that the RSA amplitude was controlled well by changing the workload. In both experiments, the value of the RSA amplitude varied among individuals and within individuals, but the sensitivity to a task remained unchanged within individuals.

著者

梶 弘和

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.56, pp.S142, 2018

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<p> 超高齢化社会を迎えた日本においてQuality Of Life(QOL)を維持するのに視覚情報は非常に貴重であるが、高齢者になるほど視覚障害の頻度が増加する。この視覚障害の原因、すなわち失明疾患の上位はすべて網膜疾患で占められ、高齢者に多い。網膜疾患の治療を困難にしているのは薬物が網膜に到達しにくい点が挙げられ、網膜に効率的かつ的確に薬物を投与できる新しいドラッグデリバリーシステムDDSの開発が喫緊の課題となっている。 我々は、DDSデバイスの形状を、薬物非透過性のリザーバーと徐放膜から成るカプセル型にすることで、一方向性の持続的な薬物徐放を可能にした。このデバイスを強膜上に留置すると、周囲血管やリンパ組織への薬物の流出が抑制でき、眼外から網膜に薬物が移行することが示された。これにより、侵襲的な眼内操作を必要としない経強膜DDSを提案した。ウノプロストン(網膜色素変性抑制剤)を搭載したカプセル型デバイスに関しては、デバイス規格の最適化を行い、GLP安全性試験もほぼ終了しており、早期の治験開始が期待される。他にも最近開発中のインジェクタブル薬物徐放シートや低侵襲細胞デリバリーシステムについても紹介する。</p>

著者

阿部 誠 新沼 大樹 吉澤 誠 杉田 典大 本間 経康 山家 智之 仁田 新一

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.1, pp.11-17, 2014-02-10 (Released:2014-05-22)

参考文献数

22

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Because of simplicity, subjective evaluation methods with questionnaires have been used conventionally to assess biological effects of viewing visual images. However, these methods have low objectivity and low reproducibility, and it is difficult to evaluate the effects as a time series. On the other hand, physiological indices based on such as electrocardiography, photoplethysmography, and electroencephalography have commonly been used to evaluate the effects objectively and continuously. However, physiological indices may include psychological effects as well as physiological effects, which have been considered little in the conventional studies. In this study, therefore, in order to remove the psychological effects from the physiological indices as much as possible and to extract the physiological effects such as eye strain or visually induced motion sickness, we performed the experiment in which the same video was shown multiple times to subjects with an expectation of attenuation of the psychological effects by adapting to the experiment. From the experimental result, a physiological index related to correlativity of the baroreflex system was increased significantly with the repeat count of the experiment. The comparison between the physiological index and the questionnaire on psychological state has suggested that this fact was caused by a decrease in not only stress or anxiety to the experiment but also a decrease in concentration or a reduction of interests in the video image.

著者

田頭 瑞萌 中川 隆文

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.59, no.1, pp.31-39, 2021-03-10 (Released:2021-04-03)

参考文献数

50

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In this paper, we present a method for facilitating the diagnosis of vascular stenosis in hemodialysis treatments. Sensory evaluation based on vascular sounds is usually used to identify vascular stenosis. However, skilled clinical judgement is required for this work. We applied the Mahalanobis-Taguchi Method to the assessment of vascular abnormalities. Mel-frequency cepstral coefficients, histogram kurtosis, and autocorrelation coefficients are used as features. The difference between normal and abnormal sounds is measured by Mahalanobis distance (MD). The performance of this method is estimated for 60 vascular sounds, with correct results obtained at a rate of 87%for abnormal sounds. The proposed method provides better discrimination than sensory evaluation. In addition, the relative change in MD values along the auscultation positions is similar to the result achieved by sensory evaluation.

著者

石原 謙

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.56, pp.S162, 2018

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<p>従来医療現場では少しでも危険な可能性があれば回避・忌避する習慣が尊重された。人の命や健康を守る立場から当然でありそれ自体は好ましい。20年前の心臓ペースメーカでは、当時の携帯電話からの電波強度で誤動作をすることが実験でたしかめられていた。しかしペースメーカー自体は当時から何重にも安全に作られていた。生存を脅かす機能停止はせぬよう設計されていた。さらにペースメーカのEMI耐性は著しく改善され、10年ほど前からの製品では医療現場を含めた生活圏における無線電波による機能異常は発生していない。PCやタブレット端末などの電波を発するNW機器についても医療機器に致命的障害を与える医療事故は報告されていない。結果としてこの20年、電波干渉による心臓ペースメーカでの死亡事故は起きていない。 病院での入院患者では携帯電話や無線LANが普段以上に有り難い存在となる。家族や友人との会話は回復への大きな励みになるし、治療部位以外は健常で仕事ができる状態の患者にはNWは必須である。 医療用電波を利用したME機器はゾーン設計の元で適切に使用されてはいるものの、無線LANや携帯電話などの無線端末が、利便性が高いために数多く導入され野放し状態に近い。 医療現場における電波利用の実態を調査し、さらに安全に電波利用を推進することが望まれ、管理監督強化ではなく、医療現場の負担を軽減する方向での活用を促進する合理的なガイドラインが望まれる。</p>

著者

竹内 智一 田中 裕幸 藤岡 英二 植野 彰規

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.55, no.6, pp.267-271, 2017-12-10 (Released:2018-03-29)

参考文献数

12

被引用文献数

2

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In this study, we developed a new approach for simultaneous noncontact measurements of electrocardiograms (ECGs) and pulse beats (PBs) using passive and semi-active capacitive-coupling methods. The applicability of this method to blood-pressure (BP) monitoring of subjects in bed was then evaluated. For ECG measurements, two sets of five-layered conductive-cloth electrodes were placed under the subject's upper back and waist. A so-called driven-seat ground (DSG) was adopted for ECG measurements to reduce interference with the PB detection circuit. The DSG signal was fed back to the fifth layer of the electrode. For PB detection, one conductive cloth sheet was placed under the right calf and another under the right heel. The sheets formed capacitive couplings with the body via clothing, and the couplings were incorporated into a multi-vibrator. Changes in the oscillatory frequency of the multi-vibrator caused by PBs were measured as voltage changes. To increase the sensitivity of PB detection under the heel, the sheet area ratio between the calf and the heel was set to 5:1. Seven participants were instructed to lie on a bed in the supine position, and experimental measurements were performed on them. In the experiment, the following procedures were conducted : the subject rested for 20 s;a Valsalva test (VT) was conducted for 15 s;and the subject rested again for 100 s. As reference signals, continuous measurements of BP from the left fingertip, as well as chest ECG and photo-plethysmographic signals from the right fingertip were recorded. For evaluation analysis, all PBs were detected over the 80-second period of the output signals beginning 10 seconds after the end of the VT. As a result, the sensitivity of the PB was 99.2±1.1%. The mean correlation coefficient between the PB arrival time and systolic BP was-0.83±0.15. These results suggest the possibility of using the proposed method for noncontact BP monitoring during rest in bed.

著者

佐藤 正明

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.57, no.4-5, pp.105-112, 2019-09-10 (Released:2019-12-19)

参考文献数

49

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The author has continued to research on cytomechanics since 1983 when he visited Professor Nerem’s laboratory, University of Houston, Texas, USA as a visiting scholar. In those days the effects of shear stress on functions of endothelial cells (EC) are focused from the point of view of atherogenesis. In this review, progress of cytomechanics on EC is mainly summarized. First, the definition and the significance of cytomechanics are introduced. EC are located at the innermost layer of vascular wall and always exposed to three different external forces (i.e. shear stress, cyclic stretch and hydrostatic pressure). These mechanical forces affect the configuration and functions of EC and the cells finally adapt a physical environment. Cultured EC elongates and aligns to direction of flow and the degree of shape change depends on many factors such as animal and cell species, magnitude of shear stress, duration of stimulation, material of substrate and so on. Cytoskeletal structure is also changed prior to change of cell shape. Cyclic stretch induces cell elongation and the orientation transversely to the strain direction. Pressured EC exhibit multilayered structure and marked elongation and orientation with the random direction, together with development of centrally located, thick stress fibers. Mechanical forces stimulate signal transduction, gene regulation, protein synthesis and so on. The details of the time course of responses is summarized in the text. Recent progresses on cytomechanics are two topics as follows. One is an effect of substrate elasticity on differentiation of stem cells. Human mesenchymal stem cells are cultured on three different elastic substrate (i.e. soft, moderate and stiff matrices), and then respectively differentiated into neuron, muscle and bone. Another is discovery of mechanosensing molecule called mechanosensor. Living cells respond to external and internal forces, however, the sensing mechanism is not elucidated yet. Mechanosensors such as stretch-activated channel in cell membrane, p130Cas, α-catenin, talin at cell junctions and stress fiber itself are explained as the typical examples.

著者

堀 拳輔 董 居忠 岡本 啓公 関 将志 村石 浩 齊藤 典生 Thet Thet LWIN 原 秀剛 渡辺 宝 橋本 雄幸 王 波 武田 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.56, no.1, pp.16-21, 2018-02-10 (Released:2018-06-15)

参考文献数

12

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Lung cancer is one of the most important diseases to overcome, and chest radiography and low-dose computed tomography (CT) have been used for lung cancer screening. In chest radiographs, nodules overlying the ribs and mediastinum are occasionally difficult to detect. Therefore, CT is used as the gold standard modality to diagnose lung cancer, despite the high radiation exposure it entails. Recently, tomosynthesis has been used to detect pulmonary nodules, but mechanical scanning and a long data acquisition time (approximately 10 seconds) are required to obtain the image. Under this circumstance, tomosynthesis using a small number of projections has been anticipated to allow omission of the mechanical system and shortening of the exposure time. A chest phantom with artificial pulmonary nodules of various sizes was imaged in rotating 360-degree projections. Tomosynthesis images were reconstructed using back projection (BP) from ±32-degrees projection data, and the projection numbers were set at 4, 6, 8, 16, 32 and 64. The images were evaluated visually and quantitatively by measuring the contrast noise ratio (CNR) and artifact spread function (ASF). Tomosynthesis images reconstructed from 4 projection images allowed visualization of an artificial nodule 10mm in diameter without overlapping the ribs or the mediastinum. The CNR of a 4-projection image normalized to that of a 64-projection image was approximately 0.34, and the ASF obtained indicated that fewer number of projections was associated with greater z-axis resolution. Thus, 4-projection tomosynthesis allows visualization of pulmonary nodules 10mm or larger in diameter, and image quality appears to be useful.

著者

前川 義量 阿部 武志 秋山 庸子 三島 史人 白井 みどり 西嶋 茂宏

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.49, no.6, pp.836-842, 2011-12-10 (Released:2012-04-10)

参考文献数

13

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In the field of nursing care for the elderly persons, understanding of their somatic sensation such as pain is very important for care workers to provide appropriate care. However, it is not always easy for elderly person with declined verbal function. Therefore, the objective evaluation method of pain intensity without verbal communication is required. In this study, pain evaluation system which can be used in daily life without verbal communication was developed. The system is noninvasive, because the information corresponding to pain intensity is extracted from facial expression. In order to digitalize the facial expression, the images of facial expression were extracted from the web cam on real time, and were analyzed sequentially. Pain stimulation test was carried out for healthy adults by dipping their hand into ice water (cold pressor test). A strong correlation was observed for young adults between pain face factor calculated from the facial expression digitalized by the system and sensory evaluation score of pain, VAS value. It indicates the validity of this system for estimation of pain intensity.

著者

江田 英雄 山崎 まどか

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.56, pp.S145, 2018

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<p>非観血的血圧計測手法の標準は水銀柱式血圧計測である。しかし十分に訓練を受けた者か有資格者が計測しなければ、水銀柱血圧計測で信頼しうる血圧値を得ることは困難である。また環境への配慮から水銀を用いない計測装置が必要とされている。一方、光技術を用いて脈波を計測し血圧推定値を計算する手法があり、カフレス連続血圧計の実現に向けて期待されている。本研究では、水銀柱式血圧計と光センサモジュールを同時計測することによって、水銀柱式血圧計測値と、カフレス連続血圧推定値とを比較した。対象は、医療系学科に在籍する大学生、及び、民間企業に在籍する健常人とした。右上腕部に水銀柱式血圧計のマンシェットを巻き、マンシェットの内側に光センサーモジュールを、右上腕動脈が触れる位置近傍に装着・固定した。水銀柱血圧計にて通常の血圧測定を行い、同時に光センサーモジュールによる連続血圧推定値を観察した。連続血圧推定値は加圧の後、減圧後約20秒以内に安定した値を示し、この値を光センサーモジュールによる血圧推定値とした。各被験者に対し、2回血圧測定をして、水銀柱血圧計計測値と光センサーモジュールによる血圧推定値の相関をBland-Altmanプロットで検討した。通常の水銀柱血圧計測で必要とされる安静時の計測では、両者は高い相関を示した。</p>

著者

吉澤 誠 杉田 典大 湯田 恵美 田中 明 本間 経康 山家 智之

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.58, pp.542-543, 2020

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<p>近年,健康管理のためにウェアラブル・センサが普及しつつある.例えば,アップル社のApple Watchの最新バージョンでは,光電脈波計ばかりではなく心電計の機能まで具備している.確かに,ウェアラブル・センサは身体に直接装着するため,常時連続的な生体情報取得が可能である.しかし当然であるが,ウェアラブル・センサは,それを購入して「装着(ウェア)」しなければセンシングできない. 一方,パーソナルコンピュータやスマートフォンに内蔵されているビデオカメラの映像信号から脈波(映像脈波)が得られる.ウェアラブル・センサに比べて映像脈波が決定的に優れているのは,何も身に付けず(ウェア"レス"に),遠隔・非接触的なセンシングができる点である. 本稿では,まず,映像脈波の計測方法とその性質について述べた後,映像脈波の幅広い応用可能性について解説する.すなわち,家庭における風呂・トイレなどでの血圧サージの検出,洗面所の鏡やスマートスピーカーでの応用可能性,あるいは自動車内での運転者のモニタリングについて触れ,最も応用可能性の高いものとして,スマートフォンを使ったクラウドサービスの概念を紹介する. 次に,映像脈波の実用上の課題と限界について述べる.すなわち,映像脈波の最大の弱点が,体動と照度変化に極端に弱いことであり,それぞれに関する対策を紹介するとともに,今後を展望する</p>

著者

山越 健弘 山越 康弘 松村 健太 廣瀬 元

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.47, no.2, pp.154-165, 2009-04-10 (Released:2009-09-09)

参考文献数

37

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Physiological monitoring was carried out during the motor sport of Racing Kart driving. In addition to highlighting the importance of physiological measurement during motor sports, this study may have social relevance through its potential to contribute to decreasing automobile accidents in overload situations by using appropriate biosignals. The measurement quantities collected in this study were instantaneous heart rate, HR, vector magnitude of acceleration, G, blood pressure, BP, and core body temperature, Teardrum. After giving informed consent 11 healthy male subjects (34.4 ± 7.7 S.D. yrs) were tested in the racing circuit. We successfully monitored the physiological variables during karting, finding a statistically significant decrease in BP (p < 0.01) and a rise in Teardrum (p < 0.01) immediately after the driving period. In addition, we have confirmed that HR was maintained at approximately 150bpm, which, by means of time-frequency analysis, could be explained by sympathetic acceleration. Furthermore, it is strongly suggested that the rise in HR could be closely related to the G forces to which the drivers were subjected. These results clearly disclose to us one aspect of the possible physiological responses and the importance of physiological monitoring during motor sports.

著者

山田 正敏 田畑 泰彦

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.43, no.2, pp.238-246, 2005 (Released:2007-01-19)

参考文献数

31

被引用文献数

1