研究者詳細 - 大澤　晋

論文 - 大澤　晋

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Development of Antimicrobial Surfaces Using Diamond-like Carbon or Diamond-like Carbon-Based Coatings. 国際誌

Yasuhiro Fujii, Tatsuyuki Nakatani, Daiki Ousaka, Susumu Oozawa, Yasushi Sasai, Shingo Kasahara

International journal of molecular sciences 25 ( 16 ) 2024年8月

記述言語：英語掲載種別：研究論文（学術雑誌）

The medical device market is a high-growth sector expected to sustain an annual growth rate of over 5%, even in developed countries. Daily, numerous patients have medical devices implanted or inserted within their bodies. While medical devices have significantly improved patient outcomes, as foreign objects, their wider use can lead to an increase in device-related infections, thereby imposing a burden on healthcare systems. Multiple materials with significant societal impact have evolved over time: the 19th century was the age of iron, the 20th century was dominated by silicon, and the 21st century is often referred to as the era of carbon. In particular, the development of nanocarbon materials and their potential applications in medicine are being explored, although the scope of these applications remains limited. Technological innovations in carbon materials are remarkable, and their application in medicine is expected to advance greatly. For example, diamond-like carbon (DLC) has garnered considerable attention for the development of antimicrobial surfaces. Both DLC itself and its derivatives have been reported to exhibit anti-microbial properties. This review discusses the current state of DLC-based antimicrobial surface development.

DOI： 10.3390/ijms25168593

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Initial trial of three‑lead wearable electrocardiogram monitoring in a full marathon.

Kenta Hirai, Noriko Sakano, Susumu Oozawa, Daiki Ousaka, Yosuke Kuroko, Shingo Kasahara

Journal of cardiology cases 30 ( 1 ) 24 - 28 2024年7月

記述言語：英語掲載種別：研究論文（学術雑誌）

UNLABELLED: Sudden cardiac arrest during exercise can occur without prior warning signs at rest, highlighting the importance of monitoring for its prevention. To detect the signs of ischemic heart disease, including coronary artery anomalies, ST changes must be detected using three‑lead electrocardiograms (ECGs) corresponding to each region of the three coronary artery branches. We conducted ECG monitoring of five runners during a marathon using a wearable three‑lead ECG device (e-skin ECG; Xenoma Inc., Tokyo, Japan). Data without noise or artifacts were successfully collected for one of five runners during the entire marathon. Within the initial hour of the marathon, poor electrode adhesion to the skin hindered the data collection for the remaining four runners, which resulted in significantly decreased acquisition rate compared with the first hour (86.7 ± 13.4 % to 37.3 ± 36.9 %, p = 0.028). Couplets of premature ventricular contractions with clear ECG waveforms in the three leads were detected in one runner during the marathon. Further device improvements are necessary to enable marathon runners to obtain ECGs efficiently without affecting their performance. This study also demonstrated the potential applications of three‑lead wearable ECG monitoring for other short-duration sports and remote home-based cardiac rehabilitation. LEARNING OBJECTIVE: This is an initial trial of a three‑lead wearable electrocardiogram (ECG) monitoring device during a full marathon. ECG data were obtained with low noise and artifacts during the first hour of the marathon; however, the data acquisition rate decreased in the middle and late stages owing to poor electrode adhesion. This study demonstrated the possibility of applying wearable ECG monitoring during short-term exercise and cardiac rehabilitation to detect warning signs and prevent sudden cardiac arrest.

DOI： 10.1016/j.jccase.2024.03.004

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大学病院と市中病院における透析内シャント設置術の患者背景及び実施術式に関する比較と考察

藤井泰宏, 竹内英実, 加藤源太郎, 井上善紀, 倉田裕次, 黒子洋介, 田邊克幸, 岡本修吾, 小松弘明, 枝木大治, 徳田雄平, 大澤晋, 浅川知彦, 山本修三, 田蒔基行, 西岡聡, 田蒔昌憲, 和田淳, 田蒔正治, 笠原真悟

日本透析医学会雑誌 57 ( Suppl.1 ) 441 - 441 2024年5月

大学病院と市中病院における透析内シャント設置術の患者背景及び実施術式に関する比較と考察

日本透析医学会雑誌 57 ( Suppl.1 ) 441 - 441 2024年5月

Catheter-directed thrombolysis for critical hand ischemia with failed distal venous arterialization.

Mitsutaka Nakashima, Hironobu Toda, Kentaro Ejiri, Susumu Ozawa, Satoshi Akagi, Kazufumi Nakamura

Cardiovascular intervention and therapeutics 2023年8月

Ultra-hydrophilic Diamond-like Carbon Coating on an Inner Surface of a Small-diameter Long Tube with an Amino Group by AC High-voltage Plasma Discharge

Yuichi Imai, Hiroyuki Fukue, Tatsuyuki Nakatani, Shinsuke Kunitsugu, Noriaki Kuwada, Yasuhiro Fujii, Daiki Ousaka, Susumu Oozawa, Tomio Uchi

Journal of Photopolymer Science and Technology 36 ( 5 ) 379 - 384 2023年6月

Diamond-like carbon coating to inner surface of polyurethane tube reduces Staphylococcus aureus bacterial adhesion and biofilm formation.

Noriaki Kuwada, Yasuhiro Fujii, Tatsuyuki Nakatani, Daiki Ousaka, Tatsunori Tsuji, Yuichi Imai, Yasuyuki Kobayashi, Susumu Oozawa, Shingo Kasahara, Kazuo Tanemoto

Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs 2023年5月

記述言語：英語掲載種別：研究論文（学術雑誌）

Staphylococcus aureus is one of the main causative bacteria for polyurethane catheter and artificial graft infection. Recently, we developed a unique technique for coating diamond-like carbon (DLC) inside the luminal resin structure of polyurethane tubes. This study aimed to elucidate the infection-preventing effects of diamond-like carbon (DLC) coating on a polyurethane surface against S. aureus. We applied DLC to polyurethane tubes and rolled polyurethane sheets with our newly developed DLC coating technique for resin tubes. The DLC-coated and uncoated polyurethane surfaces were tested in smoothness, hydrophilicity, zeta-potential, and anti-bacterial properties against S. aureus (biofilm formation and bacterial attachment) by contact with bacterial fluids under static and flow conditions. The DLC-coated polyurethane surface was significantly smoother, more hydrophilic, and had a more negative zeta-potential than did the uncoated polyurethane surface. Upon exposure to bacterial fluid under both static and flow conditions, DLC-coated polyurethane exhibited significantly less biofilm formation than uncoated polyurethane, based on absorbance measurements. In addition, the adherence of S. aureus was significantly lower for DLC-coated polyurethane than for uncoated polyurethane under both conditions, based on scanning electron microscopy. These results show that applying DLC coating to the luminal resin of polyurethane tubes may impart antimicrobial effects against S. aureus to implantable medical polyurethane devices, such as vascular grafts and central venous catheters.

DOI： 10.1007/s10047-023-01403-1

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Comprehensive hemocompatibility analysis on the application of diamond-like carbon to ePTFE artificial vascular prosthesis. 国際誌

Takashi Goyama, Yasuhiro Fujii, Genya Muraoka, Tatsuyuki Nakatani, Daiki Ousaka, Yuichi Imai, Noriaki Kuwada, Tatsunori Tsuji, Takayuki Shuku, Haruhito A Uchida, Masahiro Nishibori, Susumu Oozawa, Shingo Kasahara

Scientific reports 13 ( 1 ) 8386 - 8386 2023年5月

記述言語：英語掲載種別：研究論文（学術雑誌）

The aim of this study was to obtain comprehensive data regarding the hemocompatibility of diamond-like carbon (DLC)-coated expanded polytetrafluoroethylene (ePTFE). DLC increased the hydrophilicity and smoothened the surface and fibrillar structure, respectively, of the ePTFE. DLC-coated ePTFE had more albumin and fibrinogen adsorption and less platelet adhesion than uncoated ePTFE. There were scarce red cell attachments in in vitro human and in vivo animal (rat and swine) whole blood contact tests in both DLC-coated and uncoated ePTFE. DLC-coated ePTFE had a similar but marginally thicker band movement than uncoated-ePTFE with SDS-PAGE after human whole blood contact test. In addition, survival studies of aortic graft replacement in rats (1.5 mm graft) and arteriovenous shunt in goats (4 mm graft) were performed to compare the patency and clot formation between DLC-coated and uncoated ePTFE grafts. Comparable patency was observed in both animal models. However, clots were observed in the luminal surface of the patent 1.5 mm DLC-coated ePTFE grafts, but not in that of uncoated ePTFE grafts. In conclusions, hemocompatibility of DLC-coated ePTFE was high and comparable to that of uncoated ePTFE. However, it failed to improve the hemocompatibility of 1.5 mm ePTFE graft probably because increased fibrinogen adsorption canceled the other beneficial effects of DLC.

DOI： 10.1038/s41598-023-35594-7

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Trial of Sportswear Type ECG Sensor Device for Cardiac Safety Management during Marathon Running

Takahiro Yamane, Kazuya Hirano, Kenta Hirai, Daiki Ousaka, Noriko Sakano, Mizuki Morita, Susumu Oozawa, Shingo Kasahara

ADVANCED BIOMEDICAL ENGINEERING 11 151 - 161 2022年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JAPANESE SOC MEDICAL & BIOLOGICAL ENGINEERING

Cardiac arrest has been reported during participation in several sports. Of these sports, marathon running is a particularly popular sport but imposes high cardiac load. Indeed, its popularity has been growing worldwide. Risk of cardiac arrest during marathon races is also expected to increase. Several studies have recorded electrocardiographic (ECG) information during marathon races to protect athletes from cardiac arrest. Although evaluable ECG data have been obtained and analyzed, cost-effectiveness of the system, data quality, and clinical significance remain inadequate. This report is the first to describe an economical electrocardiograph built into a T-shirt for use during marathon race. Twenty healthy runners aged 20 to 59 years (mean 36 years) wore the ECG device while running. The ECG data were monitored and analyzed to assess the observed frequencies of specified arrhythmias and the sections of the marathon in which the arrhythmias occurred. Of the ECG data obtained from 14 runners who completed the full marathon, six ECG datasets were evaluable. In some runners, there was inadequate contact between the electrode and body surface or poor Bluetooth connection between the ECG wireless transmitter and smartphone. Regarding arrhythmia analysis, all evaluable data that were analyzed showed some rhythm fluctuations. In conclusion, this economical T-shirt type ECG sensor provided evaluable ECG data during marathon races, although the evaluable rate was not high. The data were used to analyze specified arrhythmias, but some difficulties were encountered. The ECG sensor did not function properly because of a system error. The ECG sensor was not adequately moistened to record ECGs accurately. Moreover, some runners chose an unsuitable shirt size, which impaired the stability and strength of the electrode-skin contact. These shortcomings produced noise in the ECG data, which made it difficult to analyze arrhythmias. The next step will be to solve these problems and acquire data from a large number of runners.

DOI： 10.14326/abe.11.151

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Initial evaluation of a novel electrocardiography sensor-embedded fabric wear during a full marathon.

Daiki Ousaka, Kenta Hirai, Noriko Sakano, Mizuki Morita, Madoka Haruna, Kazuya Hirano, Takahiro Yamane, Akira Teraoka, Kazuo Sanou, Susumu Oozawa, Shingo Kasahara

Heart and vessels 37 ( 3 ) 443 - 450 2021年9月

記述言語：英語掲載種別：研究論文（学術雑誌）

Sudden cardiac accident (SCA) during a marathon is a concern due to the popularity of the sport. Preventive strategies, such as cardiac screening and deployment of automated external defibrillators have controversial cost-effectiveness. We investigated the feasibility of use of a new electrocardiography (ECG) sensor-embedded fabric wear (SFW) during a marathon as a novel preventive strategy against SCA. Twenty healthy volunteers participated in a full marathon race. They were equipped with a SFW hitoe® with a transmitter connected via Bluetooth to a standard smartphone for continuous ECG recording. All data were stored in a smartphone and used to analyze the data acquisition rate. The adequate data acquisition rate was > 90% in 13, 30-90% in 3, and < 10% in 4 runners. All of 4 runners with poorly recorded data were female. Inadequate data acquisition was significantly associated with the early phase of the race compared with the mid phase (P = 0.007). Except for 3 runners with poor heart rate data, automated software calculation was significantly associated with manual analysis for both the mean (P < 0.001) and maximum (P = 0.014) heart rate. We tested the feasibility of continuously recording cardiac data during a marathon using a new ECG sensor-embedded wearable device. Although data from 65% of runners were adequately recorded, female runners and the early phase of the race tended to have poor data acquisition. Further improvements in device ergonomics and software are necessary to improve ability to detect abnormal ECGs that may precede SCA.

DOI： 10.1007/s00380-021-01939-3

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Intraluminal diamond-like carbon coating with anti-adhesion and anti-biofilm effects for uropathogens: A novel technology applicable to urinary catheters. 国際誌

Shogo Watari, Koichiro Wada, Motoo Araki, Takuya Sadahira, Daiki Ousaka, Susumu Oozawa, Tatsuyuki Nakatani, Yuichi Imai, Junichi Kato, Reiko Kariyama, Toyohiko Watanabe, Yasutomo Nasu

International journal of urology : official journal of the Japanese Urological Association 28 ( 12 ) 1282 - 1289 2021年9月

記述言語：英語掲載種別：研究論文（学術雑誌）

OBJECTIVES: To examine anti-adhesion and anti-biofilm effects of a diamond-like carbon coating deposited via a novel technique on the inner surface of a thin silicon tube. METHODS: Diamond-like carbon coatings were deposited into the lumen of a silicon tube with inner diameters of 2 mm. The surface of the diamond-like carbon was evaluated using physicochemical methods. We used three clinical isolates including green fluorescent protein-expressing Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus. We employed a continuous flow system for evaluation of both bacterial adhesion and biofilm formation. Bacterial adhesion assays consisted of counting the number of colony-forming units and visualization of adhered bacterial cells by scanning electron microscope to evaluate the diamond-like carbon-coated/uncoated samples. The biofilm structure was analyzed by confocal laser scanning microscopy on days 3, 5, 7 and 14 for green fluorescent protein-expressing Pseudomonas aeruginosa. RESULTS: The smooth and carbon-rich structure of the intraluminal diamond-like carbon film remained unchanged after the experiments. The numbers of colony-forming units suggested lower adherence of green fluorescent protein-expressing Pseudomonas aeruginosa and Escherichia coli in the diamond-like carbon-coated samples compared with the uncoated samples. The scanning electron microscope images showed adhered green fluorescent protein-expressing Pseudomonas aeruginosa cells without formation of microcolonies on the diamond-like carbon-coated samples. Finally, biofilm formation on the diamond-like carbon-coated samples was lower until at least day 14 compared with the uncoated samples. CONCLUSIONS: Intraluminal diamond-like carbon coating on a silicone tube has anti-adhesion and anti-biofilm effects. This technology can be applied to urinary catheters made from various materials.

DOI： 10.1111/iju.14675

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ウエアラブル心拍計によるマラソンランナーの心事故予防のための自己スクリーニング法の試み新しい心電図自己スクリーニングシステムの構築にむけて

坂野紀子, 逢坂大樹, 平野和也, 森田瑞樹, 珠玖隆行, 大澤晋, 佐能量雄, 笠原真悟

日本遠隔医療学会雑誌 16 ( 補刊号 ) 59 - 59 2021年4月

マラソン中の心事故予防に向けた心電モニタリングシステムの開発

笠原真悟, 逢坂大樹, 坂野紀子, 森田瑞樹, 珠玖隆行, 大澤晋

日本遠隔医療学会雑誌 16 ( 補刊号 ) 32 - 32 2021年4月

岡山大学外科GRAPESの活動とこれから

竹原裕子, 吉田龍一, 溝尾妙子, 剱持礼子, 小林純子, 新田薫, 工藤由里絵, 元木崇之, 片岡正文, 池田宏国, 菊池覚次, 黒田新士, 枝園忠彦, 山根正修, 小谷恭弘, 大澤晋, 土井原博義, 豊岡伸一, 笠原慎悟, 藤原俊義

日本外科学会定期学術集会抄録集 121回 SF - 5 2021年4月

岡山大学外科GRAPESの活動とこれから

日本外科学会定期学術集会抄録集 121回 SF - 5 2021年4月

マラソン中の心事故予防に向けた心電モニタリングシステムの開発

笠原真悟, 逢坂大樹, 坂野紀子, 森田瑞樹, 珠玖隆行, 大澤晋

日本遠隔医療学会学術大会プログラム・抄録集 24回 144 - 144 2021年2月

マラソン中の心事故予防に向けた心電モニタリングシステムの開発

笠原真悟, 逢坂大樹, 坂野紀子, 森田瑞樹, 珠玖隆行, 大澤晋

日本遠隔医療学会学術大会プログラム・抄録集 24回 144 - 144 2021年2月

タバコ窩内シャントファースト戦略での橈骨動脈AVFの臨床成績

藤井泰宏, 大澤晋, 村岡玄哉, 木佐森永理, 小松弘明, 横田豊, 迫田直也, 辻龍典, 小林泰幸, 堀尾直裕, 小林純子, 川畑拓也, 黒子洋介, 廣田真規, 末澤孝徳, 小谷恭弘, 笠原真悟

日本心臓血管外科学会学術総会抄録集 51回 OP10 - 5 2021年2月

タバコ窩内シャントファースト戦略での橈骨動脈AVFの臨床成績

日本心臓血管外科学会学術総会抄録集 51回 OP10 - 5 2021年2月

外科系新専門医制度のあるべきグランドデザイン地域枠医師に対する外科専門研修のあり方充実した地域医療の実現を目指して

黒田新士, 吉田龍一, 池田宏国, 岡崎幹生, 大澤晋, 小谷恭弘, 山根正修, 杉本誠一郎, 菊地覚次, 安井和也, 野田卓男, 笠原真悟, 豊岡伸一, 土井原博義, 藤原俊義

日本外科学会雑誌 122 ( 1 ) 83 - 85 2021年1月

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