研究者業績

中口 俊哉

ナカグチ トシヤ  (Toshiya Nakaguchi)

基本情報

所属
千葉大学 フロンティア医工学センター 教授
学位
博士(工学)(上智大学)

J-GLOBAL ID
200901090860522117
researchmap会員ID
5000048018

外部リンク

論文

 209
  • Zhe Li, Aya Kanazuka, Atsushi Hojo, Yukihiro Nomura, Toshiya Nakaguchi
    Measurement 2025年5月  
  • Huitao Wang, Takahiro Nakajima, Kohei Shikano, Yukihiro Nomura, Toshiya Nakaguchi
    Tomography 2025年2月27日  
  • Rizki Nurfauzi, Ayaka Baba, Taka-Aki Nakada, Toshiya Nakaguchi, Yukihiro Nomura
    Biomedical Physics & Engineering Express 11(2) 025026-025026 2025年2月6日  
    Abstract Traumatic injury remains a leading cause of death worldwide, with traumatic bleeding being one of its most critical and fatal consequences. The use of whole-body computed tomography (WBCT) in trauma management has rapidly expanded. However, interpreting WBCT images within the limited time available before treatment is particularly challenging for acute care physicians. Our group has previously developed an automated bleeding detection method in WBCT images. However, further reduction of false positives (FPs) is necessary for clinical application. To address this issue, we propose a novel automated detection for traumatic bleeding in CT images using deep learning and multi-organ segmentation; Methods: The proposed method integrates a three-dimensional U-Net# model for bleeding detection with an FP reduction approach based on multi-organ segmentation. The multi-organ segmentation method targets the bone, kidney, and vascular regions, where FPs are primarily found during the bleeding detection process. We evaluated the proposed method using a dataset of delayed-phase contrast-enhanced trauma CT images collected from four institutions; Results: Our method detected 70.0% of bleedings with 76.2 FPs/case. The processing time for our method was 6.3 ± 1.4 min. Compared with our previous ap-proach, the proposed method significantly reduced the number of FPs while maintaining detection sensitivity.
  • Ryo Oka, Bochong Li, Seiji Kato, Takanobu Utsumi, Takumi Endo, Naoto Kamiya, Toshiya Nakaguchi, Hiroyoshi Suzuki
    Current Urology 2025年2月3日  
    Abstract Background With the rising incidence of prostate cancer (PCa), there is a global demand for assistive tools that aid in the diagnosis of high-grade PCa. This study aimed to develop a diagnostic support system for high-grade PCa using innovative magnetic resonance imaging (MRI) sequences in conjunction with artificial intelligence (AI). Materials and methods We examined image sequences of 254 patients with PCa obtained from diffusion-weighted and T2-weighted imaging, using novel MRI sequences before prostatectomy, to elucidate the characteristics of the 3-dimensional (3D) image sequences. The presence of PCa was determined based on the final diagnosis derived from pathological results after prostatectomy. A 3D deep convolutional neural network (3DCNN) was used as the AI for image recognition. Data augmentation was conducted to enhance the image dataset. High-grade PCa was defined as Gleason grade group 4 or higher. Results We developed a learning system using a 3DCNN as a diagnostic support system for high-grade PCa. The sensitivity and area under the curve values were 85% and 0.82, respectively. Conclusions The 3DCNN-based AI diagnostic support system, developed in this study using innovative 3D multiparametric MRI sequences, has the potential to assist in identifying patients at a higher risk of pretreatment of high-grade PCa.
  • Zhe Li, Aya Kanazuka, Atsushi Hojo, Yukihiro Nomura, Toshiya Nakaguchi
    Electronics 13(19) 3882-3882 2024年9月30日  査読有り
    The COVID-19 pandemic has significantly disrupted traditional medical training, particularly in critical areas such as the injection process, which require expert supervision. To address the challenges posed by reduced face-to-face interactions, this study introduces a multi-modal fusion network designed to evaluate the timing and motion aspects of the injection training process in medical education. The proposed framework integrates 3D reconstructed data and 2D images of hand movements during the injection process. The 3D data are preprocessed and encoded by a Long Short-Term Memory (LSTM) network to extract temporal features, while a Convolutional Neural Network (CNN) processes the 2D images to capture detailed image features. These encoded features are then fused and refined through a proposed multi-head self-attention module, which enhances the model’s ability to capture and weigh important temporal and image dynamics in the injection process. The final classification of the injection process is conducted by a classifier module. The model’s performance was rigorously evaluated using video data from 255 subjects with assessments made by professional physicians according to the Objective Structured Assessment of Technical Skill—Global Rating Score (OSATS-GRS)[B] criteria for time and motion evaluation. The experimental results demonstrate that the proposed data fusion model achieves an accuracy of 0.7238, an F1-score of 0.7060, a precision of 0.7339, a recall of 0.7238, and an AUC of 0.8343. These findings highlight the model’s potential as an effective tool for providing objective feedback in medical injection training, offering a scalable solution for the post-pandemic evolution of medical education.

MISC

 186

書籍等出版物

 3

講演・口頭発表等

 577
  • 道正田洋, 金鐘泌, 中口俊哉, 津村徳道, 三宅洋一
    Japan Hardcopy 2004 Fall Meeting, p45 2004年
  • 丹治裕一, 中口俊哉, 田中衞
    信学技報 NLP2002-127, pp.73-78 2003年3月17日 電子情報通信学会
  • Jun Yamashita, Hisato Sekine, Toshiya Nakaguchi, Norimichi Tsumura and Yoichi Miyake
    Proc. of Int'l Conference on Digital Printing Technologies(NIP19), pp.769-772 2003年9月 SOC IMAGING SCIENCE & TECHNOLOGY
    We propose a new model to predict the color reproduction of digital halftone image based on the physical model of dot gain. In the previous papers, we reported that the transparency image of halftone is not influenced by optical dot gain. On the basis of this experimental result, in this paper we analyze the optical and mechanical dot gain separately by using the optical microscopes which can take the transparency and reflectance images of the same area. Transparency images of an ink dot are taken with an optical microscope with a six-band camera and the spectral transmittance of each pixel in an ink dot is estimated by the multiple regression estimation method. This obtained spectral transmittance is converted into the amount of cyan, magenta, and yellow (c,m,y) inks in each pixel. Then we can estimate the shape of ink dot by polynomial fitting of ink amount. The transmittance of c,m,y inks of printed images is estimated by using the proposed method and compared with that of practical printed images. This results show that the proposed method is significant to predict the density of inkjet images.
  • Ryota Aoki, Toshiya Nakaguchi, Tsuyoshi Otake, Mamoru Tanaka
    in Proc. of NOLTA2002, N10-9-5, Xian, China 2002年10月
  • 中口俊哉, 神野健哉, 田中衞
    信学技報 NC2001- 2002年1月28日 電子情報通信学会
  • Toshiya Nakaguchi, Kenya Jin’no, Mamoru Tanaka
    in Proc. of ICONIP 2002, TuePmRm2Ss1-2, Singapore 2002年11月 NANYANG TECHNOLOGICAL UNIV
    Hysteresis neural networks are one of the effective heuristic algorithms for constraint satisfaction problems. To overcome a serious defect of HNN which is called a periodic solution, several algorithms have been proposed. This paper describes a comparison between two algorithms of them based on tabu search. One is a previously proposed algorithm named dynamic time constant tabu hysteresis neural networks. Another is a novel algorithm named dynamic equilibrium point tabu hysteresis neural networks. These algorithms are estimated from their performances and implementation costs.
  • Toshiya Nakaguchi, Koji Omiya, Mamoru Tanaka
    in Proc. of CNNA 2002, pp.539-546, Frankfurt, Germany 2002年7月 WORLD SCIENTIFIC PUBL CO PTE LTD
    Hysteresis cellular neural networks are one of artificial neural networks which work effectively against large scale problems. In the previous work, remarkable methods have never been developed to overcome the defects of hysteresis cellular neural networks. We then propose a novel architecture for combinatorial optimization problems to overcome them. Experimental results indicate the efficiency of the architecture.
  • Toshiya Nakaguchi, Kenya Jin'no, Mamoru Tanaka
    in Proceedings of ICONIP2001, pp.1461-1465, Shanghai, China 2001年11月
  • Ryota Aoki, Toshiya Nakaguchi, Tsuyoshi Otake, Mamoru Tanaka
    in Proceedings of NOLTA2001, pp.105-108, Yamagata, Japan 2001年10月
  • Ryota Aoki, Toshiya Nakaguchi, Tsuyoshi Otake, Mamoru Tanaka
    in Proceedings of ECCTD'01, III-409, Espoo, Finland 2001年8月
  • Toshiya Nakaguchi, Kenya Jin'no, Mamoru Tanaka
    in Proceedings of IEEE/ISCAS'2001, W09-Sky3-O.2, Sydney, Australia 2001年5月
    Hysteresis neural network is applied to combinatorial optimization problems and efficiency of its parallel computing is obtained by numerical calculations. In this research, we implement hardware optimization problems solver by hysteresis neural networks. To produce hysteresis neural module, we propose a novel synapse architecture. From experimental results, we confirm the efficiency of implementation. © 2001 IEEE.
  • 中口俊哉, 神野健哉, 田中衞
    信学技報 NLP2000-112 2000年11月 電子情報通信学会
  • Shinya Isome, Toshiya Nakaguchi, Tsuyoshi Otake, Mamoru Tanaka
    in Proceedings of NOLTA2000, pp.669-672, Dresden, Germany 2000年9月
  • Toshiya Nakaguchi, Kenya Jin'no, Mamoru Tanaka
    in Proceedings of IEEE/ISCAS'2000, III-153, Geneva, Switzerland 2000年5月 IEEE
    We propose hysteresis neural networks for solving NP-Hard problems, Traveling Salesperson Problems (TSP). Since hysteresis neural networks have no local minimum, they can be applied into various optimization problems. However, since conventional system for solving TSP which is proposed by Hopfield and Tank is not adaptive for hysteresis neural networks, they haven't yet been applied into TSP. So, we propose novel system for solving TSP. We obtain improved result of TSP with proposed system on hysteresis neural networks.
  • Toshiya Nakaguchi, Yuichi Tanji, Mamoru Tanaka
    in Proceedings of IEEE/ISCAS'2000, IV-125, Geneva, Switzerland 2000年5月 IEEE
    The image intensity conversion via CNN is presented. The intensity conversion is defined as a nonlinear optimization problem, and the templates of CNN for solving it are optimally designed. Since human visual sensitivity and linear quantization of original image are used to design the templates? it gives a smooth image preserving edge information such as character parts.
  • 中口俊哉, 神野健哉, 田中衞
    第13回回路とシステム(軽井沢)ワークショップ 2000年1月
  • Toshiya Nakaguchi, Yuichi Tanji, Mamoru Tanaka
    in Proceedings of NOLTA'99, pp.411-414, Hawaii, USA 1999年11月
  • Masashi Mori, Toshiya Nakaguchi, Yuichi Tanji, Mamoru Tanaka
    in Proceedings of ECCTD'99, pp.952-955, Stresa, Italy 1999年8月
  • Toshiya Nakaguchi, Takaaki Harada, Yuichi Tanji, Kenya Jinno, Mamoru Tanaka
    in Proceedings of ECCTD'99, pp.1355-1358, Stresa, Italy 1999年8月
  • Toshiya Nakaguchi, Kenya Jin'no, Mamoru Tanaka
    in Proceedings of IEEE/ISCAS'99, V-555, Orlando, Florida, USA 1999年5月
  • 中口俊哉、神野健哉、田中衞
    1999年電子情報通信学会総合大会 A-2-3(横浜、1999.3.25-3.28) 1999年3月25日 電子情報通信学会
  • Toshiya Nakaguchi, Kenya Jin'no, Mamoru Tanaka
    in Proceedings of NOLTA'98, pp.437-440, Crans-Montana, Switzerland 1998年9月
  • 神野健哉, 中口俊哉, 田中衛
    信学技報 NLP98-5 1998年5月 一般社団法人電子情報通信学会
    ヒステリシスニューラルネットを用いた組合わせ最適化問題の解法を提案する。N-クイーン問題を本報告では組合わせ最適化問題の対象とした。Hofieldらは系に定義したエネルギー関数が単調減少するネットワークを用い、エネルギー関数と最適化問題のコスト関数とを対応させた最適化問題の解法を提案している。しかしながらこのネットワークはエネルギー関数の最小値と最適化問題の最適解とが一致していることが保証されておらず、また極小値の存在により最適解が得られない場合が多い。本論文で提案する系はエネルギー関数が単調減少する条件が保証されていないため、振動解が発生する可能性があるものの、最適化問題の最適解に対応した平衡点が安定平衡点となっている。この安定平衡点はエネルギー関数の最小値に対応しており、極小値は存在しない。このため、従来提案されている方法よりも良好な結果が得られると期待出来る。
  • Toshiya Nakaguchi, Kenya Jin'no, Mamoru Tanaka
    in Proceedings of IEEE/ISCAS'98, TAA-7, Monterey, CA, USA 1998年5月
  • 中口 俊哉, 神野 健哉, 田中 衞
    信学技報 NLP97-122 1997年11月 電子情報通信学会
  • Toshiya Nakaguchi, Kenya Jin'no, Mamoru Tanaka
    Proceedings of NOLTA'97 1997年11月1日
  • 松下 明弘, 森 諒輔, 上山 毅, 田部井 勝行, 野村 行弘, 中口 俊哉
    第21回日本VR医学会抄録集, GS2-2, p.18

共同研究・競争的資金等の研究課題

 18