Continuous blood viscosity monitoring system for cardiopulmonary bypass and its clinical application

• Project/Area Number: 16K01429
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Medical systems
• Research Institution: Junshin Gakuen University
• Principal Investigator: OKAHARA Shigeyuki 純真学園大学, 医療工学科, 准教授 (50771185)
• Co-Investigator(Kenkyū-buntansha): 辻 敏夫 広島大学, 工学研究科, 教授 (90179995) ; 曽 智 広島大学, 工学研究科, 助教 (80724351) ; 末田 泰二郎 広島大学, 医歯薬保健学研究科(医), 教授 (10162835) ; 伊藤 英史 純真学園大学, 医療工学科, 教授 (50711462)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000); Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2016: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 人工心肺 / 血液粘度 / 人工肺

Outline of Final Research Achievements

During cardiopulmonary bypass (CPB), blood viscosity conspicuously increases and decreases due to changes in hematocrit and blood temperature. Nevertheless, blood viscosity is typically not evaluated, because there is no technology that can provide simple, continuous, noncontact monitoring. First, we modeled the pressure-flow characteristics of an oxygenator in this study, and we quantified the influence of viscosity on oxygenator function. Second, we focused on pressure flow characteristics of an oxygenator and developed the continuous blood viscosity monitoring system. Last, we applied this system to clinical CPB cases and demonstrated that the estimated viscosity correlated with measured viscosity using the torsional oscillation viscometer with good accuracy.

Academic Significance and Societal Importance of the Research Achievements

人工心肺中の血液粘度は，温度，ヘマトクリットなどの非生理的な制御，不十分な抗凝固，機械的なストレスなどによって変化して，術後の心血管・脳血管合併症などに影響する可能性がある．しかし，これまで連続的に血液粘度を測定する技術が無かったので，血液粘度が人工心肺に及ぼす影響は調べられていない．本研究では，人工肺の圧力流量特性を利用した連続血液粘度モニタリングシステムを開発し，臨床症例に応用し，従来の粘度計と比較して，良好な正確性を実証した．今後，これに関連する研究が進み，心臓手術患者の合併症の最小化などに寄与できる可能性がある．

Research Products

• [Journal Article] Continuous Blood Viscosity Monitoring System for Cardiopulmonary Bypass Applications (2017)
  • Author(s): Okahara Shigeyuki、Soh Zu、Miyamoto Satoshi、Takahashi Hidenobu、Takahashi Shinya、Sueda Taijiro、Tsuji Toshio
  • Journal Title: IEEE Transactions on Biomedical Engineering Volume: 64 Issue: 7 Pages: 1503-1512
  • DOI: 10.1109/tbme.2016.2610968
  • Peer Reviewed
• [Journal Article] A novel blood viscosity estimation based on pressure -flow characteristics of an oxygenator during cardiopulmonary bypass (2017)
  • Author(s): Okahara S, Soh Z, Miyamoto S, Takahashi H, Itoh H, Takahahsi S, Sueda T, Tsuji T
  • Journal Title: Artf Organs Volume: 41 Issue: 3 Pages: 262-266
  • DOI: 10.1111/aor.12747
  • Peer Reviewed / Open Access
• [Presentation] Detection of Echinocyte during Perfusion with Oxygenator Based on Continuous Blood Viscosity Monitoring (2018)
  • Author(s): Shigeyuki Okahara
  • Organizer: 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society
  • Int'l Joint Research
• [Presentation] Blood Viscosity Monitoring During Cardiopulmonary Bypass Based on Pressure-Flow Characteristics of a Newtonian fluid (2016)
  • Author(s): Shigeyuki Okahara
  • Organizer: 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society
  • Place of Presentation: Orlando, FL, USA,
  • Year and Date: 2016-08-16
  • Int'l Joint Research