2022 Fiscal Year Final Research Report

Ultrasonic visualization of thoracic vertebrae for supporting epidural anesthesia

Research Project

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Project/Area Number	20H02156
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 21030:Measurement engineering-related
Research Institution	Tohoku University
Principal Investigator	Kanai Hiroshi 東北大学, 工学研究科, 教授 (10185895)
Co-Investigator(Kenkyū-buntansha)	荒川元孝東北大学, 医工学研究科, 准教授 (00333865) 山内正憲東北大学, 医学系研究科, 教授 (00404723) 大西詠子東北大学, 大学病院, 助教 (10822265) 森翔平東北大学, 工学研究科, 助教 (50815149)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	医用超音波計測 / 硬膜外麻酔 / 超音波散乱 / 反射波の影響 / 包絡線振幅 / 振幅角度特性 / 超音波工学 / 骨の描出
Outline of Final Research Achievements	In epidural anesthesia, in which an anesthetic needle is inserted into the thoracic space from the skin surface, it is difficult to puncture the appropriate position because the space is narrow and the spinous process extends. In clinical practice, ultrasound is sometimes used to confirm the puncture position, but the visualization of the puncture position is unclear because it is not possible to distinguish between muscle that scatters ultrasound and bone that reflects ultrasound. In the previous research, the influence of the reflected wave from the object was superimposed and the spatial resolution decreased. Therefore, in this research, (1) the difference between scattering and reflection is identified from the amplitude angle characteristics obtained from the instantaneous value of the envelope amplitude of each element, and (2) using the difference in the amplitude angle characteristics of scattering and reflection, The thoracic interspace is sharpened by emphasizing bones.
Free Research Field	医用超音波工学
Academic Significance and Societal Importance of the Research Achievements	骨では，筋組織により浅部に広がる受信信号が得られること，高強度の受信信号の位置は対象物の傾きに依存して得られることが実験的に示された．また，筋組織と骨から得られる受信信号の違いから筋組織を抑制し，骨を強調する描出法を提案し，その優位性を示した．現状では，硬膜外麻酔で，穿刺位置を確認するために，超音波を用いるが，超音波を散乱する筋肉と，超音波を反射する骨の描出を区別できず，穿刺位置の描出が不鮮明である．本研究成果は，今後の硬膜外麻酔の際の超音波ガイダンスとなり，新たな胸椎描出法を研究開発の基礎になったものと言える。さらに，整形分野での医用超音波による骨の描出能の向上にも寄与すると期待される．