2023 Fiscal Year Final Research Report

Development of 3D acoustic CT with multi-channel phonocardiogram for lung lesion detection

Research Project

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Project/Area Number	21K19880
Research Category	Grant-in-Aid for Challenging Research (Exploratory)
Allocation Type	Multi-year Fund
Review Section	Medium-sized Section 90:Biomedical engineering and related fields
Research Institution	Tohoku University
Principal Investigator	Saijo Yoshifumi 東北大学, 医工学研究科, 教授 (00292277)
Co-Investigator(Kenkyū-buntansha)	芳賀洋一東北大学, 医工学研究科, 教授 (00282096)
Project Period (FY)	2021-07-09 – 2024-03-31
Keywords	心音図 / 音響CT / 新型コロナウイルス / 肺
Outline of Final Research Achievements	A multichannel heart sound measurement system was developed. Heart sound from a point sound source in the heart passes through the surrounding lung parenchyma and is received by heart sound sensors attached to the body surface. By considering the sound velocity of the propagation path and applying the inverse problem, a calculation algorithm was established to reconstruct the sound speed distribution in the chest and to converge the position of the point sound source. Heart sound sensor based on MEMS technology was developed and constructed a multi-channel heart sound measurement system by amplifying the heart sound with eight 8-channel preamplifiers and inputting it to a PC via an audio interface capable of receiving 64 channels simultaneously. The heart sounds were received from the sensors placed on the body surface, and by estimating the source of the heart sound from the phase difference, useful data for estimating the distribution of sound speed in the thorax was obtained.
Free Research Field	医用イメージング
Academic Significance and Societal Importance of the Research Achievements	胸部疾患の画像診断としては放射線を用いたCTがゴールデンスタンダードとして用いられているが、近年の新型コロナウイルス感染症における状況を鑑みると、CT検査室に移送するのは困難で、病室やICU内で簡便に胸部疾患をスクリーニングする手法が求められている。本研究では体表に設置した64個のMEMSマイクロホンを心音センサとして心音をサンプリングし、64チャンネル同時受信可能なマルチチャンネル心音計測システムを構築した。さらに、体表で受信した心音の位相解析に逆問題の手法を応用し、胸腔内での音速分布を画像化し音響CTの基礎を築くことで、在宅医療に貢献することが期待される。