Development of non-invasive blood glucose measurement system using quantum cascade lasers with multiple wavelengths

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03242
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Electron device/Electronic equipment
• Research Institution: Tohoku University
• Principal Investigator: Matsuura Yuji 東北大学, 医工学研究科, 教授 (10241530)
• Co-Investigator(Kenkyū-buntansha): 片桐 崇史 富山大学, 学術研究部工学系, 教授 (90415125) ; 木野 彩子 東北大学, 医工学研究科, 学術研究員 (30536082)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 血糖値測定 / 赤外分光 / 量子カスケードレーザ / 中空光ファイバ

Outline of Final Research Achievements

We developed a system using multiple single wavelength quantum cascade lasers (QCL) for non-invasive blood glucose measurement based on infrared absorption spectroscopy. First, we selected two wavelengths: 1152 cm-1 which is one of the absorption wavelengths of glucose molecule, and 1186 cm-1 which does not show absorption. After that, we constructed a system using two QCLs of these wavelengths and measured the absorption spectrum of the lips. In order to reduce the dispersion of the measured values, we solved the non-uniformity of the optical power distribution on the prism surface. Thus, the divergence angle of the incident light was expanded and the incident angle was further reduced. As a result, the variability during repeated measurements was greatly reduced, and a correlation was observed between human blood glucose level and optical absorption level.

Free Research Field

医用光工学

Academic Significance and Societal Importance of the Research Achievements

本研究では，大型の分光装置によって得られる従来の連続的なスペクトルではなく，離散的な複数の波長での吸収値のみから血糖値を導きだす手法を見出した．本研究で光源として使用した量子カスケードレーザは，小型化にはきわめて有利であり，その製造コストは，将来，飛躍的に低減されることが期待できる．そのため，本研究の成果により，今後は小型かつ安価な実用的な無侵襲血糖値測定システムの実現が期待される．非侵襲測定法が確立されれば，簡易なスクリーニングが可能となり，重症化以前にはほぼ症状が現れない早期の糖尿病を検出し，爆発的に増加しつつある患者数の増大を抑制することに貢献するものと考えられる．