利用外接CO_2激光源的中红外ATR光谱仪原位无创探测人体血糖浓度

糖尿病是一种严重威胁人类健康的疾病,取血检测人体血糖浓度造成病患痛苦甚至感染。因此人体血糖浓度的无创检测技术在糖尿病的临床诊断、监测和治疗上具有重要的意义,也是一个具有挑战性的热点研究课题。在目前报道的各种测试方法中,中红外光谱测试技术受到了广泛重视。利用常规光源的中红外ATR光谱仪进行无创血糖检测时,由于探测光在人体组织中穿透深度低,难以到达含有体液的间质层乃至含有血液信息的真皮层,结果导致测试数据与人体实际血糖浓度的相关性差,限制了临床应用。考虑到高强、高纯的中红外激光在人体组织中具有较深的穿透深度,且CO2激光器的1 035cm-1的发射光非常接近葡萄糖在1 029cm-1处的基频特征吸收峰,因此本文使用外接CO2激光器作为中红外ATR光谱仪的自定义外接光源,组装了新型中红外测试系统。利用此设备,测试了人手指在1 035cm-1激光辐照下的吸光度,同时利用普通光源扫描了人手指的中红外吸收光谱,记录其在1 492cm-1的吸光度。利用常规医学方法测定了人体实际血糖值。结果显示,人手指处受1 035cm-1激光辐照的吸光度与常规光源的红外光谱中1 492cm-1处吸光度的相对强度与人体血糖浓度同步改变,两波数处吸光度的比值与人体实际血糖浓度具有一定的正相关性(R=0.812 5)。测量结果可作为人体血糖值的一个新型指标,显示了外接CO2激光源的中红外ATR光谱仪在无创探测人体血糖浓度方面的临床诊断潜力。

In-Vivo Noninvasive Measurement of Human Blood Glucose Levels by Mid-Infrared Spectrograph with External CO2 Laser Source

Diabetes is a kind of diseases which does harm to people’s health,and the detection of human blood glucose levels uti-lizing blood samples will result in pain even infection for patients.Thus the in-vivo noninvasive measurement of human blood glu-cose levels has vital value in clinical diagnosis,detection and therapy,and it also is a very hot research topic with challenging.At present,as to various noninvasive detection methods,the technology based on mid-infrared absorption spectrophotometry with ATR has been gaining increasing attention.However,when carrying out noninvasive measurement of human blood glucose levels by means of the spectrophotometry equipped with routine light sources,the penetration depth of probe light in human tissues is low and thus it is very difficult to reach the stromal layer containing body fluids and especially dermis layer containing blood for probe light,which resulting in low relativity between experimental data and real human blood glucose levels and thus limiting the clinical application.Generally,not only the mid-infrared laser with high strength and high purity can deeper penetrate the human tissues,but also the output wavelengths at 1 035 cm-1 of CO2 laser very coincide with the fundamental frequency characteristic absorption at 1 029 cm-1 of glucose.Thus,in this work,a novel noninvasive mid-infrared measurement system to detect human blood glucose levels has been successfully assembled,in which a CO2 laser was used a self-defined external light source of the new mid-infrared absorption spectrophotometry with ATR.In this system,the absorbance of human fingertip at 1 035 cm-1 has been measured when external CO2 laser source was used as probe light,at the same time,the mid-infrared absorption spectra of fingertip have been also obtained and absorbance at 1 492 cm-1 has been recorded.The human blood glucose levels were deter-mined synchronously by means of the routine medical method.The experimental results showed that the ratio in fingertip be-tween absorbance at 1 035 cm-1 from the laser source and one at 1 492 cm-1 from mid-infrared absorption spectrophotometry could synchronously change with the human blood glucose levels,and the ratio presents certain positive relativity with the real human blood glucose levels(R=0. 812 5).Thus the measurement data could be used as a new index of blood glucose level in hu-man body,which showed the potential in clinical diagnosis of the ATR mid-infrared absorption spectrophotometry with external CO2 laser source in noninvasive measurement of human blood glucose levels.