摘要
光声测温是一种利用光声效应来进行温度监控的新方法,具有非侵入式、高灵敏度和探测深度较深等优点.但现有的单波长光声测温方法极易受到系统及测量环境干扰而导致测量精度降低.为了解决这一问题,本文提出了一种双波长光声温度测量方法.在光声测温理论的基础上,分析推导了双波长光声测温的基本原理,并进行了仿体及离体组织样品的双波长光声测温实验.实验结果显示,与传统单波长模式相比,双波长模式下的光声温度测量误差明显减小,测量精度平均提高35%以上.研究结果表明双波长光声测温方法能够有效提高光声温度测量的精度和稳定性,可作为一种更精准的光声温度监控方法应用于医疗手术等领域.
Photoacoustic temperature measurement is a novel technique in which photoacoustic effect is used to measure temperature. ]t has the advantages of non-invasiveness, high sensitivity and deep penetration depth, which is suitable for monitoring the temperature distribution for the safe deposition of heat energy and efficient destruction of tumor cells during thermotherapy or cryotherapy. However, the present reported methods usually use one single wavelength for photoacoustic temperature measuring and are vulnerable to systematic and environmental influence, including the instability of system caused by fluctuation of laser energy, position displacement of transducer, and tissue complexity, which could reduce the measuring accuracy and stability. To solve this problem, a new photoacoustic temperature measuring method by employing two laser wavelengths is proposed in this paper. Firstly a brief theoretical analysis of dual-wavelengths photoacoustic temperature method is performed based on the linear relationship between photoacoustic signal and tissue temperature under two different wavelengths. Then two different samples including phantom of graphite and ex vivo pig blood are experimented respectively. The experimental temperature is set to be in a range of 26 ℃-48 ℃, which is controlled by a precise hot plate. And for improving the detection accuracy, the dual-wavelengths are selected as 760 and 900 nm for graphite phantom, 820 nm and 860 nm for ex vivo pig blood according to their absorption spectrum repetitively. The obtained results reveal that the temperature measuring correlation coefficients by dual-wavelength method can reach to 0.98 in graphite phantom and 0.99 in ex vivo tissue, respectively. And the average measurement deviation decreases to 0.88 ℃ in dual-wavelength method from 1.31 ℃ for the traditional single wavelength method for graphite phantom. While in ex vivo tissue, the measurement deviation decreases to 0.90 ℃ in dual-wavelength method from the average value 1.45 ℃ for the single wa
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2017年第11期312-319,共8页
Acta Physica Sinica
基金
江苏省国际科技合作项目(批准号:BZ2016023)
科技部重点研发项目(批准号:2016YFC0103302)
国家博士后面上项目(批准号:2015M581409)
江苏省面上研究项目(批准号:BK20161235)
苏州市前瞻性应用研究(批准号:SYG201607
SZS201510
SYS201456)资助的课题~~
关键词
光声测温
双波长
温度监控
photoacoustic temperature measurement, dual-wavelengths, temperature monitoring
