Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104, USA.
Phys Med Biol. 2010 Jul 7;55(13):3753-65. doi: 10.1088/0031-9155/55/13/012. Epub 2010 Jun 15.
We describe the development of a non-invasive method for quantitative tissue temperature measurements using Broadband diffuse optical spectroscopy (DOS). Our approach is based on well-characterized opposing shifts in near-infrared (NIR) water absorption spectra that appear with temperature and macromolecular binding state. Unlike conventional reflectance methods, DOS is used to generate scattering-corrected tissue water absorption spectra. This allows us to separate the macromolecular bound water contribution from the thermally induced spectral shift using the temperature isosbestic point at 996 nm. The method was validated in intralipid tissue phantoms by correlating DOS with thermistor measurements (R=0.96) with a difference of 1.1+/-0.91 degrees C over a range of 28-48 degrees C. Once validated, thermal and hemodynamic (i.e. oxy- and deoxy-hemoglobin concentration) changes were measured simultaneously and continuously in human subjects (forearm) during mild cold stress. DOS-measured arm temperatures were consistent with previously reported invasive deep tissue temperature studies. These results suggest that DOS can be used for non-invasive, co-registered measurements of absolute temperature and hemoglobin parameters in thick tissues, a potentially important approach for optimizing thermal diagnostics and therapeutics.
我们描述了一种使用宽带漫射光学光谱（DOS）进行定量组织温度测量的非侵入性方法的开发。我们的方法基于近红外（NIR）水吸收光谱随温度和大分子结合状态出现的特征性相反变化。与传统的反射率方法不同，DOS 用于生成散射校正的组织水吸收光谱。这使我们能够使用 996nm 的温度等吸收点，从热诱导的光谱位移中分离出大分子结合水的贡献。该方法在含有脂肪乳剂的组织模型中得到了验证，DOS 与热敏电阻测量相关联（R=0.96），在 28-48°C 的范围内差异为 1.1+/-0.91°C。验证后，在人体（前臂）轻度冷应激期间，同时连续测量热和血液动力学（即氧合和脱氧血红蛋白浓度）变化。DOS 测量的手臂温度与先前报道的侵入性深部组织温度研究一致。这些结果表明，DOS 可用于厚组织中绝对温度和血红蛋白参数的非侵入性、配准测量，这是优化热诊断和治疗的一种潜在重要方法。
