Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States.
J Biomed Opt. 2017 Jul 1;22(7):76019. doi: 10.1117/1.JBO.22.7.076019.
Spatial frequency domain imaging (SFDI) is a wide-field diffuse optical technique used to obtain optical properties and chromophore concentrations in highly scattering media, such as biological tissue. Here, we present a method for rapidly acquiring multispectral SFDI data by modulating each illumination wavelength at a different temporal frequency. In the remitted signal, each wavelength is temporally demodulated and processed using conventional SFDI techniques. We demonstrate a proof-of-concept system capable of acquiring wide-field maps (2048×1536 pixels, 8.5×6.4 cm) of optical properties at three wavelengths in under 2.5 s. Data acquired by this method show a good agreement with a commercial SFDI imaging system (with an average error of 13% in absorption and 8% in scattering). Additionally, we show that this strategy is insensitive to ambient lighting conditions, making it more practical for clinical translation. In the future, this technique could be expanded to tens or hundreds of wavelengths without increasing acquisition time.
空间频域成像（SFDI）是一种宽场漫射光学技术，用于获取高散射介质（如生物组织）中的光学特性和发色团浓度。在这里，我们提出了一种通过调制每个照明波长的不同时间频率来快速获取多光谱 SFDI 数据的方法。在发射信号中，使用传统的 SFDI 技术对每个波长进行时间解调并处理。我们展示了一个概念验证系统，能够在不到 2.5 秒的时间内获取三个波长的宽场光学特性图（2048×1536 像素，8.5×6.4 厘米）。通过该方法获取的数据与商业 SFDI 成像系统吻合较好（吸收的平均误差为 13%，散射的平均误差为 8%）。此外，我们还表明，该策略对环境光照条件不敏感，使其更适合临床转化。在未来，该技术可以扩展到数十个甚至数百个波长，而不会增加采集时间。
