Mamouei M, Qassem M, Budidha K, Baishya N, Vadgama P, Kyriacou P A
Annu Int Conf IEEE Eng Med Biol Soc. 2019 Jul;2019:3239-3242. doi: 10.1109/EMBC.2019.8856765.
Blood lactate is an important biomarker that has been linked to morbidity and mortality of critically ill patients, acute ischemic stroke, septic shock, lung injuries, insulin resistance in diabetic patients, and cancer. Currently, the clinical measurement of blood lactate is done by collecting intermittent blood samples. Therefore, noninvasive, optical measurement of this significant biomarker would lead to a big leap in healthcare. This study, presents a quantitative analysis of the optical properties of lactate. The benefits of wavelength selection for the development of accurate, robust, and interpretable predictive models have been highlighted in the literature. Additionally, there is an obvious, time- and cost-saving benefit to focusing on narrower segments of the electromagnetic spectrum in practical applications. To this end, a dataset consisting of 47 spectra of Na-lactate and Phosphate Buffer Solution (PBS) was produced using a Fourier transform infrared spectrometer, and subsequently, a comparative study of the application of a genetic algorithm-based wavelength selection and two interval selection methods was carried out. The high accuracy of predictions using the developed models underlines the potential for optical measurement of lactate. Moreover, an interesting finding is the emergence of local features in the proposed genetic algorithm, while, unlike the investigated interval selection methods, no explicit constraints on the locality of features was imposed. Finally, the proposed genetic algorithm suggests the formation of α-hydroxy-esters methyl lactate in the solutions while the other investigated methods fail to indicate this.
血乳酸是一种重要的生物标志物，与危重症患者的发病率和死亡率、急性缺血性中风、感染性休克、肺损伤、糖尿病患者的胰岛素抵抗以及癌症相关。目前，血乳酸的临床测量是通过采集间歇性血样来完成的。因此，对这种重要生物标志物进行无创光学测量将给医疗保健带来巨大飞跃。本研究对乳酸的光学特性进行了定量分析。文献中强调了波长选择对于开发准确、稳健且可解释的预测模型的益处。此外，在实际应用中聚焦于电磁频谱的较窄波段具有明显的省时和成本节约优势。为此，使用傅里叶变换红外光谱仪生成了一个由47个乳酸钠和磷酸盐缓冲溶液（PBS）光谱组成的数据集，随后，对基于遗传算法的波长选择和两种区间选择方法的应用进行了比较研究。使用所开发模型进行预测的高精度凸显了乳酸光学测量的潜力。此外，一个有趣的发现是在所提出的遗传算法中出现了局部特征，而与所研究的区间选择方法不同，对特征的局部性没有施加明确的约束。最后，所提出的遗传算法表明溶液中形成了α - 羟基 - 酯甲基乳酸，而其他所研究的方法未能表明这一点。
