Exhaled air analysis using wideband wave number tuning range infrared laser photoacoustic spectroscopy

Abstract

The infrared laser photoacoustic spectroscopy (LPAS) and the pattern-recognition-based approach for noninvasive express diagnostics of pulmonary diseases on the basis of absorption spectra analysis of the patient’s exhaled air are presented. The study involved lung cancer patients ( N = 9 ), patients with chronic obstructive pulmonary disease ( N = 12 ), and a control group of healthy, nonsmoking volunteers ( N = 11 ). The analysis of the measured absorption spectra was based at first on reduction of the dimension of the feature space using principal component analysis; thereafter, the dichotomous classification was carried out using the support vector machine. The gas chromatography–mass spectrometry method (GC–MS) was used as the reference. The estimated mean value of the sensitivity of exhaled air sample analysis by the LPAS in dichotomous classification was not less than 90% and specificity was not less than 69%; the analogous results of analysis by GC–MS were 68% and 60%, respectively. Also, the approach to differential diagnostics based on the set of SVM classifiers usage is presented.

Types of spectroscopy and microscopy techniques for cancer diagnosis: a review

“…The experimental data analysis was carried out using a support vector machine (SVM) which is a differential classification predictive machine learning. Informative feature extraction was realized by PCA, and the model provided up to 90% binary classification accuracy [125,127,128]. The PAS was used to monitor breast cancer development [129] with frequency-doubled 281-nm excitation source using an Nd:YAG and dye laser.…”

“…A mechanical chopping of a continuous wave (CW) laser radiation [ 124 ] or nanosecond pulse duration laser can be used to provide the necessary amplitude modulation to the gas sample. The construction of a photoacoustic detector (PAD) cell influences the sensitivity of PAS [ 125 ].…”

Biomedical optics applications of advanced lasers and nonlinear optics

“…15 This technique could be applied to measuring biomarkers in human breath such as NO, CO, volatile organic compounds, including ethanol, methane, and acetone, as well as sulfur-and nitrogen-containing compounds. 16 A compact, broadband continuum source as the one developed by Dr. Islam could provide the opportunity of real-time detection and analysis of biomarkers unlike gas chromatography or mass spectrometry which requires breath samples to be collected and sent to the laboratory for analysis. 17…”

Исследование Сыворотки Крови У Крыс С Трансплантированной Холангиокарциномой С Использованием Спектроскопии Комбинационного Рассеяния Света

“…Спектры КРС представляют собой данные высокой размерности, поэтому применение классических методов статистического анализа для проверки гипотезы о разделимости исследуемых групп по различиям в их спектрах КРС затруднительно. Использование метода главных компонент снижает размерность данных, выявляет информативные участки спектров и дает возможность визуализировать результаты, что позволяет оценить возможность создания модели данных для дифференцирования представителей различных экспериментальных групп [3,8,9,[12][13][14][15].…”