Photoacoustic sensor for the diagnosis of Asthma Текст научной статьи по специальности «Медицинские технологии»

ALT'22

BIOMEDICAL PHOTONICS

B-I-22

Photoacoustic sensor for the diagnosis of Asthma

Nidheesh V. Ra+, Aswini Kumar Mohapatrab, Unnikrishnan V. Ka, Vasudevan Baskaran Karthaa,

and Santhosh Chidangila*

a) Centre of Excellence for Biophotonics, Department of Atomic and Molecular Physics, Manipal Academy of Higher

Education, Manipal, Karnataka, India; b) Department of Respiratory and Pulmonary Medicine, KasturbaMedical College, Manipal, Manipal Academy of

Higher Education, Manipal, Karnataka, India *Corresponding author: santhosh.cls@manipal.edu

Photoacoustic spectroscopy (PAS) can be effectively used to detect volatile organic compounds (VOCs) present in exhaled breath. A PAS setup using laser excitation at 266nm and calibrated with Acetone, was used to record photoacoustic signals from a cohort of normal healthy volunteers and asthma patients. The photoacoustic wave-form signals were Fourier-transformed to frequency domain and subjected to Principal Component Analysis (PCA) for classification. It was shown that the two sets of photoacoustic signal data, could be discriminated from each other by distinct cluster formation in a plot of Factors PC1 and PC2. A Match/No Match analysis, using Mahalanobis Distance and Sum of Squared Differences of simulated and actual signal (Spectral Residual) using a Calibration set of Asthma samples, gave a sensitivity of 89% and specificity of 93%. A comparison of results obtained from present data with the E-nose based VOC screening of the same volunteers confirmed the validity of the PAS technique for the diagnosis of Asthma.

Keywords: Photoacoustic spectroscopy, Volatile organic compounds, Asthma, Noninvasive diagnosis, Breath analysis.