Abstract

There is a great need for cost-efficient non-invasive medical diagnostic tools for analyzing humanly exhaled air. Compared to present day methods, photoacoustic spectroscopy (PAS) can provide a compact and portable (bedside), sensitive and inexpensive solution. We demonstrate a novel portable photoacoustic spectroscopic platform for isotopic measurements of methane (${{\rm CH}_4}$). We identify and discriminate the ${^{12}{\rm CH}_4}$- and ${^{13}{\rm CH}_4}$ isotopologues and determine their mixing ratio. An Allan deviation analysis shows that the noise equivalent concentration for ${\rm CH}_4$ is 200 ppt (pmol/mol) at 100 s of integration time, corresponding to a normalized noise equivalent absorption coefficient of $5.1 \times {10^{- 9}}\;{\rm W}\;{{\rm cm}^{- 1}}\;{{\rm Hz}^{- 1/2}}$, potentially making the PAS sensor a truly disruptive instrument for bedside monitoring using isotope tracers by providing real-time metabolism data to clinical personnel.

© 2021 Optical Society of America

Versatile photoacoustic spectrometer based on a mid-infrared pulsed optical parametric oscillator

Laurent Lamard, David Balslev-Harder, Andre Peremans, Jan C. Petersen, and Mikael Lassen
Appl. Opt. 58(2) 250-256 (2019)

Real-time measurement of CO₂ isotopologue ratios in exhaled breath by a hollow waveguide based mid-infrared gas sensor

Tao Zhou, Tao Wu, Qiang Wu, Chenwen Ye, Rongjing Hu, Weidong Chen, and Xingdao He
Opt. Express 28(8) 10970-10980 (2020)

Multicomponent gas detection technology of FDM and TDM based on photoacoustic spectroscopy

Yuanfang Yu, Cunwei Tian, Zongliang Wang, Siyu Qian, Cunying Yan, and Hao Zhang
Appl. Opt. 60(4) 838-843 (2021)

Real-time isotopic methane detection using mid-infrared spectroscopy

Jinghao Yang, Junchao Zhou, and Pao Tai Lin
Appl. Opt. 59(34) 10801-10807 (2020)

Two-component gas quartz-enhanced photoacoustic spectroscopy sensor based on time-division multiplexing of distributed-feedback laser driver current

Zongliang Wang, Jun Chang, Cunwei Tian, Yiwen Feng, Cheng Wang, Hao Zhang, Qinduan Zhang, Hefu Li, Zhenbao Feng, Xiukun Zhang, and Longfei Tang
Appl. Opt. 58(31) 8479-8485 (2019)