Simultaneous NO and CO_2 measurement in human breath with a single IV–VI mid-infrared laser

Abstract

A tunable diode laser absorption spectroscopy (TDLAS) system equipped with a IV-VI mid-IR laser operating near 5.2>mu;m was used to measure exhaled nitric oxide (eNO) and carbon dioxide (CO(2)) simultaneously in human breath over a single exhalation. Breath was sampled in real time, and eNO levels were measured from seven volunteers, two steroid-naive asthmatics and five nonasthmatics. Measured CO(2) levels were used as an internal standard to verify correct breath collection and calculate eNO values. Calculated eNO concentrations agreed well with reported values for asthmatic and nonasthmatic individuals.

Advances in Electronic-Nose Technologies Developed for Biomedical Applications

“…Optical Absorption Spectroscopy (OAS) has been used to assess oxidative stress for a range of clinical applications including a wavelength-modulation system that measures ethane in breath [90], and a mid-infrared (IR) high-resolution Tunable Laser Absorption Spectroscopy (TLAS) system to measure exhaled nitric acid and carbon dioxide in human breath [91,92]. Baum et al [93] reported use of Ultraviolet Absorption Spectroscopy (UVAS) to measure acetylene in breath for monitoring cardiac output.…”

A Raman cell based on hollow core photonic crystal fiber for human breath analysis

“…Mass spectrometry techniques include gas chromatographymass spectrometry (GC-MS), 11,14 proton transfer reactionmass spectrometry (PTR-MS), 15,16 and selected ion flow tube-mass spectrometry (SIFT-MS). 17,18 Optical spectrometry techniques include cavity ring down spectroscopy (CRDS), 19,20 tunable diode laser absorption spectroscopy (TDLAS), 21 and photoacoustic spectroscopy (PAS). 22 Similar collection, purification/concentration, and analyses stages are used with these technologies and accuracies in the parts per billion by volume (ppbv) range are achievable.…”

Miniaturized Optical Sensors for Medical Diagnostics

“…Recently, a number of efforts have focused on the application of MIR spectroscopy and sensing schemes to human EB analysis for the identification of diseases [26,38,39]. The group of Mizaikoff [21] has constructed MIR broadband gas sensing systems based on FT-IR spectrometers, a 1 m long hollow-core waveguide gas cell, and a mercury-cadmium-telluride (MCT) detector, thereby successfully demonstrating simultaneous multianalyte sensing with detection sensitivities of 15.8 ppb for CO 2 and 517 ppb for CH 4 .…”

“…Roller et al [38] have constructed a tunable diode laser absorption spectroscopy (TDLAS) sensing system utilizing IV-VI narrow bandgap MIR diode lasers with an emission wavelength of 5.2 μm combined with a 107 m long multipass White cell to quantitatively detect NO and CO 2 in human breath for the diagnosis of asthmatic conditions in EB, as shown in Figure 46 QCLs, the conduction band structure of active regions and injection regions (digitally graded alloy) is schematically shown. The digitally graded alloy region also consists of several quantum wells (superlattice) with the fine structure omitted for simplicity in this diagram.…”

“…Mizaikoff and coworkers [43] have reported the detection of 30 ppb ethyl chloride from a 1.5 ml sample volume with an integrated MIR sensing system using a 1 m long photonic bandgap optical fiber serving as the waveguide and as the miniaturized sample cell and a QCL with a lasing wavelength of 10.3 μm, as described in Figure 46.5. The system consists of a tunable MIR diode laser made from narrow bandgap semiconductor materials, a multipass gas cell in a White configuration, and a cooled detector [38]. Tittel et al [44] have shown the applicability of tunable laser absorption spectroscopy (TLAS) sensing system to detect approximately 30 ppb carbonyl sulfide (COS), which is a biomarker for failure of the liver function and acute lung transplant rejection.…”