SBIR-STTR Award

We propose a high resolution THz spectroscopic sensor for analysis of exhaled human breath related to sleep deprivation-induced fatigue by leveraging the PI’s past and current DOD-sponsored research. Sensors based on terahertz molecular spectra achieve ‘absolute’ specificity, high sensitivity, and high throughput, with a clear path towards inexpensive and miniature implementations. This novel sensing platform technology is suitable for a number of DOD and civilian applications. The PI has also begun demonstration of the sensor technology towards breath analysis. Fatigue can be induced by several factors, such as sleep deprivation, physical exertion, or continuous mental tasking, and is often cited as a cause in DOD mishaps. In Phase I, we will analyze breath biomarkers of fatigue in sleep derived subjects. Samples of breath will be collected in a controlled laboratory setting, and the level of fatigue will be assessed using standard cognitive metrics. Breath samples will be analyzed in parallel using a commercial analytical facility specializing in Gas Chromatography-Mass Spectrometry analysis in conjunction with THz analysis. The initial results will used to assess the THz detectability and sensitivity limits for compounds correlated with fatigue.

Benefits:
The proposed THz spectroscopy and sensor technology represents a significant leap in biomarker detection over current methods, such as GC-MS, and, due to the nature of detection, will have near perfect specificity for identification of a compound’s molecular “fingerprint.” The sensor technology can be miniaturized to fit in hand-held devices, a cockpit setting, or headgear to detect fatigue. The commercial applications extend far beyond DoD requirements, and will have applications in which human performance and fatigue must be monitored.

Keywords:
Terahertz spectroscopy, gas chromatography-mass spectroscopy, isoprene, sleep restriction, breath biomarkers, human performance, complementary metal-oxide semiconductor, photoacoustic spectroscopy

Sleep deprivation, exercise, or continuous mental tasking are fatigue-related contributors in DoD mishaps. Therefore, a critical need exists for fatigue detection technologies which are real-time, non-invasive, compact, portable, and accurate to aid decisions to replace or rest an individual as a preventative measure. Certain compounds in human breath have been linked to disease states, and it is anticipated that fatigue affects breath composition similarly. Our approach utilizes THz spectroscopy which is capable of detecting and measuring numerous breath biomarkers with ‘absolute’ specificity, high sensitivity, and high throughput. In Phase I, the THz spectroscopy detection method was validated against GC/MS methods and identified breath compounds – isoprene, dimethyl sulfide, and acetaldehyde – in sleep-deprived individuals that correlate well with results from cognitive tests measuring fatigue. In Phase II, we will extend GC/MS and THz spectroscopy analysis in sleep-deprived subjects to acquire data for algorithm development to validate predictive capabilities of breath biomarker analysis for fatigue. We will also build and validate a compact, portable, integrated table top THz chemical sensor capable of monitoring breath compounds in real-time. Advratech is poised to collaborate with Boeing, WPAFB (Human Systems Division and AFRL/711th HPW) and TITUS during Phase II to accelerate commercialization of the proposed technology.

Benefits:
The field of breath biomarkers is relatively unexplored compared to tests and diagnostics based on blood, urine, or other bodily parameters (i.e., EKG). The benefits and potential commercial applications of THz sensor technology address both issues of breath diagnostics and the detection of a wide array of compounds. THz spectroscopic sensors are unique in their ability to achieve high sensitivity and near absolute specificity and are amenable to miniaturization, portability, and high-throughput. We will refine our algorithms in Phase II for the putative biomarkers to develop a predictive capability of when an individual may be fatigued and a drop in performance may occur. This non-invasive approach to detect fatigue will benefit DoD and commercial industries in which fatigue has contributed to accidents, i.e., commercial pilots and drivers. Athletes and Special Operations Forces, who engage in strenuous training and sometimes irregular sleep, will also benefit from early fatigue warnings before conditions such as rhabdomyolysis develop. Lastly, THz spectroscopy is ideal for environmental monitoring ‘in the field’ as this technique can detect most light compounds with electric dipole moments. Thus, with spectroscopic library, hardware and software development, THz sensors can be utilized in a variety of health, human performance, and environmental settings.

Keywords:
Sensor, fatigue, biomarkers, sleep deprivation, isoprene, dimethyl sulfide, Psychomotor Vigilance Test, Terahertz