Showing papers by "Mohammed N. Islam published in 2020"

Stand-off non-destructive determination of protein level in wheat flour with a super-continuum laser

Abstract: We demonstrate an all-fiber super-continuum (SC) laser based near infrared (1160nm to 2350nm) spectroscopy system that is capable of measuring protein (gluten) levels in wheat flour, at a stand-off distance. We show that reflectance spectrum between 1160nm and 2350nm can be used to measure protein levels in wheat flour. The measured protein concentration with the partial least square regression shows a good linear correlation (R square >0.95) to the protein level measured by the Dumas method with standard error variance down to 0.5 percent. Our system could be used for non-destructive, real-time determination of the protein level of wheat flour at a stand-off distance in industrial settings such as food factories or flour milling plants.

Non-invasive measurement of blood within the skin using array of laser diodes with Bragg reflectors and a camera system

Abstract: A measurement system comprises a pulsed, near-infrared array of laser diodes, the laser diode array comprising Bragg reflectors, and wherein laser diode light is configured to penetrate tissue comprising skin. A detection system comprising a camera is synchronized to the laser diodes, and the camera is configured to receive some of the laser diode light reflected from the tissue. The detection system is configured to non-invasively measure blood within the skin, the detection system is configured to measure absorption of hemoglobin in the wavelength range between 700 and 1300 nanometers, and the processor is configured to compare the absorption of hemoglobin between different spatial locations of tissue and over a period of time. Physiological parameters are measured by the system. The measurement system is configured to use artificial intelligence in making decisions, and the system is further configured to use regression signal processing, multivariate data analysis, or component analysis techniques.

Brain metabolism monitoring through CCO measurements using all-fiber-integrated super-continuum source

Abstract: For monitoring of concussion, brain function, organ condition and other medical applications, what is needed is a non-invasive method of monitoring tissue metabolism. MRI-based functional imaging technology detects changes in blood oxygenation, a correlate of neural activity, and thus may offer a prediction of prognosis in cases of concussion and other cerebral traumas. Yet, potential relationships between perturbations to cerebral metabolism and patient outcomes cannot be effectively exploited clinically because we lack a practical, low-cost, non-invasive means to monitor cerebral oxygenation and metabolism in the emergency department, operating room, or medical facilities. We have developed a device to optically assay the redox state of Cytochrome-C-Oxidase (CCO), the mitochondrial enzyme responsible for the last step of the electron transport chain. Changes in CCO redox reflect changes in respiratory flux, and thus changes in the rate of oxidative adenosine triphosphate (ATP) synthesis. In other words, changes in CCO reflect brain cell’s metabolic activity more directly than the traditional blood oxygenation measurement methods. To non-invasively measure changes in CCO as well as blood oxygenation, we have developed a SuperContinuum Infrared Spectroscopy of Cytochrome-C-Oxidase (SCISCCO) system that uses an all-fiber integrated, supercontinuum light source to simultaneously measure both of the new (CCO) and the traditional (blood oxygenation) markers of neural metabolism. The SCISCCO system is validated by confirming the near-infrared spectrum of CCO in vitro. To demonstrate in vivo feasibility, the measured responses of oxygenation and CCO responses to acute ischemia (e.g., blood pressure tests) in human participants are compared to data from the literature. Furthermore, we show that the new device’s measurements of oxygenated (HbO) and deoxygenated (HbR) hemoglobin in response to breath hold challenges are principled and consistent with previously reported findings. The validated SCISCCO system is finally applied to measure cerebral oxygenation and the redox state of CCO in participants during an attention test protocol. Twenty-five healthy adults completed an attention task that included nine 60-second periods of attention task, interleaved with 60-s periods of resting baseline. It has been well established that the frontal lobe of the human brain is active during tasks of attention. We therefore predicted that attention task should elicit an increase in HbO concentration accompanied by a decrease in redox state of CCO (e.g., ratio of oxidized CCO to reduced CCO) in frontal lobe brain regions as measured with the SCISCCO system. Our findings are consistent with our predictions: HbO concentration increases while CCO concentration decreases during the attention blocks relative to the resting baseline, thereby indicating an increase in oxidative metabolism of the frontal lobe brain regions of interest. Our systematic, multi-method approach thus validates the new device as well as the validity of the metabolic biomarkers that it measures. The SCISCCO system could be a new tool for monitoring brain and organ metabolism, which could be invaluable for screening concussion patients or use in an operating or emergency room to gauge patient’s organ response to treatments.

Scattering spectra from trace particles actively illuminated by a mid-infrared supercontinuum FTIR sensor

Abstract: We measure and simulate the diffuse scattering return from sparse particles of RDX, caffeine, and acetaminophen deposited on substrates consisting of smooth aluminum, silicon, and glass substrates at a distance of 3.6 m using a mid-infrared supercontinuum FTIR sensor. The measured spectra show that molecular fingerprint regime contains reflectance peaks that can be used for chemical identification and the mid-wave infrared provides information for target orientation. Furthermore, we demonstrate that spectra obtained using our supercontinuum FTIR sensor can be accurately simulated using a Bobbert-Vlieger model. The Bobbert-Vlieger model can then be used to create a library that can account for the trace chemical, underlying substrate, and target orientation, for stand-off chemical identification.

Long-wave infrared scattering spectra and modeling of trace particles on surfaces for standoff detection

Abstract: We experimentally measure the scattered reflectance of particles deposited on smooth substrates with a mid-wave to long-wave supercontinuum source and a FTIR based sensor at 36 m We measure the scattering return from sparse particles of 1,3,5-Trinitroperhydro-1,3,5-triazine, caffeine, and acetaminophen deposited on smooth aluminum, silicon, and glass substrates We also measure mono-disperse 54, 108, and 194 μm diameter polystyrene spheres deposited on aluminum We demonstrate that spectra obtained using our supercontinuum FTIR sensor can be accurately simulated using a Bobbert–Vlieger model, and non-spherical particle spectra can be approximated by spherical results The Bobbert–Vlieger model can then be used to create a library that can account for the trace chemical and underlying substrate for standoff chemical identification