Article
Spectroscopy
Dongdong Ni, Heather E. Smyth, Michael J. Gidley, Daniel Cozzolino
Summary: This study aimed to compare the spectral characteristics of dry and whole saliva samples and to investigate the influence of gender and age on MIR spectra. The results showed that dried saliva spectra were more consistent and better at distinguishing individual differences. Specific MIR regions associated with age and gender were identified, particularly in relation to proteins and DNA.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2021)
Article
Chemistry, Analytical
Heydar Khadem, Hoda Nemat, Jackie Elliott, Mohammed Benaissa
Summary: This paper proposes a feature vector generation method based on signal fragmentation, combined with a model interpretation module, to enhance the quantification of glucose from absorption spectroscopy signals. The method dissects a given spectrum into fragments, and estimates the reference glucose concentration from each fragment using a base-learner. The estimates from all fragments are then stacked to form a feature vector, which is studied by a meta-learner to yield a final estimation of the glucose concentration. The proposed method is evaluated under different scenarios and found to be effective in benchmarked modelling procedures. SHapley additive exPlanations (SHAP) is leveraged for transparency and interpretation of the quantification outcomes.
Article
Chemistry, Applied
Di Chen, Cheng Guo, Wenjing Lu, Cen Zhang, Chaogeng Xiao
Summary: To accurately and quickly determine the quality of royal jelly, a qualitative discrimination model was established based on the fusion of conventional parameters and mid-infrared spectrum, using support vector machine. Prediction models for three representative quality parameters were developed using different algorithms. The results showed improved recognition rate and ensured accuracy for non-destructive rapid detection of royal jelly quality.
Article
Chemistry, Analytical
Nicolas Sobanski, Bela Tuzson, Philipp Scheidegger, Herbert Looser, Christoph Hueglin, Lukas Emmenegger
Summary: This study presents a custom field-deployable direct absorption laser spectrometer for in situ atmospheric HNO3 measurements. Detailed laboratory characterizations were conducted to evaluate the instrument's response under tropospheric conditions, and a three-week field measurement campaign was carried out to monitor the HNO3 level in ambient air.
Article
Chemistry, Analytical
Abdulrahman Aloraynan, Shazzad Rassel, Chao Xu, Dayan Ban
Summary: Diabetes is a global issue, and the development of noninvasive monitors is crucial for diabetes management. Optical spectroscopy, particularly using a single wavelength quantum cascade laser, has shown high accuracy and sensitivity in glucose monitoring. The integration of machine learning techniques has further improved the accuracy of glucose detection.
Article
Automation & Control Systems
Jiming Sa, Yuyan Song, Hanwen Gu, Zhushanying Zhang
Summary: Mid-infrared absorption spectroscopy is a promising technique for non-invasive blood glucose detection. However, current detectors based on this technology lack the required accuracy. In order to improve the prediction performance, an effective variable selection method is proposed, which generates importance index for wavenumber to reduce time cost, applies tournament selection to maintain exploration ability, and uses L1 regularization to address overfitting. Experimental results demonstrate that this method outperforms alternative approaches and achieves higher accuracy and robustness in variable selection.
CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS
(2023)
Article
Chemistry, Analytical
Zhongyue Guo, Yeran Bai, Meng Zhang, Lu Lan, Ji-Xin Cheng
Summary: Antimicrobial resistance poses a major threat to global health and economics, necessitating rapid AST methods. We introduce a rapid AST method based on wide-field mid-infrared photothermal imaging, capable of metabolic imaging for hundreds of bacteria at single-cell resolution within seconds. This method enables probing of perturbed microbial protein synthesis within 1 hour after antibiotic treatment in E. coli cells, providing insights into antibiotic susceptibility.
ANALYTICAL CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Tim Kuemmel, Bjoern van Marwick, Miriam Rittel, Carina Ramallo Guevara, Felix Wuehler, Tobias Teumer, Bjoern Waengler, Carsten Hopf, Matthias Raedle
Summary: Frozen section analysis is a commonly used method for tissue examination, especially in tumor detection. This research introduces a fast spectroscopic measurement device and workflow that significantly improves the speed and accuracy of frozen tissue section analysis, allowing for rapid visualization of tissue structures and tumor margins based on their lipid and protein molecular vibrations.
SCIENTIFIC REPORTS
(2021)
Article
Chemistry, Analytical
David J. Rowe, Daniel R. Owens, Suzanne L. Parker, Saul N. Faust, James S. Wilkinson, Goran Z. Mashanovich
Summary: Recent advances suggest that miniaturised mid-infrared devices could replace laboratory-based techniques for clinical diagnostics. This study uses Fourier transform infrared spectroscopy to show that the MIR refractive index of whole blood varies with haematocrit. Calibration measurements of haematocrit can be used to correct errors introduced by cellular content, allowing for plasma spectra and analyte concentrations to be indirectly calculated from a whole blood sample.
Article
Chemistry, Analytical
Jinhwa Gene, Min Yong Jeon, Sun Do Lim
Summary: The study utilized two types of spectral reflectometers to measure absolute and relative reflectances of diffusely reflecting surfaces, achieving this through different methods. By conducting ray-tracing simulations, researchers evaluated the overall standard uncertainty of the experimental data.
Article
Chemistry, Analytical
Lukasz Scislo, Nina Szczepanik-Scislo
Summary: This article proposes a cost-effective mobile test station for on-site material measurements and immediate evaluation results. The station utilizes the Impulse Excitation Technique (IET) to effectively determine crucial elastic properties and verify material compliance. The developed test station demonstrated versatility and reliability in evaluating typical construction materials.
Article
Chemistry, Analytical
Thulya Chakkumpulakkal Puthan Veettil, Bayden R. Wood
Summary: Serum is a valuable source for proteomics analysis, but the high concentration range of protein/peptide species makes it challenging to detect low-molecular-weight compounds. In this study, a combination of near-infrared and mid-infrared spectroscopy was used to improve the detection limit of LMW amino acids in serum.
Article
Chemistry, Analytical
Juan Melendez, Guillermo Guarnizo
Summary: An imaging Fourier-transform spectrometer was used to acquire transmittance spectra of atmospheric pollutants with known column densities. Principal component analysis was utilized to reconstruct gas spectra with high fidelity, improve signal-to-noise ratio, and speed up retrieval process significantly. Retrieval can be further simplified by obtaining T and Q as quadratic functions of the first two principal components.
Article
Nuclear Science & Technology
Catriona McFarlan, Alison Nordon, Mark Sarsfield, Robin Taylor, Hongyan Chen
Summary: This study compared Raman and mid-infrared (MIR) spectroscopy as alternatives to titration for quantifying nitric acid concentration in the PUREX process. The MIR spectra required less pre-processing and provided more accurate predictions of nitric acid concentration in the aqueous phase, while Raman spectroscopy yielded better predictions in the organic phase.
PROGRESS IN NUCLEAR ENERGY
(2023)
Review
Chemistry, Analytical
Md Rejvi Kaysir, Jiaqi Song, Shazzad Rassel, Abdulrahman Aloraynan, Dayan Ban
Summary: The prevalence of diabetes is increasing worldwide, leading to severe health complications. The development of non-invasive techniques for blood glucose measurement based on photoacoustic spectroscopy (PAS) has shown great promise. However, there are challenges with penetration depth and interference from other components in blood. This review paper describes the basics of PAS in the MIR region, recent developments, challenges, and proposes improvements, including incorporating machine learning, to enhance glucose detection sensitivity.
Article
Engineering, Electrical & Electronic
Durmus Umutcan Uguz, Zehra Tugce Canbaz, Christoph Hoog Antink, Markus Lueken, Steffen Leonhardt
Summary: This article proposes a new technique called modulated ECG (mECG) for improving the measurement of capacitive electrocardiogram (cECG) by introducing high-frequency sinusoidal variations in contact pressure. The study shows that the amplitude of the ECG signal can be modulated by the multiplicative interaction between the source signal and the coupling impedance, and the resulting waveform can be merged with the envelope of a carrier wave. The feasibility of this technique is validated through numerical and physical simulations. Factors such as textile type, contact pressure, and modulation frequency influence the mECG measurements, and the mECG amplitudes are found to be significantly lower than those of cECG.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2022)
Article
Engineering, Mechanical
Lin Liu, Steffen Leonhardt, Lukas Bergmann, Berno J. E. Misgeld
Summary: This paper presents an integration of reducing the output impedance and the vibration at the trajectory tracking into one variable stiffness actuator (VSA) system. The VSA operates within the cascade impedance control framework with the unknown input observer (UIO) in the inner torque control loop. By utilizing gain-scheduled UIO and the low and high physical stiffness of VSA, the paper achieves low-output impedance and steady trajectory tracking.
MECHANISM AND MACHINE THEORY
(2023)
Article
Chemistry, Analytical
Simon Lyra, Arian Mustafa, Joeran Rixen, Stefan Borik, Markus Lueken, Steffen Leonhardt
Summary: This study investigates the application of a conditional generative adversarial network to augment limited neonatal image datasets by using edge detection frames from neonates to generate RGB images. The quality of the generated RGB images was evaluated using a multistage survey and the FID score. The promising results indicate the potential of conditional generative adversarial networks for training and application in neonatal care.
Article
Computer Science, Artificial Intelligence
Joeran Rixen, Steffen Leonhardt, Jochen Moll, Duy Hai Nguyen, Chuong Ngo
Summary: Electrical impedance tomography (EIT) is limited in spatial resolution due to sensitivity to noise. We investigate a technique to improve EIT reconstructions by incorporating a priori information into the D-Bar algorithm. Our paper aims to explain the behavior and implementation of the D-Bar algorithm, as well as the effect of adding prior information from a radar setup. We analyze different parameters of the reconstruction algorithm using GREIT figures of merit and find that even limited prior information can significantly improve reconstruction quality.
Article
Chemistry, Analytical
Thulya Chakkumpulakkal Puthan Veettil, Rebekah N. Duffin, Supti Roy, Jitraporn Vongsvivut, Mark J. Tobin, Miguela Martin, John A. Adegoke, Philip C. Andrews, Bayden R. Wood
Summary: Neglected tropical diseases, including leishmaniasis, are becoming more widespread. This study demonstrates the potential of using synchrotron Fourier transform infrared microspectroscopy and machine learning models to accurately predict Leishmania infection. The use of this technique could pave the way for future clinical studies using portable devices.
ANALYTICAL CHEMISTRY
(2023)
Article
Instruments & Instrumentation
Miguela Martin, Molin Wongwattanakul, Noppmats Khemtonglang, Pakaphan Kiatchoosakun, Philip Heraud, Patcharee Jearanaikoon, Bayden R. Wood
Summary: Glucose-6 phosphate dehydrogenase (G6PD) deficiency is a common blood disease, affecting 400 million people globally, especially in malaria-endemic regions. Accurate diagnosis of this deficiency is crucial for malaria eradication efforts. This study investigates the use of attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) as a potential diagnostic technique. Results show that ATR FT-IR combined with multivariate data analysis can accurately classify fully deficient participants and partially deficient females who are often misdiagnosed. This approach has the potential to become a frontline screening tool, improving tailored drug treatments and saving lives.
APPLIED SPECTROSCOPY
(2023)
Article
Automation & Control Systems
Lukas Bergmann, Oliver Lueck, Daniel Voss, Philipp Buschermoehle, Lin Liu, Steffen Leonhardt, Chuong Ngo
Summary: This study presents the design of a new lower limb exoskeleton with variable stiffness actuators for compliant coupling. By using a nonlinear state estimation method, the subject's motion intention can be accurately estimated, providing more robust results.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2023)
Article
Chemistry, Analytical
Onno Linschmann, Durmus Umutcan Uguz, Bianca Romanski, Immo Baarlink, Pujitha Gunaratne, Steffen Leonhardt, Marian Walter, Markus Lueken
Summary: With the increasing level of automation in vehicles, it is crucial to have robust driver monitoring systems to ensure driver intervention at any time. A portable cushion with multiple sensors is presented in this paper to monitor the heart and respiratory rates of a vehicle driver. The initial study with twenty participants in a driving simulator showed promising results in accurately measuring heart and respiratory rates, as well as the potential for monitoring changes in the electrocardiogram. These measurements can be used to detect drowsiness, stress, and predict cardiovascular diseases.
Article
Chemistry, Analytical
Markus Lueken, Michael Gramlich, Steffen Leonhardt, Nikolaus Marx, Matthias D. Zink
Summary: Atrial fibrillation (AF) is a common cardiac disorder that often goes undetected due to its asymptomatic and paroxysmal nature. Large-scale screenings can help identify silent AF early and prevent complications. This study presents a machine learning-based algorithm for assessing the signal quality of hand-held diagnostic ECG devices to improve accuracy in detecting AF.
Article
Medicine, General & Internal
Thomas Muders, Benjamin Hentze, Steffen Leonhardt, Christian Putensen
Summary: Monitoring regional blood flow distribution in the lungs is useful for optimizing ventilation therapy. Electrical impedance tomography (EIT) can measure regional lung perfusion using different contrast agents. The study evaluated the suitability of five clinically approved solutions as EIT contrast agents. NaCl 5.85% and sodium-bicarbonate 8.4% showed the best results, while Iomeprol and Glucose 5% also produced usable signals. Isotonic balanced crystalloid solution was not effective. Further research is needed to determine optimal doses and balance reliability with potential side effects.
JOURNAL OF CLINICAL MEDICINE
(2023)
Review
Instruments & Instrumentation
Callum Gassner, Jitraporn Vongsvivut, Soon Hock Ng, Meguya Ryu, Mark J. J. Tobin, Saulius Juodkazis, Junko Morikawa, Bayden R. R. Wood
Summary: This review provides an overview of the knowledge gathered through polarized infrared spectroscopy on biological materials, including biomolecules, cells, and tissues. The review discusses the factors that can affect the analysis, such as sample preparation, sample properties, and instrumentation. It also highlights the potential impacts of using inherently polarized light sources for biological sample analysis.
APPLIED SPECTROSCOPY
(2023)
Article
Engineering, Mechanical
Chenglin Lyu, Pedro Truppel Morim, Bernhard Penzlin, Felix Roehren, Lukas Bergmann, Philip von Platen, Cornelius Bollheimer, Steffen Leonhardt, Chuong Ngo
Summary: This study proposes a hybrid exoskeleton approach combining a traditional exoskeleton and functional electrical stimulation (FES) for the rehabilitation of paralysis caused by a stroke or a spinal cord injury. The closed-loop FES control strategy is demonstrated to be feasible for training and shows improved performance compared to open-loop control, with reduced muscle fatigue and increased robustness.
Article
Chemistry, Analytical
Thulya Chakkumpulakkal Puthan Veettil, Diana Alves, Jitraporn Vongsvivut, Rosemary L. Sparrow, Bayden R. Wood, Gil Garnier
Summary: Oxidative treatment of RBCs prior to freeze-drying stabilizes the cells for storage at room temperature. Synchrotron-based FTIR microspectroscopy was used to analyze single RBCs and compare lipid and protein spectral data before and after oxidation and freeze-drying. The analysis showed that oxidized and freeze-dried RBCs have different spectral profiles compared to untreated RBCs, indicating changes in lipid peroxidation, stiffness of the membrane, and protein secondary structure. Freeze-drying did not introduce additional changes. This study highlights the potential of freeze-dried RBCs as a stable source for blood serology testing and demonstrates the power of synchrotron FTIR microspectroscopic live-cell analysis.
Article
Chemistry, Analytical
John A. Adegoke, Callum Gassner, Varun J. Sharma, Sheila K. Patel, Louise Jackett, Isaac O. Afara, Jaishankar Raman, Louise M. Burrell, Bayden R. Wood
Summary: This study demonstrates that a portable handheld near-infrared spectrometer coupled with machine learning algorithms can effectively differentiate between kidney and cardiac fibrosis in a rat model of kidney failure, providing a potential intraoperative surgical tool for detecting and quantifying fibrosis in the heart and kidney.
ANALYSIS & SENSING
(2023)
Article
Chemistry, Analytical
Zack Richardson, Adele Kincses, Elif Ekinci, David Perez-Guaita, Karin Jandeleit-Dahm, Bayden R. Wood
Summary: In this study, a method combining ultracentrifugation, infrared spectroscopy, and machine learning was developed to accurately quantify low level microalbuminuria in urine samples. The results showed high sensitivity and specificity in discriminating between normal and micro/macroalbuminuric samples, and regression analysis provided quantification of albumin concentration. This approach is cost-effective, quick, and portable, making it a valuable tool for early screening of diabetic kidney disease.
ANALYSIS & SENSING
(2023)
