225 research outputs found
Contactless Heart Rate Detection Using MM-Wave Radar Systems Advancements
In recent years, there has been a significant surge in the development of non-contact methods for detecting heart and breathing rates. Various Millimeter-wave (MM-wave) radar systems, operating at different frequency bands like 10 GHz, 24 GHz, 77 GHz, and 122 GHz, have been effectively deployed for this purpose. This paper explores the vital application of contactless systems in the medical field, particularly during disasters and epidemics. These systems are crucial for detecting the heart and breathing rates of individuals trapped under debris, in military operations, long-term vital sign monitoring in hospitals, and aiding the elderly in public spaces. Consequently, our focus is on heart and breathing rate detection using radar systems. This paper highlights the significance of capturing the electrical representation of the heart signal. This approach is known for its trustworthiness and accuracy in identifying various medical conditions. Furthermore, a traditional method based on Fourier transform is presented for heart and respiration rate estimation. This method leverages the direct proportionality between heart and breathing rates and the frequencies of raw radar signals. To estimate the breathing rate, it identifies the maximum peak within the frequency range of 0.15 to 0.4 Hz in the frequency domain and multiplies the corresponding frequency by 60 to obtain the rate per minute. For heart rate estimation, it detects the maximum peak within the frequency range of 0.8 to 2 Hz and calculates the rate per minute accordingly
Contactless Heart Rate Detection Using MM-Wave Radar Systems Advancements
In recent years, there has been a significant surge in the development of non-contact methods for detecting heart and breathing rates. Various Millimeter-wave (MM-wave) radar systems, operating at different frequency bands like 10 GHz, 24 GHz, 77 GHz, and 122 GHz, have been effectively deployed for this purpose. This paper explores the vital application of contactless systems in the medical field, particularly during disasters and epidemics. These systems are crucial for detecting the heart and breathing rates of individuals trapped under debris, in military operations, long-term vital sign monitoring in hospitals, and aiding the elderly in public spaces. Consequently, our focus is on heart and breathing rate detection using radar systems. This paper highlights the significance of capturing the electrical representation of the heart signal. This approach is known for its trustworthiness and accuracy in identifying various medical conditions. Furthermore, a traditional method based on Fourier transform is presented for heart and respiration rate estimation. This method leverages the direct proportionality between heart and breathing rates and the frequencies of raw radar signals. To estimate the breathing rate, it identifies the maximum peak within the frequency range of 0.15 to 0.4 Hz in the frequency domain and multiplies the corresponding frequency by 60 to obtain the rate per minute. For heart rate estimation, it detects the maximum peak within the frequency range of 0.8 to 2 Hz and calculates the rate per minute accordingly
Accuracy of Goldmann, ocular response analyser, Pascal and TonoPen XL tonometry in keratoconic and normal eyes
Aim: The aim of this study was to evaluate the practicality and accuracy of tonometers used in routine clinical practice for established keratoconus (KC). Methods: This was a prospective study of 118 normal and 76 keratoconic eyes where intraocular pressure (IOP) was measured in random order using the Goldman applanation tonometer (GAT), Pascal dynamic contour tonometer (DCT), Reichert ocular response analyser (ORA) and TonoPen XL tonometer. Corneal hysteresis (CH) and corneal resistance factor (CRF), as calculated by the ORA, were recorded. Central corneal thickness (CCT) was measured using an ultrasound pachymeter. Results: The difference in IOP values between instruments was highly significant in both study groups (p<0.001). All other IOP measures were significantly higher than those for GAT, except for the Goldmann-correlated IOP (average of the two applanation pressure points) (IOPg) as measured by ORA in the control group and the CH-corrected IOP (corneal-compensated IOP value) (IOPcc) measures in the KC group. CCT, CH and CRF were significantly less in the KC group (p<0.001). Apart from the DCT, all techniques tended to measure IOP higher in eyes with thicker corneas. Conclusion: The DCT and the ORA are currently the most appropriate tonometers to use in KC for the measurement of IOPcc. Corneal factors such as CH and CRT may be of more importance than CCT in causing inaccuracies in applanation tonometry techniques
Cationic Gemini Surfactants For Carbon Steel In Sea Water
Abstract Corrosion inhibition of carbon steel alloy in sea water by different synthesized gemini surfactants {12-2-12, 14-2-14 and 16-2-16} have been investigated using weight loss, potentiodynamic polarization and surface tension measurements. The data obtained from all the used methods are in good agreement with each other and ensure the excellent inhibition efficiency of the tested surfactants for carbon steel in sea water. The inhibition efficiency increases with increasing the concentration of the studied inhibitors. Also, the adsorption ability of the surfactant molecules on carbon steel surface increases with the increase in the hydrocarbon chain length of the surfactant molecule from 12 to 16 and through 14 C atoms; meanwhile, the isotherm of 16-2-16 declares the formation of multilayer onto the used metal surface. The inhibitive action of the studied surfactants follows the order: 16-2-16 > 14-2-14> 12-2-12. The morphological changes of carbon steel surface were studied by Scanning Electron Microscope [SEM] ] and the study shows well inhibited surface on adding the cationic Gemini surfactants to the immersion solution . [Nessim I .M.; Hamdy A.; Osman M.M. and Shalaby M. N. Inhibitory Effect Of Som
Scalable Synthesis of Few-Layered 2D Tungsten Diselenide (2H-WSe2) Nanosheets Directly Grown on Tungsten (W) Foil Using Ambient-Pressure Chemical Vapor Deposition for Reversible Li-Ion Storage
We report a facile two-furnace APCVD synthesis of 2H-WSe2. A systematic study of the process parameters is performed to show the formation of the phase-pure material. Extensive characterization of the bulk and exfoliated material confirm that 2H-WSe2 is layered (i.e., 2D). X-ray diffraction (XRD) confirms the phase, while high-resolution scanning electron microscopy (HRSEM), high-resolution transmission electron microscopy (HRTEM), and atomic force microscopy (AFM) clarify the morphology of the material. Focused ion beam scanning electron microscopy (FIB-SEM) estimates the depth of the 2H-WSe2 formed on W foil to be around 5-8 μm, and Raman/UV-vis measurements prove the quality of the exfoliated 2H-WSe2. Studies on the redox processes of lithium-ion batteries (LiBs) show an increase in capacity up to 500 cycles. On prolonged cycling, the discharge capacity up to the 50th cycle at 250 mA/g of the material shows a stable value of 550 mAh/g. These observations indicate that exfoliated 2H-WSe2 has promising applications as an LiB electrode material
Optical Properties and Ultrafast Near‐Infrared Localized Surface Plasmon Dynamics in Naturally p‐Type Digenite Films
Copper chalcogenides are materials characterized by intrinsic doping properties, allowing them to display high carrier concentrations due to their defect-heavy structures, independent of the preparation method. Such high doping enables these materials to display plasmonic resonances, tunable by varying their stoichiometry, as shown previously for Cu2-xS, Cu2-xSe, and Cu2-xTe, with 0 1 ns) signal associated with phonon-phonon scattering relaxation. These results confirm the possibility of fabricating Cu9S5 films retaining the plasmonic properties of individual NCs, anticipating integrating these films into heterojunctions with suitable hole acceptor materials to build hot-hole-transfer-based optoelectronic devices
An Assessment of Dialysis Provider's Attitudes towards Timing of Dialysis Initiation in Canada
Background: Physicians' perceptions and opinions may influence when to initiate dialysis. Objective: To examine providers' perspectives and opinions regarding the timing of dialysis initiation. Design: Online survey. Setting: Community and academic dialysis practices in Canada. Participants: A nationally-representative sample of dialysis providers. Measurements and Methods: Dialysis providers opinions assessing reasons to initiate dialysis at low or high eGFR. Responses were obtained using a 9-point Likert scale. Early dialysis was defined as initiation of dialysis in an individual with an eGFR greater than or equal to 10.5 ml/min/m 2 . A detailed survey was emailed to all members of the Canadian Society of Nephrology (CSN) in February 2013. The survey was designed and pre-tested to evaluate duration and ease of administration. Results: One hundred and forty one (25% response rate) physicians participated in the survey. The majority were from urban, academic centres and practiced in regionally administered renal programs. Very few respondents had a formal policy regarding the timing of dialysis initiation or formally reviewed new dialysis starts (N = 4, 3.1%). The majority of respondents were either neutral or disagreed that late compared to early dialysis initiation improved outcomes (85–88%), had a negative impact on quality of life (89%), worsened AVF or PD use (84–90%), led to sicker patients (83%) or was cost effective (61%). Fifty-seven percent of respondents felt uremic symptoms occurred earlier in patients with advancing age or co-morbid illness. Half (51.8%) of the respondents felt there was an absolute eGFR at which they would initiate dialysis in an asymptomatic patient. The majority of respondents would initiate dialysis for classic indications for dialysis, such as volume overload (90.1%) and cachexia (83.7%) however a significant number chose other factors that may lead them to early dialysis initiation including avoiding an emergency (28.4%), patient preference (21.3%) and non-compliance (8.5%). Limitations: 25% response rate. Conclusions: Although the majority of nephrologists in Canada who responded followed evidence-based practice regarding the timing of dialysis initiation, knowledge gaps and areas of clinical uncertainty exist. The implementation and evaluation of formal policies and knowledge translation activities may limit potentially unnecessary early dialysis initiation
Probiotic Limosilactobacillus reuteri DSM 17938 Changes Foxp3 Deficiency-Induced Dyslipidemia and Chronic Hepatitis in Mice
The probiotic Limosilactobacillus reuteri DSM 17938 produces anti-inflammatory effects in scurfy (SF) mice, a model characterized by immune dysregulation, polyendocrinopathy, enteropathy, and X-linked inheritance (called IPEX syndrome in humans), caused by regulatory T cell (Treg) deficiency and is due to a Foxp3 gene mutation. Considering the pivotal role of lipids in autoimmune inflammatory processes, we investigated alterations in the relative abundance of lipid profiles in SF mice (± treatment with DSM 17938) compared to normal WT mice. We also examined the correlation between plasma lipids and gut microbiota and circulating inflammatory markers. We noted a significant upregulation of plasma lipids associated with autoimmune disease in SF mice, many of which were downregulated by DSM 17938. The upregulated lipids in SF mice demonstrated a significant correlation with gut bacteria known to be implicated in the pathogenesis of various autoimmune diseases. Chronic hepatitis in SF livers responded to DSM 17938 treatment with a reduction in hepatic inflammation. Altered gene expression associated with lipid metabolism and the positive correlation between lipids and inflammatory cytokines together suggest that autoimmunity leads to dyslipidemia with impaired fatty acid oxidation in SF mice. Probiotics are presumed to contribute to the reduction of lipids by reducing inflammatory pathways
Ultrasound Stimulation of Piezoelectric Nanocomposite Hydrogels Boosts Chondrogenic Differentiation in Vitro, in Both a Normal and Inflammatory Milieu
The use of piezoelectric nanomaterials combined with ultrasound stimulation is emerging as a promising approach for wirelessly triggering the regeneration of different tissue types. However, it has never been explored for boosting chondrogenesis. Furthermore, the ultrasound stimulation parameters used are often not adequately controlled. In this study, we show that adipose-tissue-derived mesenchymal stromal cells embedded in a nanocomposite hydrogel containing piezoelectric barium titanate nanoparticles and graphene oxide nanoflakes and stimulated with ultrasound waves with precisely controlled parameters (1 MHz and 250 mW/cm2, for 5 min once every 2 days for 10 days) dramatically boost chondrogenic cell commitment in vitro. Moreover, fibrotic and catabolic factors are strongly down-modulated: proteomic analyses reveal that such stimulation influences biological processes involved in cytoskeleton and extracellular matrix organization, collagen fibril organization, and metabolic processes. The optimal stimulation regimen also has a considerable anti-inflammatory effect and keeps its ability to boost chondrogenesis in vitro, even in an inflammatory milieu. An analytical model to predict the voltage generated by piezoelectric nanoparticles invested by ultrasound waves is proposed, together with a computational tool that takes into consideration nanoparticle clustering within the cell vacuoles and predicts the electric field streamline distribution in the cell cytoplasm. The proposed nanocomposite hydrogel shows good injectability and adhesion to the cartilage tissue ex vivo, as well as excellent biocompatibility in vivo, according to ISO 10993. Future perspectives will involve preclinical testing of this paradigm for cartilage regeneration
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