scholarly journals Analysis of a Low-Cost EEG Monitoring System and Dry Electrodes toward Clinical Use in the Neonatal ICU

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2637 ◽  
Author(s):  
Mark O’Sullivan ◽  
Andriy Temko ◽  
Andrea Bocchino ◽  
Conor O’Mahony ◽  
Geraldine Boylan ◽  
...  

Electroencephalography (EEG) is an important clinical tool for monitoring neurological health. However, the required equipment, expertise, and patient preparation inhibits its use outside of tertiary care. Non-experts struggle to obtain high-quality EEG due to its low amplitude and artefact susceptibility. Wet electrodes are currently used, which require abrasive/conductive gels to reduce skin-electrode impedance. Advances in dry electrodes, which do not require gels, have simplified this process. However, the assessment of dry electrodes on neonates is limited due to health and safety barriers. This study presents a simulation framework for assessing the quality of EEG systems using a neonatal EEG database, without the use of human participants. The framework is used to evaluate a low-cost EEG acquisition system and compare performance of wet and dry (Micro Transdermal Interface Platforms (MicroTIPs), g.tec-g.SAHARA) electrodes using accurately acquired impedance models. A separate experiment assessing the electrodes on adult participants was conducted to verify the simulation framework’s efficacy. Dry electrodes have higher impedance than wet electrodes, causing a reduction in signal quality. However, MicroTIPs perform comparably to wet electrodes at the frontal region and g.tec-g.SAHARA performs well at the occipital region. Using the simulation framework, a 25dB signal-to-noise ratio (SNR) was obtained for the low-cost EEG system. The tests on adults closely matched the simulated results.

Author(s):  
Marco Vinicio Alban ◽  
Haechang Lee ◽  
Hanul Moon ◽  
Seunghyup Yoo

Abstract Thin dry electrodes are promising components in wearable healthcare devices. Assessing the condition of the human body by monitoring biopotentials facilitates the early diagnosis of diseases as well as their prevention, treatment, and therapy. Existing clinical-use electrodes have limited wearable-device usage because they use gels, require preparation steps, and are uncomfortable to wear. While dry electrodes can improve these issues and have demonstrated performance on par with gel-based electrodes, providing advantages in mobile and wearable applications; the materials and fabrication methods used are not yet at the level of disposable gel electrodes for low-cost mass manufacturing and wide adoption. Here, a low-cost manufacturing process for thin dry electrodes with a conductive micro-pyramidal array is presented for large-scale on-skin wearable applications. The electrode is fabricated using micromolding techniques in conjunction with solution processes in order to guarantee ease of fabrication, high device yield, and the possibility of mass production compatible with current semiconductor production processes. Fabricated using a conductive paste and an epoxy resin that are both biocompatible, the developed micro-pyramidal array electrode operates in a conformal, non-invasive manner, with low skin irritation, which ensures improved comfort for brief or extended use. The operation of the developed electrode was examined by analyzing electrode-skin-electrode impedance, electroencephalography, electrocardiography, and electromyography signals and comparing them with those measured simultaneously using gel electrodes.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3629
Author(s):  
Granch Berhe Tseghai ◽  
Benny Malengier ◽  
Kinde Anlay Fante ◽  
Lieva Van Langenhove

It is important to go through a validation process when developing new electroencephalography (EEG) electrodes, but it is impossible to keep the human mind constant, making the process difficult. It is also very difficult to identify noise and signals as the input signal is unknown. In this work, we have validated textile-based EEG electrodes constructed from a poly(3,4-ethylene dioxythiophene) polystyrene sulfonate:/polydimethylsiloxane coated cotton fabric using a textile-based head phantom. The performance of the textile-based electrode has also been compared against a commercial dry electrode. The textile electrodes collected a signal to a smaller skin-to-electrode impedance (−18.9%) and a higher signal-to-noise ratio (+3.45%) than Ag/AgCl dry electrodes. From an EEGLAB, it was observed that the inter-trial coherence and event-related spectral perturbation graphs of the textile-based electrodes were identical to the Ag/AgCl electrodes. Thus, these textile-based electrodes can be a potential alternative to monitor brain activity.


Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3747
Author(s):  
Adriana Lipovac ◽  
Vlatko Lipovac ◽  
Borivoj Modlic

Contemporary wireless networks dramatically enhance data rates and latency to become a key enabler of massive communication among various low-cost devices of limited computational power, standardized by the Long-Term Evolution (LTE) downscaled derivations LTE-M or narrowband Internet of Things (NB IoT), in particular. Specifically, assessment of the physical-layer transmission performance is important for higher-layer protocols determining the extent of the potential error recovery escalation upwards the protocol stack. Thereby, it is needed that the end-points of low processing capacity most efficiently estimate the residual bit error rate (BER) solely determined by the main orthogonal frequency-division multiplexing (OFDM) impairment–carrier frequency offset (CFO), specifically in small cells, where the signal-to-noise ratio is large enough, as well as the OFDM symbol cyclic prefix, preventing inter-symbol interference. However, in contrast to earlier analytical models with computationally demanding estimation of BER from the phase deviation caused by CFO, in this paper, after identifying the optimal sample instant in a power delay profile, we abstract the CFO by equivalent time dispersion (i.e., by additional spreading of the power delay profile that would produce the same BER degradation as the CFO). The proposed BER estimation is verified by means of the industry-standard LTE software simulator.


2021 ◽  
Vol 11 (4) ◽  
pp. 1499
Author(s):  
Bingchen Han ◽  
Junyu Xu ◽  
Pengfei Chen ◽  
Rongrong Guo ◽  
Yuanqi Gu ◽  
...  

An all-optical non-inverted parity generator and checker based on semiconductor optical amplifiers (SOAs) are proposed with four-wave mixing (FWM) and cross-gain modulation (XGM) non-linear effects. A 2-bit parity generator and checker using by exclusive NOR (XNOR) and exclusive OR (XOR) gates are implemented by first SOA and second SOA with 10 Gb/s return-to-zero (RZ) code, respectively. The parity and check bits are provided by adjusting the center wavelength of the tunable optical bandpass filter (TOBPF). A saturable absorber (SA) is used to reduce the negative effect of small signal clock (Clk) probe light to improve extinction ratio (ER) and optical signal-to-noise ratio (OSNR). For Pe and Ce (even parity bit and even check bit) without Clk probe light, ER and OSNR still maintain good performance because of the amplified effect of SOA. For Po (odd parity bit), ER and OSNR are improved to 1 dB difference for the original value. For Co (odd check bit), ER is deteriorated by 4 dB without SA, while OSNR is deteriorated by 12 dB. ER and OSNR are improved by about 2 dB for the original value with the SA. This design has the advantages of simple structure and great integration capability and low cost.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4623
Author(s):  
Sinead Barton ◽  
Salaheddin Alakkari ◽  
Kevin O’Dwyer ◽  
Tomas Ward ◽  
Bryan Hennelly

Raman spectroscopy is a powerful diagnostic tool in biomedical science, whereby different disease groups can be classified based on subtle differences in the cell or tissue spectra. A key component in the classification of Raman spectra is the application of multi-variate statistical models. However, Raman scattering is a weak process, resulting in a trade-off between acquisition times and signal-to-noise ratios, which has limited its more widespread adoption as a clinical tool. Typically denoising is applied to the Raman spectrum from a biological sample to improve the signal-to-noise ratio before application of statistical modeling. A popular method for performing this is Savitsky–Golay filtering. Such an algorithm is difficult to tailor so that it can strike a balance between denoising and excessive smoothing of spectral peaks, the characteristics of which are critically important for classification purposes. In this paper, we demonstrate how Convolutional Neural Networks may be enhanced with a non-standard loss function in order to improve the overall signal-to-noise ratio of spectra while limiting corruption of the spectral peaks. Simulated Raman spectra and experimental data are used to train and evaluate the performance of the algorithm in terms of the signal to noise ratio and peak fidelity. The proposed method is demonstrated to effectively smooth noise while preserving spectral features in low intensity spectra which is advantageous when compared with Savitzky–Golay filtering. For low intensity spectra the proposed algorithm was shown to improve the signal to noise ratios by up to 100% in terms of both local and overall signal to noise ratios, indicating that this method would be most suitable for low light or high throughput applications.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2406
Author(s):  
Mashaalah Zarejousheghani ◽  
Parvaneh Rahimi ◽  
Helko Borsdorf ◽  
Stefan Zimmermann ◽  
Yvonne Joseph

Globally, there is growing concern about the health risks of water and air pollution. The U.S. Environmental Protection Agency (EPA) has developed a list of priority pollutants containing 129 different chemical compounds. All of these chemicals are of significant interest due to their serious health and safety issues. Permanent exposure to some concentrations of these chemicals can cause severe and irrecoverable health effects, which can be easily prevented by their early identification. Molecularly imprinted polymers (MIPs) offer great potential for selective adsorption of chemicals from water and air samples. These selective artificial bio(mimetic) receptors are promising candidates for modification of sensors, especially disposable sensors, due to their low-cost, long-term stability, ease of engineering, simplicity of production and their applicability for a wide range of targets. Herein, innovative strategies used to develop MIP-based sensors for EPA priority pollutants will be reviewed.


1997 ◽  
Vol 51 (8) ◽  
pp. 1106-1112 ◽  
Author(s):  
H. Weidner ◽  
R. E. Peale

A low-cost method of adding time-resolving capability to commercial Fourier transform spectrometers with a continuously scanning Michelson interferometer has been developed. This method is specifically designed to eliminate noise and artifacts caused by mirror-speed variations in the interferometer. The method exists of two parts: (1) a novel timing scheme for synchronizing the transient events under study and the digitizing of the interferogram and (2) a mathematical algorithm for extracting the spectral information from the recorded data. The novel timing scheme is a modification of the well-known interleaved, or stroboscopic, method. It achieves the same timing accuracy, signal-to-noise ratio, and freedom from artifacts as step-scan time-resolving Fourier spectrometers by locking the sampling of the interferogram to a stable time base rather than to the occurrences of the HeNe fringes. The necessary pathlength-difference information at which samples are taken is obtained from a record of the mirror speed. The resulting interferograms with uneven pathlength-difference spacings are transformed into wavenumber space by least-squares fits of periodic functions. Spectra from the far-infrared to the upper visible at resolutions up to 0.2 cm−1 are used to demonstrate the utility of this method.


2021 ◽  
pp. 54-59
Author(s):  
Md. Mahidy Hossain ◽  
Nadim Khandaker

In every aspect of Engineering more advanced, efficient and progressive solutions are required. The modern age of science requires innovative minds. The field of environmental engineering is also advancing with modern science and technology innovations. Measuring of methane concentration and flow rate is nothing new, yet a complicated process. The need for more accurate measurement is a necessity in proper operation of bio digesters for methane generation. The traditional process of the measuring methane content in biogas is time consuming yet complicated. The need for development and application of methane measurement techniques is not only limited to biogas but has other monitoring value as well in other health and safety applications in built environments. Winsen Electronics and Hanwei Electronics are two of the leading sensor-manufactures of China who are providing a wide range of gas detecting sensors that are locally available in Bangladesh and yet has not been applied to methane content measurement in biogas operations. In This paper we are reporting on the application of a purpose-built propane, butane detector for methane gas detection within the range of accuracy for it to be applied in methane detection in a biogas stream. This paper, reports on application and calibration of the methane detecting sensor MQ-4 with promising result. Based on the study we postulate that the sensor can be used to detect methane for an on-line monitoring of many environmental, industrial purposes such as bio digesters, integrated waste management facility. The cost of fabrication of the sensor system is only $18 making it a viable sensor with respect to cost for application in Bangladesh.


2021 ◽  
pp. 53-55
Author(s):  
Harsimran Singh Das

Introduction:qCSI (Quick COVID severity index) is a clinical tool established recently post pandemic to predict respiratory failure within 24 hours of admission in COVID-19 patients; respiratory failure being explain as increased oxygen requirement greater than 6L/min by low ow device, high ow device, noninvasive or invasive ventilation to maintain spO2 of greater than or equal to 94%, or death. Aim:To verify and validate the application of the qCSI in Emergency Department in Indian demographic for evidence-based guidance to aid physician decision making in safely dispositioning adult patients with COVID-19 with oxygen requirement less than or equal to 6L/min via low ow devices including nasal cannula and oxygen mask Materials and methods:This is an observational, retrospective study from Emergency Department in a private tertiary care hospital of admitted adult patients with COVID-19 disease. Clinical parameters in qCSI and disposition of 210 patients admitted through Emergency Department included in this study selected randomly was sought on admission and clinical status with level of care 24 hours following admission was recorded and compared with prediction based on qCSI from a period of 1 May 2020 to 31 October 2020. Result:We found that19(9.0%) patients Initial qCSI Score was Low, 80(38.1%) patients Initial qCSI Score was Low-intermediate, 84(40.0%) patients Initial qCSI Score was High-intermediate and 27(12.9%)patients Initial qCSI Score was High.qCSI Score after 24 hours 16(11.4%) patients were Low, 43(30.7%) patients were Low-intermediate, 63(45.0%) patients was High-intermediate and 18(12.9%) patients was High.Out of 210(100.0%) patients, 70 (33.3%) patients were critically ill. Conclusion:In conclusion these data show that the quick COVID-19 Severity Index provides easily accessed risk stratication relevant to Emergency Department provider.


Author(s):  
Sumitra Yadav ◽  
Ruchi Joshi ◽  
Monica Solanki

Background: PPIUCDs are the only method for couples requesting a highly effective and reversible, yet long acting, family planning method that can be initiated during the immediate postpartum phase. World Health Organization (WHO) medical eligibility criteria state that it is generally safe for postpartum lactating women to use a PPIUCD, with the advantages outweighing the disadvantages. PPIUCDs are cost-effective and they are low-cost intervention that reduces maternal, infant, and under-five Child mortality.Methods: After approval from the ethical committee and consent from the patients, the study was performed on 1000 postpartum women within 10 min. of delivery and up to 6 weeks of delivery at Labour Room of, M.Y. Hospital, Indore.Results: Majority of acceptor (72.5%) belong to age group of 18-25 years and 53% belonged to urban area. Acceptance was more in those who completed their secondary school level education (33%). Working women (55.5%) accepted PPIUCD more than the non-working. Out of 1000 women counselled only 10% agreed for PPIUVD insertion. During the study of 1 year duration (3.5%) of non-acceptors become pregnant and none of the acceptors conceived. Most common reason stated for accepting PPIUCD among acceptors, was that it is a reversible method (66%). Most common reason for not accepting PPIUCD among non-acceptors, because they are interested in Other Method of Family Planning (60%).Conclusions: Verbal acceptance is more than actual insertion of PPIUCD because of adoption of other method of family planning, family pressure, nonacceptance by partner, lack of awareness, fear of complication. Proper counselling can help to generate awareness and compliance for PPIUCD use in postpartum mother who have institutional delivery. Inserting CuT 380A within 10 min after placental delivery is safe and effective, has high retention rate. The expulsion rate was not high, and further can be reduced with practice could not be predicted.


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