scholarly journals An Insulated Flexible Sensor for Stable Electromyography Detection: Application to Prosthesis Control

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 961 ◽  
Author(s):  
Theresa Roland ◽  
Kerstin Wimberger ◽  
Sebastian Amsuess ◽  
Michael Russold ◽  
Werner Baumgartner
Keyword(s):  
Low Power ◽  
Skin Condition ◽  
Motion Artifacts ◽  
High Signal ◽  
Skin Preparation ◽  
Flexible Sensor ◽  
Upper Limb Prostheses ◽  
Materials Used ◽  
Prosthesis Control ◽  
Set Up

Electromyography (EMG), the measurement of electrical muscle activity, is used in a variety of applications, including myoelectric upper-limb prostheses, which help amputees to regain independence and a higher quality of life. The state-of-the-art sensors in prostheses have a conductive connection to the skin and are therefore sensitive to sweat and require preparation of the skin. They are applied with some pressure to ensure a conductive connection, which may result in pressure marks and can be problematic for patients with circulatory disorders, who constitute a major group of amputees. Due to their insulating layer between skin and sensor area, capacitive sensors are insensitive to the skin condition, they require neither conductive connection to the skin nor electrolytic paste or skin preparation. Here, we describe a highly stable, low-power capacitive EMG measurement set-up that is suitable for real-world application. Various flexible multi-layer sensor set-ups made of copper and insulating foils, flex print and textiles were compared. These flexible sensor set-ups adapt to the anatomy of the human forearm, therefore they provide high wearing comfort and ensure stability against motion artifacts. The influence of the materials used in the sensor set-up on the magnitude of the coupled signal was demonstrated based on both theoretical analysis and measurement.The amplifier circuit was optimized for high signal quality, low power consumption and mobile application. Different shielding and guarding concepts were compared, leading to high SNR.

scholarly journals Ultra-Low-Power Digital Filtering for Insulated EMG Sensing

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 959 ◽  
Author(s):  
Theresa Roland ◽  
Sebastian Amsuess ◽  
Michael Russold ◽  
Werner Baumgartner
Keyword(s):  
Low Power ◽  
Noise Suppression ◽  
Low Cost ◽  
Digital Signal ◽  
External Noise ◽  
High Signal ◽  
Skin Preparation ◽  
Ultra Low Power ◽  
Myoelectric Prostheses ◽  
Emg Signal

Myoelectric prostheses help amputees to regain independence and a higher quality of life. These prostheses are controlled by state-of-the-art electromyography sensors, which use a conductive connection to the skin and are therefore sensitive to sweat. They are applied with some pressure to ensure a conductive connection, which may result in pressure marks and can be problematic for patients with circulatory disorders, who constitute a major group of amputees. Here, we present ultra-low-power digital signal processing algorithms for an insulated EMG sensor which couples the EMG signal capacitively. These sensors require neither conductive connection to the skin nor electrolytic paste or skin preparation. Capacitive sensors allow straightforward application. However, they make a sophisticated signal amplification and noise suppression necessary. A low-cost sensor has been developed for real-time myoelectric prostheses control. The major hurdles in measuring the EMG are movement artifacts and external noise. We designed various digital filters to attenuate this noise. Optimal system setup and filter parameters for the trade-off between attenuation of this noise and sufficient EMG signal power for high signal quality were investigated. Additionally, an algorithm for movement artifact suppression, enabling robust application in real-world environments, is presented. The algorithms, which require minimal calculation resources and memory, are implemented on an ultra-low-power microcontroller.

Growth and yield of okra (Abelmoschus esculentus (L.) Moench) grown in the marginal upland area of Sta. Rita, Samar as influenced by different planting densities and mulching materials

2017 ◽  
pp. 44-54
Author(s):  
Zenaida Gonzaga ◽  
Warren Obeda ◽  
Ana Linda Gorme ◽  
Jessie Rom ◽  
Oscar Abrantes ◽  
...  
Keyword(s):  
Bare Soil ◽  
Abelmoschus Esculentus ◽  
Growth And Yield ◽  
Planting Density ◽  
Rice Hull ◽  
Plastic Mulch ◽  
Lady’S Finger ◽  
Materials Used ◽  
Set Up ◽  
A Minor

Okra or Lady’s finger, botanically known as Abelmoschus esculentus (L.) Moench, is a tropical and sub-tropical indigenous vegetable crop commonly grown for its fibrous, slimy, and nutritious fruits and consumed by all classes of population. It has also several medicinal and economic values. Despite its many uses and potential value, its importance is under estimated, under-utilized, and considered a minor crop and little attention was paid to its improvement. The study was conducted to evaluate the effects of different planting densities and mulching materials on the growth and yield of okra grown in slightly sloping area in the marginal uplands in Sta. Rita, Samar, Philippines. A split-plot experiment was set up with planting density as main plot and the different mulching materials as the sub-plot which were: unmulched or bare soil, rice straw, rice hull, hagonoy and plastic mulch. Planting density did not significantly affect the growth and yield of okra. Regardless ofthe mulching materials used, mulched plants were taller and yielded higher compared to unmulched plants. Moreover, the use of plastic mulch resulted to the highest total fruit yield. The results indicate the potential of mulching in increasing yield and thus profitability of okra production under marginal upland conditions.

scholarly journals A Scale Model of Tension Structures in Road Tunnels to Optimize the Use of Solar Light for Energy Saving

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Antonio Peña-García ◽  
Luisa-María Gil-Martín ◽  
Roberto Escribano ◽  
Antonio Espín-Estrella
Keyword(s):  
Energy Savings ◽  
Construction Materials ◽  
Electricity Consumption ◽  
Scale Model ◽  
Major Influence ◽  
Road Tunnels ◽  
Tension Structures ◽  
Materials Used ◽  
Set Up ◽  
New Equation

Shifting the threshold zone of road tunnels with semitransparent tension structures has shown itself to be an effective way of saving energy in regards to electricity consumption, maintenance, and construction materials used in the electrical lighting, thus lessening negative environmental impacts. Even though the shape of the tension structure has a major influence on energy savings, the optimal type of structure for each tunnel is often difficult to determine, because experiments using real tunnels are extremely expensive. It is thus necessary to find methods of doing this that are both reliable as well as economical. In this research study, three candidate structures were set up at the portal of a scale model of a real tunnel. The energy savings in each case were analyzed and compared. As a result, it was possible to formulate a new equation that calculates the energy savings in the threshold zone.

scholarly journals The Effects of Plaster Thicknesses on Cyclic Behavior of Infill Walls with Different Materials

2020 ◽  
Author(s):  
Mehmet Emin Arslan ◽  
Elif Ağcakoca ◽  
Merve Şentürk
Keyword(s):  
Energy Dissipation ◽  
Cyclic Behavior ◽  
Dissipated Energy ◽  
Cyclic Loads ◽  
Reinforced Concrete Structure ◽  
Backbone Curve ◽  
Infill Walls ◽  
Load Carrying ◽  
Materials Used ◽  
Set Up

Reinforced concrete structure systems are usually designed as frame or shear wall-frame systems. It is possible to reduce the deformation and displacement in the system by increasing the structural stiffness. Besides, large displacements on the floors caused by horizontal load are damped by the cracks in these walls. The present paper aims to examine the effects of materials used in the wall construction as well as thickness of the plaster on the behavior of infill walls under cyclic loads. In order to investigate the above mentioned effects, three Infill walls that were produced from three different materials namely, horizontal hollow bricks, pumice blocks and aerated concrete blocks were tested in three setups (without plaster, with 1 cm plaster and 2.5 cm plaster on it). In order to determine pure wall contribution, the infill walls were placed in a steel frame test set-up which was hinged from all four corners and were then exposed to cyclic loads taking into account the displacement controlled loading protocol proposed in FEMA 461. Right after applying the plaster to the infill walls, load carrying and energy dissipation capacities of the walls were examined comparatively. Load-displacement, backbone curve and cumulative dissipated energy curves of each infill walls are generated using the data collected from the experiments and the infill walls behaviors are graphically explained. Test results showed that existence and thickness of plaster significantly affected cyclic behavior of the test walls by increasing energy dissipation capacities and load carrying capacities.

scholarly journals SeeTB: A novel alternative to sputum smear microscopy to diagnose tuberculosis in high burden countries

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Vikas Pandey ◽  
Pooja Singh ◽  
Saumya Singh ◽  
Naresh Arora ◽  
Neha Quadir ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
High Signal ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Fluorescence Excitation ◽  
Case Identification ◽  
Resource Limited ◽  
Realistic Option ◽  
Viscous Polymer ◽  
Set Up

Abstract Microscopy-based tuberculosis (TB) diagnosis i.e. Ziehl-Neelsen screening still remains the primary diagnostic method in resource poor and high TB burden countries, however this method has poor sensitivity (~60%). Bringing three million TB patients who are left undiagnosed under the treatment has been a major focus as part of END-TB strategy across the world. We have developed a portable set-up called ‘SeeTB’ that converts a bright-field microscope into fluorescence microscope (FM) with minimal interventions. SeeTB, a total internal reflection-based fluorescence excitation system allows visualization of auramine-O stained bacilli efficiently with high signal-to-noise ratio. Along with the device, we have developed a sputum-processing reagent called ‘CLR’ that homogenizes and digests the viscous polymer matrix of sputum. We have compared the performance of SeeTB system in 237 clinical sputum samples along with FM, GeneXpert and liquid culture. In comparison with culture as gold standard, FM has sensitivity of 63.77% and SeeTB has improved sensitivity to 76.06%. In comparison with GeneXpert, FM has sensitivity of 73.91% while SeeTB has improved sensitivity to 85.51%. However, there is no significant change in the specificity between FM and SeeTB system. In short, SeeTB system offers the most realistic option for improved TB case identification in resource-limited settings.

Dimensional Effects on the Measurement of Permittivity of Semiconducting Materials Used in High Voltage XLPE Cables

2008 ◽  
Vol 9 (1) ◽  
Author(s):  
Juan Juan Yang ◽  
Da Ming Zhang
Keyword(s):  
High Voltage ◽  
Partial Discharge ◽  
Semiconducting Materials ◽  
Dimensional Effect ◽  
Semiconducting Material ◽  
Dimensional Effects ◽  
Different Dimensions ◽  
The Difference ◽  
Materials Used ◽  
Set Up

The intrinsic permittivity, not apparent permittivity, of semiconducting layers of high voltage cross-linked polyethylene (XLPE) cables imposes a significant influence on the design of partial discharge detecting sensors. It has extremely high permittivity, resulting in a dimensional effect, an embodiment of the difference between the intrinsic permittivity and apparent or measurable permittivity. To investigate this dimensional effect in semiconducting material, a mathematical model is set up in this paper for a capacitor with two rectangular-shaped electrodes in parallel, between which is inserted a semi-conducting sample. First, the expression of the electric field in the semiconducting material is worked out theoretically. Then, the measurable or apparent complex permittivity is expressed as a function of intrinsic permittivity, dimensions of the sample and frequency. Next, five blocks with different dimensions are introduced to study the dimensional effect. The numerical analysis demonstrates that above 10 MHz, samples with different dimensions result in different apparent permittivity or measurable permittivity if experiments are carried out for the samples with the assumed dimensions. This implies that dimensional effects should be considered when accurate intrinsic permittivity of the semiconducting materials is needed.

scholarly journals The Tournemire industrial analogue: reactive-transport modelling of a cement–clay interface

Clay Minerals ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 167-184 ◽  
Author(s):  
C. Watson ◽  
D. Savage ◽  
J. Wilson ◽  
S. Benbow ◽  
C. Walker ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Reactive Transport ◽  
Transport Model ◽  
Surface Complexation ◽  
General Purpose ◽  
Transport Modelling ◽  
Mineralogical Characterization ◽  
Modelling Techniques ◽  
Materials Used ◽  
Set Up

AbstractIn the post-closure period of a geological disposal facility for radioactive waste, leaching of cement components is likely to give rise to an alkaline plume which will be in chemical disequilibrium with the host rock (which is clay in some concepts) and other engineered barrier system materials used in the facility, such as bentonite. An industrial analogue for cement-clay interaction can be found at Tournemire, southern France, where boreholes filled with concrete and cement remained in contact with the natural mudstone for 15–20 years. The boreholes have been overcored, extracted and mineralogical characterization has been performed. In this study, a reactive-transport model of the Tournemire system has been set up using the general-purpose modelling tool QPAC. Previous modelling work has been built upon by using the most up-to-date data and modelling techniques, and by adding both ion exchange and surface complexation processes in the mudstone. The main features observed at Tournemire were replicated by the model, including porosity variations and precipitation of carbonates, K-feldspar, ettringite and calcite. It was found that ion exchange needed to be included in order for C-S-H minerals to precipitate in the mudstone, providing a better match with the mineralogical characterization. The additional inclusion of surface complexation, however, led to limited calcite growth at the concrete-mudstone interface unlike samples taken from the Tournemire site that have a visible line of crusty carbonates along the interface.

scholarly journals Electromechanical Design of Self-Similar Inspired Surface Electrodes for Human-Machine Interaction

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
YongAn Huang ◽  
Wentao Dong ◽  
Chen Zhu ◽  
Lin Xiao
Keyword(s):  
High Performance ◽  
Electrical Coupling ◽  
Interfacial Strength ◽  
Motion Artifacts ◽  
High Signal ◽  
Electrical Stability ◽  
Human Machine Interaction ◽  
Surface Electrodes ◽  
Self Similar ◽  
Machine Interaction

Stable acquisition of electromyography (EMG)/electrocardiograph (ECG) signal is critical and challenging in dynamic human-machine interaction. Here, self-similar inspired configuration is presented to design surface electrodes with high mechanical adaptability (stretchability and conformability with skin) and electrical sensitivity/stability which are usually a pair of paradoxes. Mechanical and electrical coupling optimization strategies are proposed to optimize the surface electrodes with the 2nd-order self-similar serpentine configuration. It is devoted the relationship between the geometric shape parameters (height-space ratio η, scale factor β, and line width w), the areal coverage α, and mechanical adaptability, based on which an open network-shaped electrode is designed to stably collect high signal-to-noise ratio signals. The theoretical and experimental results show that the electrodes can be stretched > 30% and conform with skin wrinkle. The interfacial strength of electrode and skin is measured by homemade peeling test experiment platform. The surface electrodes with different line widths are used to record ECG signals for validating the electrical stability. Conformability reduces background noises and motion artifacts which provides stable recording of ECG/EMG signals. Further, the thin, stretchable electrodes are mounted on the human epidermis for continuous, stable biopotential signal records which suggests the way to high-performance electrodes in human-machine interaction.

An Economic Analysis and Calculation for Selecting of the Phase-Change Heat Storage Materials Used in the Roof with a Solar Energy Storage Ventilation Systems

2012 ◽  
Vol 479-481 ◽  
pp. 578-585
Author(s):  
Juan Zhao ◽  
Jun Lu ◽  
Peng Chen ◽  
Ya Qin Zhang ◽  
Liao Liao
Keyword(s):  
Energy Storage ◽  
Solar Energy ◽  
Economic Analysis ◽  
Phase Change ◽  
Phase Change Materials ◽  
Heat Storage ◽  
Solar Energy Storage ◽  
Heat Storage Materials ◽  
Materials Used ◽  
Set Up

the experiments set up a roof model with a solar energy heat storage ventilation. According to the actual demands of experiments, through an economic analysis it results the preliminary investment of the solar energy storage ventilationthe system is between 307~367Yuan/m2 by calculating a energy balance in some way and choosing some type of heat storage phase change materials with a suitable quantity to fit for the model.

Electrode Challenges in Amplitude-Integrated Electroencephalography (aEEG): Research Application of a Novel Noninvasive Measure of Brain Function in Preterm Infants

2011 ◽  
Vol 13 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Shuyuann Wang Foreman ◽  
Lauren Thorngate ◽  
Robert L. Burr ◽  
Karen A. Thomas
Keyword(s):  
Intensive Care ◽  
Preterm Infants ◽  
Brain Function ◽  
Neonatal Intensive Care ◽  
Skin Irritation ◽  
Electrical Equipment ◽  
Skin Condition ◽  
Skin Impedance ◽  
Electrode Placement ◽  
Skin Preparation

Continuous real-time brain function monitoring of preterm infants offers a novel way to evaluate neurological development in neonatal intensive care. Direct measurement of brain function is difficult and complicated by vulnerabilities of the preterm infant population. This study illustrates the feasibility of using noninvasive hydrogel electrodes with amplitude-integrated electroencephalography (aEEG) as a simplified brain monitor in preterm infants. This article presents a systematic exploration of factors influencing the accuracy of aEEG measurement, especially skin preparation procedures and skin condition after electrode placement. The authors conducted aEEG recordings on 16 medically stable preterm infants at 31—36 weeks postmenstrual age in the neonatal intensive care unit between feedings and caregiving for approximately 3 hr. The authors systematically performed several strategies to improve electrode placement procedures and reduce skin impedance, including (a) examination of possible influences of environmental electrical equipment, (b) comparison of different hydrogel electrode types, (c) modification of skin preparation procedures, and (d) assessment of impacts of different skin conditions. The authors achieved improvements in the impedance value, length of uninterrupted recording, and percentage of the recording duration with measured impedance <20 kΩ (recommended acceptable limit). There was no report of skin irritation during or after the recording. The aEEG measurement at the bedside using hydrogel electrodes is noninvasive and feasible for reliable brain monitoring in preterm infants. This study demonstrated the importance of establishing systematic methods to ensure the accuracy and feasibility of physiologic measurements for nurse researchers.

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