Impact of size and shape for textile surface electromyography electrodes: a study of the biceps brachii muscle

2021 ◽  
pp. 004051752110489
Author(s):  
Carolina Solorzano Barrera ◽  
Eduardo Piña-Martínez ◽  
Ricardo Roberts ◽  
Ernesto Rodriguez-Leal

Electromyography is a technique to record and analyze signals from muscle tissue. Commonly, gel-based (Ag/AgCl) electrodes are used to detect muscle action potentials. Current gel-based electrode designs, however, do not perform well under constant movement and therefore are less suitable to monitor muscle behavior under everyday activities. Textile electrodes do well under movement and extended use, but produce weaker signals than their gel-based counterparts. This work points towards a reduction of this performance gap when the textile electrodes are designed to fit the target muscle. Four textile electrodes of different sizes and shapes are tested on the biceps brachii of 13 subjects. Signal parameters such as the signal-to-noise ratio and voltage root-mean-square are used to determine the quality of the myoelectric signals generated by these electrodes. Results with statistically significant differences show that the electrode area and alignment to the muscle fibers affect signal quality and strength. These results indicate that target muscle characteristics should dictate the electrode dimensional parameters to optimize surface electromyography signal acquisition.

2021 ◽  
Vol 40 (1) ◽  
pp. 81-88
Author(s):  
E.E.C. Igbonoba ◽  
O. Omoifo

This study presents the evaluation of digital video broadcasting-terrestrial second generation (DVB-T2) Television signal quality in Jos using Integrated Television Services Limited signal. The delivery of quality Television signal remains problematic in Nigeria due to signal attenuation and degradation between the transmitter and receiver station. This is primarily due to environmental and atmospheric perturbations prevalent along the signal paths. This research aim is to determine the signal quality of DVB-T2 Television system in Jos, Plateau State. The simple field measurement methodology was adopted in measuring field strength and channel power parameters. These measurement parameters were used to calculate for carrier-to-noise ratio (CNR) and signal-to-noise ratio (SNR) through empirical method. Finally, CNR and SNR were used to determine the signal quality of DVB-T2 signal in Jos. The result of the research shows that DVB-T2 signal in the primary service areas has good and reliable signal apart from the rocky environments.


Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6233
Author(s):  
Abreha Bayrau Nigusse ◽  
Benny Malengier ◽  
Desalegn Alemu Mengistie ◽  
Granch Berhe Tseghai ◽  
Lieva Van Langenhove

Long-term electrocardiography (ECG) monitoring is very essential for the early detection and treatment of cardiovascular disorders. However, commercially used silver/silver chloride (Ag/AgCl) electrodes have drawbacks, and these become more obvious during long-term signal monitoring, making them inconvenient for this use. In this study, we developed silver printed textile electrodes from knitted cotton and polyester fabric for ECG monitoring. The surface resistance of printed electrodes was 1.64 Ω/sq for cotton and 1.78 Ω/sq for polyester electrodes. The ECG detection performance of the electrodes was studied by placing three electrodes around the wrist where the electrodes were embedded on an elastic strap with Velcro. The ECG signals collected using textile electrodes had a comparable waveform to those acquired using standard Ag/AgCl electrodes with a signal to noise ratio (SNR) of 33.10, 30.17, and 33.52 dB for signals collected from cotton, polyester, and Ag/AgCl electrodes, respectively. The signal quality increased as the tightness of the elastic strap increased. Signals acquired at 15 mmHg pressure level with the textile electrodes provided a similar quality to those acquired using standard electrodes. Interestingly, the textile electrodes gave acceptable signal quality even after ten washing cycles.


Author(s):  
M. Wan ◽  
Y. Guo ◽  
S. Li ◽  
T. Liu

Abstract. The final output signal quality of TDICCD is related to the key parameters such as working mode, output mode, signal-to-noise ratio, dynamic range and so on. We can improve these parameters of TDICCD by reasonably designing the sensor clocking. Therefore, this text discussed four methods of improved TDICCD sensor clocking to solve some problem in TDICCD application based on using the principle of TDICCD. The technique of TDICCD Taps merging can reduce the number of TDICCD Taps, which helps to reduce the size of the TDICCD rear-end circuit significantly; The technique of TDICCD continuous transfer clocking can improve the charge transfer efficiency, which helps to promote the final signal-to-noise ratio; The technique of pixel binning clocking can enlarge the dynamic range of image; The technique of TDICCD area-array working mode can extend the field of TDICCD working; The principle, derivation process, clocking sequence diagram and application range of these clocking design schemes are given in this paper. At the same time, it also explains its actual effect and the matters to be noted.


Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7246
Author(s):  
Noemi Giordano ◽  
Samanta Rosati ◽  
Marco Knaflitz

The signal quality limits the applicability of phonocardiography at the patients’ domicile. This work proposes the signal-to-noise ratio of the recorded signal as its main quality metrics. Moreover, we define the minimum acceptable values of the signal-to-noise ratio that warrantee an accuracy of the derived parameters acceptable in clinics. We considered 25 original heart sounds recordings, which we corrupted by adding noise to decrease their signal-to-noise ratio. We found that a signal-to-noise ratio equal to or higher than 14 dB warrants an uncertainty of the estimate of the valve closure latencies below 1 ms. This accuracy is higher than that required by most clinical applications. We validated the proposed method against a public database, obtaining results comparable to those obtained on our sample population. In conclusion, we defined (a) the signal-to-noise ratio of the phonocardiographic signal as the preferred metric to evaluate its quality and (b) the minimum values of the signal-to-noise ratio required to obtain an uncertainty of the latency of heart sound components compatible with clinical applications. We believe these results are crucial for the development of home monitoring systems aimed at preventing acute episodes of heart failure and that can be safely operated by naïve users.


2021 ◽  
Vol 2 ◽  
Author(s):  
Katherine Le ◽  
Amir Servati ◽  
Saeid Soltanian ◽  
Peyman Servati ◽  
Frank Ko

Electronic textile (e-textile) systems applied to biological signal monitoring are of great interest to the healthcare industry, given the potential to provide continuous and long-term monitoring of healthy individuals and patients. Most developments in e-textiles have focused on novel materials and systems without systematic considerations into how the hierarchical structure of fibrous assemblies may influence performance and compatibility of the materials during use. This study examines mechanisms underlying the stability and quality of textile-based electrocardiogram (ECG) electrodes used in a smart bra. Signal quality of the biometric data obtained affects feedback and user experience and may be influenced by characteristics and properties of the material. Under stationary and dynamic conditions, analysis of the raw ECG signal and heart rate, with respect to textile-electrode material properties have been performed. Currently, there is no standardized procedure to compare the ECG signal between electrode materials. In this study, several methods have been applied to compare differences between silver-based textile electrodes and silver/silver-chloride gel electrodes. The comparison methods serve to complement visual observations of the ECG signal acquired, as possible quantitative means to differentiate electrode materials and their performance. From the results obtained, signal quality, and heart rate (HR) detection were found to improve with increased skin contact, and textile structures with lower stretch and surface resistance, especially under dynamic/movement test conditions. It was found that the performance of the textile electrode materials compared exceeded ECG signal quality thresholds previously established for acceptable signal quality, specifically for the kurtosis (K > 5), and Pearson correlation coefficients (r ≥ 0.66) taken from average ECG waveforms calculated.


2013 ◽  
Vol 11 (1) ◽  
pp. 8-13
Author(s):  
V. Behar ◽  
V. Bogdanova

Abstract In this paper the use of a set of nonlinear edge-preserving filters is proposed as a pre-processing stage with the purpose to improve the quality of hyperspectral images before object detection. The capability of each nonlinear filter to improve images, corrupted by spatially and spectrally correlated Gaussian noise, is evaluated in terms of the average Improvement factor in the Peak Signal to Noise Ratio (IPSNR), estimated at the filter output. The simulation results demonstrate that this pre-processing procedure is efficient only in case the spatial and spectral correlation coefficients of noise do not exceed the value of 0.6


2014 ◽  
Vol 2 (2) ◽  
pp. 47-58
Author(s):  
Ismail Sh. Baqer

A two Level Image Quality enhancement is proposed in this paper. In the first level, Dualistic Sub-Image Histogram Equalization DSIHE method decomposes the original image into two sub-images based on median of original images. The second level deals with spikes shaped noise that may appear in the image after processing. We presents three methods of image enhancement GHE, LHE and proposed DSIHE that improve the visual quality of images. A comparative calculations is being carried out on above mentioned techniques to examine objective and subjective image quality parameters e.g. Peak Signal-to-Noise Ratio PSNR values, entropy H and mean squared error MSE to measure the quality of gray scale enhanced images. For handling gray-level images, convenient Histogram Equalization methods e.g. GHE and LHE tend to change the mean brightness of an image to middle level of the gray-level range limiting their appropriateness for contrast enhancement in consumer electronics such as TV monitors. The DSIHE methods seem to overcome this disadvantage as they tend to preserve both, the brightness and contrast enhancement. Experimental results show that the proposed technique gives better results in terms of Discrete Entropy, Signal to Noise ratio and Mean Squared Error values than the Global and Local histogram-based equalization methods


2012 ◽  
Vol 6 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Michael R Dawson ◽  
Farbod Fahimi ◽  
Jason P Carey

The objective of above-elbow myoelectric prostheses is to reestablish the functionality of missing limbs and increase the quality of life of amputees. By using electromyography (EMG) electrodes attached to the surface of the skin, amputees are able to control motors in myoelectric prostheses by voluntarily contracting the muscles of their residual limb. This work describes the development of an inexpensive myoelectric training tool (MTT) designed to help upper limb amputees learn how to use myoelectric technology in advance of receiving their actual myoelectric prosthesis. The training tool consists of a physical and simulated robotic arm, signal acquisition hardware, controller software, and a graphical user interface. The MTT improves over earlier training systems by allowing a targeted muscle reinnervation (TMR) patient to control up to two degrees of freedom simultaneously. The training tool has also been designed to function as a research prototype for novel myoelectric controllers. A preliminary experiment was performed in order to evaluate the effectiveness of the MTT as a learning tool and to identify any issues with the system. Five able-bodied participants performed a motor-learning task using the EMG controlled robotic arm with the goal of moving five balls from one box to another as quickly as possible. The results indicate that the subjects improved their skill in myoelectric control over the course of the trials. A usability survey was administered to the subjects after their trials. Results from the survey showed that the shoulder degree of freedom was the most difficult to control.


Author(s):  
Mourad Talbi ◽  
Med Salim Bouhlel

Background: In this paper, we propose a secure image watermarking technique which is applied to grayscale and color images. It consists in applying the SVD (Singular Value Decomposition) in the Lifting Wavelet Transform domain for embedding a speech image (the watermark) into the host image. Methods: It also uses signature in the embedding and extraction steps. Its performance is justified by the computation of PSNR (Pick Signal to Noise Ratio), SSIM (Structural Similarity), SNR (Signal to Noise Ratio), SegSNR (Segmental SNR) and PESQ (Perceptual Evaluation Speech Quality). Results: The PSNR and SSIM are used for evaluating the perceptual quality of the watermarked image compared to the original image. The SNR, SegSNR and PESQ are used for evaluating the perceptual quality of the reconstructed or extracted speech signal compared to the original speech signal. Conclusion: The Results obtained from computation of PSNR, SSIM, SNR, SegSNR and PESQ show the performance of the proposed technique.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1817
Author(s):  
Jiawen Xue ◽  
Li Yin ◽  
Zehua Lan ◽  
Mingzhu Long ◽  
Guolin Li ◽  
...  

This paper proposes a novel 3D discrete cosine transform (DCT) based image compression method for medical endoscopic applications. Due to the high correlation among color components of wireless capsule endoscopy (WCE) images, the original 2D Bayer data pattern is reconstructed into a new 3D data pattern, and 3D DCT is adopted to compress the 3D data for high compression ratio and high quality. For the low computational complexity of 3D-DCT, an optimized 4-point DCT butterfly structure without multiplication operation is proposed. Due to the unique characteristics of the 3D data pattern, the quantization and zigzag scan are ameliorated. To further improve the visual quality of decompressed images, a frequency-domain filter is proposed to eliminate the blocking artifacts adaptively. Experiments show that our method attains an average compression ratio (CR) of 22.94:1 with the peak signal to noise ratio (PSNR) of 40.73 dB, which outperforms state-of-the-art methods.


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