The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Vincent A. Nierstrasz - One of the best experts on this subject based on the ideXlab platform.
-
Novel Skin-Electrode Conductive Adhesives to Improve the Quality of Recorded Body Signals in Smart Medical Garments
Proceedings, 2019Co-Authors: Azadeh Soroudi, Mikael Skrifvars, Vincent A. NierstraszAbstract:A main barrier to widespread use of electrocardiography garments for long term heart monitoring of elderly and patients is a poor Skin-Electrode signal transfer because of a high contact impedance ...
-
Surface modification of textile Electrodes to improve electrocardiography signals in wearable smart garment
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Azadeh Soroudi, Niina Hernández, Jan Wipenmyr, Vincent A. NierstraszAbstract:Recording high quality biosignals by dry textile Electrodes is a common challenge in medical health monitoring garments. The aim of this study was to improve Skin–Electrode interface and enhance the quality of recorded electrocardiography (ECG) signals by modification of textile Electrodes embedded in WearItMed smart garment. The garment has been developed for long-term health monitoring in patients suffering from epilepsy and Parkinson’s disease. A Skin-friendly electro-conductive elastic paste was formulated to coat and modify the surface of the knitted textile Electrodes. The modifications improved the surface characteristics of the Electrodes by promoting a more effective contact area between Skin and Electrode owing to a more even surface, fewer pores, greater surface stability against touch, and introduction of humidity barrier properties. The modifications decreased the Skin–Electrode contact impedance, and consequently improved the recorded ECG signals obviously when low pressure was applied to the Electrodes, therefore contributed to greater patient comfort. The created contact surface allowed the natural humidity of the Skin/sweat to ease the signal transfer between the Electrode and the body, while introducing a shorter settling time and retaining moisture over a longer time. Microscopic images, ECG signal measurements, Electrode–Skin contact impedance at different pressures and times, and water absorbency were measured and reported.
-
Surface modification of textile Electrodes to improve electrocardiography signals in wearable smart garment
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Azadeh Soroudi, Niina Hernández, Jan Wipenmyr, Vincent A. NierstraszAbstract:Recording high quality biosignals by dry textile Electrodes is a common challenge in medical health monitoring garments. The aim of this study was to improve Skin–Electrode interface and enhance th ...
Azadeh Soroudi - One of the best experts on this subject based on the ideXlab platform.
-
Novel Skin-Electrode Conductive Adhesives to Improve the Quality of Recorded Body Signals in Smart Medical Garments
Proceedings, 2019Co-Authors: Azadeh Soroudi, Mikael Skrifvars, Vincent A. NierstraszAbstract:A main barrier to widespread use of electrocardiography garments for long term heart monitoring of elderly and patients is a poor Skin-Electrode signal transfer because of a high contact impedance ...
-
Surface modification of textile Electrodes to improve electrocardiography signals in wearable smart garment
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Azadeh Soroudi, Niina Hernández, Jan Wipenmyr, Vincent A. NierstraszAbstract:Recording high quality biosignals by dry textile Electrodes is a common challenge in medical health monitoring garments. The aim of this study was to improve Skin–Electrode interface and enhance the quality of recorded electrocardiography (ECG) signals by modification of textile Electrodes embedded in WearItMed smart garment. The garment has been developed for long-term health monitoring in patients suffering from epilepsy and Parkinson’s disease. A Skin-friendly electro-conductive elastic paste was formulated to coat and modify the surface of the knitted textile Electrodes. The modifications improved the surface characteristics of the Electrodes by promoting a more effective contact area between Skin and Electrode owing to a more even surface, fewer pores, greater surface stability against touch, and introduction of humidity barrier properties. The modifications decreased the Skin–Electrode contact impedance, and consequently improved the recorded ECG signals obviously when low pressure was applied to the Electrodes, therefore contributed to greater patient comfort. The created contact surface allowed the natural humidity of the Skin/sweat to ease the signal transfer between the Electrode and the body, while introducing a shorter settling time and retaining moisture over a longer time. Microscopic images, ECG signal measurements, Electrode–Skin contact impedance at different pressures and times, and water absorbency were measured and reported.
-
Surface modification of textile Electrodes to improve electrocardiography signals in wearable smart garment
Journal of Materials Science: Materials in Electronics, 2019Co-Authors: Azadeh Soroudi, Niina Hernández, Jan Wipenmyr, Vincent A. NierstraszAbstract:Recording high quality biosignals by dry textile Electrodes is a common challenge in medical health monitoring garments. The aim of this study was to improve Skin–Electrode interface and enhance th ...
Winfried Mayr - One of the best experts on this subject based on the ideXlab platform.
-
correction dynamic impedance model of the Skin Electrode interface for transcutaneous electrical stimulation
PLOS ONE, 2015Co-Authors: Jose Luis Vargas Luna, Matthias Krenn, Jorge Ramirez, Winfried MayrAbstract:A funder is missing from the manuscript’s Funding section. The correct funding statement is as follows: JLVL was supported by the Mexican Council of Research and Technology (CONACYT) grant: 236850 (www.conacyt.mx). This work was also supported by the Vienna Science and Technology Fund (WWTF), Proj.Nr. LS11-057 (www.wwtf.at), and the Wings for Life Spinal Cord Research Foundation (WfL), Proj.Nr. WFL-AT-007/11 (http://www.wingsforlife.com). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
-
dynamic impedance model of the Skin Electrode interface for transcutaneous electrical stimulation
PLOS ONE, 2015Co-Authors: Jose Luis Vargas Luna, Matthias Krenn, Jorge Ramirez, Winfried MayrAbstract:Transcutaneous electrical stimulation can depolarize nerve or muscle cells applying impulses through Electrodes attached on the Skin. For these applications, the Electrode-Skin impedance is an important factor which influences effectiveness. Various models describe the interface using constant or current-depending resistive-capacitive equivalent circuit. Here, we develop a dynamic impedance model valid for a wide range stimulation intensities. The model considers electroporation and charge-dependent effects to describe the impedance variation, which allows to describe high-charge pulses. The parameters were adjusted based on rectangular, biphasic stimulation pulses generated by a stimulator, providing optionally current or voltage-controlled impulses, and applied through Electrodes of different sizes. Both control methods deliver a different electrical field to the tissue, which is constant throughout the impulse duration for current-controlled mode or have a very current peak for voltage-controlled. The results show a predominant dependence in the current intensity in the case of both stimulation techniques that allows to keep a simple model. A verification simulation using the proposed dynamic model shows coefficient of determination of around 0.99 in both stimulation types. The presented method for fitting Electrode-Skin impedance can be simple extended to other stimulation waveforms and Electrode configuration. Therefore, it can be embedded in optimization algorithms for designing electrical stimulation applications even for pulses with high charges and high current spikes.
Jerald Yoo - One of the best experts on this subject based on the ideXlab platform.
-
a 1 1 mw ground effect resilient body coupled communication transceiver with pseudo ofdm for head and body area network
IEEE Journal of Solid-state Circuits, 2017Co-Authors: Wala Saadeh, Muhammad Awais Bin Altaf, Haneen Alsuradi, Jerald YooAbstract:This paper presents a body-coupled communication (BCC) transceiver (TRX) that mitigates all the practical impairments of the body channel at once. The proposed pseudo orthogonal frequency-division multiplexing (P-OFDM) TRX combines baseband BPSK–OFDM with frequency-shift keying (FSK) to alleviate the impacts of variable ground effect and variable Skin-Electrode contact impedance, which have been the two major issues on the BCC. It can tolerate up to 20 dB of channel gain variation with measured bit error rate improvement of >70% compared to FSK modulation alone. The RC relaxed contact impedance monitor continuously monitors and compensates the variable Skin-Electrode contact impedance at both transmitter (TX) and receiver (RX). The proposed power-gated 8-point inverse fast Fourier transform/fast Fourier transform with no floating-point multipliers (FPMs) reduces the gate count and power by 54% and 30% compared to conventional FPMs, respectively. Additionally, the simple floating-point adder (FPA) reduces the gate count and energy consumption by 34% and 20% compared to conventional FPAs, respectively. A high input impedance glitch-free FSK demodulation RX with variable threshold limiter and all digital cycle correction is also proposed to support a scalable data rate (200 Kbps–2 Mbps). The 0.54 mm2 TRX in 65-nm CMOS consumes 1.1 mW.
-
a 16 channel patient specific seizure onset and termination detection soc with impedance adaptive transcranial electrical stimulator
IEEE Journal of Solid-state Circuits, 2015Co-Authors: Muhammad Awais Bin Altaf, Chen Zhang, Jerald YooAbstract:A 16-channel noninvasive closed-loop beginning- and end-of-seizure detection SoC is presented. The dual-channel charge recycled (DCCR) analog front end (AFE) achieves chopping and time-multiplexing an amplifier between two channels simultaneously which exploits fast-settling DC servo-loop with current consumption and NEF of $0.9\;\upmu\text{A}$ /channel and 3.29/channel, respectively. The dual-detector architecture ( $\text{D}^2 \text{A}$ ) classification processor utilizes two linear support-vector machine (LSVM) classifiers based on digital hysteresis to enhance both the sensitivity and the specificity simultaneously. The pulsating voltage transcranial electrical stimulator (PVTES) automatically configures the number of pulses to control the amount of charge delivered based on Skin-Electrode impedance variation in efforts to suppress the seizure activity, while burning only $2.45\;\upmu\text{W}$ . The $25\;\text{mm}^2$ SoC implemented in $0.18\;\upmu\text{m}$ CMOS consumes $2.73\;\upmu\text{J}$ /classification for 16 channels with an average sensitivity, specificity, and latency of 95.7%, 98%, and 1 s, respectively.
-
BioCAS - A 2.45μW patient-specific non-invasive transcranial electrical stimulator with an adaptive Skin-Electrode impedance monitor
2015 IEEE Biomedical Circuits and Systems Conference (BioCAS), 2015Co-Authors: Muhammad Awais Bin Altaf, Jerald YooAbstract:This paper presents a power-efficient non-invasive transcranial electrical stimulator (tES) with patient-specific impedance adaptation. The proposed tES exploits the varying Skin-Electrode impedance which results in different RC relaxation time, where the tES adapts the number of pulses to deliver a constant charge. This eliminates the need of an additional current source for impedance monitoring widely used in conventional stimulation techniques, thereby reducing power consumption. To ensure safety for patients, a charge balanced bi-phasic stimulation is implemented with maximum current of
Kwang Suk Park - One of the best experts on this subject based on the ideXlab platform.
-
reverse curve arch shaped dry eeg Electrode for increased Skin Electrode contact area on hairy scalps
Electronics Letters, 2015Co-Authors: Jeong Su Lee, Chungmin Han, Jee-hoon Kim, Kwang Suk ParkAbstract:Electroencephalography (EEG) is electrical brain activity that can be measured on the scalp with Ag/AgCl Electrodes and conductive gel. However, time-consuming preparation procedures, dehydration of the gel, and Skin irritation are crucial drawbacks of using such Electrodes. Alternative approaches involving the use of spiky dry Electrodes have their own drawbacks such as limited Skin–Electrode contact area, high Skin–Electrode impedance, and pain. Reverse-curve-arch-shaped dry EEG Electrodes for use in increasing the Skin–Electrode contact area on hairy scalps are presented. The proposed Electrode was fabricated from sterling silver using a three-dimensional printer. To increase the contact area between the Skin and an Electrode, an Electrode was designed to have reverse-curve arches which were arranged in a row on the Electrode base. The curvature of the arches was designed to match the curvature of the scalp to maximise the contact area and disperse the pressing force. To validate the proposed Electrode design, comparison experiments for EEG and Skin–Electrode contact impedance were conducted, and the proposed Electrode was found to perform better than a commercially available finger-type dry Electrode.
-
Reverse-curve-arch-shaped dry EEG Electrode for increased Skin–Electrode contact area on hairy scalps
Electronics Letters, 2015Co-Authors: Jeong Su Lee, Chungmin Han, Jee-hoon Kim, Kwang Suk ParkAbstract:Electroencephalography (EEG) is electrical brain activity that can be measured on the scalp with Ag/AgCl Electrodes and conductive gel. However, time-consuming preparation procedures, dehydration of the gel, and Skin irritation are crucial drawbacks of using such Electrodes. Alternative approaches involving the use of spiky dry Electrodes have their own drawbacks such as limited Skin–Electrode contact area, high Skin–Electrode impedance, and pain. Reverse-curve-arch-shaped dry EEG Electrodes for use in increasing the Skin–Electrode contact area on hairy scalps are presented. The proposed Electrode was fabricated from sterling silver using a three-dimensional printer. To increase the contact area between the Skin and an Electrode, an Electrode was designed to have reverse-curve arches which were arranged in a row on the Electrode base. The curvature of the arches was designed to match the curvature of the scalp to maximise the contact area and disperse the pressing force. To validate the proposed Electrode design, comparison experiments for EEG and Skin–Electrode contact impedance were conducted, and the proposed Electrode was found to perform better than a commercially available finger-type dry Electrode.