scholarly journals Noise-Reducing Fabric Electrode for ECG Measurement

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4305
Author(s):  
Takamasa Terada ◽  
Masahiro Toyoura ◽  
Takahide Sato ◽  
Xiaoyang Mao
Keyword(s):  
Special Structure ◽  
Electrode Impedance ◽  
Electrode Structure ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Chip Type ◽  
Low Pass ◽  
Filter Fabric

In this work, we propose a fabric electrode with a special structure that can play the role of a noise reduction filter. Fabric electrodes made of the conductive fabric have been used for long-term ECG measurements because of their flexibility and non-invasiveness; however, due to the large impedance between the skin and the fabric electrodes, noise is easily introduced into the ECG signal. In contrast to conventional work, in which chip-type passive elements are glued to the electrode to reduce noise, the proposed electrode can obtain a noise-reduced ECG by changing the structure of fabric. Specifically, the proposed electrode was folded multiple times to form a capacitor with a capacitance of about 3 nF. It is combined with the skin-electrode impedance to form a low-pass filter. In the experiment, we made a prototype of the electrodes and measured ECG at rest and during EMG-induced exercise. As a result, the SNR values at rest and during exercise were improved about 12.02 and 10.29 , respectively, compared with the fabric electrode without special structure. In conclusion, we have shown that changing the fabric electrode structure effectively removes noise in ECG measurement.

scholarly journals Dynamic Integrative Synaptic Plasticity Explains the Spacing Effect in the Transition from Short- to Long-Term Memory

2019 ◽  
Vol 31 (11) ◽  
pp. 2212-2251 ◽  
Author(s):  
Terry Elliott
Keyword(s):  
Synaptic Plasticity ◽  
Mapk Pathway ◽  
Spacing Effect ◽  
Long Term Memory ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Term Memory ◽  
Low Pass

Repeated stimuli that are spaced apart in time promote the transition from short- to long-term memory, while massing repetitions together does not. Previously, we showed that a model of integrative synaptic plasticity, in which plasticity induction signals are integrated by a low-pass filter before plasticity is expressed, gives rise to a natural timescale at which to repeat stimuli, hinting at a partial account of this spacing effect. The account was only partial because the important role of neuromodulation was not considered. We now show that by extending the model to allow dynamic integrative synaptic plasticity, the model permits synapses to robustly discriminate between spaced and massed repetition protocols, suppressing the response to massed stimuli while maintaining that to spaced stimuli. This is achieved by dynamically coupling the filter decay rate to neuromodulatory signaling in a very simple model of the signaling cascades downstream from cAMP production. In particular, the model's parameters may be interpreted as corresponding to the duration and amplitude of the waves of activity in the MAPK pathway. We identify choices of parameters and repetition times for stimuli in this model that optimize the ability of synapses to discriminate between spaced and massed repetition protocols. The model is very robust to reasonable changes around these optimal parameters and times, but for large changes in parameters, the model predicts that massed and spaced stimuli cannot be distinguished or that the responses to both patterns are suppressed. A model of dynamic integrative synaptic plasticity therefore explains the spacing effect under normal conditions and also predicts its breakdown under abnormal conditions.

RETUNABLE REJECTION FILTERS

2021 ◽  
pp. 67-75
Author(s):  
I. M. Yasinskiy ◽  
A. I. Tyumentsev ◽  
A. N. Yakovlev
Keyword(s):  
Narrow Band ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

The possibilities of realizing retunable rejection filters are considered, in which two-pole networks are introduced into the low-pass filter, which play the role of narrow-band rejection circuits. Methods for analyzing rejection circuits and formulas for calculating elements are presented.

scholarly journals A novel configuration of THz photonic transmitter

2019 ◽  
Vol 13 (1) ◽  
pp. 258
Author(s):  
Ibtissame Moumane ◽  
Jamal Zbitou ◽  
M. Latrach ◽  
A. Errkik ◽  
O. Chakkor
Keyword(s):  
Electrical Signal ◽  
Design System ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Rf Signal ◽  
Thz Applications ◽  
Thz Waves ◽  
Thz Antenna

In this paper we present a new design of a photonic transmitter based on multi-layers substrate GaAs and using for generation of THz waves. The proposed circuit is composed from a photodetector (PD) “which converts the light to the electrical signal”, THz Antenna, low-pass filter and DC probe. Firstly we have optimized the THz antenna using an EM solver which is Momentum integrated in ADS “Advanced Design System”.Then we have optimized the low pass filter which plays the role of inductance that is an RF choke permiting to separate the RF signal from the DC one. Finally, we have associated the different components, add the DC probe and simulate the whole proposed system. The dimensions of the final circuit are 400.317x167.16 UM2 . The obtain results permit to validate the final circuit at THz and make it suitable for THz applications.

scholarly journals Active Filter Analysis on Designing Electronic Stethoscope

2019 ◽  
Vol 19 (2) ◽  
pp. 51
Author(s):  
Prihatin Oktivasari ◽  
Riandini Riandini ◽  
Rahmah A. Fitri ◽  
Sungguh I. Malaon
Keyword(s):  
Fourth Order ◽  
Heart Sound ◽  
Cutoff Frequency ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Electronic Stethoscope ◽  
Recorded Sound ◽  
Low Pass ◽  
High Pass

Early heart disease detection could be vital and some other diagnostic ways are being developed. In this paper, a lowcost tool for a diagnostic that analyzes the digitized heartbeat sound is given. This can be used to detect heart anomalies. The instrument shows the heart sound and also keeps a patient's long-term record for future use. The signal from the heart provides a lot of knowledge about the heart and offers an initial diagnosis recommendation. The electronic stethoscope uses the condenser microphone, preamplifier circuit, and filter circuit. The optimum filter is Butterworth with a fourth-order Sallen key low pass filter topology with a gain of 0.707 volts, -3.01 dB, and a fourth-order high pass filter with a gain of 0.782 volts, -2.137 dB. The frequency of the heart sound is about 20 Hz – 120 Hz in general. Therefore, the lower cutoff frequency of the filter is set to 20 Hz, while the higher cutoff frequency set to 120 Hz. The evaluation used to measure the performance of an electronic stethoscope is to compare with a conventional stethoscope, the recorded sound is the same.

Design of Programmable Wideband Low Pass Filter with Continuous-Time/Discrete-Time Hybrid Architecture

2017 ◽  
Vol E100.C (10) ◽  
pp. 858-865 ◽  
Author(s):  
Yohei MORISHITA ◽  
Koichi MIZUNO ◽  
Junji SATO ◽  
Koji TAKINAMI ◽  
Kazuaki TAKAHASHI
Keyword(s):  
Discrete Time ◽  
Continuous Time ◽  
Hybrid Architecture ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass

ANALYSIS AND IMPROVEMENT TECHNIQUES FOR THE TRANSFER FUNCTION OF A PLANAR LOW - PASS FILTER

2016 ◽  
Vol 15 (12) ◽  
pp. 2579-2586
Author(s):  
Adina Racasan ◽  
Calin Munteanu ◽  
Vasile Topa ◽  
Claudia Pacurar ◽  
Claudia Hebedean
Keyword(s):  
Transfer Function ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass
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