scholarly journals Multiple Channel Electrocardiogram QRS Detection by Temporal Pattern Search

2021 ◽  
Author(s):  
Bruce R Hopenfeld
Keyword(s):  
Temporal Pattern ◽  
Single Channel ◽  
Synthetic Data ◽  
Pattern Search ◽  
Peak Time ◽  
Noise Resistance ◽  
Multiple Channel ◽  
False Discovery ◽  
Capacitive Electrode ◽  
Matching Window

A highly constrained temporal pattern search based multiple channel heartbeat detector (TEPS) is described. TEPS generates sequences of peaks and statistically scores them according to: 1) peak time coherence across channels; 2) peak prominence; 3) temporal regularity; and 4) number of skipped beats. TEPS was tested on 31 records of three channel capacitive electrode data from the UnoViS automobile database. TEPS showed a sensitivity (SE) of 91.3% and a false discovery rate (FDR) of 3.0% compared to an SE and FDR of 75.3% and 65.0% respectively for a conventional single channel detector (OSEA) applied separately to the three channels. The peak matching window was 30ms. The percentage of 5 second segments with average heart rates within 5 beats/minute of reference was also measured. In 6 of the 31 records, the TEPS percentage was at least 30% greater than that of OSEA. TEPS was also applied to synthetic data comprising a known signal corrupted with calibrated amounts of noise. At a fixed SE of 85%, increasing the number of channels from one to two resulted in an improvement of approximately 5dB in noise resistance, while increasing the number of channels from two to four resulted in an improvement of approximately 3dB in noise resistance. The quantification of noise resistance as a function of the number of channels could help guide the development of wearable electrocardiogram monitors.

Application of complex-trace analysis to seismic data for random-noise suppression and temporal resolution improvement

Geophysics ◽  
2006 ◽  
Vol 71 (3) ◽  
pp. V79-V86 ◽  
Author(s):  
Hakan Karsli ◽  
Derman Dondurur ◽  
Günay Çifçi
Keyword(s):  
Seismic Data ◽  
Trace Analysis ◽  
Noise Suppression ◽  
Single Channel ◽  
Random Noise ◽  
Synthetic Data ◽  
Low Frequency ◽  
Bright Spot ◽  
Phase Information ◽  
Resolution Improvement

Time-dependent amplitude and phase information of stacked seismic data are processed independently using complex trace analysis in order to facilitate interpretation by improving resolution and decreasing random noise. We represent seismic traces using their envelopes and instantaneous phases obtained by the Hilbert transform. The proposed method reduces the amplitudes of the low-frequency components of the envelope, while preserving the phase information. Several tests are performed in order to investigate the behavior of the present method for resolution improvement and noise suppression. Applications on both 1D and 2D synthetic data show that the method is capable of reducing the amplitudes and temporal widths of the side lobes of the input wavelets, and hence, the spectral bandwidth of the input seismic data is enhanced, resulting in an improvement in the signal-to-noise ratio. The bright-spot anomalies observed on the stacked sections become clearer because the output seismic traces have a simplified appearance allowing an easier data interpretation. We recommend applying this simple signal processing for signal enhancement prior to interpretation, especially for single channel and low-fold seismic data.

scholarly journals ANALISIS KINERJA SISTEM ANTRIAN DALAM MENGOPTIMALKAN PELAYANAN PASIEN RAWAT JALAN DI RSUD HAJI MAKASSAR

2018 ◽  
Vol 14 (3) ◽  
pp. 228-238
Author(s):  
Maat Pono
Keyword(s):  
Single Channel ◽  
Multiple Channel ◽  
Query System

Tujuan dari penelitian ini untuk mengetahui kinerja sistem antrian yang saat ini digunakan oleh RSUD Haji Makassar. Berdasarkan hasil penelitian, model antrian yang saat ini diterapkan pada bagian registrasi pasien rawat jalan di RSUD Haji Makassar menunjukkan kinerja yang belum begitu baik pada loket pendaftaran, adapun model yang saat ini digunakan adalah sistem antrian model jalur tunggal atau Single Channel Query System (M/M/1). Berdasarkan hasil observasi dan perhitungan menggunakan rumus dari model (M/M/1) diketahui pasien lama membutuhkan waktu berada dalam antrian adalah selama 57,27 menit serta orang dalam antrian sebanyak 21 orang dan ini terjadi pada periode waktu 09.00-10.00 sampai 10.00-11.00. Untuk pasien baru membutuhkan waktu berada dalam antrian selama 50 menit dan jumlah orang dalam antrian sebanyak 5 orang dan ini terjadi pada periode waktu 09.00-10.00 sampai 11.00-12.00. Alternatif yang dapat menangani masalah pada loket pendaftaran adalah dengan merubah komposisi server dengan menggunakan Multiple Channel Query System (M/M/s) melalui model ini waktu yang dibutuhkan pasien lama didalam antrian menurun menjadi 0,8 menit, serta pasien lama dalam antrian yang awalnya 21 orang menjadi 1,24 orang, dengan alternatif ini kinerja sistem antrian dapat lebih optimal.

Euclid and the art of wavelet estimation, Part II: Robust algorithm and field‐data examples

Geophysics ◽  
1997 ◽  
Vol 62 (6) ◽  
pp. 1939-1946 ◽  
Author(s):  
Eike Rietsch
Keyword(s):  
Field Data ◽  
Synthetic Data ◽  
Noise Resistance ◽  
Zero Eigenvalue ◽  
Seismic Line ◽  
Robust Algorithm ◽  
Seismic Wavelet ◽  
Time Zones ◽  
The Common ◽  
Common Signal

In this second part of a two‐part work, a more robust algorithm is derived and used for the estimation of the seismic wavelet as the common signal of two or more seismic traces. It is based on the properties of the eigenvectors with zero eigenvalue of a matrix derived in the first part, whose elements are the samples of the autocorrelation functions and crosscorrelation functions of these seismic traces for a number of lags. The noise resistance of this algorithm is illustrated by means of a synthetic‐data example and then demonstrated on field data. In one field‐data example, the so‐called Euclid wavelet is compared with one derived deterministically by means of an impedance log. The other example relates three quite different Euclid wavelets determined in three different time zones on a seismic line to one another by showing that their differences can be explained by absorption.

Effects of Expansion Algorithms on Speech Reception Thresholds

2008 ◽  
Vol 19 (02) ◽  
pp. 147-157 ◽  
Author(s):  
Christi L. Wise ◽  
Justin A. Zakis
Keyword(s):  
Hearing Aids ◽  
Single Channel ◽  
Multiple Channel ◽  
Low Level ◽  
Speech Reception ◽  
Average Spectrum ◽  
Channel Expansion ◽  
The Difference ◽  
Speech Reception Thresholds ◽  
The Impact

Expansion is commonly used to reduce microphone noise and low-level environmental noises that can be annoying to hearing aid users. It may also improve or reduce the perception of low-level speech. This study assessed the impact of two expansion algorithms, single and multiple channel, on speech reception thresholds (SRT) with 10 hearing impaired listeners wearing hearing aids with ADRO® processing. The single-channel algorithm suppressed sounds below 45 dB A, while the multiple-channel algorithm suppressed sounds below the long-term average spectrum of speech at either 55 or 45 dB SPL. The mean HINT SRTs in quiet were 39.4, 40.7, 40.6, and 41.8 dB A without expansion, with single-channel expansion, and with multiple-channel expansion at expansion thresholds of 45 and 55 dB SPL, respectively. The difference in mean SRT was only statistically significant between no expansion and multiple-channel expansion at a 55 dB SPL threshold. A regression analysis between the change in individual SRT for each expansion condition and pure tone average hearing loss showed no correlation. Our calculations indicate that only those with exceptionally good hearing will find microphone noise audible. The current practice of prescribing expansion algorithms based on hearing thresholds alone is questioned, and other rationales are discussed. La expansión se utiliza comúnmente para reducir el ruido de los micrófonos y los ruidos ambientales de bajo nivel que pueden ser perturbadores para los usuarios de auxiliares auditivos. También puede mejorar o reducir la percepción de lenguaje a bajo voumen. Este estudio evaluó el impacto de dos algoritmos de expansión, de canal múltiple y el canal único, sobre los umbrales de recepción del lenguaje (SRT) con 10 sujetos hipoacúsicos utilizando auxiliares auditivos con procesamiento ADRO®. El algoritmo de canal único suprimió sonidos por debajo de 45 dB A, mientras que el algoritmo de canal múltiple suprimió sonidos por debajo del espectro promedio a largo plazo del lenguaje, a 55 ó 45 dB SPL, respectivamente. La diferencia en el SRT medio fue sólo estadísticamente significativa entre la no expansión y la expansión de canal múltiple a un umbral de 55 dB SPL. Un análisis de regresión no mostró correlación entre el cambio en los SRT individuales para cada condición de expansión y la pérdida auditiva promedio para tonos puros. Nuestros cálculos indican que solamente aquellos con una audición excepcionalmente buena encontrarán audible el ruido del micrófono. Se cuestiona la práctica actual de prescribir algoritmos de expansión con base sólo en umbrales auditivos, y se discuten otros razonamientos.

scholarly journals Accurate Optic Disc and Cup Segmentation from Retinal Images Using a Multi-Feature Based Approach for Glaucoma Assessment

Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1267 ◽  
Author(s):  
Yuan Gao ◽  
Xiaosheng Yu ◽  
Chengdong Wu ◽  
Wei Zhou ◽  
Xiaonan Wang ◽  
...  
Keyword(s):  
Optic Disc ◽  
Single Channel ◽  
Automatic Segmentation ◽  
Critical Role ◽  
Image Space ◽  
Image Clustering ◽  
Vessel Occlusion ◽  
Multiple Channel ◽  
Complex Anatomy ◽  
Contour Evolution

Accurate optic disc (OD) and optic cup (OC) segmentation play a critical role in automatic glaucoma diagnosis. In this paper, we present an automatic segmentation technique regarding the OD and the OC for glaucoma assessment. First, the robust adaptive approach for initializing the level set is designed to increase the performance of contour evolution. Afterwards, in order to handle the complex OD appearance affected by intensity inhomogeneity, pathological changes, and vessel occlusion, a novel model that integrates ample information of OD with the effective local intensity clustering (LIC) model together is presented. For the OC segmentation, to overcome the segmentation challenge as the OC’s complex anatomy location, a novel preprocessing method based on structure prior information between the OD and the OC is designed to guide contour evolution in an effective region. Then, a novel implicit region based on modified data term using a richer form of local image clustering information at each point of interest gathered over a multiple-channel feature image space is presented, to enhance the robustness of the variations found in and around the OC region. The presented models symmetrically integrate the information at each point in a single-channel image from a multiple-channel feature image space. Thus, these models correlate with the concept of symmetry. The proposed models are tested on the publicly available DRISHTI-GS database and the experimental results demonstrate that the models outperform state-of-the-art methods.

Ca(2+)-dependent Cl- channels in undifferentiated human colonic cells (HT-29). I. Single-channel properties

1993 ◽  
Vol 264 (4) ◽  
pp. C968-C976 ◽  
Author(s):  
A. P. Morris ◽  
R. A. Frizzell
Keyword(s):  
Single Channel ◽  
Voltage Sensitivity ◽  
Channel Activity ◽  
Patch Clamp Technique ◽  
Channel Activation ◽  
Whole Cell ◽  
Multiple Channel ◽  
Cl Channel ◽  
Cl Channels ◽  
Ht 29

The patch-clamp technique was combined with camera-based intracellular Ca2+ concentration ([Ca2+]i) imaging to identify the single-channel basis of the Ca(2+)-dependent Cl- conductance in human colonic adenocarcinoma cells (HT-29). Cl- channels were activated when membrane patches were excised into solutions containing high (1 microM) Ca2+ concentrations. Their single-channel conductance, measured by amplitude histogram analysis, averaged 13 pS at -90 mV and 16 pS at +90 mV membrane potential (MP). In multiple channel patches, Cl- currents showed properties similar to Ca(2+)-activated whole cell currents: outward rectification and time-dependent activation at depolarizing MP. Channel activity disappeared shortly after patch excision from the cell. In cell-attached patches, Cl- channel opening was infrequent at resting [Ca2+]i values (96 +/- 18 nM), but when [Ca2+]i was increased by the Ca2+ ionophore ionomycin (1 microM), Cl- channels were activated with a time course that paralleled the [Ca2+]i rise. Repetitive ionophore exposure produced equivalent rises in [Ca2+]i, but the corresponding Cl- channel activity became progressively reduced. The Ca(2+)-mediated agonist neurotensin (50 nM) elicited a transient Cl- channel activation that preceded the generalized cellular [Ca2+]i rise. Channel activation with neurotensin occurred in the absence of pipette Ca2+ but was abolished by preloading cells with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. Thus, in response to the Ca(2+)-mediated agonist neurotensin, Cl- channel activation results from Ca2+ mobilization from intracellular pools localized within the vicinity of the plasma membrane. The Ca2+ dependency, voltage sensitivity, and kinetics of this 15-pS Cl- channel indicate that it is the basis of the whole cell Ca(2+)-activated Cl- current.

scholarly journals An Instantaneous Correlation Coefficient and Simplified Coherent Averaging Method for Single-Channel Foetal ECG Extraction

2020 ◽  
Vol 10 (16) ◽  
pp. 5634
Author(s):  
Miao Zhang ◽  
Guo Wei
Keyword(s):  
Correlation Coefficient ◽  
Averaging Method ◽  
Single Channel ◽  
Synthetic Data ◽  
P Wave ◽  
Ecg Signal ◽  
Threshold Method ◽  
Residual Noise ◽  
Coherent Averaging ◽  
Foetal Ecg

In this paper, an instantaneous correlation coefficient and simplified coherent averaging method for single-channel foetal ECG (FECG) extraction is proposed. The instantaneous correlation coefficient is used to determine the position of the R peak of the measured ECG signal, and the simplified coherent averaging method is used to extract the main information of the ECG signal. The loss of the nonlinear and nonstationary characteristics by coherent averaging is recovered by threshold processing of the residual signal. The FECG signal extraction is performed in three steps. In the first step, the main information of the maternal electrocardiogram (MECG) is extracted from the abdomen electrocardiogram (AECG) signal by means of the instantaneous correlation coefficient and simplified coherent averaging method, and then the noisy FECG is obtained by subtracting the MECG obtained by simplified coherent averaging from the AECG. The second step is to extract the main information of the FECG by applying the instantaneous correlation coefficient and simplified coherent averaging method to the noisy FECG. The remaining signal is obtained by subtracting the simplified coherent averaging FECG from the noisy FECG. Thirdly, the threshold method is utilised to remove MECG residual noise and random gross value noise from the remaining signal to extract the nonlinear and nonstationary information, and the final FECG extraction is obtained by adding the nonlinear and nonstationary information to the simplified coherent averaging FECG. The validity of the proposed method is verified by experiments using synthetic data and real database data. FECG extracted by the method has the advantages of clear QRS complex wave, reasonable enhancement of P wave and T wave morphology, and no loss of nonlinear and nonstationary characteristics.

scholarly journals EBSeq: improving mixing computations for multi-group differential expression analysis

2020 ◽  
Author(s):  
Xiuyu Ma ◽  
Christina Kendziorski ◽  
Michael A. Newton
Keyword(s):  
Differential Expression ◽  
Clustering Algorithms ◽  
Differential Expression Analysis ◽  
Synthetic Data ◽  
Data Sets ◽  
Empirical Bayesian ◽  
False Discovery Rates ◽  
Data Analyst ◽  
False Discovery ◽  
Multiple Sample

ABSTRACTEBSeq is a Bioconductor package designed to calculate empirical-Bayesian inference summaries from sequence-based gene-expression (RNA-Seq) data. It produces gene or isoform-specific scores that measure various patterns of differential expression among a set of sample groups, and is most commonly deployed to measure differential expression between two groups. Its use of local posterior probabilities from a fitted mixture model provides the data analyst a direct way to score the false discovery rate of any reported list of genes, and it is one of the only tools that can address local false discovery rates when analyzing multiple sample groups. Contemporary applications have increasing numbers of sample groups, and the algorithms deployed in EBSeq are neither space nor time efficient in this important case. We describe a version update utilizing code improvements and novel pruning and clustering algorithms in order to reduce the complexity of mixture computations. The algorithms are supported by a theoretical analysis and tested empirically on a variety of benchmark and synthetic data sets.

scholarly journals ANALISIS PERBANDINGAN SISTEM ANTRIAN MODEL M/M/1 DAN M/M/S UNTUK PELAYANAN PBB DI DPKAD KABUPATEN PURWAKARTA

2018 ◽  
Vol 3 (2) ◽  
pp. 19-30
Author(s):  
Edi Susanto ◽  
Fidianti SE
Keyword(s):  
Queue Length ◽  
Busy Period ◽  
Single Channel ◽  
Optimal Number ◽  
Queuing System ◽  
Average Amount ◽  
Channel System ◽  
Time Service ◽  
Multiple Channel ◽  
Query System

Research on the comparative analysis of single channel queuing system and multiple channel query system with 2 fasilties and 3 facilities. This study aims to investigate how the optimal number of facilities due to the large queues waiting for their turn receive services especially Pajak Bumi dan Bangunan in the Office of Dinas Pengelola Keuangan dan Aset Daerah Kabupaten Purwakarta.The analytical method used is the model M / M / 1 for single channel system query and M / M / S is used for multiple channel query system. based on the results of the analysis using the model found that the results of a query using a single channel system services Pajak Bumi dan Bangunan certainly not optimal due to the ability of the service itself 12 people per hour. On the other side using the model M / M / S found the average amount of time service during rush hour period 10:00 to 11:00 of 0:15 hours or can be 9 minute and an average queue length 1.0667. In contrast to the number 3 facility, the taxpayer at a busy period 10:00 to 11:00 can wait with a difference of only 0.0923 hours or 5:54 minutes and the number of queues waiting with an average of 0.1446.Suggestion research obtained in order to use the three facilities while maintaining the service with optimal. So that all service activities will not be interrupted and did not make the queue longer taxpayer.Keyword : Queue, single channel queuing system and multiple channel query system, services, tax payer

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