Performance of the mean frequency Doppler modulator

1979 ◽  
Vol 5 (3) ◽  
pp. 237-247 ◽  
Author(s):  
R.W. Gill
Keyword(s):  
Mean Frequency ◽  
The Mean

35Cl NQR Spectroscopy on Salts and Molecular Compounds of Trichloroacetic Acid

1986 ◽  
Vol 41 (1-2) ◽  
pp. 215-224 ◽  
Author(s):  
Winfried Fichtner ◽  
Axel Markworth ◽  
Norbert Weiden ◽  
Alarich Weiss
Keyword(s):  
Frequency Shift ◽  
Temperature Dependence ◽  
Linear Relation ◽  
Trichloroacetic Acid ◽  
Mean Frequency ◽  
35Cl Nqr ◽  
The Mean ◽  
Molecular Compounds

The temperature dependence of salts M(1)H(Cl3CCOO)2 and molecular compounds of trichloroacetic acid with amines and benzaldehydes, TCA · X, was studied,The data fit rather well to the known dependence of the mean frequency shift Δ <v(35Cl)> on the pkadifference of X with respect to TCA. A linear relation is observed between the bleaching out temperature Tb of the 35Cl NQR lines and Δ <v(35Cl)> for M(1)H(Cl3CCOO)2 and for TCA · X, X = benzaldehydes.

scholarly journals Improving peripherally inserted central catheter appropriateness and reducing device-related complications: a quasiexperimental study in 52 Michigan hospitals

2021 ◽  
pp. bmjqs-2021-013015
Author(s):  
Vineet Chopra ◽  
Megan O'Malley ◽  
Jennifer Horowitz ◽  
Qisu Zhang ◽  
Elizabeth McLaughlin ◽  
...  
Keyword(s):  
Central Line ◽  
Hospital Performance ◽  
Policy Implications ◽  
Change Point Analysis ◽  
Absolute Difference ◽  
Peripherally Inserted Central Catheter ◽  
Central Catheter ◽  
Appropriateness Criteria ◽  
Mean Frequency ◽  
The Mean

BackgroundThe Michigan Appropriateness Guide for Intravenous Catheters (MAGIC) provides evidence-based criteria for peripherally inserted central catheter (PICC) use. Whether implementing MAGIC improves PICC appropriateness and reduces complications is unknown.MethodsA quasiexperimental study design to implement MAGIC in 52 Michigan hospitals was used. Data were collected from medical records by trained abstractors. Hospital performance on three appropriateness criteria was measured: short-term PICC use (≤5 days), use of multilumen PICCs and PICC placement in patients with chronic kidney disease. PICC appropriateness and device complications preintervention (January 2013 to December 2016) versus postintervention (January 2017 to January 2020) were compared. Change-point analysis was used to evaluate the effect of the intervention on device appropriateness. Logistic regression and Poisson models were fit to assess the association between appropriateness and complications (composite of catheter occlusion, venous thromboembolism (VTE) and central line-associated bloodstream infection (CLABSI)).ResultsAmong 38 592 PICCs, median catheter dwell ranged from 8 to 56 days. During the preintervention period, the mean frequency of appropriate PICC use was 31.9% and the mean frequency of complications was 14.7%. Following the intervention, PICC appropriateness increased to 49.0% (absolute difference 17.1%, p<0.001) while complications decreased to 10.7% (absolute difference 4.0%, p=0.001). Compared with patients with inappropriate PICC placement, appropriate PICC use was associated with a significantly lower odds of complications (OR 0.29, 95% CI 0.25 to 0.34), including decreases in occlusion (OR 0.25, 95% CI 0.21 to 0.29), CLABSI (OR 0.61, 95% CI 0.46 to 0.81) and VTE (OR 0.40, 95% CI 0.33 to 0.47, all p<0.01). Patients with appropriate PICC placement had lower rate of complications than those with inappropriate PICC use (incidence rate ratio 0.987, 95% CI 0.98 to 0.99, p<0.001).ConclusionsImplementation of MAGIC in Michigan hospitals was associated with improved PICC appropriateness and fewer complications. These findings have important quality, safety and policy implications for hospitals, patients and payors.

scholarly journals Assessing the SNR Influence in the Estimation of the Mean Frequency of Lower Limbs sEMG Signals

2018 ◽  
Vol 16 (8) ◽  
pp. 2108-2114 ◽  
Author(s):  
Andres Rojas ◽  
Angel Farfan ◽  
Esteban Mora ◽  
Luis I. Minchala ◽  
Sara Wong
Keyword(s):  
Lower Limbs ◽  
Mean Frequency ◽  
The Mean ◽  
Semg Signals

scholarly journals Neurophysiological Characterization of Thalamic Nuclei in Epileptic Anaesthetized Patients

2019 ◽  
Vol 9 (11) ◽  
pp. 312 ◽  
Author(s):  
Vega-Zelaya ◽  
Torres ◽  
Navas ◽  
Pastor
Keyword(s):  
General Anesthesia ◽  
Interspike Interval ◽  
The Other ◽  
Electrode Placement ◽  
Thalamic Nuclei ◽  
Mean Frequency ◽  
The Mean ◽  
Tonic Pattern ◽  
Deep Brain

Deep brain stimulation (DBS) requires precise localization, which is especially difficult at the thalamus, and even more difficult in anesthetized patients. We aimed to characterize the neurophysiological properties of the ventral intermediate (V.im), ventral caudal (V.c), and centromedian parvo (Ce.pc) and the magnocellular (Ce.mc) thalamic nuclei. We obtained microelectrode recordings from five patients with refractory epilepsy under general anesthesia. Somatosensory evoked potentials recorded by microelectrodes were used to identify the V.c nucleus. Trajectories were reconstructed off-line to identify the nucleus recorded, and the amplitude of the action potential (AP) and the tonic (i.e., mean frequency, density, probability of interspike interval) and phasic (i.e., burst index, pause index, and pause ratio) properties of the pattern discharges were analyzed. The Mahalanobis metric was used to evaluate the similarity of the patterns. The mean AP amplitude was higher for the V.im nucleus (172.7 ± 7.6 µV) than for the other nuclei, and the mean frequency was lower for the Ce.pc nucleus (7.2 ± 0.8 Hz) and higher for the V.c nucleus (11.9 ± 0.8 Hz) than for the other nuclei. The phasic properties showed a bursting pattern for the V.c nucleus and a tonic pattern for the centromedian and V.im nuclei. The Mahalanobis distance was the shortest for the V.im/V.c and Ce.mp/Ce.pc pairs. Therefore, the different properties of the thalamic nuclei, even for patients under general anesthesia, can be used to positively define the recorded structure, improving the exactness of electrode placement in DBS.

scholarly journals Automatic wheeze detection based on auditory modelling

2005 ◽  
Vol 219 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Y Qiu ◽  
A R Whittaker ◽  
M Lucas ◽  
K Anderson
Keyword(s):  
Marked Improvement ◽  
Historical Record ◽  
Frequency Range ◽  
Mean Frequency ◽  
Threshold Algorithm ◽  
Global Power ◽  
Potential Benefits ◽  
The Mean ◽  
Partial Success ◽  
Improved Algorithm

Automatic wheeze detection has several potential benefits compared with reliance on human auscultation: it is experience independent, an automated historical record can easily be kept, and it allows quantification of wheeze severity. Previous attempts to detect wheezes automatically have had partial success but have not been reliable enough to become widely accepted as a useful tool. In this paper an improved algorithm for automatic wheeze detection based on auditory modelling is developed, called the frequency- and duration-dependent threshold algorithm. The mean frequency and duration of each wheeze component are obtained automatically. The detected wheezes are marked on a spectrogram. In the new algorithm, the concept of a frequency- and duration-dependent threshold for wheeze detection is introduced. Another departure from previous work is that the threshold is based not on global power but on power corresponding to a particular frequency range. The algorithm has been tested on 36 subjects, 11 of whom exhibited characteristics of wheeze. The results show a marked improvement in the accuracy of wheeze detection when compared with previous algorithms.

Crystal Dynamics of the Alloy Cu3Au

1974 ◽  
Vol 52 (22) ◽  
pp. 2235-2239 ◽  
Author(s):  
E. D. Hallman
Keyword(s):  
Inelastic Scattering ◽  
Frequency Ratio ◽  
Large Scale ◽  
Lattice Vibrations ◽  
Frequency Wave ◽  
Mean Frequency ◽  
Resonance Behavior ◽  
The Mean ◽  
Crystal Dynamics ◽  
Disordered Alloy

Using inelastic scattering of slow neutrons, the frequency wave vector dispersion relations for the lattice vibrations in the disordered alloy Cu3Au have been measured at 296 K. The results are similar to those for copper, with the mean frequency ratio (alloy/copper) being 0.778. A Born–von Kármán fit to the data is given. Although detailed measurements of phonon widths have not yet been made, phonons were generally well defined, with no large scale resonance behavior of frequencies or widths observed.

scholarly journals High-Frequency Homologous Recombination betweenBaculoviruses Involves DNAReplication

2003 ◽  
Vol 77 (24) ◽  
pp. 13053-13061 ◽  
Author(s):  
Shizuo George Kamita ◽  
Susumu Maeda ◽  
Bruce D. Hammock
Keyword(s):  
Dna Replication ◽  
High Frequency ◽  
Heliothis Virescens ◽  
Recombination Frequency ◽  
Dna Recombination ◽  
Marker Genes ◽  
Gene Marker ◽  
Mean Frequency ◽  
The Mean ◽  
Bmn Cells

ABSTRACT We determined the frequency of DNA recombination between Bombyx mori nucleopolyhedroviruses (BmNPVs) and between BmNPV and the closely related Autographa californica NPV (AcMNPV) in BmN cells, Sf-21 cells, and larvae of Heliothis virescens. The BmN cells were coinfected with two BmNPVs, one with a mutation at the polyhedrin gene (polh) locus and a second carrying a lacZ gene marker cassette. Eleven different BmNPV mutants carrying the lacZ gene marker at various distances (1.4 to 61.7 kb) from polh were used for the coinfections. The Sf-21 cells and larvae of H. virescens were coinfected with wild-type AcMNPV and 1 of the 11 lacZ-marked BmNPV mutants. In BmN cells, high-frequency recombination was detected as early as 15 h postcoinfection but not at 12 h postcoinfection. At 18 h postcoinfection, the mean frequency of recombination ranged between 20.0 and 35.4% when the polh and lacZ marker genes were separated by at least 9.7 kb. When these marker genes were separated by only 1.4 kb, the mean frequency of recombination was 2.7%. In BmN cells, the mean recombination frequency between two BmNPVs increased only marginally when the multiplicity of infection of each virus was increased 10-fold. In Sf-21 cells and the larvae of H. virescens, the recombination frequency between BmNPV and AcMNPV was ≤1.0%. AcMNPV DNA replication occurred normally after the coinfection of Sf-21 cells. BmNPV DNA replication, however, was not detected, indicating that normal DNA replication by both viruses is required for high-frequency recombination.

An Adaptive Approach to Computing the Spectrum and Mean Frequency of Doppler Signals

1995 ◽  
Vol 17 (1) ◽  
pp. 1-26 ◽  
Author(s):  
A. Herment ◽  
J.F. Giovannelli
Keyword(s):  
Spectral Analysis ◽  
Frame Rate ◽  
High Resolution Spectrum ◽  
Data Sets ◽  
Color Flow ◽  
Mean Frequency ◽  
Color Flow Imaging ◽  
Doppler Data ◽  
The Mean ◽  
Frequency Estimator

Modern ultrasound Doppler systems are facing the problem of processing increasingly shorter data sets. Spectral analysis of the strongly nonstationary Doppler signal needs to shorten the analysis window while maintaining a low variance and high resolution spectrum. Color flow imaging requires estimation of the Doppler mean frequency from even shorter Doppler data sets to obtain both a high frame rate and high spatial resolution. We reconsider these two estimation problems in light of adaptive methods. A regularized parametric method for spectral analysis as well as an adapted mean frequency estimator are developed. The choice of the adaptive criterion is then addressed and adaptive spectral and mean frequency estimators are developed to minimize the mean square error on estimation in the presence of noise. Two suboptimal spectral and mean-frequency estimators are then derived for real-time applications. Finally, their performance is compared to that of both the FFT based periodogram and the AR parametric spectral analysis for the spectral estimator, and, to both the correlation angle and the Kristoffersen's [8] estimators for the mean frequency estimator using Doppler data recorded in vitro.

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