Automatic wheeze detection based on auditory modelling

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.

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An Analysis of Vocal Communication in the Adult Brown Noddy (Anous stolidus)

The Auk ◽

10.1093/auk/103.2.359 ◽

1986 ◽

Vol 103 (2) ◽

pp. 359-369 ◽

Cited By ~ 4

Author(s):

Diane E. Riska

Keyword(s):

Vocal Communication ◽

Wide Band ◽

Basic Unit ◽

Frequency Range ◽

Mean Frequency ◽

Dry Tortugas ◽

Msec Duration ◽

Vocal Signals ◽

The Mean ◽

Nesting Season

Abstract I analyzed vocal signals of marked adult Brown Noddies (Anous stolidus) throughout their nesting season in the Dry Tortugas, Florida from 1979 to 1982. The basic unit of the adult repertoire is a wide-band click, less than 4 msec duration, ranging in frequency from 200 to 3,300 Hz. I identified nine temporal arrangements of these clicks, which form the notes of the calls. These calls differ little in frequency range, but they differ in the mean frequency of the most intense sound energy band, in note duration, in the number of clicks per note, and in internote interval. These calls are used in different contexts, which sometimes overlap. Frequency, note duration, and internote interval do not differ between sexes. Mean frequency and note length varied among individuals for some calls. No tonal elements characteristic of calls of Brown Noddy nestlings remain in the adult repertoire.

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Hemifacial Spasm: Endoscopic Vascular Decompression

Otolaryngology ◽

10.1016/s0194-5998(97)70118-9 ◽

1997 ◽

Vol 117 (4) ◽

pp. 308-314 ◽

Cited By ~ 32

Author(s):

J. Magnan ◽

F. Caces ◽

P. Locatelli ◽

A. Chays

Keyword(s):

Hemifacial Spasm ◽

Marked Improvement ◽

Cerebellopontine Angle ◽

Posterior Inferior Cerebellar Artery ◽

Endoscopic Examination ◽

Anterior Inferior Cerebellar Artery ◽

Cerebellar Artery ◽

The Mean ◽

Vascular Decompression

Sixty patients with primitive hemifacial spasm were treated by means of a minimally invasive retrosigmoid approach in which endoscopic and microsurgical procedures were combined. Intraoperative endoscopic examination of the cerebellopontine angle showed that for 56 of the patients vessel-nerve conflict was the cause of hemifacial spasm. The most common offending vessel was the posterior inferior cerebellar artery (39 patients), next was the vertebral artery (23 patients), and last was the anterior inferior cerebellar artery (16 patients). Nineteen of the patients had multiple offending vascular loops. In one patient, another cause of hemifacial spasm was an epidermoid tumor of the cerebellopontine angle. For three patients, it was not possible to determine the exact cause of the facial disorder. Follow-up information was reviewed for 54 of 60 patients; the mean follow-up period was 14 months. Fifty of the patients were in the vessel-nerve conflict group. Forty of the 50 were free of symptoms, and four had marked improvement. The overall success rate was 88%, and there was minimal morbidity (no facial palsy, two cases of severe hearing loss).

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An Electrophysiological Measure of Temporal Resolution in Normal Subjects Using Frequency Modulated Signals

American Journal of Audiology ◽

10.1044/1059-0889(2002/007) ◽

2002 ◽

Vol 11 (1) ◽

pp. 42-49

Author(s):

Devin L. McCaslin ◽

Lawrence L. Feth ◽

Gary P. Jacobson ◽

Pamela J. Mishler

Keyword(s):

Temporal Resolution ◽

Mismatch Negativity ◽

Normal Subjects ◽

Single Step ◽

Event Related Potential ◽

Frequency Range ◽

Temporal Properties ◽

Step Duration ◽

The Mean ◽

Modulated Signals

This investigation was conducted to determine whether an exogenous event-related potential called the mismatch negativity (MMN) would change systematically in response to frequency-modulated signals with varying temporal properties. Both N1 and P2 waveforms were recorded for 50-ms frequency-modulated signals from normal hearing listeners. The standard stimuli for this investigation were continuous sweep tones with center frequencies of 1000 Hz that traversed a frequency range of 200 Hz in a single step. The rare stimuli were signals that traversed the same frequency range in two, four, six, or eight discrete steps. Results suggest that for the 10 participants, 1) the mean MMN peak-to-peak amplitude and mean area decreased significantly with decreases in step duration, 2) MMN area amplitude was the best indicator of psychophysical performance for the two magnitude measures, and 3) MMN onsets and peak latencies did not show either a significant increase or decrease in latency as step duration decreased.

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Residual gastric volume evaluation with ultrasonography after ingestion of carbohydrate- or carbohydrate plus glutamine-enriched beverages: a randomized, crossover clinical trial with healthy volunteers

Arquivos de Gastroenterologia ◽

10.1590/s0004-2803.2017v54n1-06 ◽

2017 ◽

Vol 54 (1) ◽

pp. 33-36 ◽

Cited By ~ 2

Author(s):

Paulo Cesar GOMES ◽

Cervantes CAPOROSSI ◽

Jose Eduardo AGUILAR-NASCIMENTO ◽

Ageo Mario Candido da SILVA ◽

Viviane Maeve Tavares de ARAUJO

Keyword(s):

Clinical Trial ◽

Healthy Volunteers ◽

Postoperative Recovery ◽

Gastric Volume ◽

Safe Procedure ◽

Abdominal Ultrasonography ◽

Residual Gastric Volume ◽

Potential Benefits ◽

The Mean ◽

To Receive

ABSTRACT BACKGROUND Abbreviation of preoperative fasting to 2 hours with maltodextrin (CHO)-enriched beverage is a safe procedure and may enhance postoperative recovery. Addition of glutamine (GLN) to CHO beverages may include potential benefits to the metabolism. However, by adding a nitrogenous source to CHO beverages, gastric emptying may be delayed and increase the risk of bronchoaspiration during anesthesia. OBJECTIVE In this study of safety, we aimed at investigating the residual gastric volume (RGV) 2 hours after the intake of either CHO beverage alone or CHO beverage combined with GLN. METHODS We performed a randomized, crossover clinical trial. We assessed RGV by means of abdominal ultrasonography (US) in 20 healthy volunteers (10 males and 10 females) after an overnight fast of 8 hours. Then, they were randomized to receive 600 mL (400 mL immediately after US followed by another 200 mL 2 hours afterwards) of either CHO (12.5% maltodextrin) or CHO-GLN (12.5% maltodextrin plus 15 g GLN). Two sequential US evaluations were done at 120 and 180 minutes after ingestion of the second dose. The interval of time between ingestion of the two types of beverages was 2 weeks. RESULTS The mean (SD) RGV observed after 8 hours fasting (13.56±13.25 mL) did not statistically differ (P>0.05) from the RGV observed after ingesting CHO beverage at both 120 (16.32±11.78 mL) and 180 minutes (14.60±10.39 mL). The RGV obtained at 120 (15.63±18.83 mL) and 180 (13.65±10.27 mL) minutes after CHO-GLN beverage also was not significantly different from the fasting condition. CONCLUSION The RGV at 120 and 180 minutes after ingestion of CHO beverage combined with GLN is similar to that observed after an overnight fast.

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

Zeitschrift für Naturforschung A ◽

10.1515/zna-1986-1-238 ◽

1986 ◽

Vol 41 (1-2) ◽

pp. 215-224 ◽

Cited By ~ 2

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.

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Performance of the mean frequency Doppler modulator

Ultrasound in Medicine & Biology ◽

10.1016/0301-5629(79)90015-2 ◽

1979 ◽

Vol 5 (3) ◽

pp. 237-247 ◽

Cited By ~ 56

Author(s):

R.W. Gill

Keyword(s):

Mean Frequency ◽

The Mean

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Improved estimation of low velocities in color Doppler imaging by adapting the mean frequency estimator to the clutter rejection filter

IEEE Transactions on Biomedical Engineering ◽

10.1109/10.532126 ◽

1996 ◽

Vol 43 (9) ◽

pp. 919-927 ◽

Cited By ~ 10

Author(s):

A. Herment ◽

G. Demoment ◽

P. Dumee

Keyword(s):

Color Doppler ◽

Color Doppler Imaging ◽

Doppler Imaging ◽

Mean Frequency ◽

Clutter Rejection ◽

Rejection Filter ◽

The Mean ◽

Frequency Estimator

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

BMJ Quality & Safety ◽

10.1136/bmjqs-2021-013015 ◽

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.

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Topographic Analysis of Steady-State Visual Evoked Potentials (SVEPs) in The Medium Frequency Range in Migraine With and Without Aura

Cephalalgia ◽

10.1046/j.1468-2982.1992.1204244.x ◽

1992 ◽

Vol 12 (4) ◽

pp. 244-249 ◽

Cited By ~ 14

Author(s):

Franco M Puca ◽

Marina de Tommaso ◽

Maria A Savarese ◽

Sergio Genco ◽

Addolorata Prudenzano

Keyword(s):

Steady State ◽

Frequency Range ◽

Medium Frequency ◽

Topographic Analysis ◽

Absolute Power ◽

Interhemispheric Coherence ◽

The Mean ◽

Student’S T ◽

Medium Frequency Range ◽

Student’S T Test

Topographic analysis of SVEPs in the medium frequencies range was performed in 30 migraineurs without aura, 20 migraineurs with aura and in 20 control subjects. The mean absolute power values of the fundamental component F1, the subharmonic F1/2 and the first harmonic F2, corrected by logarithmic transformation, were computed in each group and then compared using Student's t-test. The interhemispheric coherence of the F1 component was also evaluated. The 18, 21 and 27 Hz F1 components were increased in both migraineurs with and without aura, particularly in the temporo-parietal regions. The 24 Hz F1 component was augmented only in migraineurs without aura in the parieto-occipital regions in comparison with migraineurs with aura and controls. Migraine with aura patients had a reduced interhemispheric coherence mostly of 12 Hz and 15 Hz F1 components in frontal and temporo-parietal regions. Results of the study confirm abnormalities of SVEPs in migraineurs with and without aura. These consist of widespread increases of F1 components in the medium frequency range over the temporo-parietal regions.

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