Signal Interpretation Considerations When Estimating Subglottal Pressure From Oral Air Pressure

2019 ◽  
Vol 62 (5) ◽  
pp. 1326-1337 ◽  
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer ◽  
Jason A. Whitfield
Keyword(s):  
Standard Condition ◽  
Word Production ◽  
Air Pressure ◽  
Pressure Waveform ◽  
Pressure Measurements ◽  
Air Leak ◽  
Pressure Signal ◽  
Adult Participants ◽  
Syllable Repetition ◽  
Subglottal Pressure

Purpose Oral air pressure measurements during lip occlusion for /pVpV/ syllable strings are used to estimate subglottal pressure during the vowel. Accuracy of this method relies on smoothly produced syllable repetitions. The purpose of this study was to investigate the oral air pressure waveform during the /p/ lip occlusions and propose physiological explanations for nonflat shapes. Method Ten adult participants were trained to produce the “standard condition” and were instructed to produce nonstandard tasks. Results from 8 participants are included. The standard condition required participants to produce /pːiːpːiː.../ syllables smoothly at approximately 1.5 syllables/s. The nonstandard tasks included an air leak between the lips, faster syllable repetition rates, an initial voiced consonant, and 2-syllable word productions. Results Eleven oral air pressure waveform shapes were identified during the lip occlusions, and plausible physiological explanations for each shape are provided based on the tasks in which they occurred. Training the use of the standard condition, the initial voice consonant condition, and the 2-syllable word production increased the likelihood of rectangular oral air pressure waveform shapes. Increasing the rate beyond 1.5 syllables/s improved the probability of producing rectangular oral air pressure signal shapes in some participants. Conclusions Visual and verbal feedback improved the likelihood of producing rectangular oral air pressure signal shapes. The physiological explanations of variations in the oral air pressure waveform shape may provide direction to the clinician or researcher when providing feedback to increase the accuracy of estimating subglottal pressure from oral air pressure.

scholarly journals Detailed Pressure Measurements During the Transition to Rotating Stall in an Axial Compressor: Influence of the Throttling Process

2018 ◽  
Author(s):  
Gabriel Margalida ◽  
Antoine Dazin ◽  
Pierric Joseph ◽  
Olivier Roussette
Keyword(s):  
Axial Compressor ◽  
Warning Signal ◽  
Rotating Stall ◽  
Pressure Measurements ◽  
Pressure Signal ◽  
Instability Development ◽  
Stable Operating ◽  
Instantaneous Pressure ◽  
Reference Pressure ◽  
Unsteady Pressure Measurements

This paper presents experimental unsteady pressure measurements gathered on a single stage axial compressor during pre-stall and transition to stall operations. The aim of this study is to analyze the transition from a stable operating point to the fully developed rotating stall regime, and more specifically, the effect of the throttling process on the development of the instabilities. To do so, experiments have been repeated leading the compressor to stall operations with various throttling speed. On one hand, this paper analyses the effect of the throttling speed on the dynamic of the instability development from the first detection of spike type precursors to completely developed rotating stall. On the other hand, a stall warning signal based on the correlation of the instantaneous pressure signal with a reference pressure signal is built. The influence of the location of the pressure transducer used for the warning signal is first analyzed. Then an analysis of the effect of the throttling process on the time between the warning signal and the effective stall development is proposed.

Influence of Light Leakage from Q-Switched Laser on Laser-Induced Shock Wave

2011 ◽  
Vol 314-316 ◽  
pp. 1895-1899
Author(s):  
Yun Xia Ye ◽  
Zhong Wu ◽  
Hai Bing Guan
Keyword(s):  
Shock Wave ◽  
Delay Time ◽  
Pressure Wave ◽  
Pressure Waveform ◽  
Laser Shock ◽  
Laser Shock Processing ◽  
Pressure Signal ◽  
Beneficial Effects ◽  
Laser Pumping ◽  
Shock Processing

Experiments were performed to study the influence of light leakage from Q-switched laser on laser-induced shock wave. Through changing the voltage applied on the Q switch crystal and the delay time between opening Q switch and triggering laser pumping source, different amount of light leakage can be obtained. It is ascertained that longer-pulse light leakage from Q-switched laser is responsible for the second weaker pressure signal appearing on the tested pressure waveform. The results show that the leakage energy not only has not beneficial effects on laser shock processing, but also will weaken the main pressure wave.

Changes in Interface Pressure under Elastic and Short-Stretch Bandages during Posture Changes and Exercise

1998 ◽  
Vol 13 (1) ◽  
pp. 25-28 ◽  
Author(s):  
M. Hirai
Keyword(s):  
Clinical Practice ◽  
Prospective Study ◽  
Pressure Difference ◽  
Pressure Waveform ◽  
Pressure Measurements ◽  
Interface Pressure ◽  
Working Pressure ◽  
Time Of Application ◽  
College Of Nursing ◽  
Contraction And Relaxation

Objective: To evaluate the pressure under short-stretch and elastic bandages. Design: Prospective study in 20 healthy volunteers, comparing the two different kinds of bandages. Setting: Department of Surgery, Aichi Prefectural College of Nursing, Nagoya, Japan. Main outcome measures: Pressure measurements were made beneath the bandages with different initial pressures of 10, 20, 30, 40, 50, 60, and 70 mmHg, during supine resting, standing, tip-toe exercise and walking. Results: Short-stretch bandages showed a significant increase in pressure during standing and exercise at lower initial pressures compared with elastic bandages. In analysing the pressure waveform during tip-toe exercise and walking, a significantly greater pressure difference between muscle contraction and relaxation was noted for short-stretch bandages compared with elastic bandages at any initial pressures. Conclusions: Short-stretch bandages produce a higher working pressure and a larger pressure difference during exercise. However, the effect depends on the initial pressures at the time of application. In clinical practice, prevention of a decrease in pressure with time and uniform application of bandages are important.

scholarly journals Prevalence, Awareness, Treatment, and Control of Hypertension among Saudi Adult Population: A National Survey

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Abdalla A. Saeed ◽  
Nasser A. Al-Hamdan ◽  
Ahmed A. Bahnassy ◽  
Abdelshakour M. Abdalla ◽  
Mostafa A. F. Abbas ◽  
...  
Keyword(s):  
Physical Activity ◽  
Adult Population ◽  
Geographical Location ◽  
Cross Sectional Study ◽  
Pressure Measurements ◽  
Treatment Control ◽  
Cross Sectional ◽  
Adult Participants ◽  
Low Education ◽  
And Control

This cross-sectional study aimed at estimating prevalence, awareness, treatment, control, and predictors of hypertension among Saudi adult population. Multistage stratified sampling was used to select 4758 adult participants. Three blood pressure measurements using an automatic sphygmomanometer, sociodemographics, and antihypertensive modalities were obtained. The overall prevalence of hypertension was 25.5%. Only 44.7% of hypertensives were aware, 71.8% of them received pharmacotherapy, and only 37.0% were controlled. Awareness was significantly associated with gender, age, geographical location, occupation, and comorbidity. Applying drug treatment was significantly more among older patients, but control was significantly higher among younger patients and patients with higher level of physical activity. Significant predictors of hypertension included male gender, urbanization, low education, low physical activity, obesity, diabetes, and hypercholesterolemia. In conclusion prevalence is high, but awareness, treatment, and control levels are low indicating a need to develop a national program for prevention, early detection, and control of hypertension.

scholarly journals Condition Monitoring of Centrifugal Pumps Based on Pressure Measurements

2019 ◽  
Vol 63 (2) ◽  
pp. 80-90
Author(s):  
Csanád Kalmár ◽  
Ferenc Hegedűs
Keyword(s):  
Condition Monitoring ◽  
Rotational Speed ◽  
Characteristic Curve ◽  
Vibration Measurement ◽  
Pressure Side ◽  
Pressure Measurements ◽  
Centrifugal Pumps ◽  
Angular Misalignment ◽  
Pressure Signal ◽  
Heavy Damage

The purpose of the present study is the investigation of condition of centrifugal pumps via pressure signals. Instead of vibration measurement on the housings that is widely used in industry, our method is based on pressure signal measurement on the pressure side of the pump. Fourier transforming such a signal can get us to make conclusions about the behavior of the pump. By changing the operating point along a characteristic curve, we can create waterfall diagrams that provide useful information about the pump at constant rotational speed. For example, it is possible to differentiate the mechanical and the hydrodynamical effects predicting the occurrence of many constructional failures (such as unbalance, angular misalignment, bearing misalignment, motor instability, etc.); thus, preventing heavy damage of the equipment.

Design and Implementation of Mandarin Air Pressure Corpus Processing Manufacturing Platform

2011 ◽  
Vol 323 ◽  
pp. 109-113
Author(s):  
Yang Liu ◽  
Yong Hong Li ◽  
Axu Hu ◽  
Jian Bin Wang
Keyword(s):  
Feature Detection ◽  
Peak Detection ◽  
Air Pressure ◽  
Pressure Signal ◽  
Design And Implementation ◽  
Matlab Program ◽  
Manufacturing Platform

This article discusses the design of mandarin air pressure corpus processing manufacturing platform edited by Matlab program. It is argured that double checking, airflow peak detection and consonants’ feature detection contribute the realization of this platform. What’s more, the endpoint of the various language units in air pressure signal can be detected and be separated automatically with the accuracy of over 90% under this platform.

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