Effect of ventilation by high-frequency oscillation on lung and chest wall mechanics in the dog

Lung ◽  
1985 ◽  
Vol 163 (1) ◽  
pp. 317-325 ◽  
Author(s):  
Delmar J. Gillespie ◽  
Robert E. Hyatt ◽  
Keyword(s):  
Chest Wall ◽  
High Frequency ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Chest Wall Mechanics

Ventilatory saving by external chest wall compression or oral high-frequency oscillation in normal subjects and those with chronic airflow obstruction

1985 ◽  
Vol 69 (3) ◽  
pp. 349-359 ◽  
Author(s):  
R. J. D. George ◽  
R. J. D. Winter ◽  
S. J. Flockton ◽  
D. M. Geddes
Keyword(s):  
Chest Wall ◽  
High Frequency ◽  
Minute Ventilation ◽  
Airflow Obstruction ◽  
Normal Subjects ◽  
High Frequency Oscillation ◽  
Tidal Breathing ◽  
Frequency Oscillation ◽  
Resonant Frequencies ◽  
High Frequency Oscillations

1. Oscillation of the air within the lungs at high frequency is associated with an increased clearance of CO2. Because of the high frequency and low volume of these oscillations, spontaneous breathing is unhindered and the technique has potential value as a supplement to ventilation. 2. High-frequency oscillations were superimposed upon tidal breathing by using a loudspeaker attached to a mouthpiece (oral high-frequency oscillation, OHFO) or by external chest wall compression (ECWC). We set out (a) to compare the changes in ventilation and breathlessness by using OHFO and ECWC in normal subjects with those in patients with chronic airflow obstruction (CAO), and (b) to relate the pattern of saving to the resonant frequencies of the respiratory system as a whole (fOT, 5–10 Hz in normal subjects, 16–26 Hz in CAO) and those of the ribcage(foc,70 Hz). 3. OHFO reduced minute ventilation (VE) by up to 46% in normal subjects (P < 0.01) and 29% in CAO (P < 0.01) without any rise in CO2. ECWC reduced VE by 27% in normal subjects (P < 0.01) and 16% in CAO (P < 0.01) without a rise in CO2. 4. High-frequency oscillation by either method relieved breathlessness in those with CAO and was comfortable and well tolerated. 5. In normal subjects for was discrete and varied little with respiration. Maximum savings occurred around for (5–10 Hz). 6. In CAO, there was no obvious single resonant frequency and flow and pressure signals were intermittently in phase over a band of about 10 Hz. Thus the reductions in minute ventilation were only loosely related to for (13–26 Hz). Neither group reduced VE at foc (65–75 Hz). 7. OHFO has considerable potential in the management of patients with CAO, where it may be of value as an assistance to breathing and in the relief of breathlessness. ECWC, although effective in principle, is impractical by our methods and awaits the development of an acceptable delivery system.

scholarly journals Acoustic Correlatives of Chest Wall Volumetric Motion During High Frequency Oscillation (HFO). 1503

1997 ◽  
Vol 41 ◽  
pp. 253-253
Author(s):  
Mitchell Goldstein ◽  
Robert Kopotic ◽  
Wade Rich ◽  
Ricardo Liberman ◽  
John Vogt ◽  
...  
Keyword(s):  
Chest Wall ◽  
High Frequency ◽  
High Frequency Oscillation ◽  
Frequency Oscillation

High-Frequency Oscillation and Chronic Lung Disease in Very Low Birth Weight Infants

PEDIATRICS ◽  
2001 ◽  
Vol 108 (1) ◽  
pp. 212-214
Author(s):  
J. P. Shenai; ◽  
P. Rimensberger; ◽  
U. Thome ◽  
F. Pohlandt; ◽  
P. Rimensberger
Keyword(s):  
Birth Weight ◽  
Low Birth Weight ◽  
Lung Disease ◽  
Chronic Lung Disease ◽  
High Frequency ◽  
Very Low Birth Weight ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Low Birth Weight Infants

scholarly journals A Comprehensive Investigation on High-Frequency Oscillation in DC Microgrid

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Mohammad Habibullah ◽  
Nadarajah Mithulananthan ◽  
Krischonme Bhumkittipich ◽  
Mohammad Amin
Keyword(s):  
High Frequency ◽  
High Frequency Oscillation ◽  
Frequency Oscillation ◽  
Comprehensive Investigation ◽  
Dc Microgrid

scholarly journals Distinct EEG seizure patterns reflect different seizure generation mechanisms

2015 ◽  
Vol 113 (7) ◽  
pp. 2840-2844 ◽  
Author(s):  
Pariya Salami ◽  
Maxime Lévesque ◽  
Jean Gotman ◽  
Massimo Avoli
Keyword(s):  
High Frequency ◽  
Channel Blocker ◽  
Seizure Activity ◽  
Low Voltage ◽  
High Frequency Oscillation ◽  
Seizure Onset ◽  
Frequency Oscillation ◽  
Oscillation Analysis ◽  
Pilocarpine Model ◽  
Generation Mechanisms

Low-voltage fast (LVF)- and hypersynchronous (HYP)-seizure onset patterns can be recognized in the EEG of epileptic animals and patients with temporal lobe epilepsy. Ripples (80–200 Hz) and fast ripples (250–500 Hz) have been linked to each pattern, with ripples predominating during LVF seizures and fast ripples predominating during HYP seizures in the rat pilocarpine model. This evidence led us to hypothesize that these two seizure-onset patterns reflect the contribution of neural networks with distinct transmitter signaling characteristics. Here, we tested this hypothesis by analyzing the seizure activity induced with the K+ channel blocker 4-aminopyridine (4AP, 4–5 mg/kg ip), which enhances both glutamatergic and GABAergic transmission, or the GABAA receptor antagonist picrotoxin (3–5 mg/kg ip); rats were implanted with electrodes in the hippocampus, the entorhinal cortex, and the subiculum. We found that LVF onset occurred in 82% of 4AP-induced seizures whereas seizures after picrotoxin were always HYP. In addition, high-frequency oscillation analysis revealed that 4AP-induced LVF seizures were associated with higher ripple rates compared with fast ripples ( P < 0.05), whereas picrotoxin-induced seizures contained higher rates of fast ripples compared with ripples ( P < 0.05). These results support the hypothesis that two distinct patterns of seizure onset result from different pathophysiological mechanisms.

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