Indices of Upper Airway Obstruction in Patients with Simultaneous Chronic Airflow Limitation

Respiration ◽  
1994 ◽  
Vol 61 (3) ◽  
pp. 121-125 ◽  
Author(s):  
Eduardo García-Pachón ◽  
Pere Casan ◽  
Joaquín Sanchis
Keyword(s):  
Airway Obstruction ◽  
Upper Airway ◽  
Upper Airway Obstruction ◽  
Airflow Limitation

scholarly journals The effect of leptin replacement on sleep-disordered breathing in the leptin-deficient ob/ob mouse

2016 ◽  
Vol 120 (1) ◽  
pp. 78-86 ◽  
Author(s):  
H. Pho ◽  
A. B. Hernandez ◽  
R. S. Arias ◽  
E. B. Leitner ◽  
S. Van Kooten ◽  
...  
Keyword(s):  
Airway Obstruction ◽  
Duty Cycle ◽  
Rem Sleep ◽  
Minute Ventilation ◽  
Upper Airway ◽  
Neuromuscular Control ◽  
Inspiratory Flow ◽  
Upper Airway Obstruction ◽  
Airflow Limitation ◽  
Breathing Patterns

Obese leptin-deficient ( ob/ob) mice demonstrate defects in upper airway structural and neuromuscular control. We hypothesized that these defects predispose to upper airway obstruction during sleep, and improve with leptin administration. High-fidelity polysomnographic recordings were conducted to characterize sleep and breathing patterns in conscious, unrestrained ob/ob mice (23 wk, 67.2 ± 4.1 g, n = 13). In a parallel-arm crossover study, we compared responses to subcutaneous leptin (1 μg/h) vs. vehicle on respiratory parameters during NREM and REM sleep. Upper airway obstruction was defined by the presence of inspiratory airflow limitation (IFL), as characterized by an early inspiratory plateau in airflow at a maximum level (V̇imax) with increasing effort. The severity of upper airway obstruction (V̇imax) was assessed along with minute ventilation (V̇e), tidal volume (VT), respiratory rate (RR), inspiratory duty cycle, and mean inspiratory flow at each time point. IFL occurred more frequently in REM sleep (37.6 ± 0.2% vs. 1.1 ± 0.0% in NREM sleep, P < 0.001), and leptin did not alter its frequency. V̇imax (3.7 ± 1.1 vs. 2.7 ± 0.8 ml/s, P < 0.001) and V̇e increased (55.4 ± 22.0 vs. 39.8 ± 16.4 ml/min, P < 0.001) with leptin vs. vehicle administration. The increase in V̇e was due to a significant increase in VT (0.20 ± 0.06 vs. 0.16 ± 0.05 ml, P < 0.01) rather than RR. Increases in V̇e were attributable to increases in mean inspiratory flow (2.5 ± 0.8 vs. 1.8 ± 0.6 ml/s, P < 0.001) rather than inspiratory duty cycle. Similar increases in V̇e and its components were observed in non-flow-limited breaths during NREM and REM sleep. These responses suggest that leptin stabilized pharyngeal patency and increased drive to both the upper airway and diaphragm during sleep.

scholarly journals Classification of directionally specific vagus nerve activity using an upper airway obstruction model in anesthetized rodents

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. Sabetian ◽  
Y. Sadat-Nejad ◽  
Paul B. Yoo
Keyword(s):  
Airway Obstruction ◽  
Upper Airway ◽  
Low Noise ◽  
Upper Airway Obstruction ◽  
Gaussian Kernel ◽  
Recording Electrode ◽  
Cuff Electrode ◽  
Nerve Cuff ◽  
Svm Model ◽  
Nerve Cuff Electrode

AbstractElectrical signals from the peripheral nervous system have the potential to provide the necessary motor, sensory or autonomic information for implementing closed-loop control of neuroprosthetic or neuromodulatory systems. However, developing methods to recover information encoded in these signals is a significant challenge. Our goal was to test the feasibility of measuring physiologically generated nerve action potentials that can be classified as sensory or motor signals. A tetrapolar recording nerve cuff electrode was used to measure vagal nerve (VN) activity in a rodent model of upper airway obstruction. The effect of upper airway occlusions on VN activity related to respiration (RnP) was calculated and compared for 4 different cases: (1) intact VN, (2) VN transection only proximal to recording electrode, (3) VN transection only distal to the recording electrode, and (4) transection of VN proximal and distal to electrode. We employed a Support Vector Machine (SVM) model with Gaussian Kernel to learn a model capable of classifying efferent and afferent waveforms obtained from the tetrapolar electrode. In vivo results showed that the RnP values decreased significantly during obstruction by 91.7% ± 3.1%, and 78.2% ± 3.4% for cases of intact VN or proximal transection, respectively. In contrast, there were no significant changes for cases of VN transection at the distal end or both ends of the electrode. The SVM model yielded an 85.8% accuracy in distinguishing motor and sensory signals. The feasibility of measuring low-noise directionally-sensitive neural activity using a tetrapolar nerve cuff electrode along with the use of an SVM classifier was shown. Future experimental work in chronic implant studies is needed to support clinical translatability.

Upper Airway Obstruction in Paediatrics

1985 ◽  
Vol 3 (3) ◽  
pp. 721-738
Author(s):  
Elliot J. Rhine ◽  
Gary G. Johnson
Keyword(s):  
Airway Obstruction ◽  
Upper Airway ◽  
Upper Airway Obstruction
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