scholarly journals Unconstrained Respiration States Classification by Detecting Respiratory Cycle Using Autocorrelation

2021 ◽  
Vol ISASE2021 (0) ◽  
pp. 1-4
Author(s):  
Misaki KOHAMA ◽  
Keita NISHIO ◽  
Yuri HAMADA ◽  
Takashi KABURAGI ◽  
Yosuke KURIHARA
Keyword(s):  
Respiratory Cycle

scholarly journals Diagnostic characteristics of 11 formulae for calculating corrected flow time as measured by a wearable Doppler patch

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Jon-Émile S. Kenny ◽  
Igor Barjaktarevic ◽  
David C. Mackenzie ◽  
Andrew M. Eibl ◽  
Matthew Parrotta ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Sensitivity And Specificity ◽  
Doppler Ultrasound ◽  
Flow Time ◽  
Cardiac Preload ◽  
Respiratory Cycle ◽  
Quiet Breathing ◽  
Diagnostic Characteristics ◽  
Corrected Flow Time ◽  
Corrected Flow

Abstract Background Change of the corrected flow time (Ftc) is a surrogate for tracking stroke volume (SV) in the intensive care unit. Multiple Ftc equations have been proposed; many have not had their diagnostic characteristics for detecting SV change reported. Further, little is known about the inherent Ftc variability induced by the respiratory cycle. Materials and methods Using a wearable Doppler ultrasound patch, we studied the clinical performance of 11 Ftc equations to detect a 10% change in SV measured by non-invasive pulse contour analysis; 26 healthy volunteers performed a standardized cardiac preload modifying maneuver. Results One hundred changes in cardiac preload and 3890 carotid beats were analyzed. Most of the 11 Ftc equations studied had similar diagnostic attributes. Wodeys’ and Chambers’ formulae had identical results; a 2% change in Ftc detected a 10% change in SV with a sensitivity and specificity of 96% and 93%, respectively. Similarly, a 3% change in Ftc calculated by Bazett’s formula displayed a sensitivity and specificity of 91% and 93%. FtcWodey had 100% concordance and an R2 of 0.75 with change in SV; these values were 99%, 0.76 and 98%, 0.71 for FtcChambers and FtcBazetts, respectively. As an exploratory analysis, we studied 3335 carotid beats for the dispersion of Ftc during quiet breathing using the equations of Wodey and Bazett. The coefficient of variation of Ftc during quiet breathing for these formulae were 0.06 and 0.07, respectively. Conclusions Most of the 11 different equations used to calculate carotid artery Ftc from a wearable Doppler ultrasound patch had similar thresholds and abilities to detect SV change in healthy volunteers. Variation in Ftc induced by the respiratory cycle is important; measuring a clinically significant change in Ftc with statistical confidence requires a large sample of beats.

Modeling liver motion and deformation during the respiratory cycle using intensity-based free-form registration of gated MR images

2001 ◽  
Author(s):  
Torsten Rohlfing ◽  
Calvin R. Maurer, Jr. ◽  
Walter G. O'Dell ◽  
Jianhui Zhong
Keyword(s):  
Respiratory Cycle ◽  
Free Form ◽  
Mr Images

Detection Latency of Added Loads to Breathing

1982 ◽  
Vol 63 (1) ◽  
pp. 11-15 ◽  
Author(s):  
J. G. W. Burdon ◽  
K. J. Killian ◽  
E. J. M. Campbell
Keyword(s):  
Peak Inspiratory Pressure ◽  
Normal Subjects ◽  
Reciprocal Relationship ◽  
Respiratory Cycle ◽  
Curvilinear Relationship ◽  
Similar Relationship ◽  
Detection Latency ◽  
Mechanical Information ◽  
Resistive Loads ◽  
Comparable Magnitude

1. Detection latency of a range of added elastic (0·95–4·50 kPa/l) and resistive (0·73–3·29 kPa l−1 s) loads to breathing were measured in five normal subjects. Detection latency was defined as the time from the onset of the breath to detection of the load. 2. Detection latency followed a curvilinear relationship when plotted as a function of the magnitude of the added loads. A similar relationship was found with both elastic and resistive loads although detection latencies to added elastances were longer than for added resistances. 3. When the added load was expressed in terms of comparable magnitude (peak inspiratory pressure) detection latencies for added elastances were found to be consistently longer than for added resistive loads. 4. These studies show that the detection latency to added inspiratory loads follows a reciprocal relationship, that detection latencies for elastic and resistive loads are clearly different and suggest that these loads are detected during the respiratory cycle at a time when the mechanical information regarding muscular pressure is greatest.

scholarly journals Laryngeal Movements During the Respiratory Cycle Measured with an Endoscopic Imaging Technique in the Conscious Horse at Rest

1999 ◽  
Vol 84 (4) ◽  
pp. 739-746 ◽  
Author(s):  
Claudio L. Lafortuna ◽  
Mariangela Albertini ◽  
Francesco Ferrucci ◽  
Enrica Zucca ◽  
Martina Braghieri ◽  
...  
Keyword(s):  
Imaging Technique ◽  
Respiratory Cycle ◽  
Endoscopic Imaging

Numerical simulation of humidification and heating during inspiration within an adult nose

2012 ◽  
Vol 50 (2) ◽  
pp. 157-164
Author(s):  
F. Sommer ◽  
R. Kroger ◽  
J. Lindemann
Keyword(s):  
Numerical Simulations ◽  
High Speed ◽  
Middle Turbinate ◽  
Multislice Ct ◽  
Respiratory Cycle ◽  
In Vivo Measurements ◽  
Airflow Distribution ◽  
The Impact ◽  
Human Nose

Background: The temperature of inhaled air is highly relevant for the humidification process. Narrow anatomical conditions limit possibilities for in vivo measurements. Numerical simulations offer a great potential to examine the function of the human nose. Objective: In the present study, the nasal humidification of inhaled air was simulated simultaneously with temperature distribution during a respiratory cycle. Methods: A realistic nose model based on a multislice CT scan was created. The simulation was performed by the Software Fluent(r). Boundary conditions were based on previous in vivo measurements. Inhaled air had a temperature of 20(deg)C and relative humidity of 30%. The wall temperature was assumed to be variable from 34(deg)C to 30(deg)C with constant humidity saturation of 100% during the respiratory cycle. Results: A substantial increase in temperature and humidity can be observed after passing the nasal valve area. Areas with high speed air flow, e.g. the space around the turbinates, show an intensive humidification and heating potential. Inspired air reaches 95% humidity and 28(deg)C within the nasopharynx. Conclusion: The human nose features an enormous humidification and heating capability. Warming and humidification are dependent on each other and show a similar spacial pattern. Concerning the climatisation function, the middle turbinate is of high importance. In contrast to in vivo measurements, numerical simulations can explore the impact of airflow distribution on nasal air conditioning. They are an effective method to investigate nasal pathologies and impacts of surgical procedures.

scholarly journals Anatomy and physiology of phrenic afferent neurons

2017 ◽  
Vol 118 (6) ◽  
pp. 2975-2990 ◽  
Author(s):  
Jayakrishnan Nair ◽  
Kristi A. Streeter ◽  
Sara M. F. Turner ◽  
Michael D. Sunshine ◽  
Donald C. Bolser ◽  
...  
Keyword(s):  
Potential Role ◽  
Large Diameter ◽  
Respiratory Cycle ◽  
Conscious Perception ◽  
Relative Impact ◽  
Afferent Neurons ◽  
Sensory Afferents ◽  
Synaptic Contacts ◽  
Anatomy And Physiology

Large-diameter myelinated phrenic afferents discharge in phase with diaphragm contraction, and smaller diameter fibers discharge across the respiratory cycle. In this article, we review the phrenic afferent literature and highlight areas in need of further study. We conclude that 1) activation of both myelinated and nonmyelinated phrenic sensory afferents can influence respiratory motor output on a breath-by-breath basis; 2) the relative impact of phrenic afferents substantially increases with diaphragm work and fatigue; 3) activation of phrenic afferents has a powerful impact on sympathetic motor outflow, and 4) phrenic afferents contribute to diaphragm somatosensation and the conscious perception of breathing. Much remains to be learned regarding the spinal and supraspinal distribution and synaptic contacts of myelinated and nonmyelinated phrenic afferents. Similarly, very little is known regarding the potential role of phrenic afferent neurons in triggering or modulating expression of respiratory neuroplasticity.

Effect of lung inflation on lung blood volume and pulmonary venous flow

1985 ◽  
Vol 58 (3) ◽  
pp. 954-963 ◽  
Author(s):  
R. Brower ◽  
R. A. Wise ◽  
C. Hassapoyannes ◽  
B. Bromberger-Barnea ◽  
S. Permutt
Keyword(s):  
Blood Volume ◽  
Transpulmonary Pressure ◽  
Left Ventricular ◽  
Respiratory Cycle ◽  
Pulmonary Vasculature ◽  
Venous Flow ◽  
Lung Inflation ◽  
Pulmonary Venous Flow ◽  
Respiratory Wave ◽  
Left Ventricular Preload

Phasic changes in lung blood volume (LBV) during the respiratory cycle may play an important role in the genesis of the respiratory wave in arterial pressure, or pulsus paradoxus. To better understand the effects of lung inflation on LBV, we studied the effect of changes in transpulmonary pressure (delta Ptp) on pulmonary venous flow (Qv) in eight isolated canine lungs with constant inflow. Inflation when the zone 2 condition was predominant resulted in transient decreases in Qv associated with increases in LBV. In contrast, inflation when the zone 3 condition was predominant resulted in transient increases in Qv associated with decreases in LBV. These findings are consistent with a model of the pulmonary vasculature that consists of alveolar and extra-alveolar vessels. Blood may be expelled from alveolar vessels but is retained in extra-alveolar vessels with each inflation. The net effect on LBV and thus on Qv is dependent on the zone conditions that predominate during inflation, with alveolar or extra-alveolar effects being greater when the zone 3 or zone 2 conditions predominate, respectively. Lung inflation may therefore result in either transiently augmented or diminished Qv. Phasic changes in left ventricular preload may therefore depend on the zone conditions of the lungs during the respiratory cycle. This may be an important modulator of respiratory variations in cardiac output and blood pressure.

Respiratory dynamic resistance

1962 ◽  
Vol 17 (4) ◽  
pp. 609-612 ◽  
Author(s):  
Ernest Croft Long ◽  
Wayland Elroy Hull ◽  
Emile Louis Gebel
Keyword(s):  
Respiratory Cycle ◽  
Dynamic Resistance ◽  
Respiratory Resistance ◽  
Differential Coefficient ◽  
Energy Dissipated ◽  
Nonlinear Resistance

Sinusoidal forcing at frequencies up to 17 cycles/sec was applied to the anesthetized, apneic dog by a body respirator. Forcing pressure and volume displacement were displayed in quadrature on an oscilloscope and planimetric integration of these loops indicated an increase in energy dissipated by total respiratory resistance per liter of air displaced, due to turbulence and changing airway geometry, with increasing frequency. Nonlinear resistance was calculated and the differential coefficient, dP/dV (dynamic resistance), was determined at 10° intervals throughout the respiratory cycle, at each of three frequencies in four dogs. Total respiratory resistance is a “nonohmic” dependent variable and changes progressively throughout the cycle. Submitted on October 20, 1961

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