A phrenic nerve-actuated electronically controlled positive-pressure ventilator

1987 ◽  
Vol 62 (5) ◽  
pp. 2121-2125 ◽  
Author(s):  
E. R. Schertel ◽  
D. A. Schneider ◽  
D. L. Howard ◽  
J. F. Green
Keyword(s):  
Moving Average ◽  
Inspiratory Flow ◽  
Positive Pressure ◽  
Feedback Signal ◽  
Position Signal ◽  
Tracheal Pressure ◽  
Valve Position ◽  
Air Valve ◽  
The Difference ◽  
Operational Modes

We have constructed an electronically controlled positive-pressure ventilator actuated by phrenic neural activity for use in open-chested or paralyzed experimental animals for the study of breathing pattern. A Bird Mark 14 positive-pressure ventilator was modified such that flow is a linear function of a command signal. Flow is delivered by advancing an air valve with a servo-motor that is controlled by one of three different operational modes. In two of the modes, the difference between the electronic average of inspiratory phrenic activity (moving average) and a feedback signal determines the inspiratory flow. The feedback signal is derived from either tracheal pressure or an electronic measure of inspired volume. In the third mode, the moving average is differentiated to provide control of inspiratory flow and volume. Physiological flow profiles were created using all three operational modes. Integration of an air-valve position signal provides an electronic measure of tidal volume. An additional feature of this ventilator allows inspiratory flow and duration to be predetermined for a given breath.

scholarly journals Effects of inspiratory and expiratory positive pressure difference on airflow dynamics during sleep

1998 ◽  
Vol 85 (5) ◽  
pp. 1855-1862 ◽  
Author(s):  
F. Sériès ◽  
I. Marc
Keyword(s):  
Sleep Apnea ◽  
Pressure Difference ◽  
Positive Relationship ◽  
Inspiratory Flow ◽  
Pressure Response ◽  
Positive Pressure ◽  
Flow Limitation ◽  
Recording Session ◽  
The Difference ◽  
Different Levels

We measured the effects of dissociating inspiratory and expiratory positive pressure (Pi and Pe, respectively) on the inspiratory flow limitation pattern and on genioglossus (GG) activity in nine sleep apnea patients. Measurements were made at two different levels of Pi with stepwise increases in Pe. Flow-limited breaths were observed during each recording session. In six of nine subjects, maximal inspiratory flow (V˙i max) was correlated with the difference between Pi and Pe (correlations were negative in 5 subjects, positive in 1 subject). In three other patients,V˙i maxwas not influenced by the amount of pressure difference. A positive relationship between tonic and/or phasic GG electromyographic activities and Pi-Pedifference was observed at least at one Pi level in all patients. This correlation was observed independently of the presence or absence of any relationship betweenV˙i maxand the amount of pressure difference. Our results suggest that increasing the Pi-Pedifference (i.e., decreasing Pe) may be associated with a significant worsening in inspiratory flow limitation and that theV˙i max-pressure difference behavior is not dependent on the GG electromyographic-pressure response.

Pressure-flow behavior of a bronchopleural fistula during mechanical ventilation with positive pressure

1989 ◽  
Vol 66 (4) ◽  
pp. 1789-1799 ◽  
Author(s):  
J. J. Perez Fontan ◽  
A. O. Ray
Keyword(s):  
Gas Flow ◽  
Flow Behavior ◽  
Bronchopleural Fistula ◽  
Transmural Pressure ◽  
Positive Pressure ◽  
Inflation Pressure ◽  
Tracheal Pressure ◽  
Flow Through ◽  
The Difference ◽  
The Relationship

We examined the mechanical behavior of a bronchopleural fistula created by sectioning a small subpleural bronchus in seven anesthetized lambs. The pressure across the fistula was measured as the difference between the pressure recorded by a retrograde bronchial catheter inserted in the vicinity of the fistula and the outflow pressure at the fistula exit. The effective resistance of the fistula (Rf) was computed by dividing this pressure difference by the gas flow through the fistula measured at the outlet of an intrapleural tube adjacent to the fistula. Rf increased by 114 +/- 25% (SE) when we inflated the lungs in a stepwise manner from a tracheal pressure of 2–20 cmH2O. Rf also increased when inflation pressure varied continuously; this increase, however, was less evident when we decreased the inflation time from 1.0 to 0.2 s. The relationship between Rf and lung volume was similar during the stepwise inflations and deflations but showed marked hysteresis during the continuous inflation-deflation maneuvers, when Rf was greater during deflation than inflation. Our results suggest that the fistula behaves as a compliant pathway whose relevant transmural pressure is the transmural pressure at or near the fistula's exit. We attribute the increase in Rf during inflation to decreases in transmural pressure caused by convective and dissipative losses inside the fistula and by the stress applied by the chest wall on the outer surface of the fistula.

Servo respirator constructed from a positive-pressure ventilator

1976 ◽  
Vol 41 (2) ◽  
pp. 252-255 ◽  
Author(s):  
J. E. Remmers ◽  
H. Gautier
Keyword(s):  
Negative Feedback ◽  
Differential Amplifier ◽  
Positive Pressure ◽  
Precise Control ◽  
Pressure Signal ◽  
Response Characteristics ◽  
Tracheal Pressure ◽  
Selection Of

We have constructed an electronically controlled respirator from three commercially available components: a positive-pressure ventilator, a recorder pen motor, and a differential amplifier. Using negative feedback derived from a tracheal pressure signal, the instrument functions as a servo respirator which provides precise control of tracheal pressure. The system's power and response characteristics are well suited for ventilation of anesthetized cats and dogs. The servo respirator can be used as an externallycontrolled respiratory pump which provides flexibility in selection of the parameters of the ventilatory cycle. Alternatively, it can function as a “demand” respirator which generates transthoracic pressure proportional to efferent respiratory discharge.

scholarly journals Prediksi Pemakaian Listrik Kelompok Tarif Menggunakan Jaringan Syaraf Tiruan dan ARIMA

2013 ◽  
Vol 7 (2) ◽  
pp. 189
Author(s):  
Silviani E Rumagit ◽  
Azhari SN
Keyword(s):  
Neural Network ◽  
Artificial Intelligence ◽  
Neural Networks ◽  
Statistical Method ◽  
Moving Average ◽  
Electric Energy ◽  
Backpropagation Neural Network ◽  
The Difference ◽  
The Government ◽  
Increasing Demand

AbstrakLatar Belakang penelitian ini dibuat dimana semakin meningkatnya kebutuhan listrik di setiap kelompok tarif. Yang dimaksud dengan kelompok tarif dalam penelitian ini adalah kelompok tarif sosial, kelompok tarif rumah tangga, kelompok tarif bisnis, kelompok tarif industri dan kelompok tarif pemerintah. Prediksi merupakan kebutuhan penting bagi penyedia tenaga listrik dalam mengambil keputusan berkaitan dengan ketersediaan energi listik. Dalam melakukan prediksi dapat dilakukan dengan metode statistik maupun kecerdasan buatan.            ARIMA merupakan salah satu metode statistik yang banyak digunakan untuk prediksi dimana ARIMA mengikuti model autoregressive (AR) moving average (MA). Syarat dari ARIMA adalah data harus stasioner, data yang tidak stasioner harus distasionerkan dengan differencing. Selain metode statistik, prediksi juga dapat dilakukan dengan teknik kecerdasan buatan, dimana dalam penelitian ini jaringan syaraf tiruan backpropagation dipilih untuk melakukan prediksi. Dari hasil pengujian yang dilakukan selisih MSE ARIMA, JST dan penggabungan ARIMA, jaringan syaraf tiruan tidak berbeda secara signifikan. Kata Kunci— ARIMA, jaringan syaraf tiruan, kelompok tarif.  AbstractBackground this research was made where the increasing demand for electricity in each group. The meaning this group is social, the household, business, industry groups and the government fare. Prediction is an important requirement for electricity providers in making decisions related to the availability of electric energy. In doing predictions can be made by statistical methods and artificial intelligence.            ARIMA is a statistical method that is widely used to predict where the ARIMA modeled autoregressive (AR) moving average (MA). Terms of ARIMA is the data must be stationary, the data is not stationary should be stationary  use differencing. In addition to the statistical method, predictions can also be done by artificial intelligence techniques, which in this study selected Backpropagation neural network to predict. From the results of tests made the difference in MSE ARIMA, ANN and merging ARIMA, artificial neural networks are not significantly different. Keyword—ARIMA, neural network, tarif groups

Continuous Autoregressive Moving Average Models

2021 ◽  
pp. 118-141
Author(s):  
Yakup Ari
Keyword(s):  
Time Series ◽  
Parameter Estimation ◽  
Differential Equations ◽  
Stochastic Differential Equations ◽  
Discrete Time ◽  
Moving Average ◽  
Likelihood Estimation ◽  
Real Data ◽  
Autoregressive Moving Average ◽  
The Difference

The financial time series have a high frequency and the difference between their observations is not regular. Therefore, continuous models can be used instead of discrete-time series models. The purpose of this chapter is to define Lévy-driven continuous autoregressive moving average (CARMA) models and their applications. The CARMA model is an explicit solution to stochastic differential equations, and also, it is analogue to the discrete ARMA models. In order to form a basis for CARMA processes, the structures of discrete-time processes models are examined. Then stochastic differential equations, Lévy processes, compound Poisson processes, and variance gamma processes are defined. Finally, the parameter estimation of CARMA(2,1) is discussed as an example. The most common method for the parameter estimation of the CARMA process is the pseudo maximum likelihood estimation (PMLE) method by mapping the ARMA coefficients to the corresponding estimates of the CARMA coefficients. Furthermore, a simulation study and a real data application are given as examples.

Effect of changes in inspiratory flow rate on cough responses to inhaled capsaicin

1991 ◽  
Vol 81 (s25) ◽  
pp. 539-542 ◽  
Author(s):  
M. J. Barros ◽  
S. L. Zammattio ◽  
P. J. Rees
Keyword(s):  
Citric Acid ◽  
Confidence Interval ◽  
Flow Rate ◽  
Negative Relationship ◽  
Random Order ◽  
Inspiratory Flow ◽  
Inspiratory Flow Rate ◽  
Flow Rates ◽  
Cough Response ◽  
The Difference

1. Twelve non-smoking subjects inhaled capsaicin at three different inspiratory flow rates: 50, 100 and 150 litres/min. Capsaicin was delivered by a breath-actuated dosimeter; inhalations consisted of 0.21–13.6 nmol of capsaicin in doubling amounts given in random order. 2. The mean number of coughs per challenge decreased with increasing inspiratory flow rate. The difference in cough numbers were significant: 7.7 (95% confidence interval 2.5–12.8) for 50 versus 100 litres/min and 10.9 (95% confidence interval 5.0–16.9) for 100 versus 150 litres/min. 3. On a separate day, a cough threshold was measured by giving increasing doses of citric acid that were inhaled at 50 litres/min. There was a positive correlation between the sensitivity to capsaicin and the cough threshold to citric acid (r = 0.69, P = 0.01), and also between the cough latencies (r = 0.67, P = 0.02). 4. The negative relationship between the cough response and the inspiratory flow rate may be caused by increased laryngeal deposition at lower inspiratory flow rates. 5. These results are compatible with a similar anatomical distribution of cough receptors for capsaicin and citric acid. 6. These results suggest that changes in inspiratory flow rate may affect the results of cough challenges.

Comparison of Regional Lung Deformation Between Dynamic and Static CT Imagery Using Inverse Consistent Registration

2009 ◽  
Author(s):  
Ryan Amelon ◽  
Kai Ding ◽  
Kunlin Cao ◽  
Gary E. Christensen ◽  
Joseph M. Reinhardt ◽  
...  
Keyword(s):  
Image Data ◽  
Lung Mechanics ◽  
Ct Scans ◽  
Positive Pressure ◽  
Displacement Fields ◽  
Regional Patterns ◽  
Recent Developments ◽  
The Difference ◽  
Key Aspects ◽  
Lung Deformation

The mechanics of lung deformation is traditionally assessed at a whole-lung or lobar level. We submit that key aspects of lung mechanics maybe better understood by studying regional patterns of lung deformation by leveraging recent developments in tomographic imaging and image processing techniques. Our group has developed an inverse consistent registration technique for estimating local displacement distributions from paired lung CT volumes [1,2]. This facilitates the estimation of strain distributions and consequently, the regional patterns in volume change and its preferential directionalities (anisotropy in deformation). In this study, we use this novel method to compare regional deformation in the lungs between static and dynamic inflations in an adult sheep. Much of our research has focused on registration of static lung images at different positive end-expiratory pressures (PEEP). More recently, respiratory-gated CT scans of supine, positive-pressure inflated sheep lungs have been gathered in order to compare the displacement fields of a dynamically inflating lung to the static lung scans. The theory is that scanning a dynamically inflating lung will more accurately reflect natural deformation during breathing by realizing time-dependent mechanical properties (viscoelasticity). The downside to human dynamic lung imaging is the increased radiation dose necessary to acquire the image data across the respiratory cycle, though low-dose CT scans are an option [3]. This experiment observed the difference in strain distribution between dynamically inflated lungs versus static apneic lungs using the inverse consistent image registration developed in our lab.

Effects of baclofen on the Hering-Breuer inspiratory-inhibitory and deflation reflexes in rats

1998 ◽  
Vol 274 (2) ◽  
pp. R462-R469 ◽  
Author(s):  
Erin Seifert ◽  
Teresa Trippenbach
Keyword(s):  
Aminobutyric Acid ◽  
Type B ◽  
Rapid Adaptation ◽  
Inspiratory Time ◽  
Airway Occlusion ◽  
Acid Type ◽  
Tracheal Pressure ◽  
The Difference ◽  
Respiratory Phases ◽  
Stimulation Of

The objective of this study was to evaluate effects of baclofen, a γ-aminobutyric acid type B (GABAB) receptor agonist, injected into the nucleus of the solitary tract, on the Hering-Breuer inspiratory-inhibitory (Ti-inhibitory) and deflation reflexes in urethan-anesthetized adult Wistar rats ( n = 7). The Ti-inhibitory reflex was estimated from changes in peak amplitude of the integrated diaphragmatic electromyogram and inspiratory time (Ti) provoked by airway occlusion at end expiration. The deflation reflex was evaluated from changes in Ti and expiration (Te) of the first two breaths (Ti-1, Te-1 and Ti-2, Te-2) immediately after a decrease in tracheal pressure (Ptr). Under control conditions, airway occlusion at end-Te prolonged Ti (66 ± 5%; mean ± SE) and the following Te (54 ± 11%). Decreases in Ptr, from −2 to −5 cmH2O, evoked an increase in Ti and shortening of Te of both breaths. Both effects were Ptr dependent, and Ti-1 and Te-1 differed from Ti-2 and Te-2, suggesting a rapid adaptation to the stimulus. At Ptr of −5 cmH2O, Ti-1 and Ti-2 increased by 30 ± 2 and 43 ± 6%, respectively, and Te-1 and Te-2 decreased by 53 ± 4 and 33 ± 7%, respectively. During unloaded breathing, 60 pmol baclofen prolonged Ti by 120 ± 11% and left Te unaffected. Baclofen abolished vagally mediated changes in Te. On the other hand, the Ti increases caused by either airway occlusion (24 ± 8%) or Ptr of −5 cmH2O (Ti-1; 16 ± 5%) were still significant, but Ti-1 and Ti-2 were not different. A GABAB receptor antagonist, CGP-35348 (2.8 nmol), reversed these effects of baclofen. These results imply that stimulation of GABAB receptors attenuates but does abolish vagally mediated control of Ti. The difference in effects of baclofen on the central and vagal control of Ti and Te suggests different distribution of GABAB receptors in neuronal networks controlling each of these respiratory phases.

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