Respiratory Control : A Modeling Perspective

The fourth Oxford Conference entitled "Control of Breathing: A Model ing Perspective" was held in September of 1988 at Grand Lake, Colorado. Grand Lake, also called Spirit Lake, was chosen for the fourth meet i ng so as to continue the meditative atmosphere of the previ ous meetings and to put the conference on a new higher plane (8,500 feet). The weather, as promised, exhibited its random-like rain showers. The snow report became essential for traveling the 12,000 foot passes to and from Grand Lake. Even the servi ces such as telephone and elect ri city proved to be uncertain. In all, the overall atmosphere of Spirit Lake contributed to an uninhibited free-style of presentation and interaction. All of us who attend the Oxford Conferences share a common interest in exploring respiratory control and the regulation of breathing. Modeling has become an adjunct to our exploration process. For us, models are tools that extend our ability to conceptualize just as instruments are tools that extend our ability to measure. And so these meetings attract physicians, physiologists, mathematicians and engineers who are modelers and modelers who are engineers, mathematicians, physiologists and physicians. Four of these physician-modelers have now passed away. They have been very important mentors for many of us. J. W. Bellville was my Ph.D. dissertation advisor at Stanford who introduced me to the intrigue of respiratory control. G. F. Filley was my colleague at the University of Colorado who enhanced my thinking about respiratory control. E. S.

Introductory Address: Oxford and Yale Physiologists in Colorado in 1911.- Respiratory Control and Gas Exchange Kinetics During Exercise.- Does Arterial Plasma Potassium Contribute to Exercise Hyperpnoea?.- Regulation of Alveolar Ventilation and Arterial Blood Gases During Exercise.- Evidence for Possible “Cardiogenic” Respiratory Drives in Exercising Man.- The Validity of the Cardiodynamic Hypothesis for Exercise Hyperpnea in Man.- Neurogenic and Cardiodynamic Drives in the Early Phase of Exercise Hyperpnea in Man.- The Effect of Exercise on The Central and Peripheral Chemoreceptor Thresholds to Carbon Dioxide in Man.- Modelling the Ventilatory Response to Pulses of Inhaled Carbon Dioxide in Exercise.- Control of Ventilation During Heavy Exercise in Man.- Estimating Arterial PCO2 From Flow-Weighted and Time-Average Alveolar PCO2 During Exercise.- The Effect of Exercise Intensity on the Linearity of Ventilatory and Gas Exchange Responses to Exercise.- Interrelation of Respiratory Responses to VCO2 Pedal Rate and Loading Force During Cycle Exercise.- On Smoothing Gas Exchange Data and Estimation of the Ventilatory Threshold.- Kinetics of Oxygen Uptake Studied with Two Different Pseudorandom Binary Sequences.- Gas Exchange Inferences for the Proportionality of the Cardiopulmonary Responses During Phase I of Exercise.- On Modelling Alveolar Oxygen Uptake Kinetics.- A General-Purpose Model for Investigating Dynamic Cardiopulmonary Responses During Exercise.- Lactate Balance During Low Levels of Exercise.- Oxygen Kinetics in the Elderly.- Breath-by-breath Gas Exchange: Data Collection and Analysis.- Respiratory Control During Altered Gas Mixtures.- Increased Arterial Potassium Levels May Contribute to the Drive to Breathe at Very High Altitude.- Hypoxia > 25 Years After Carotid Body Resection Causes More Tachycardia Although Less Hyperventilation Than in Controls.- The Transients in Ventilation Arising from a Period of Hypoxia at Near Normal and Raised Levels of End-Tidal CO2 in Man.- Asymmetry in the Ventilatory Response to a Bout of Hypoxia in Human Beings.- Studies on Exercise Hyperpnea in Relation with Hypoxic Ventilatory Chemosensitivity Measured at Rest.- Dynamics of the Ventilatory Controller and Hypoxic Stimulation in Man.- Building Dynamic Models of the Control of Breathing During Hypoxia.- Evidence in Man to Suggest Interaction Between the Peripheral and Central Chemoreceptors.- Modelling the Dynamic Ventilatory Response to Carbon Dioxide in Healthy Human Subjects During Normoxia.- Dynamics of the Peripheral Chemoreflex Loop Following Acute Acid-Base Disturbances in Cats.- 3-D Theory of Respiration: The Steady-State Case.- Inhaled CO2 as a Constant Fraction in Inspired Air and as Early-Inspired Pulses.- Breathing Patterns and Neural Factors.- Adaptive Multivariate Autoregressive Modelling of Respiratory Cycle Variables.- Factors Inducing Periodic Breathing in Man During Acclimatization to Chronic Hypoxia.- A Model of Respiratory Variability During Non-Rem Sleep.- The Use of Deep Non-Rem Sleep to Study the Pattern of Breathing in the Absence of Any Forebrain Influences.- Modelling the Breath by Breath Variability in Respiratory Data.- Is the Respiratory Rhythm Multistable in Man?.- Ventilatory Responses to Short Carotid Sinus Pressure Stimuli: Interpretation Using a Model of Rhythm Generation.- Comparison of Unification Techniques for Inconstant Intervals of Breath-by-Breath Sequence.- Phase Resetting of Respiratory Rhythm Studied in a Model of a Limit-Cycle Oscillator: Influence of Stochastic Processes.- Intracycle Relationship Between Successive Phases of the Respiration: A New Modelling Assumption.- Is Respiratory Period Spectrum Characteristic of State, Individual, Sex and Species?.- Isopnoeic Analyses of Human Steady-State Flow Profiles.- In Favour of an “Holistic” Approach to the Analysis of the Pattern of Breathing.- Vagal Control on Exercise-Induced Hyperpnea in Conscious Dogs.- Expiratory Activity Recorded During Exercise from Human M. Biceps Brachii Reinnervated by Internal Intercostal Nerves.- Recruitment and Frequency Coding of Diaphragm Motor Units during Ventilatory and Non-Ventilatory Behaviors.- Supraspinal Descending Control of Propriospinal Respiratory Neurons in the Cat.