Biomaterial Database

Theory of resistive load detection. 1983

C K Mahutte, and E J Campbell, and K J Killian

During normal breathing the brain sets the required muscle pressure to overcome resistance and elastance and presumably monitors the resultant flow (rate of change of volume). The lag in flow compared to the pressure can be described by a phase angle. When a small resistive load is added the resultant flow is delayed further and the phase angle increases. We postulate that if the change in phase angle exceeds a critical phase lag, the added load is detected. Over a wide range of basal resistances, R, the mathematical analysis predicts that detection occurs if the just noticeable added resistance, delta R, is a constant fraction of the basal resistance. Resistive load detection thus obeys the Weber psychophysical law, delta R/R = constant. This is in accord with previous experimental observations. The theory also predicts that delta R/R increases at low basal resistance in accord with recent experimental observations. Further as yet untested predictions of the theory are that breathing frequency and elastance should affect the Weber relationship.

UI	MeSH Term	Description	Entries
D008170	Lung Compliance	The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)	Compliance, Lung,Compliances, Lung,Lung Compliances
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D012123	Pulmonary Ventilation	The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.	Respiratory Airflow,Ventilation Tests,Ventilation, Pulmonary,Expiratory Airflow,Airflow, Expiratory,Airflow, Respiratory,Test, Ventilation,Tests, Ventilation,Ventilation Test
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000403	Airway Resistance	Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.	Airway Resistances,Resistance, Airway,Resistances, Airway
D014939	Work of Breathing	RESPIRATORY MUSCLE contraction during INHALATION. The work is accomplished in three phases: LUNG COMPLIANCE work, that required to expand the LUNGS against its elastic forces; tissue resistance work, that required to overcome the viscosity of the lung and chest wall structures; and AIRWAY RESISTANCE work, that required to overcome airway resistance during the movement of air into the lungs. Work of breathing does not refer to expiration, which is entirely a passive process caused by elastic recoil of the lung and chest cage. (Guyton, Textbook of Medical Physiology, 8th ed, p406)	Breathing Work,Breathing Works