Biomaterial Database

A threshold loading device for testing of inspiratory muscle performance. 1995

P R Eastwood, and D R Hillman

Dept of Pulmonary Physiology, Sir Charles Gairdner Hospital, Nedlands, Western Australia.

Threshold loading is a method of incrementally loading the inspiratory muscles, which requires development of an adjustable threshold pressure (Pth) before air will flow. In the ideal device, flow is independent of pressure once Pth is exceeded. A "weighted plunger" apparatus is commonly used, but devices described previously perform unreliably at high inspiratory load. We have modified this apparatus using the diaphragm and valve seating from a threshold valve used to deliver positive airway pressure (AMBU 10, AMBU International, Denmark) to yield improved pressure-flow characteristics. With this device, there was a linear relationship between Pth and weight on the plunger (r = 0.998), and flow was largely independent of pressure once Pth was exceeded: pressure developed at an inspiratory flow of 1.3 +/- 0.1 l.s-1 was 13.6 +/- 7.0% below Pth. Our modified weighted plunger apparatus allows consistent and reliable threshold loading of inspiratory muscles, even at high inspiratory loads.

UI	MeSH Term	Description	Entries
D011175	Positive-Pressure Respiration	A method of mechanical ventilation in which pressure is maintained to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange.	Positive End-Expiratory Pressure,Positive-Pressure Ventilation,End-Expiratory Pressure, Positive,End-Expiratory Pressures, Positive,Positive End Expiratory Pressure,Positive End-Expiratory Pressures,Positive Pressure Respiration,Positive Pressure Ventilation,Positive-Pressure Respirations,Positive-Pressure Ventilations,Pressure, Positive End-Expiratory,Pressures, Positive End-Expiratory,Respiration, Positive-Pressure,Respirations, Positive-Pressure,Ventilation, Positive-Pressure,Ventilations, Positive-Pressure
D012129	Respiratory Function Tests	Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.	Lung Function Tests,Pulmonary Function Tests,Function Test, Pulmonary,Function Tests, Pulmonary,Pulmonary Function Test,Test, Pulmonary Function,Tests, Pulmonary Function,Function Test, Lung,Function Test, Respiratory,Function Tests, Lung,Function Tests, Respiratory,Lung Function Test,Respiratory Function Test,Test, Lung Function,Test, Respiratory Function,Tests, Lung Function,Tests, Respiratory Function
D012132	Respiratory Muscles	These include the muscles of the DIAPHRAGM and the INTERCOSTAL MUSCLES.	Ventilatory Muscles,Respiratory Muscle,Muscle, Respiratory,Muscle, Ventilatory,Muscles, Respiratory,Muscles, Ventilatory,Ventilatory Muscle
D004867	Equipment Design	Methods and patterns of fabricating machines and related hardware.	Design, Equipment,Device Design,Medical Device Design,Design, Medical Device,Designs, Medical Device,Device Design, Medical,Device Designs, Medical,Medical Device Designs,Design, Device,Designs, Device,Designs, Equipment,Device Designs,Equipment Designs
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man