Engineering topics
Publications and source records attributed to Skundberg, Thomas L..
An animal feeder for use in a metabolic cage is introduced. The feeder includes a confined passageway and an adjustable notched gate proceeding a food cup. The gate is adjusted so that the entry area to the food cup approximates the cross sectional head area of the animal. Food ejected from the food cup by a caged animal is dropped through a grate into a spill tray.
Astronauts experience many physiological changes during spaceflight and exposure to microgravity. There is a headwardshift of fluids, muscles atrophy, and changes occur in the body's bone structure and hormone levels. This paper describes a unique metabolic cage that was developed to evaluate ground simulation of these effects. Hindlimb or tail suspension in rats has been studied as a model to create the effects of microgravity in order to study how to counteract them. This suspension model, developed by Holton, accurately simulates the effects of weightlessness during spaceflight by unloading the hindlimbs and producing a head-ward shift of fluids. However, obtaining quantitative data on the nutritional state, the gastrointestinal and renal function of these animals has not been possible, until now. Using Holton's tail suspension model, the new metabolic suspension cage effectively separates urine and feces samples for analysis allowing investigators to examine the effects of microgravity in many complex body systems. A description of the cage system, its design, and results of its use is provided along with pictures and details for replication of the cages.