Biorheology,information theory and cybernetics 1

Abstract

The connection between rheology on the one hand, and information theory and cybernetics on the other, can generate useful insights and new lines of inquiry for biorheology, as well as for the understanding of biological control mechanisms. Biological materials, and particularly biological fluids, serve to convey not only mass, heat or momentum, but also information. The nature, attenuation, modulation and bandwidth of the signal conveyed, and the information capacity of the channel, are related to rheological factors. Analyses show that the information capacity of the major arteries is likely to be moderate, but that of the capillaries is much higher. Cybernetically, the rheological characteristics of biological materials, like those of any other materials, can be viewed as filters limiting the range of responses of the material. Since a filter is also a channel of communication, a connection is established between communication theory and rheology. Significant consequences include the propositions that any given rheological behavior can be produced by a number of possible microscopic arrangements, and that the memory of biological materials is not a wholly objective property of the fluid. Intrinsically, furthermore, rheological characteristics endow biological fluids with an ability to regulate and control flows.