Viscoelastic and viscoplastic glucose theory (VGT 5): Three developed postprandial plasma glucose (PPG) stress-strain diagrams for the PPG levels of <140 mg/dL, 140-170 mg/dL, and >170 mg/dL, to illustrate the correlation between biomedical diabetes conditions and biophysical illustrations of glucose behaviors using linear elasticity theory (time-independent), plasticity theory (time-independent), and viscoplasticity theory (time-dependent) based on GHMethod: math-physical medicine (No. 582)

Abstract

Gerald C Hsu

The author has studied strength of materials and theory of elasticity through his undergraduate courses at the University of Iowa. He also conducted research work to earn a master’s degree in Biomechanics under Professor James Andrews. At that time, he used the spring and dashpot models to simulate the behaviors of human joints, bones, muscles, and tendons in order to investigate the human-weapon interactions during the Vietnam war era. Later, he went to MIT to pursue his PhD study under Professor Norman Jones, who taught him theory of plasticity and dynamic plastic behaviors of various structure elements. He also took additional graduate courses in the field of fluid dynamics and thermodynamics. Since then, many advancements have been made in the biomechanics branch, especially with human body tissues that possess certain viscoelastic characteristics, such as bones, muscles, cartilages, tendons (connect bone to muscle), ligaments (connect bone to bone), fascia, and skin. For example, the author suffered plantar fasciitis for many years. He understood that the night splint dorsiflexes forefoot, at the back of the foot, increases plantar fascia tension to offer stress-relaxation for the pain. This model of muscles and tendons connecting the lower leg and foot is a form of viscoelastic study and problem solving. However, when dealing with human internal organs, it is not easy to conduct live experiments to obtain accurate measurements for the biomedical material properties. Although blood itself is a viscous (time-dependent) material, its viscosity factor may fall between water, honey, syrup, or gel. The author’s research subject is “glucose” where the carbohydrates and sugar amount is produced by the liver and is carried by red blood cells, not the blood itself. It is nearly impossible to measure material geometry or certain engineering properties of glucose, for example, to determine the viscosity of “glucose”. Therefore, the best he could do is to apply the “concept of viscoelasticity and/or viscoplasticity” to construct an analogy model of time-dependent glucose behaviors.

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