Biomimetic phenomenological modeling of skeletal muscle isometric contraction and its application to a pneumatic muscle force control system

This dissertation entails the development, implementation, and validation of a unique biomimetic phenomenological model for biological skeletal muscle, as innovatively represented by four principal and consecutive compartments (biophysical, biochemical, and biomechanical phases) characteristic of isometric excitation-contraction physiology, and coupled by a system of simultaneous, first-order linear ordinary differential equations. The model is based upon biological compartmental transport kinetics and irreversible thermodynamic energy transformation, and represents a distinct improvement over other biomimetic models since it additionally accounts for the spatiotemporal recruitment and neuromuscular control strategies employed by the peripheral nervous system. The biomimetic model was derived and validated using physiological parameter data published in the literature, and subsequently implemented in a C ++ authored software controller for the force control of a pneumatic muscle actuator. The work represents a unique and significant contribution to the fundamental knowledge base of biomedical engineering as the new mathematical model can be directly translated into engineering design practice through optimization of the pneumatic muscle plant.; A revision of the Hill-type muscle model is introduced that describes the chemo-mechanical energy conversion process (energetic) and the internal element stiffness variation (viscoelastic) during a skeletal muscle isometric force twitch contraction. The derivation of this energetic-viscoelastic model is described by a parsimonious first-order linear ordinary differential equation with constant energetic and viscoelastic coefficients. The model has been implemented as part of a new biomimetic phenomenological model, which describes the excitation-contraction coupling process in biological skeletal muscle.; Finally, this dissertation describes the development, implementation, and validation of a unique biomimetic software controller for open- and closed-loop isometric force control of pneumatic muscle. The biomimetic controller is based upon the physiological spatiotemporal strength-recruitment strategies characteristic of motor units within the biological peripheral nervous system for isometric force target tracking and acquisition, and consists of four C++ sub-controllers (baseline biomimetic differential equations without recruitment, pure spatial recruitment, pure temporal recruitment, and combined spatiotemporal recruitment). Based upon our review of the literature, this research represents a unique application in isometric force control of pneumatic muscle, and represents the first report of a biomimetic software controller design that actually performs combined spatiotemporal recruitment.