Hierarchical block diagram

One approach to incorporating a stronger neurophysiological foundation has been to utilize an architecture for the overall control system that is based upon neurophysiological models, that is, mimicking the neurophysiological system at a block diagram level. This type of approach has led to the development of hierarchical control systems that are based upon the hierarchical structure of the human motor control system [Kawato et al, 1987 Srinivasan et al., 1992]. 

A biomedical control system that utilizes a neurophysiologically-based approach has been developed for use in Functional Neuromuscular Stimulation (FNS) systems [Abbas, 1995 Abbas and Chizeck, 1995). FNS is a rehabilitation engineering technique that uses computer-controlled electrical stimuli to activate paralyzed muscle. The task of a control system is to determine appropriate stimulation levels to generate a given movement or posture. The neural network control system utilizes a block diagram structure that is based on hierarchical models of the locomotor control system. It also utilizes a heterogenous network of neurons, some of which are capable of endogenous oscillation. This network has been shown to provide rapid adaptation of the control system parameters [Abbas and Chizeck, 1995 Abbas and Triolo, 1997] and has been shown to exhibit modulation of reflex responses [Abbas, 1995]. 

A block diagram in Figure 3 displays the way of discrimination among the 23 rival kinetic models that was based on the results from either reactor. Fixed bed reactor data have been treated at three hierarchical levels with increasing complexity in computation complications. Kinetic parameters were evaluated and tested at each level. Then models that could not meet the statistical criteria were rejected. The calculated parameters were sent to the next level as initial values. 

Figure 5.7 Block Diagram Showing a Hierarchical Design...

---