Intelligent vibrotactile biofeedback system for real-time postural correction on perturbed surfaces

Biofeedbacks delivery during rehabilitation have been known to improve postural control and shorten rehabilitation periods. A biofeedback system communicates with the human central nervous system (CNS) through a variety of feedback modalities. Among the many available modalities vibrotactile feedback devices are gaining much attention. This is due to their desirable characteristics and simplistic manner of presenting information to the CNS. An intelligent biofeedback system integrated with wireless sensors for monitoring postural control during rehabilitation was hypothesized to shorten rehabilitation periods. This work presents the design of a postural control measuring device integrated with real-time intelligent biofeedback for postural correction. The system integrates three modules: (a) inertial measurement units (IMUs), (b) fuzzy knowledge base, and (c) feedback driver circuit. Human posture is measured using Euler angular measurements from the IMUs. A fuzzy inference system (FIS) was used to determine quality of postural control, based on measurements from the IMUs. Forewarning of poor postural control is given by vibrotactile actuators (biofeedback). Experiments were conducted to test viability of the system in achieving accurate real-time measurements and interventions. The results observed improvements in postural control when biofeedback intervention was present

Global entrainment effect on biped robot locomotion energy

In recent years, many researchers have studied the generation of rhythmic movement emerge as a stable limit cycle from global entrainment between biological neural networks that include central pattern generators (CPGs) and physical systems (i.e. robot arm) interacting with external environment. However, the e�ect of global entrainment on biped locomotion energy has yet to be addressed. This paper delineates an approach to minimize biped�s locomotion energy by means of global entrainment. The rhythmic movements for biped locomotion such as walking and running are generated by CPG using coupled nonlinear oscillators of Van Der Pol (VDP). Tuning VDP oscillator parameters to meet certain criteria (i.e. minimum energy) is a di�cult task to accomplish. This is due to the nonlinearity and the coupling of the oscillators. To overcome these di�culties, response surface methodology (RSM) has been proposed to characterize VDP parameters to achieve e�cient energy for biped locomotion. Then, global entrainment has been implemented between �ve-link biped robot and the constructed CPG. As a result, the sensory information modulates VDP oscillators� frequencies and tuned them to the resonance frequencies of the biped link lengths. The obtained results show an evidence of the importance of global entrainment in achieving lower energy for biped locomotion while maintaining the same or even higher forward velocity