Evaluation of eye metrics as a detector of fatigue.

Objectives: This study evaluated oculometrics as a detector of fatigue in Air Force-relevant tasks after sleep deprivation. Using the metrics of total eye closure duration (PERCLOS) and approximate entropy (ApEn), the relation between these eye metrics and fatigue-induced performance decrements was investigated.

Background: One damaging effect to the successful outcome of operational military missions is that attributed to sleep deprivation-induced fatigue.

Haptic devices as a paradigm to enhance learning/function--theory and empirical studies.

Haptics is a modern term employed to describe both afferent and efferent flows of forces with humans. The appropriate design of these force flow fields when coordinated with information to and from computers and other devices to physically challenged individuals can empower the performance of certain tasks previously not attainable. Extensive empirical work presented herein has demonstrated that proper augmentation of particular dynamic force fields, synchronised with certain cognitive tasks, can lead to improved functionality.

Pneumatic muscle actuator for resistive exercise in microgravity: test with a leg model.

Introduction: A proof-of-concept demonstration is described in which a DC servomotor (simulating the quadriceps of a human operator) rotated a pulley 90 degrees (simulating knee extension). A pneumatic muscle actuator (PMA) generated an opposing force (antagonist) to the rotating pulley. One application of such a device is for use in microgravity environments because the PMA is compact, simple, and of relatively small mass (283 g).

Characterisation of a phenomenological model for commercial pneumatic muscle actuators.

This study focuses on the parameter characterisation of a three-element phenomenological model for commercially available pneumatic muscle actuators (PMAs). This model consists of a spring, damping and contractile element arranged in parallel. Data collected from static loading, contraction and relaxation experiments were fitted to theoretical solutions of the governing equation for the three-element model resulting in prediction profiles for the spring, damping and contractile force coefficient.

Characterisation of a pneumatic muscle test station with two dynamic plants in cascade.

Pneumatic muscle actuators (PMAs) offer significant advantages over more traditional actuators, which make them prime candidates in rehabilitation devices. A dynamic test station (DTS) is modified to demonstrate the use of a PMA for this application. The DTS includes two dynamic systems: a PMA and a DC servomotor.