Abstract:It is a general assumption that pneumatic muscle-type actuators will play an important role in the development of an assistive rehabilitation robotics system. In the last decade, the development of a pneumatic muscle actuated lower-limb leg orthosis has been rather slow compared to other types of actuated leg orthoses that use AC motors, DC motors, pneumatic cylinders, linear actuators, series elastic actuators (SEA) and brushless servomotors. However, recent years have shown that the interest in this field has grown exponentially, mainly due to the demand for a more compliant and interactive human-robotics system. This paper presents a survey of existing lower-limb leg orthoses for rehabilitation, which implement pneumatic muscle-type actuators, such as McKibben artificial muscles, rubbertuators, air muscles, pneumatic artificial muscles (PAM) or pneumatic muscle actuators (PMA). It reviews all the currently existing lower-limb rehabilitation orthosis systems in terms of comparison and evaluation of the design, as well as the control scheme and strategy, with the aim of clarifying the current and on-going research in the lower-limb robotic rehabilitation field.

Indoor air may be polluted by various types of pollutants which may come from cleaning products, construction activities, perfumes, cigarette smoke, water-damaged building materials and outdoor pollutants. Although these gases are usually safe for humans, they could be hazardous if their amount exceeded certain limits of exposure for human health. A sophisticated indoor air quality (IAQ) monitoring system which could classify the specific type of pollutants is very helpful. This study proposes an enhanced indoor air quality monitoring system (IAQMS) which could recognize the pollutants by utilizing supervised machine learning algorithms: multilayer perceptron (MLP), K-nearest neighbour (KNN) and linear discrimination analysis (LDA). Five sources of indoor air pollutants have been tested: ambient air, combustion activity, presence of chemicals, presence of fragrances and presence of food and beverages. The results showed that the three algorithms successfully classify the five sources of indoor air pollution (IAP) with a classification rate of up to 100 percent. An MLP classifier with a model structure of 9-3-5 has been chosen to be embedded into the IAQMS. The system has also been tested with all sources of IAP presented together. The result shows that the system is able to classify when single and two mixed sources are presented together. However, when more than two sources of IAP are presented at the same period, the system will classify the sources as 'unknown', because the system cannot recognize the input of the new pattern.

Understanding the actual spinal kinematics in completing critical daily activities is utmost important for human being as it can lead for better quality of life. Two of the most common functions which are necessary for human being are standing up and bend forward. Researchers tried to explore the kinematics of human spine during Sit-to-Stand (STS) and Stand-to-Flexion (STF) but most of them only focussed on thoracic and lumbar spine. Literatures of similar study within thoracic spine only divide the region up to three segments thus reducing the accuracy of actual thoracic multi segments behaviours in completing daily task. This paper aims to study the differences of spinal kinematics contribution between cervical and multi-segmental thoracic spine during STS & STF among healthy Asian adults using non-invasive approach. Interclass correlation coefficient (ICC) for both tasks specified during the study showed excellent reliability with all ICC value were above 0.90 (0.932-0.976). During STS, cervical region displayed quicker flexion-extension transition response. Roughly equivalent behaviour was observed within all thoracic segments. Lower thoracic segments (T10-12) exhibited passive increment behaviour upon reaching upright standing compared with other segments. All segments displayed increase of angular displacement during upright standing. Peak of flexion during STF was achieved at 50% phase with latter response within lower thoracic segments (T8-12). Throughout the completion of STF, most of the segments shared approximately identical behaviour with the adjacent segment. The results provide a clear explanation of the healthy spinal condition of asymptomatic adults and may serve for spinal treatment and rehabilitation purposes.

This paper introduces the body weight support gait training system known as the AIRGAIT exoskeleton and delves into the design and evaluation of its leg orthosis control algorithm. The implementation of the mono- and biarticular pneumatic muscle actuators (PMAs) as the actuation system was initiated to generate more power and precisely control the leg orthosis. This research proposes a simple paradigm for controlling the mono- and bi-articular actuator movements cocontractively by introducing a cocontraction model. Three tests were performed. The first test involved control of the orthosis with monoarticular actuators alone without a subject (WO/S); the second involved control of the orthosis with mono- and bi-articular actuators tested WO/S; and the third test involved control of the orthosis with mono- and bi-articular actuators tested with a subject (W/S). Full body weight support (BWS) was implemented in this study during the test W/S as the load supported by the orthosis was at its maximum capacity. This assessment will optimize the control system strategy so that the system operates to its full capacity. The results revealed that the proposed control strategy was able to co-contractively actuate the mono- and bi-articular actuators simultaneously and increase stiffness at both hip and knee joints.