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Recognizing Activities and Spatial Context Using Wearable Sensors  [PDF]
Amarnag Subramanya,Alvin Raj,Jeff A. Bilmes,Dieter Fox
Computer Science , 2012,
Abstract: We introduce a new dynamic model with the capability of recognizing both activities that an individual is performing as well as where that ndividual is located. Our model is novel in that it utilizes a dynamic graphical model to jointly estimate both activity and spatial context over time based on the simultaneous use of asynchronous observations consisting of GPS measurements, and measurements from a small mountable sensor board. Joint inference is quite desirable as it has the ability to improve accuracy of the model. A key goal, however, in designing our overall system is to be able to perform accurate inference decisions while minimizing the amount of hardware an individual must wear. This minimization leads to greater comfort and flexibility, decreased power requirements and therefore increased battery life, and reduced cost. We show results indicating that our joint measurement model outperforms measurements from either the sensor board or GPS alone, using two types of probabilistic inference procedures, namely particle filtering and pruned exact inference.
The Use of Wearable Inertial Motion Sensors in Human Lower Limb Biomechanics Studies: A Systematic Review  [PDF]
Daniel Tik-Pui Fong,Yue-Yan Chan
Sensors , 2010, DOI: 10.3390/s101211556
Abstract: Wearable motion sensors consisting of accelerometers, gyroscopes and magnetic sensors are readily available nowadays. The small size and low production costs of motion sensors make them a very good tool for human motions analysis. However, data processing and accuracy of the collected data are important issues for research purposes. In this paper, we aim to review the literature related to usage of inertial sensors in human lower limb biomechanics studies. A systematic search was done in the following search engines: ISI Web of Knowledge, Medline, SportDiscus and IEEE Xplore. Thirty nine full papers and conference abstracts with related topics were included in this review. The type of sensor involved, data collection methods, study design, validation methods and its applications were reviewed.
Wearable kinesthetic system for capturing and classifying upper limb gesture in post-stroke rehabilitation
Alessandro Tognetti, Federico Lorussi, Raphael Bartalesi, Silvana Quaglini, Mario Tesconi, Giuseppe Zupone, Danilo De Rossi
Journal of NeuroEngineering and Rehabilitation , 2005, DOI: 10.1186/1743-0003-2-8
Abstract: This paper deals with the design, the development and implementation of a sensing garment, from the characterization of innovative comfortable and diffuse sensors we used to the methodologies employed to gather information on the posture and movement which derive from the entire garments. Several new algorithms devoted to the signal acquisition, the treatment and posture and gesture reconstruction are introduced and tested.Data obtained by means of the sensing garment are analyzed and compared with the ones recorded using a traditional movement tracking system.The main results treated in this work are summarized and remarked. The system was compared with a commercial movement tracking system (a set of electrogoniometers) and it performed the same accuracy in detecting upper limb postures and movements.This work deals with the development of an innovative measuring system devoted to the analysis of the human movement. Our main aim is to provide a valid alternative comfortable instrumentation useful in several rehabilitation areas. In particular we focused our attention on the remote treatment of post-stroke patients [1].The analysis of human movement is generally performed by measuring kinematic variables of anatomic segments by employing accelerometers, electrogoniometers, electromagnetic sensors or cameras integrated in finer equipment as stereophotogrammetric systems. In remote rehabilitation tasks, several disadvantages derive from the use of these technologies, which are mainly applied in the realization of robotics or mechatronics machines (such as MIME or MIT-MANUS [2]) which result invasive, complex and often unable to satisfy safety requirements for the presence of mechanical parts in movement. In literature, several studies are devoted to realize electric devices with properties of hight wearability [3-5]. The main drawbacks of wearable sensing systems available on the market are their weight, the rigidity of the fabric which they are made of, the dimension
Symmetry and Asymmetry in Bouncing Gaits  [PDF]
Giovanni A. Cavagna
Symmetry , 2010, DOI: 10.3390/sym2031270
Abstract: In running, hopping and trotting gaits, the center of mass of the body oscillates each step below and above an equilibrium position where the vertical force on the ground equals body weight. In trotting and low speed human running, the average vertical acceleration of the center of mass during the lower part of the oscillation equals that of the upper part, the duration of the lower part equals that of the upper part and the step frequency equals the resonant frequency of the bouncing system: we define this as on-offground symmetric rebound. In hopping and high speed human running, the average vertical acceleration of the center of mass during the lower part of the oscillation exceeds that of the upper part, the duration of the upper part exceeds that of the lower part and the step frequency is lower than the resonant frequency of the bouncing system: we define this as on-off-ground asymmetric rebound. Here we examine the physical and physiological constraints resulting in this on-off-ground symmetry and asymmetry of the rebound. Furthermore, the average force exerted during the brake when the body decelerates downwards and forwards is greater than that exerted during the push when the body is reaccelerated upwards and forwards. This landing-takeoff asymmetry, which would be nil in the elastic rebound of the symmetric spring-mass model for running and hopping, suggests a less efficient elastic energy storage and recovery during the bouncing step. During hopping, running and trotting the landing-takeoff asymmetry and the mass-specific vertical stiffness are smaller in larger animals than in the smaller animals suggesting a more efficient rebound in larger animals.
Toward Intelligent Biped-Humanoids Gaits Generation  [PDF]
Nizar Rokbani,Boudour Ammar Cherif,Adel M. Alimi
Computer Science , 2012, DOI: 10.5772/6732
Abstract: In this chapter we will highlight our experimental studies on natural human walking analysis and introduce a biologically inspired design for simple bipedal locomotion system of humanoid robots. Inspiration comes directly from human walking analysis and human muscles mechanism and control. A hybrid algorithm for walking gaits generation is then proposed as an innovative alternative to classically used kinematics and dynamic equations solving, the gaits include knee, ankle and hip trajectories. The proposed algorithm is an intelligent evolutionary based on particle swarm optimization paradigm. This proposal can be used for small size humanoid robots, with a knee an ankle and a hip and at least six Degrees of Freedom (DOF).
Wearable Gait Measurement System with an Instrumented Cane for Exoskeleton Control  [PDF]
Modar Hassan,Hideki Kadone,Kenji Suzuki,Yoshiyuki Sankai
Sensors , 2014, DOI: 10.3390/s140101705
Abstract: In this research we introduce a wearable sensory system for motion intention estimation and control of exoskeleton robot. The system comprises wearable inertial motion sensors and shoe-embedded force sensors. The system utilizes an instrumented cane as a part of the interface between the user and the robot. The cane reflects the motion of upper limbs, and is used in terms of human inter-limb synergies. The developed control system provides assisted motion in coherence with the motion of other unassisted limbs. The system utilizes the instrumented cane together with body worn sensors, and provides assistance for start, stop and continuous walking. We verified the function of the proposed method and the developed wearable system through gait trials on treadmill and on ground. The achievement contributes to finding an intuitive and feasible interface between human and robot through wearable gait sensors for practical use of assistive technology. It also contributes to the technology for cognitively assisted locomotion, which helps the locomotion of physically challenged people.
A Comparative Study of Biologically Inspired Walking Gaits through Waypoint Navigation  [PDF]
Umar Asif,Javaid Iqbal
Advances in Mechanical Engineering , 2011, DOI: 10.1155/2011/737403
Abstract: This paper investigates the locomotion of a walking robot by delivering a comparative study of three different biologically inspired walking gaits, namely: tripod, ripple, and wave, in terms of ground slippage they experience while walking. The objective of this study is to identify the gait model which experiences the minimum slippage while walking on a ground with a specific coefficient of friction. To accomplish this feat, the robot is steered over a reference path using a waypoint navigation algorithm, and the divergence of the robot from the reference path is investigated in terms of slip errors. Experiments are conducted through closed-loop simulations using an open dynamics engine which emphasizes the fact that due to uneven and unsymmetrical distribution of payload in tripod and ripple gait models, the robot experiences comparatively larger drift in these gaits than when using the wave gait model in which the distribution of payload is even and symmetrical on both sides of the robot body. The paper investigates this phenomenon on the basis of force distribution of supporting legs in each gait model. 1. Introduction The development of a scheme to generate leg sequential movements representing particular walking gaits is an important aspect in the design and realization of walking systems [1]. In order to realize the utilization and implementation of walking robots in real world scenarios and natural environments, generation of appropriate walking gaits is an imperative requirement. The performance of a walking gait is generally ensured in terms of its mobility and stability as addressed in [2]. Gait analysis involves inspection and evaluation of various gait variables that include its speed, stability, adaptability to a specific terrain, and so forth. Periodic gaits which include tripod, wave and in-phase gaits as discussed in [3, 4] investigate the walking patterns in terms of coordinated placements of footholds and body motions in order to transit from one pose to another. Furthermore, in the context of generation of stepping patterns for walking, free gaits have been studied in [5]. Follow-the-leader gaits as discussed in [6, 7] deliver a study on adaptive gaits. In another related study [8], stepping sequences of insects are investigated to describe a straight-line walking gait for a hexapod robot by considering alternating tripod gaits. The purpose of this paper is to deliver a comparative study on various walking gaits found in nature. The study encompasses the comparison of walking gaits in terms of their speed and ground slippage while
Auditive Discrimination of Equine Gaits by Parade Horses
Duilio Cruz-Becerra,Enrique Burunat-Gutiérrez,Aldo Hernández-Barrios,Andrés Manuel Pérez-Acosta
Universitas Psychologica , 2009,
Abstract: The purpose of this study was to examine parade horses’ auditory discriminationamong four types of equine gaits: paso-fino (“fine step”), trote-reunido(“two-beat trot”), trocha (“trot”), and galope-reunido (“gallop”). Two experimentallyna ve horses were trained to discriminate the sound of their owngait (paso-fino or fine step), through an experimental module that dispensedfood if the subject pressed a lever after hearing a sound reproduction of aparticular gait. Three experimental phases were developed, defined by theperiod of exposure to the sounds (20, 10, and 5 seconds, respectively). Thechoice between pairs of sounds including the horse’s own gait (fine stepand two-beat trot; fine step and gallop; and fine step and trot) was reinforceddifferentially. The results indicate that the fine step horses are able todiscriminate their own gait from others, and that receptivity to their ownsounds could be included in their training regime.
Analytical Survey of Wearable Sensors  [PDF]
A. Rehman,M. Mustafa,N. Javaid,U. Qasim,Z. A. Khan
Computer Science , 2012,
Abstract: Wearable sensors inWireless Body Area Networks (WBANs) provide health and physical activity monitoring. Modern communication systems have extended this monitoring remotely. In this survey, various types of wearable sensors discussed, their medical applications like ECG, EEG, blood pressure, detection of blood glucose level, pulse rate, respiration rate and non medical applications like daily exercise monitoring and motion detection of different body parts. Different types of noise removing filters also discussed at the end that are helpful in to remove noise from ECG signals. Main purpose of this survey is to provide a platform for researchers in wearable sensors for WBANs.
Auditive Discrimination of Equine Gaits by Parade Horses
CRUZ-BECERRA,DUILIO; BURUNAT-GUTIéRREZ,ENRIQUE; HERNáNDEZ-BARRIOS,ALDO; PéREZ-ACOSTA,ANDRéS MANUEL;
Universitas Psychologica , 2009,
Abstract: the purpose of this study was to examine parade horses' auditory discrimination among four types of equine gaits: paso-fino ("fine step"), trote-reunido ("two -beat trot"), trocha ("trot"), and galope -reunido ("gallop"). two experimentally naive horses were trained to discriminate the sound of their own gait (paso-fino or fine step), through an experimental module that dispensed food if the subject pressed a lever after hearing a sound reproduction of a particular gait. three experimental phases were developed, defined by the period of exposure to the sounds (20, 10, and 5 seconds, respectively). the choice between pairs of sounds including the horse's own gait (fine step and two-beat trot; fine step and gallop; and fine step and trot) was reinforced differentially. the results indicate that the fine step horses are able to discriminate their own gait from others, and that receptivity to their own sounds could be included in their training regime.
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