Abstract In this issue, we will focus wearable technology on two themes. One is sports and fitness, and the other one is how to provide special protection and mobility aid for vulnerable groups, such as infants, elderlies and disabled persons. Two editor board members offered related articles for us. Prof. Paul D. Rosero-Montalvo from Salamanca University developed the embedded system inside the intelligent textile to realize the early warning and prevention (falls, burns and personal injuries) of accidents for infants in crawling stage. Meanwhile, Prof. Carlos Alberto Catalina Ortega from Burgos University developed advanced augmented reality (RA) technology and Internet services and mobile device interfaces specially designed for the elderly to provide autonomy and better quality of life in their daily activities. These articles were published firstly in Spanish, and we requested the authorization to translate them into English and republish. Also, we collected some articles on wearable technology in sports and fitness, including related policies in different countries, competitive advantage of wearable technology in sports training, great potential of wearable skin-interfaced microfluidic systems and so on.   Editor-in-chief Dr. Zhen Cao

Abstract Based on the Expectation Confirmation Model of Information System(ECM-IS), three personal characteristic factors of self-efficacy, privacy concerns, and innovation as well as two external environmental factors of subjective reference and switching costs were introduced to construct a model of factors affecting users’ continuance intention of wearable devices from the perspective of “technology-individual-environment”. 356 valid samples were collected through the questionnaire for empirical analysis. The results of the study show that self-efficacy, switching costs, and perceived usefulness in the ECM-IS model have a significant effect on users’ continuance intention at p <0.001 level while innovativeness and subjective references affect users’ continuance intention at p <0.05, but privacy concerns have no effect on continuance intention.

Abstract Objective: A new wearable upper limb rehabilitation robot is designed to address the disadvantages of the current desktop upper limb rehabilitation robot, which is bulky and inconvenient to move, and the rationality of the design is verified through the analysis of its motion characteristics and the calculation of joint moments. Methods: Firstly, according to the principle of modular design, the overall structure was designed. Secondly, the SOILDWORKS is used for three-dimensional modeling, and the SOILDWORKS Motion is used to simulate the elbow flexion/extension movement, shoulder flexion/extension movement and shoulder-elbow joint linkage movement of the robot. Finally, the dynamic equation of the system is established based on Lagrange method, and the change curve of the joint torque of the manipulator is calculated by MATLAB software. Results: The simulation results confirmed that the motion simulation curves of shoulder joint, elbow joint and wrist joint were smooth. The dynamic analysis confirmed that the joint torque variation curve was smooth and the maximum joint torque was less than the rated torque of the motor after deceleration. Conclusion: The design of wearable upper limb rehabilitation robot is reasonable, which lays a theoretical foundation for the subsequent research on upper limb rehabilitation robot.

Abstract According to the special characteristics of children’s body and mind and the concept of human–computer interaction, the research and development model of children’s intelligent safety clothing is explored and a A practical research model. Based on the multi–dimensional needs of consumers for children’s clothing and the performance of smart components, we explore the combination of smart wearable equipment and children’s safety clothing, and propose a design process architecture that takes into account function and aesthetics. Through the analysis of the connection technology between smart clothing and mobile terminals, we propose the idea from single interaction to multi–device co–connection, and establish a multi–interaction smart clothing based on the optimal allocation of energy and high. Through the analysis of the connection technology between smart clothing and mobile terminals, we propose the idea of moving from single interaction to multi–device co–connection, and establish the R&D process of multi–interaction smart wearable devices based on optimal energy allocation and efficient information transmission.

Abstract Quantitative analysis of sports is an important development direction of scientific skiing training, and the digital expression of human movement patterns during skiing is the basis for scientific quantitative analysis. A human motion capture and attitude reconstruction system based on a wearable BSBD inertial measurement unit was designed and built, combined with the human multi-rigid body motion model to realize the human body reconstruction during the skiing, and applied to the auxiliary training of slewing movements in alpine skiing. At the same time, for the indoor training scene based on the multi-degree-of-freedom simulated ski training platform, a digital evaluation method suitable for ski slalom is proposed. The method uses motion capture system and posture reconstruction system to extract five kinds of sliding characteristic data of skiers, and realizes the evaluation of skiers’ technical parameters through similarity measurement and linear fitting with high-level athletes’ motion parameters, so as to assist scientific training. Finally, experiments are carried out on the indoor Olymp simulated ski training bench to verify the effectiveness of the method.

Abstract The feasibility of using transfemoral prosthesis Otto bock with 3R80 knee and articulated ankle1C30 “Trias” was analyzed from the perspective of dynamics and clinic. The kinematic and kinetic study of gait were performed on 5 amputated volunteers and 5 controls using videography techniques and force platform. Kinetic asymmetry gait is one of the main causes of hip joint degeneration. Combining kinematic and kinetic variables, we can draw important conclusions related to the dynamic imbalance of the main causes of hip degenerative diseases through the clinical trials of radiography film and density measurement, which has become an important tool to evaluate the feasibility of prosthetic design.

Abstract This document outlines wearable technology and the sources, related topics and authors of major publications on this subject in recent years. It is worth mentioning that wearable or wearable technology is also called “wearables” in English. It refers to theincorporationation of microprocessors, sensors and transducersthat we wear daily, which acts as a computer that always works with users, and can be used in a defined space for continuous interaction with users, wearable technology can be defined as an electronic device that can be embedded into human body to continuously obtain information. The purpose of this paper is to understand the development and current situation of this new technology, and apply it to new research findings and the development of wearable devices. The disciplinary connection between different knowledge fields provides a clear starting point for the development of research topics. In specific case of interest, the research focuses on the devices applied to sports, which are used to analyze the strength, flexibility and speed of athletes’ lower limbs, and generate sports evidence related to numerical data, so as to further analyze, explain and produce conclusive results. Electronic engineering performs all data processing similar to electricity, thus defining a part of wearable design for adaptation during physical activity. In the field of programming, system engineering is very important for the data conversion of sensors and the representation of these data in a way that people can understand. This new technology allows the generation of a wide variety of data, but integrates multiple disciplines at the same time. With the understanding of sports, people will test the complex problems around the human body and how to correctly explain the results of clothing elements that can be designed technically.

Abstract Infant crawling is a method to discover and learn its motor, cognitive, social and emotional functions. Therefore, infants face different risks, such as falls, burns and personal injuries. The most common is that the family is the place where the main event occurs. Therefore, the focus of this research is to develop the embedded system inside the intelligent textile to realize the early warning and prevention of accidents. The system is located in a clothing harness with a crawling knee pad connection including a magnetic sensor. These devices are responsible for detecting security tapes previously placed in the most dangerous location in the home. Therefore, the system gives an alarm with a response time of 7.6 seconds after activation.

Abstract Technology offers many possibilities, but older people often do not fully enjoy these opportunities and are frustrated or afraid of these new devices. This has led to their gradual isolation in a society where different forms of communication through the Internet and ICT are essential. In this article, we describe a study conducted during the nacodeal project, which aims to provide technical solutions for the elderly to provide autonomy and better quality of life in their daily activities by integrating information and communication technologies. In order to achieve this goal, advanced augmented reality (RA) technology and Internet services and mobile device interfaces specially designed for the elderly have been developed. These technologies use the underlying structure of most home and geriatric care centers. We propose a prototype system composed of tablet computers and portable RA devices, and analyze the impact of society on user interaction, as well as the evaluation of acceptability and usability. The assessment was conducted through focus groups and individual pilot tests with 48 participants: The elderly, caregivers and experts. His comments concluded that older people have a strong interest and interest in RA based nursing information and communication technologies, especially those related to communication and autonomy.

Abstract In order to rapidly promote the application of wearable plantar pressure monitoring system, the physiological structure of human foot, the source of plantar pressure and exercise step frequency are introduced. Based on the current research status of wearable plantar pressure monitoring systems, the fabrication materials and response principles of the fabric sensor-based integrated pressure monitoring socks are explored, the principle of selecting the features of the wearable plantar pressure monitoring system and its application in the field of the pressure monitoring system is explained. The principle of selecting the features of wearable plantar pressure monitoring system and its application in fall detection, foot disease diagnosis, and plantar pressure database are explained. Finally, we discussed the problems in the industrialization of wearable plantar pressure monitoring system at this stage. The problems of poor material performance and short wireless transmission distance in the industrialization of wearable plantar pressure monitoring systems are discussed, and a better integrated system based on biomechanics, textile materials and electronic communication is proposed. A better application prospect based on the cross-fusion integration of biomechanics, textile materials and electronic communication is proposed.

Abstract This article describes the research that leads to the development of a wireless optical device capable of generating vibrotactile mechanical stimuli at different points on the skin and at desired frequencies by means of sixteen actuators contained in a portable bracelet designed for any extremity of the human body. This prototype allows control over each actuator used as a stimulation point, actuated independently by wirelessly transmitted commands to a rechargeable stand-alone control system in the bracelet. Usability tests were carried out, with respect to tactile perception, which proved the correct functioning of the device. In perspective, the development, after a variety of validation tests with a large sample of patients with and without neuropathy, aims at creating a database to be used as set point values in front of these patients with the expectation that the system will also be used in patients with movement deficits, and employing tactile perception as a psychomotor stimulant in the execution of motor activities.

Abstract The wearable body surface microfluidic system has great application potential in the field of sports. The use of the wearable body surface microfluidic system to monitor the physiological state of athletes can solve problems faced such as long inspection cycle in sports monitoring, difficulties in continuous monitoring, dependence on laboratory platforms, athlete resistance and other problems faced in technological integration to promote the development of the sports field. In recent years, the development of key technologies such as microfluidic chips and microneedle delivery provides an ideal solution for real-time monitoring and even immediate intervention of physiological states during exercise. This paper summarizes the latest research progress of wearable body surface microfluidic systems and focuses on eight wearable body surface microfluidic systems that may be applied in the field of sports, with their application prospects in sports analyzed and discussed. Finally, the application direction of the wearable body surface microfluidic system that may achieve breakthroughs is illustrated with the prospect demonstration of the future research and development direction of wearable sports equipment. This paper aims to focus on technical problems in the development of the sports field, provide multi-disciplinary solutions and advocate technology integration as well as provide scientific and technological assistance for the development of the sports field.

Abstract Using the literature method and the logical analysis method, the study of “Internet +” to help the national fitness is conducted. The value of “Internet +” in helping national fitness: helping the government to reform the national fitness sector in terms of “decentralization, management and service”; helping the national fitness service to match supply and demand accurately; helping the national fitness sector to develop intelligently. The existing dilemmas: the popularity of “Internet +” national fitness integration is not high, the platform construction is insufficient, and the supervision ability is not strong. Accordingly, the development path of “Internet +” to help national fitness is proposed: based on the integration and popularization, to enhance the ability of the masses to apply online fitness; platform construction as the core, to strengthen the governance capacity of national fitness; innovation–driven focus, to promote the intelligent empowerment of national fitness; rule of law construction as a guarantee, to enhance the ability of national fitness network supervision.