Medical Exoskeleton Research Articles

Research on enhancing human-machine interaction in medical exoskeleton devices through the integration of artificial intelligence

This paper explores the integration of Artificial Intelligence (AI) to enhance human-machine interaction in medical exoskeleton devices. AI technologies such as machine learning, natural language processing (NLP), and predictive analytics can significantly improve the efficiency and comfort of these devices. Machine learning algorithms analyze sensor data in real-time, optimizing control strategies to adapt to user movements. NLP enables intuitive control through voice commands, reducing the cognitive and physical burden on users. Predictive analytics anticipates user needs, enhancing responsiveness and reducing the risk of errors. Case studies of AI-integrated exoskeletons, like the EksoGT and ReWalk, demonstrate improved rehabilitation outcomes and user satisfaction. Despite challenges such as data privacy and the need for significant investment, the benefits of AI integration are substantial. This paper provides insights into the potential of AI to transform medical exoskeletons, offering new levels of independence and quality of life for individuals with mobility impairments. Future research should focus on developing advanced AI algorithms and exploring new applications to further enhance user experience and device performance.

Finite Element Analysis Optimises Material Selection and 3D Printing of Lower Limb Exoskeletons

The purpose of the technology behind exoskeletons is to achieve human-machine motor function. The performance of the military, industry, and the medical field is all improved with exoskeletons. Rehabilitative benefits can be gained from using medical exoskeletons. The design and development of mechanical structures have an impact on the cost of metabolic processes, as well as size, portability, and cost. Exoskeletons are now within reach of consumers in underdeveloped nations thanks to the miniaturisation of components including electronics, controls, motors, and drives. The use of alternative material for the exoskeleton structure improves both its safety and its strength while simultaneously reducing its overall cost. Frames can be made out of metals, composites, or polymers. In this study, the technology of additive manufacturing is used to choose the components that will go into an exoskeleton frame for lower limb rehabilitation. CATIA v5 generates a 3D model, and Ansys carries out a finite element analysis to estimate the deformation of the material and determine whether or not it is appropriate for use by various age groups.

Design and Development of a Multi-Functional Bioinspired Soft Robotic Actuator via Additive Manufacturing.

The industrial revolution 4.0 has led to a burst in the development of robotic automation and platforms to increase productivity in the industrial and health domains. Hence, there is a necessity for the design and production of smart and multi-functional tools, which combine several cutting-edge technologies, including additive manufacturing and smart control systems. In the current article, a novel multi-functional biomimetic soft actuator with a pneumatic motion system was designed and fabricated by combining different additive manufacturing techniques. The developed actuator was bioinspired by the natural kinematics, namely the motion mechanism of worms, and was designed to imitate the movement of a human finger. Furthermore, due to its modular design and the ability to adapt the actuator’s external covers depending on the requested task, this actuator is suitable for a wide range of applications, from soft (i.e., fruit grasping) or industrial grippers to medical exoskeletons for patients with mobility difficulties and neurological disorders. In detail, the motion system operates with two pneumatic chambers bonded to each other and fabricated from silicone rubber compounds molded with additively manufactured dies made of polymers. Moreover, the pneumatic system offers multiple-degrees-of-freedom motion and it is capable of bending in the range of −180° to 180°. The overall pneumatic system is protected by external covers made of 3D printed components whose material could be changed from rigid polymer for industrial applications to thermoplastic elastomer for complete soft robotic applications. In addition, these 3D printed parts control the angular range of the actuator in order to avoid the reaching of extreme configurations. Finally, the bio-robotic actuator is electronically controlled by PID controllers and its real-time position is monitored by a one-axis soft flex sensor which is embedded in the actuator’s configuration.

АНАЛИЗ РАЗВИТИЯ И РАСПРОСТРАНЕНИЯ ЭКЗОСКЕЛЕТОВ

The article analyzes the features of the development and diffusion of active and passive exoskeletons for industry and healthcare in Russia and abroad. Particular attention is paid to Russian developments in connection with the sanctions imposed by a number of countries on the supply of high-tech products to Russia. Models of the dynamics of technical indicators of industrial exoskeletons were built, it was carried out the study of the development trends of medical exoskeletons based on the analysis of their technical and economic indicators.

Suggestions for the order of military exoskeletons classification

The article defines the role and place of exoskeletal structures for military purposes in the military equipment of military personnel, and provides a brief analysis of the functional tasks assigned to them. Based on the results of the analysis, a new formulation of the concept of «military exoskeletons» is proposed, and the order of their classification is recommended. Based on the practical experience of creating and using exoskeletons for military purposes, a general description of all the proposed classification groups and their features is given. Key words Military exoskeleton, military combat equipment, classification groups, active assault-type exoskeleton, passive exoskeleton, explosive exoskeleton, rigging exoskeleton, medical exoskeleton.

ИССЛЕДОВАНИЕ ДИНАМИКИ ИСПОЛНИТЕЛЬНОГО МЕХАНИЗМА ЭКЗОСКЕЛЕТА

A person has more than 300 degrees of mobility, but it is practically impossible to recreate such a kinematic scheme. In this article, a kinematic scheme of the exoskeleton is proposed that is most necessary for human movement. A 3D model of the exoskeleton actuating unit with an electrohydraulic drive has been developed in the CAD system and the values of masses, coordinates of mass centers, inertia tensors of the links of the exoskeleton actuating unit have been calculated. A launch file has been developed in the MATLAB environment for modeling the dynamics of the exoskeleton actuating unit. The control laws in the degrees of mobility of the actuating unit of the exoskeleton are selected. As a result of the theoretical study, the ranges of changes in the generalized coordinates for the joints under study are determined. The dependences of the power and the moment in the joints 9, 10 on time are obtained. The conducted studies have shown that lifting the leg will require more energy and this makes it necessary to develop power plants, explore various types of drives and ways to control them energy-efficiently. The obtained data can serve in the development of a medical exoskeleton.

Design and characterization of a pneumatic muscle actuator with novel end-fittings for medical assistive applications

Pneumatic muscle actuators (PMA) are a class of soft actuators known for their high power to weight ratio and inherent compliance. The pneumatic muscle's inherent properties make them very favorable for assistive applications (e.g., medical exoskeletons). This study presents a novel end-fitting design that makes the developed pneumatic muscle actuator lightweight, cost-effective, and modular, thus simplifying the process of assembly and maintenance. The pneumatic muscle actuator assembled using the novel end fittings achieves a shorter overall length without compromising its contraction. The pneumatic muscle actuator has been assembled using a commercial bladder and a braided sleeve alongside a pair of 3D printed novel end-fittings. The paper also details the developed actuator's characterization for force and deflection parameters at various operating pressures. A total of four muscle actuators of varying diameters with constant actuation length (100 mm) were developed and tested to showcase the effect of size on the muscle actuator's behavior. The study presented here also involved comparing three mathematical models developed for pneumatic muscles in order to find a model which closely resembles the developed muscle actuator. Finally, the developed pneumatic muscle actuator's behavior is compared with a commercially available muscle to determine the efficacy of the developed muscle's design. The tests showed that the muscle using a bladder of smaller volume but higher tensile modulus had a higher accuracy and stable performance. As the muscle is intended for medical applications, it was also put through an endurance test with realistic loading and pressure conditions, which revealed very promising results.

Effects of Wearable Powered Exoskeletal Training on Functional Mobility, Physiological Health and Quality of Life in Non-ambulatory Spinal Cord Injury Patients.

BackgroundSpinal cord injury (SCI) is a serious clinical condition that impacts a patient's physical, psychological, and socio-economic status. The aim of this pilot study was to evaluate the effects of training with a newly developed powered wearable exoskeleton (Hyundai Medical Exoskeleton [H-MEX]) on functional mobility, physiological health, and quality of life in non-ambulatory SCI patients.MethodsParticipants received 60 minutes of walking training with a powered exoskeleton 3 times per week for 10 weeks (total 30 sessions). The 6-minute walking test (6MWT) and timed-up-and-go test (TUGT) were performed to assess ambulatory function. The physiological outcomes of interest after exoskeleton-assisted walking training were spasticity, pulmonary function, bone mineral density, colon transit time, and serum inflammatory markers. Effects of walking training on subjective outcomes were estimated by the Korean version of the Falls Efficacy Scale—International and the 36-Item Short-Form Health Survey version 2.ResultsTen participants finished 30 sessions of training and could ambulate independently. No severe adverse events were reported during the study. After training, the mean distance walked in the 6MWT (49.13 m) was significantly enhanced compared with baseline (20.65 m). The results of the TUGT also indicated a statistically significant improvement in the times required to stand up, walk 3 m and sit down. Although not statistically significant, clinically meaningful changes in some secondary physiological outcomes and/or quality of life were reported in some participants.ConclusionIn conclusion, this study demonstrated that the newly developed wearable exoskeleton, H-MEX is safe and feasible for non-ambulatory SCI patients, and may have potential to improve quality of life of patients by assisting bipedal ambulation. These results suggest that the H-MEX can be considered a beneficial device for chronic non-ambulatory SCI patients.Trial RegistrationClinicalTrials.gov Identifier: NCT04055610

The recent development of 3D printing in developing lower-leg exoskeleton: A review

The research in wearable lower limb exoskeletons is showing an increasing interest in the last few years. An exoskeleton is a structure that helps paralyzed patients stand and walk. Nowadays, wearable exoskeletons have a growing interest in healthcare, as they help make patient's rehabilitation process more comfortable and more natural. External exoskeletons help people recover after accidents; they may help older people keep their habitual lives. Besides, they can be used for constructors, army soldiers, and workers to reduce the possibility of a work injury, making the work process less painful and tiring as they help distribute the load evenly. This review paper presents current techniques and methods implemented in medical rehabilitation. The work briefly describes the main types of medical exoskeletons, their technical characteristics, main features, and the detailed connection to the area's existing trends. The study also focused on the development of 3D printed leg exoskeletons, their drawbacks, fabricating challenges, and prospects. Various methods that are being developed may influence and increase the potential of 3D printed leg exoskeletons for biomedical applications. The application of 3D printing in rehabilitation opens the opportunity to decrease the weight and the development cost of the exoskeletons, as well as make human rehabilitation more affordable.

Medical exoskeleton “Remotion” with an intelligent control system: Modeling, implementation, and testing

This article presents the intelligent control system of the lower limb medical exoskeleton “Remotion”, and describes the salient features of the system. Special attention is paid to simulation and modeling of the human gait and movement parameters, as well as testing the developed device, based on theoretical assumptions. The main parts of the system are presented in this paper, including drives control system, a bimodal user interface and walking pattern control system. The paper continues a series of works concerning the “Remotion” medical exoskeleton.

Anthropomorphic mechatronics for sports and medicine

The article describes the prospects for the development and implementation of anthropomorphic mechatronics to the practice of sports and medicine. The main objects of research were sport and medical exoskeletons. The main function of a sport exoskeleton is to get the best conditions for the formation and increasing of the effectiveness of sport technique. The technology offers a completely new approach to the transfer of "sports" knowledge and skills. Usually, the coach affects on audiovisual channels, but a sport exoskeleton transmits a significant amount of information through proprioceptive channels (sensations) when performing a real exercise, and not only ideomotor one. Thus, control of the athlete's body segments is carried out independently on the basis of the received signals from his body, and not only because feedback from the coach. This is the main effect for athlete, due to which it is possible to significantly increase the quickness of transmission of training information and, as a consequence, the quickness of mastering of effective sport technique. The using of exoskeletons in rehabilitee medicine is primarily need for a comprehensive solution in the rehabilitation of patients with impaired or loss of motor function due to diseases of various etiologies. In this case, the exoskeleton acts as a mechanism that determines the body segment movement. Management of such an exoskeleton is carried out through a special interface "brain–computer". The task of training medical personnel using robotic complexes generally coincides with the sports tasks associated with the formation of a stable motor skill and the improvement of the technique of movement action. The medical exoskeleton is used as a simulator for the training the structure and the needed characteristics of the movement at performing the operations.

Walking propulsion generation in double stance by powered exoskeleton for paraplegics

This paper introduces an electric Hyundai Medical Exoskeleton (H-MEX). It is specially designed to enable disabled people (e.g. spinal cord injury individuals below T10, stroke patients) to walk again, according to a basic walking control strategy. H-MEX is easily assembled with mechanically/electrically block-by-block connections, and its built-in control framework provides an unique control interface. Through this interface, the H-MEX wearer can customize gait parameters (viz., the step length, step period, and default torso tilt angle). With the proposed framework, trajectories for each active joint are planned for generating propulsion (i.e., angular momentum) in double-stance gait. This facilitates stability and convenience for H-MEX wearers. A dynamic simulation was conducted on a simplified planar model that describes an average human body: the intended propulsion generation during the double-stance phase was verified to lead to angular momentum with respect to a leading stance leg, for more stable and convenient step walking. Also, the degree of propulsion was shown to be adjusted by setting kinematic percentage of intended double-stance motion.The proposed control method was evaluated with five healthy subjects on a treadmill as one of initial performance tests: kinematic data on subjects’ torsos given from basic walking at a velocity of 0.7 km/h and 1.2 km/h indicated the effectiveness of the proposed control strategy.

Assessment of the moment of stability when providing frontal stability of the exoskeleton

In medical exoskeletons, it is necessary to support a stable vertical position of a person. Based on the use of mathematical modeling and theoretical mechanics methods, estimation of the moment of stability is performed while ensuring the frontal (lateral) stability of a person in a medical exoskeleton. This will allow to receive the maximum allowable safe speed, eliminating the fall in the frontal plane. Recommendations for providing frontal (lateral) stability are given.

Transformations of a system state under the sequence of conditions

The algorithm of transformation of a system states is established on the basis of applying the methods of mathematical modelling and theoretical mechanics, providing preservation of a stationary property of the system.The form and the sizes of dangerous zones for a moving exosystem (a person in a medical exoskeleton) are determined as well.This will allow to produce the maximum allowable velocity,avoiding both lateral overturning of the exo system, and collision with obstacles during its movement.

Ergonomic Design Strategy for Crutches of a Lower-limb Exoskeleton for Paraplegic Individuals: An Experimental Study

This paper presents a design strategy for crutches used to operate paraplegic exoskeletons. With Hyundai Medical Exoskeleton (H-MEX) and its controller crutch, we conducted an experiment performing a series of movements with 30 subjects followed by post-interviews. With regard to previous design of crutches, significant design issues such as operational logic and button layout were identified. We suggest HMI strategies to improve the crutch in four specific directions: simple operation, comfortable shape and arrangement, clear information feedback, and enhanced convenience. A new design has been proposed by applying the HMI strategy and will help patients more effectively by reducing burden and fatigue when using crutch.

Lower-limb exoskeletons

With the recent progress in personal care robots, interest in wearable exoskeletons has been increasing due to the demand for assistive technologies generally and specifically to meet the concerns in the increasing ageing society. Despite this global trend, research focus has been on load augmentation for soldiers/workers, assisting trauma patients, paraplegics, spinal cord injured persons and for rehabilitation purposes. Barring the military-focused activities, most of the work to date has focused on medical applications. However, there is a need to shift attention towards the growing needs of elderly people, that is, by realizing assistive exoskeletons that can help them to stay independent and maintain a good quality of life. Therefore, the present article covers the rapidly evolving area of wearable exoskeletons in a holistic manner, for both medical and non-medical applications, so that relevant current developments and future issues can be addressed; this includes how the physical assistance/rehabilitation/compensation can be provided to supplement capabilities in a natural manner. Regulatory guidelines, important for realizing new markets for these emerging technologies, are also explored in this work. For these, emerging international safety requirements are presented for non-medical and medical exoskeleton applications, so that the central requirement of close human–robot interactions can be adequately addressed for the intended tasks to be carried out. An example case study on developing and commercializing wearable exoskeletons to help support living activities of healthy elderly persons is presented to highlight the main issues in non-medical mobility exoskeletons. This also paves the way for the potential future trends to use exoskeletons as physical assistant robots, as covered by the recently published safety standard ISO 13482, to help elderly people perform their activities of daily living.

Risk management and regulations for lower limb medical exoskeletons: a review.

Gait disability is a major health care problem worldwide. Powered exoskeletons have recently emerged as devices that can enable users with gait disabilities to ambulate in an upright posture, and potentially bring other clinical benefits. In 2014, the US Food and Drug Administration approved marketing of the ReWalk™ Personal Exoskeleton as a class II medical device with special controls. Since then, Indego™ and Ekso™ have also received regulatory approval. With similar trends worldwide, this industry is likely to grow rapidly. On the other hand, the regulatory science of powered exoskeletons is still developing. The type and extent of probable risks of these devices are yet to be understood, and industry standards are yet to be developed. To address this gap, Manufacturer and User Facility Device Experience, Clinicaltrials.gov, and PubMed databases were searched for reports of adverse events and inclusion and exclusion criteria involving the use of lower limb powered exoskeletons. Current inclusion and exclusion criteria, which can determine probable risks, were found to be diverse. Reported adverse events and identified risks of current devices are also wide-ranging. In light of these findings, current regulations, standards, and regulatory procedures for medical device applications in the USA, Europe, and Japan were also compared. There is a need to raise awareness of probable risks associated with the use of powered exoskeletons and to develop adequate countermeasures, standards, and regulations for these human-machine systems. With appropriate risk mitigation strategies, adequate standards, comprehensive reporting of adverse events, and regulatory oversight, powered exoskeletons may one day allow individuals with gait disabilities to safely and independently ambulate.

Goniometric Sensor Interface for Exoskeleton System Control Device

The results of development of a monitoring system for a medical exoskeleton are presented. A subsystem of sensors consisting of a MEMS sensor and a group of magnetic inclinometers is described. The problem of the interface between the sensor subsystem and the exoskeleton control system is discussed. The characteristics of the developed system for exoskeleton monitoring are analyzed. The system is shown to hold promise for application in medical rehabilitation systems.

Mathematical modeling of crutch walking

Crutch walking is studied. A plane mechanism with five heavy links (body, two shins and two thighs) and attached weightless feet and weightless crutch is used as the mathematical model. By the crutch, we mean the crutch itself with the arm holding it. The gait in which the crutches execute synchronous motion is considered; for this reason, both crutches are considered as a single crutch. The links of the mechanism and the crutch are assumed to be absolutely solid bodies. Using a motion capture system, the trajectories of a healthy individual and the crutches are registered. Using these trajectories, variations of the angles in the individual's joints as functions of time and their first and second derivatives are obtained. Using force platforms, the support reactions applied to the individual's feet and the coordinates where these forces are applied are found. By solving the inverse dynamics problem, the torques developed at the joints and creating power torques are found. They can be used for choosing actuators for the joints of medical exoskeletons. The interjoint angles obtained experimentally can be used as tracked programmed trajectories for the organization of the motion of a medical exoskeleton put on a paraplegic. The overdetermined systems of equations arising in the inverse dynamics problem are solved using the least squares method.

Design of a Minimally Actuated Medical Exoskeleton With Mechanical Swing-Phase Gait Generation and Sit-Stand Assistance

This article describes the design of Austin exoskeleton – a minimally actuated medical exoskeleton with mechanical swing-phase gait generation and sit-stand assistance. The Austin exoskeleton is an accessible lightweight system that enables individuals with paraplegia to walk. The gait generation hardware of the Austin exoskeleton suit consists of three major components: hip actuation, a hip-knee coupler, and a controllable locking knee. Users operate the exoskeleton with a simple wireless user interface consisting of two push buttons that are installed on the handle of the stability aid. Electrical components are located on the back of the exoskeleton. A single actuator per leg and a mechanical hip-knee coupler power the knee during swing phase and provide assistance for sitting and standing. The suit’s design embeds gait generation into hardware, decreasing controller complexity. By using a bio-inspired coupling mechanism, the Austin system is able to power both the hip and knee joints using a single hip actuator.