Posts Tagged Exoskeleton

[VIDEO] Fourier X1 Exoskeleton – Fourier Intelligence – YouTube

Δημοσιεύτηκε στις 23 Μαρ 2017

At Fourier Intelligence, we do not believe these people are fated to sit on the wheelchair in their rest life. To let them stand up, and to allow them to walk again, we started to develop a genuinely new exoskeleton products- The Fourier X1

, , , ,

Leave a comment

[ARTICLE] A wearable exoskeleton suit for motion assistance to paralysed patients – Full Text

Summary

Background/Objective

The number of patients paralysed due to stroke, spinal cord injury, or other related diseases is increasing. In order to improve the physical and mental health of these patients, robotic devices that can help them to regain the mobility to stand and walk are highly desirable. The aim of this study is to develop a wearable exoskeleton suit to help paralysed patients regain the ability to stand up/sit down (STS) and walk.

Methods

A lower extremity exoskeleton named CUHK-EXO was developed with considerations of ergonomics, user-friendly interface, safety, and comfort. The mechanical structure, human-machine interface, reference trajectories of the exoskeleton hip and knee joints, and control architecture of CUHK-EXO were designed. Clinical trials with a paralysed patient were performed to validate the effectiveness of the whole system design.

Results

With the assistance provided by CUHK-EXO, the paralysed patient was able to STS and walk. As designed, the actual joint angles of the exoskeleton well followed the designed reference trajectories, and assistive torques generated from the exoskeleton actuators were able to support the patient’s STS and walking motions.

Conclusion

The whole system design of CUHK-EXO is effective and can be optimised for clinical application. The exoskeleton can provide proper assistance in enabling paralysed patients to STS and walk.

Continue —> A wearable exoskeleton suit for motion assistance to paralysed patients

 

Figure 1

Figure 1. The wearable exoskeleton suit CUHK-EXO. (A) A patient with the wearable exoskeleton suit CUHK-EXO supported by a pair of smart crutches; (B) diagram of the overall mechanical structure of CUHK-EXO; (C) waist structure of CUHK-EXO; (D) thigh structure of CUHK-EXO; (E) shank structure of CUHK-EXO. (F) foot structure of CUHK-EXO.

, , , ,

Leave a comment

[WEB SITE] One step at a time

IMAGE: DR. KIM (LEFT) WITH DR. SHARMA AND A HYBRID EXOSKELETON PROTOTYPE IN THE NEUROMUSCULAR CONTROL AND ROBOTICS LABORATORY IN THE SWANSON SCHOOL OF ENGINEERING. view more CREDIT: SWANSON SCHOOL OF ENGINEERING

PITTSBURGH (March 7, 2017) … The promise of exoskeleton technology that would allow individuals with motor impairment to walk has been a challenge for decades. A major difficulty to overcome is that even though a patient is unable to control leg muscles, a powered exoskeleton could still cause muscle fatigue and potential injury.

However, an award from the National Science Foundation’s Cyber-Physical Systems (CPS) program will enable researchers at the University of Pittsburgh to develop an ultrasound sensor system at the heart of a hybrid exoskeleton that utilizes both electrical nerve stimulation and external motors.

Principal investigator of the three year, $400,000 award is Nitin Sharma, assistant professor of mechanical engineering and materials science at Pitt’s Swanson School of Engineering. Co-PI is Kang Kim, associate professor of medicine and bioengineering. The Pitt team is collaborating with researchers led by Siddhartha Sikdar, associate professor of bioengineering and electrical and computer engineering at George Mason University, who also received a $400,000 award for the CPS proposal, “Synergy: Collaborative Research: Closed-loop Hybrid Exoskeleton utilizing Wearable Ultrasound Imaging Sensors for Measuring Fatigue.”

This latest funding furthers Dr. Sharma’s development of hybrid exoskeletons that combine functional electrical stimulation (FES), which uses low-level electrical currents to activate leg muscles, with powered exoskeletons, which use electric motors mounted on an external frame to move the wearer’s joints.

“One of the most serious impediments to developing a human exoskeleton is determining how a person who has lost gait function knows whether his or her muscles are fatigued. An exoskeleton has no interface with a human neuromuscular system, and the patient doesn’t necessarily know if the leg muscles are tired, and that can lead to injury,” Dr. Sharma explained. “Electromyography (EMG), the current method to measure muscle fatigue, is not reliable because there is a great deal of electrical “cross-talk” between muscles and so differentiating signals in the forearm or thigh is a challenge.”

To overcome the low signal-to-noise ratio of traditional EMG, Dr. Sharma partnered with Dr. Kim, whose research in ultrasound focuses on analyzing muscle fatigue.

“An exoskeleton biosensor needs to be noninvasive, but systems like EMG aren’t sensitive enough to distinguish signals in complex muscle groups,” Dr. Kim said. “Ultrasound provides image-based, real-time sensing of complex physical phenomena like neuromuscular activity and fatigue. This allows Nitin’s hybrid exoskeleton to switch between joint actuators and FES, depending upon the patient’s muscle fatigue.”

In addition to mating Dr. Sharma’s hybrid exoskeleton to Dr. Kim’s ultrasound sensors, the research group will develop computational algorithms for real-time sensing of muscle function and fatigue. Human subjects using a leg-extension machine will enable detailed measurement of strain rates, transition to fatigue, and full fatigue to create a novel muscle-fatigue prediction model. Future phases will allow the Pitt and George Mason researchers to develop a wearable device for patients with motor impairment.

“Right now an exoskeleton combined with ultrasound sensors is just a big machine, and you don’t want to weigh down a patient with a backpack of computer systems and batteries,” Dr. Sharma said. “The translational research with George Mason will enable us to integrate a wearable ultrasound sensor with a hybrid exoskeleton, and develop a fully functional system that will aid in rehabilitation and mobility for individuals who have suffered spinal cord injuries or strokes.”

###

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

Source: One step at a time | EurekAlert! Science News

, , , , , , , ,

Leave a comment

[ARTICLE] The Efficacy of State of the Art Overground Gait Rehabilitation Robotics: A Bird’s Eye View – Full Text

Abstract

To date, rehabilitation robotics has come a long way effectively aiding the rehabilitation process of the patients suffering from paraplegia or hemiplegia due to spinal cord injury (SCI) or stroke respectively, through partial or even full functional recovery of the affected limb. The increased therapeutic outcome primarily results from a combination of increased patient independence and as well as reduced physical burden on the therapist. Especially for the case of gait rehabilitation following SCI or stroke, the rehab robots have the potential to significantly increase the independence of the patient during the rehabilitation process without the patient’s safety being compromised. An intensive gait-oriented rehabilitation therapy is often effective irrespective of the type of rehabilitation paradigm. However, eventually overground gait training, in comparison with body-weight supported treadmill training (BWSTT), has the potential of higher therapeutic outcome due its associated biomechanics being very close to that of the natural gait. Recognizing the apparent superiority of the overground gait training paradigms, a through literature survey on all the major overground robotic gait rehabilitation approaches was carried out and is presented in this paper. The survey includes an in-depth comparative study amongst these robotic approaches in terms of gait rehabilitation efficacy.

Download full text in PDF

Source: The Efficacy of State of the Art Overground Gait Rehabilitation Robotics: A Bird’s Eye View

, , , , , , , , , ,

Leave a comment

[ARTICLE] Weight compensation characteristics of Armeo®Spring exoskeleton: implications for clinical practice and research – Full Text

Abstract

Background

Armeo®Spring exoskeleton is widely used for upper extremity rehabilitation; however, weight compensation provided by the device appears insufficiently characterized to fully utilize it in clinical and research settings.

Methods

Weight compensation was quantified by measuring static force in the sagittal plane with a load cell attached to the elbow joint of Armeo®Spring. All upper spring settings were examined in 5° increments at the minimum, maximum, and two intermediate upper and lower module length settings, while keeping the lower spring at minimum. The same measurements were made for minimum upper spring setting and maximum lower spring setting at minimum and maximum module lengths. Weight compensation was plotted against upper module angles, and slope was analyzed for each condition.

Results

The Armeo®Spring design prompted defining the slack angle and exoskeleton balance angle, which, depending on spring and length settings, divide the operating range into different unloading and loading regions. Higher spring tensions and shorter module lengths provided greater unloading (≤6.32 kg of support). Weight compensation slope decreased faster with shorter length settings (minimum length = −0.082 ± 0.002 kg/°; maximum length = −0.046 ± 0.001 kg/°) independent of spring settings.

Conclusions

Understanding the impact of different settings on the Armeo®Spring weight compensation should help define best clinical practice and improve fidelity of research.

Continue —> Weight compensation characteristics of Armeo®Spring exoskeleton: implications for clinical practice and research | Journal of NeuroEngineering and Rehabilitation | Full Text

, , , , , , ,

Leave a comment

[ARTICLE] Development and assessment of a hand assist device: GRIPIT – Full Text

Abstract

Background

Although various hand assist devices have been commercialized for people with paralysis, they are somewhat limited in terms of tool fixation and device attachment method. Hand exoskeleton robots allow users to grasp a wider range of tools but are heavy, complicated, and bulky owing to the presence of numerous actuators and controllers. The GRIPIT hand assist device overcomes the limitations of both conventional devices and exoskeleton robots by providing improved tool fixation and device attachment in a lightweight and compact device. GRIPIT has been designed to assist tripod grasp for people with spinal cord injury because this grasp posture is frequently used in school and offices for such activities as writing and grasping small objects.

Methods

The main development objective of GRIPIT is to assist users to grasp tools with their own hand using a lightweight, compact assistive device that is manually operated via a single wire. GRIPIT consists of only a glove, a wire, and a small structure that maintains tendon tension to permit a stable grasp. The tendon routing points are designed to apply force to the thumb, index finger, and middle finger to form a tripod grasp. A tension-maintenance structure sustains the grasp posture with appropriate tension. Following device development, four people with spinal cord injury were recruited to verify the writing performance of GRIPIT compared to the performance of a conventional penholder and handwriting. Writing was chosen as the assessment task because it requires a tripod grasp, which is one of the main performance objectives of GRIPIT.

Results

New assessment, which includes six different writing tasks, was devised to measure writing ability from various viewpoints including both qualitative and quantitative methods, while most conventional assessments include only qualitative methods or simple time measuring assessments. Appearance, portability, difficulty of wearing, difficulty of grasping the subject, writing sensation, fatigability, and legibility were measured to assess qualitative performance while writing various words and sentences. Results showed that GRIPIT is relatively complicated to wear and use compared to a conventional assist device but has advantages for writing sensation, fatigability, and legibility because it affords sufficient grasp force during writing. Two quantitative performance factors were assessed, accuracy of writing and solidity of writing. To assess accuracy of writing, we asked subjects to draw various figures under given conditions. To assess solidity of writing, pen tip force and the angle variation of the pen were measured. Quantitative evaluation results showed that GRIPIT helps users to write accurately without pen shakes even high force is applied on the pen.

Conclusions

Qualitative and quantitative results were better when subjects used GRIPIT than when they used the conventional penholder, mainly because GRIPIT allowed them to exert a higher grasp force. Grasp force is important because disabled people cannot control their fingers and thus need to move their entire arm to write, while non-disabled people only need to move their fingers to write. The tension-maintenance structure developed for GRIPIT provides appropriate grasp force and moment balance on the user’s hand, but the other writing method only fixes the pen using friction force or requires the user’s arm to generate a grasp force.

Background

The hand is one of the most essential body parts for independent living because so many tasks of daily life, such as writing, eating, and grasping, require a functional hand. People who suffer from permanent paralysis of the hand owing to cerebral palsy, spinal cord injury (SCI), stroke, and other neurological disorders require assistive or rehabilitation devices in order to regain independence and return to work [1, 2].

A selection of commercialized hand assist devices is shown in Fig. 1. These devices are attached to the user’s arm or hand with Velcro® or elastic bands, and hand tools such as pens, forks, and paintbrushes are clamped into a hole in the devices. One drawback of these devices is that they can only grasp one type of tool because the receiving hole is a constant size. Users also must sometimes sustain an awkward posture to use a tool because it is mounted into the device in an unfamiliar position. Additionally, the Velcro or elastic band used to fix the device can apply high pressure to the skin if the strapping is too tight, and tools can be too shaky to use if the strapping becomes too loose. These problems reduce the usability of these devices and require users to put in a certain of amount of training time to become familiar with their use.

Fig. 1 Various types of hand assist devices for people with hand paralysis. a Writing aid. b Eating aid. c Grasping aid. d Cooking aid

Continue —> Development and assessment of a hand assist device: GRIPIT | Journal of NeuroEngineering and Rehabilitation | Full Text

, , , , , , , , , , ,

Leave a comment

[BLOG POST] Superflex: Soft Exoskeleton For Elderly That Can Be Worn Like Underwear.

FEBRUARY 6, 2017

Photo of the back of an elderly person with wavy white hair. She is seen wearing a soft exoskeleton and holding both her arms.

One third of adults over 65 report difficulty walking three blocks. Mobility is a serious concern for the aging population which stems from the fact that other physical ailments and issues force them to stay at home, leading to loss of freedom, increased depression, and risks of getting other diseases like diabetes.

To cater to that population, SRI International is designing an exoskeleton that can be worn like an undergarment. This soft exoskeleton, weighing four pounds, wraps around the user’s core, and provides another set of mechanical muscles that can help elderly sit, stand, and even walk. An in built computer makes sure that the flexing happens along with the real muscles to supplement the energy generated by them. The first version of this suit may require it to be charged once a day.

diagram showing how super flex fits the body.  It covers the chest and torso and goes down till the knees. this photo has two bodies - one male and other female.

The “powered suit” (called Superflex) is designed not just to provide convenience but comfort as well. Rich Mahoney, the CEO, has hired a team of textile and fashion designers to ensure that this suit is worn easily, looks attractive & feels comfortable, and also lets the person use bathroom with ease.

This suit can be used not just by elderly people who complain of a sedentary lifestyle but also by people who have injuries and are in rehabilitation. Superflex is targeting to launch sometime in Mid 2018. Although there is no information on price, the company says that it will be affordable, and people interested in it wouldn’t have to depend on insurance subsidies.

Source: Fast Co Design

Source: Superflex: Soft Exoskeleton For Elderly That Can Be Worn Like Underwear – Assistive Technology Blog

, , , ,

Leave a comment

[WEB PAGE] ‘Knitted muscles’ provide power

January 25, 2017
'Knitted muscles' provide power

Conceptual model of a textile exoskeleton with the textile actuator (black) on an elastic elbow sleeve (white). Credit: Thor Balkhed/Linköping University

Researchers have coated normal fabric with an electroactive material, and in this way given it the ability to actuate in the same way as muscle fibres. The technology opens new opportunities to design “textile muscles” that could, for example, be incorporated into clothes, making it easier for people with disabilities to move. The study, which has been carried out by researchers at Linköping University and the University of Borås in Sweden, has been published in Science Advances.

Developments in robot technology and prostheses have been rapid, due to technological breakthroughs. For example, devices known as “” that act as an external skeleton and muscles have been developed to reinforce a person’s own mobility.

“Enormous and impressive advances have been made in the development of exoskeletons, which now enable people with disabilities to walk again. But the existing technology looks like rigid robotic suits. It is our dream to create exoskeletons that are similar to items of clothing, such as “running tights” that you can wear under your normal clothes. Such device could make it easier for older persons and those with impaired mobility to walk,” says Edwin Jager, associate professor at Division of Sensor and Actuator Systems, Linköping University.

Current exoskeletons are driven by motors or pressurised air and develop power in this way. In the new study, the researchers have instead used the advantages provided by lightweight and flexible fabrics, and developed what can be described as “textile muscles”. The researchers have used mass-producible fabric and coated it with an electroactive material. It is in this special coating that the force in the textile muscles arises. A low voltage applied to the fabric causes the electroactive material to change volume, causing the yarn or fibres to increase in length. The properties of the textile are controlled by its woven or knitted structure. Researchers can exploit this principle, depending on how the textile is to be used.

'Knitted muscles' provide power

A photograph of a knitted textile actuator (or textile muscle) including the electrical and mechanical contacts made of copper tape. Credit: Thor Balkhed/Linköping University

“If we weave the fabric, for example, we can design it to produce a high force. In this case, the extension of the fabric is the same as that of the individual threads. But what happens is that the force developed is much higher when the threads are connected in parallel in the weave. This is the same as in our muscles. Alternatively, we can use an extremely stretchable knitted structure in order to increase the effective extension,” says Nils-Krister Persson, associate professor in the Smart Textiles Initiative at the Swedish School of Textiles, University of Borås.

The researchers show in the article that the textile muscles can be used in a simple robot device to lift a small weight. They demonstrate that the technology enables new ways to design and manufacture devices known as “actuators”, which – like motors and biological muscles – can exert a force.

'Knitted muscles' provide power

From left to right: A single yarn coated with the electroactive polymer (polypyrrole); a knitted textile actuator (or textile muscle) including the electrical and mechanical contacts made of copper tape; and a piece of knitwear coated with the electroactive polymer (polypyrrole). Credit: Thor Balkhed/Linköping University

“Our approach may make it possible in the long term to manufacture actuators in a simple way and hopefully at a reasonable cost by using already existing textile production technologies. What’s more interesting, however, is that it may open completely new applications in the future, such as integrating textile muscles into items of clothing,” says Edwin Jager.

'Knitted muscles' provide power

Photo of the knitted textile actuator mounted in the force measurement setup. On the top the actuator is mounted to the lever arm of the force sensor using a small electrically insulated hook. On the bottom it is both electrically and mechanically connected in a beaker that contains the liquid electrolyte. A second, auxiliary electrode (the piece of gold coated plastic) is also inserted in the container to close the electrical circuit. Credit: Thor Balkhed/Linköping University

Explore further: ‘Space cloth’ to revolutionise textiles industry

More information: “Knitting and weaving artificial muscles,” Science Advances, DOI: 10.1126/sciadv.1600327 , http://advances.sciencemag.org/content/3/1/e1600327

Source: ‘Knitted muscles’ provide power

, , , , , ,

Leave a comment

[Abstract] Robotic and Mechanotherapeutic Technology to Restore the Functions of the Upper Limbs: Prospects for Development (Review).

Abstract

We have analyzed the advantages and disadvantages of the robotic and mechanotherapeutic technologies used for rehabilitation of the upper limbs. Robotic and mechanotherapeutic devices started as simple controllers and upper limb weight support systems in kinesitherapy, but have subsequently shown their potential as systems for providing task oriented movement training, by efforts to maximize the correspondence between the features of anatomical and biomechanical arms. Integration of functional neuromuscular electrostimulation with robotic and mechanotherapeutic technology considerably widens the possibilities of using robots for rehabilitation and for providing mechanical assistance, while the appearance of portable and fixed exoskeletons is leading to completely new devices based on both rehabilitation and assistive technologies. Currently prototypes of robotic assistive and rehabilitation devices controlled by brain-computer interfaces are being developed.

For access to this entire article and additional high quality information, please check with your college/university library, local public library, or affiliated institution.

 

Source: EBSCOhost | 120466983 | Robotic and Mechanotherapeutic Technology to Restore the Functions of the Upper Limbs: Prospects for Development (Review).

, , , , , , ,

Leave a comment

[ARTICLE] Hybrid EEG/EOG-based brain/neural hand exoskeleton restores fully independent daily living activities after quadriplegia – Full Text

Abstract

Direct brain control of advanced robotic systems promises substantial improvements in health care, for example, to restore intuitive control of hand movements required for activities of daily living in quadriplegics, like holding a cup and drinking, eating with cutlery, or manipulating different objects. However, such integrated, brain- or neural-controlled robotic systems have yet to enter broader clinical use or daily life environments. We demonstrate full restoration of independent daily living activities, such as eating and drinking, in an everyday life scenario across six paraplegic individuals (five males, 30 ± 14 years) who used a noninvasive, hybrid brain/neural hand exoskeleton (B/NHE) to open and close their paralyzed hand. The results broadly suggest that brain/neural-assistive technology can restore autonomy and independence in quadriplegic individuals’ everyday life.

INTRODUCTION

Quadriplegia, the loss of motor function of both arms and legs, is often caused by traumatic cervical spinal cord injury (SCI) affecting 1 in 10,000 people worldwide (1, 2). Although SCI is associated with lower life expectancy and quality of life (3, 4), it typically affects younger individuals, leading to substantial loss of their independence and autonomy. Regaining hand and arm function was identified as the most critical need in this population (5). Although SCI remains an incurable condition with most treatment approaches aimed at minimizing secondary medical complications and maximizing residual function, the development of brain-machine interfaces (BMIs) has recently fueled hope that by bypassing the lesioned spinal system, independence and autonomy of individuals with severe paralysis could be restored (69). In particular, the possibility that repeated use of such BMI-based bypass could trigger neurological recovery despite clinically complete and chronic SCI (10) points to new avenues in the treatment of severe paralysis that build on fostering neuroplasticity through direct brain- or neural-robot interactions. BMIs translate electric, magnetic, or metabolic brain activity (e.g., associated with the intention to reach and grasp) into control signals of external machines, exoskeletons, or robots (11). Because mental imagery (e.g., the visualization of a closing hand) results in an actual hand-closing motion performed by a robotic device or exoskeleton in such a paradigm, BMI control is particularly intuitive.

Although implantable BMIs have recently been shown to allow versatile control of a robotic arm in patients with chronic quadriplegia (8, 12, 13), the required craniotomy entails the risk of surgical complications, for example, infections or bleedings. Also, implantable systems have to be explanted after some time, posing an ethical and clinical dilemma. Thus, implantation of a BMI for controlling such versatile robots is mainly attractive for individuals who are completely paralyzed, for example, after severe brainstem stroke or in the late stage of a neurodegenerative disease.

To date, we know of no patient who has used a BMI outside the laboratory to perform activities of daily living (ADLs), for example, having a full meal in an outside restaurant. The main obstacle for such application relates to the nonstationarity of brain activity and susceptibility to environmental artifacts, particularly in noninvasive brain activity recordings that provide lower signal-to-noise ratios compared with invasive recordings (14). Thus, hybrid systems that combine BMI technology with other biosignals (1517) or eye gaze (18, 19) to improve system control have been proposed. Previous work demonstrated that the combination of electroencephalography (EEG) and electrooculography (EOG) can be used for hand exoskeleton control in healthy volunteers under laboratory conditions (16, 17). The translational value of this approach for restoration of hand function in real-life environments after quadriplegia, a condition for which there is currently no effective treatment, was not known. Here, we address this question and show the restoration of fully independent ADLs, such as eating and drinking, across six quadriplegic individuals with cervical SCI.

Study participants used a noninvasive brain/neural hand exoskeleton (B/NHE) that translates brain electric signals accompanying the intention to grasp into actual exoskeleton-driven hand-closing motions and EOG signals related to voluntary horizontal eye movements [horizontal oculoversions (HOVs)] into exoskeleton-driven hand-opening motions (Figs. 1 and 2). The participants were asked to perform self-initiated reaching and grasping actions, for example, eating and drinking in a nearby restaurant and outdoors. The ability to grasp and manipulate daily life objects was assessed using the Toronto Rehabilitation Institute–Hand Function Test (TRI-HFT) with and without the B/NHE system. Reliability, tolerability, and practicability to perform ADLs were rated by each participant after the end of the session.

Fig. 1 Scheme of process pipeline to control the hand exoskeleton. EEG and EOG signals were transmitted to a wireless tablet computer performing real-time signal processing and translation into control signals sent to a control box and actuators moving the hand exoskeleton via a flexible cable sheath system.

 

Fig. 2 Design of hybrid biosignal processing for reliable hand exoskeleton control. Signals related to the detection of HOVs and intention to grasp as measured by electrooculographic (A) and brain electric (B) activity were used for the hybrid BMI hand exoskeleton control (C). Hand exoskeleton closing movements were initiated by the detection of SMR-ERD, whereas hand exoskeleton opening movements were controlled by HOVs’ EOG activity exceeding the eye movement detection threshold [red dashed line in (A)]. In case EOG activity exceeded the eye movement detection threshold during SMR-ERD [indicated by the red dashed rectangle in (B)], the hand exoskeleton opened, and brain control was blocked for 1.5 s [indicated by the red rectangles in (C)] to ensure safety during performing daily life actions.

Continue —> Hybrid EEG/EOG-based brain/neural hand exoskeleton restores fully independent daily living activities after quadriplegia | Science Robotics

, , , , , , , , , ,

Leave a comment

%d bloggers like this: