Posts Tagged robotic arm

[Study] Design a Smart Exoskeleton Robotic Arm for Elbow Rehabilitation – Full Text PDF


This study presents a smart arm exoskeleton roboticdevice that designed to perform the physical therapy for disabled patients in order to rehabilitate the affected limb. The basic principle of this exoskeleton is its dependence on electromyography signal; MyoWare sensor was used to measure surface electromyography signal. Surface electrodes were used between skin and MyoWare to pick up the signal from biceps brachii muscle. The microcontroller processes the signal of muscle activity and outputs a voltage to control the direction of a motor. The motor moves the actuator arm through Bowden cable. The exoskeleton robot is one degree of freedom performs the flexion and extension of the elbow joint. After the design was completed, it was tested according to some parameters to check its efficiency. The resultsindicated the feasibility of this exoskeleton to move according to muscle’s signal and to tolerate the human arm’s weight whatever the human weight.

 Full Text PDF

Source: D Suárez-Iglesias, C Ayán Perez, N Mendoza-Laiz… – Frontiers in Psychology, 2020

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[WEB SITE] PolyU develops robotic arm for self-help mobile rehabilitation for stroke patients


The PolyU-developed robotic arm is the first-of-its-kind integration of exo-skeleton, soft robot and exo-nerve stimulation technologies. It is light in weight, compact in size, fast in response and demands minimal power supply, thus suitable for use in both indoor and outdoor environment.
The Hong Kong Polytechnic University


(October 31, 2018) The Hong Kong Polytechnic University (PolyU) recently developed a robotic arm to facilitate self-help and upper-limb mobile rehabilitation for stroke patients. The lightweight device enables the patients to engage in intensive and effective self-help rehabilitation exercise anywhere, anytime after they are discharged from hospital. The robotic arm, called “mobile exo-neuro-musculo-skeleton”, is the first-of-its-kind integration of exo-skeleton, soft robot and exo-nerve stimulation technologies.

Stroke is the third leading cause of disability worldwide. In Hong Kong, there are about 25,000 new incidences of stroke annually in recent years. Research studies have proven that intensive, repeated and long-term rehabilitation training are critical for enhancing the physical mobility of stroke patients, thus help alleviating post-stroke symptoms such as disability. However, access to the outpatient rehabilitation service for stroke patients has been difficult. Due to the overwhelming demand for rehabilitation services, patients have to queue up for a long time to get a slot for rehabilitation training. As such, they can’t get timely support and routine rehabilitation exercises. Stroke patients also find it challenging to travel from home to outpatient clinics.

The “mobile exo-neuro-musculo-skeleton”, developed by Dr Hu Xiao-ling and her research team in the Department of Biomedical Engineering (BME) of PolyU, features lightweight design (up to 300g for wearable upper limb components, which are fit for different functional training needs), low power demand (12V rechargeable battery supply for 4-hour continuous use), and sportswear features. The robotic arm thus provides a flexible, self-help, easy-to-use, mobile tool for patients to supplement their rehabilitation sessions at the clinic. The innovative training option can effectively enhance the rehabilitation progress.

Dr Hu Xiaoling said development of the novel device was inspired by the feedback of many stroke patients who were discharged from hospital. They faced problems in having regular and intensive rehabilitation training crucial for limb recovery. “We are confident that with our mobile exo-neuro-musculo-skeleton, stroke patients can conduct rehabilitation training anytime and anywhere, turning the training into part of their daily activities. We hope such flexible self-help training can well supplement traditional outpatient rehabilitation services, helping stroke patients achieve a much better rehabilitation progress.” Her team anticipated that the robotic arm can be commercialised in two years.

The BME innovation integrates exo-skeleton and soft robot structural designs – the two technologies commonly adopted in existing upper-limb rehabilitation training devices for stroke patients as well as the PolyU-patented exo-nerve stimulation technology.

Integration of exo-skeleton, soft robot and exo-nerve stimulation technologies

The working principle of both exo-skeleton and soft robot designs is to provide external mechanical forces driven by voluntary muscle signals to assist the patient’s desired joint movement. Conventional exo-skeleton structure is mainly constructed by orthotic materials such as metal and plastic, simulating external bones of the patient. Although it is compact in size, it is heavy and uncomfortable to wear. Soft robot, made of air-filled or liquid-filled pipes to simulate one’s external muscles, is light in weight but very bulky in size. Both types of structures demand high electrical power for driving motors or pumps, thus it is not convenient for patients to use them outside hospitals or rehabilitation centres. Combining the advantages of both structural designs, the BME innovative robotic arm is light in weight, compact in size, fast in response and demands minimal power supply, therefore it is suitable for use in both indoor and outdoor environment.

The robotic arm is unique in performing outstanding rehabilitation effect by further integrating the external mechanical force design with the PolyU-patented Neuro-muscular Electrical Stimulation (NMES) technology. Upon detecting the electromyography signals at the user’s muscles, the device will respond by applying NMES to contract the muscles, as well as exerting external mechanical forces to assist the joint’s desired voluntary movement. Research studies found that the combination of muscle strength triggered by NMES and external mechanical forces is 40% more effective for stroke rehabilitation than applying external mechanical forces alone.

Rehabilitation effect proven in trials

An initial trial of the robotic arm on 10 stroke patients indicated better muscle coordination, wrist and finger functions, and lower muscle spasticity of all after they have completed 20 two-hour training sessions. Further clinical trials will be carried out in collaboration with hospitals and clinics.

The robotic arm consists of components for wrist/hand, elbow, and fingers which can be worn separately or together for different functional training needs. The sportswear design, using washable fabric with ultraviolet protection and good ventilation, also makes the robotic arm a comfortable wear for the patients.

The device also has a value-added feature of connecting to a mobile application (APP) where user can use the APP interface to control their own training. The APP also records real-time training data for better monitoring of the rehabilitation progress by both healthcare practitioners and the patients themselves. It can also serve as a social network platform for stroke patients to communicate online with each other for mutual support.


Press Contacts:

Dr Hu Xiaoling, Assistant Professor
Department of Biomedical Engineering, PolyU
Telephone : 3400 3206
Email :


via PolyU develops robotic arm for self-help mobile rehabilitation for stroke patients | EurekAlert! Science News

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[Abstract] Biomechatronics design of a robotic arm for rehabilitation – IEEE Conference Publication


Rehabilitation is an important process to restore muscle strength and joint’s range of motion. This paper proposes a biomechatronic design of a robotic arm that is able to mimic the natural movement of the human shoulder, elbow and wrist joint. In a preliminary experiment, a subject was asked to perform four different arm movements using the developed robotic arm for a period of two weeks. The experimental results were recorded and can be plotted into graphical results using Matlab. Based on the results, the robotic arm shows encouraging effect by increasing the performance of rehabilitation process. This is proven when the result in degree value are accurate when being compared with the flexion of both shoulder and elbow joints. This project can give advantages on research if the input parameter needed in the flexion of elbow and wrist.

I. Introduction

According to the United Nations (UN), by 2030 the number of people over 60 years will increase by 56 per cent, from 901 million to more than 1.4 billion worldwide [1]. As the number of older persons is expected to grow, it is imperative that government and private health care providers prepare adequate and modern facilities that can provide quality services for the needs of older persons especially in rehabilitation centers. Implementation of robotic technology in rehabilitation process is a modern method and definitely can contribute in this policy and capable in promoting early recovery and motor learning [2]. Furthermore, systematic application of robotic technology can produce significant clinical results in motor recovery of post-traumatic central nervous system injury by assisting in physical exercise based on voluntary movement in rehabilitation [3].

via Biomechatronics design of a robotic arm for rehabilitation – IEEE Conference Publication

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[WEB SITE] Paralyzed man uses intention of movement to control robotic arm – Medical News Today

A 34-year-old man left paralyzed after suffering a bullet wound has become the first person to have a neuroprosthetic device implanted in the brain region responsible for movement intention, allowing him to control a robotic arm with his mind.
Erik Sorto controlling the robotic arm with his mind
Thanks to the neuroprosthetic device, Sorta is able to control a robotic arm with just his thoughts.
Image credit: Spencer Kellis, Caltech

Erik Sorto, a father of two from California, endured a gunshot wound at the age of 21, severing his spinal cord and leaving him unable to move his arms and legs. Thanks to the new device, Sorto is now able to shake hands, pick up a beverage and even play “rock, paper, scissors.”

“I was surprised at how easy it was [to control the robotic arm],” says Sorto. “I remember just having this out-of-body experience, and I wanted to just run around and high-five everybody.”

The success of the neuroprosthetic device is the result of a joint project involving researchers from the California Institute of Technology (Caltech), Keck Medicine of the University of Southern California (USC) and the Rancho Los Amigos National Rehabilitation Center in Downey, CA.

In the journal Science, principal investigator Richard Anderson, James G. Boswell professor of neuroscience at Caltech, and colleagues explain how they implanted the device and how it works.

Previously, research into neuroprosthetics has focused on implanting devices in the motor cortex – the area of the brain that controls movement. Though this has allowed patients to possess some control over robotic limbs, results have been inconsistent, with motion often being severely delayed or shaky.

For this project, the team focused on the posterior parietal cortex (PPC) – the brain region that controls the intention of movement rather than movement itself.

PPC activity recorded by tiny electrode arrays and decoded to control robotic arm

Surgeons from Keck Medicine of USC implanted two small electrode arrays – 4 mm x 4 mm in size – into Sorta’s PPC. One electrode array controls reach, while the other controls grasp. Each array consists of 96 active electrodes that note the activity of each nerve cell in the PPC.

A cable connects the electrode arrays to a computer system that reads nerve cell activity in the PPC, decoding it to determine the brain’s intention of movement and control devices it is connected to – in this case, a robotic arm and a computer cursor.

The surgery – conducted on April 17th, 2013 – was a complex procedure and took 5 hours to complete, according to the team.

“These arrays are very small so their placement has to be exceptionally precise, and it took a tremendous amount of planning – working with the Caltech team to make sure we got it right,” says neurosurgeon Charles Liu, professor of neurological surgery and neurology and biomedical engineering at USC.

“Because it was the first time anyone had implanted this part of the human brain, everything about the surgery was different: the location, the positioning and how you manage the hardware,” he adds. “Keep in mind that what we’re able to do – the ability to record the brain’s signals and decode them to eventually move the robotic arm – is critically dependent on the functionality of these arrays, which is determined largely at the time of surgery.”

Sorta and the research team talk more about the procedure in the video below:

Study offers hope for patients with paralysis

Sorto started rehabilitation at the Rancho Los Amigos National Rehabilitation Center 16 days after the procedure.

Though he was able to use his thoughts to move the robotic arm immediately, it took weeks of mind training to refine arm movements. Now, Sorta is able to carry out a number of tasks using the arm, such as picking up a beverage.

“He’s been able to do various things,” Andersen told The Washington Post. “He can play video games and do rock paper scissors, he can grasp objects. And of course he had a personal goal, which is to control the speed at which he drinks a beer, so we implemented that first.”

According to the Christopher & Dana Reeve Foundation, around 6 million people in the US are living with some form of paralysis – the equivalent to almost 1 in 50 Americans.

The success of the neuroprosthetic device so far has excited neurological researchers, representing another step toward helping patients with full or partial paralysis.

Study investigator Christine Heck, associate professor of neurology and co-director of the Neurorestoration Center at USC, says:

“We are at a point in human research where we are making huge strides in overcoming a lot of neurologic disease.

These very important early clinical trials could provide hope for patients with all sorts of neurologic problems that involve paralysis such as stroke, brain injury,ALS and even multiple sclerosis.”

The project is ongoing, with Sorto committing to another year of study.”This study has been very meaningful to me,” he says. “As much as the project needed me, I needed the project. It gives me great pleasure to be part of the solution for improving paralyzed patients’ lives.”

The National Institutes of Health, the Boswell Foundation, the Department of Defense and the USC Neurorestoration Center funded the study.

In December 2014, Medical News Today reported on a study published in the Journal of Neural Engineering, in which researchers revealed how a 52-year-old quadriplegic woman was able to control a robotic arm with her mind.

That study detailed similar techniques to those used in this latest research, though the electrode arrays were implanted into the patients left motor cortex rather than the PPC.

Source: Paralyzed man uses intention of movement to control robotic arm – Medical News Today

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[REVIEW] Effects and impacts of a robotic arm used by individuals with upper limb motor impairment: A scoping review


Individuals with motor impairments may be limited in the realization of their activities of daily living, their leisure activities or their work activities. To overcome these limitations, the involvement of a caregiver and/or the acquisition of assistive devices are often necessary. In the last few years, more and more assistance robots have been developed and the interest they generate is growing. Among these, there are robotic arms aiming to improve the functional autonomy of people living with upper limb motor impairment.


Since the effects and impacts of the use of a robotic arm by these individuals are not well documented, this study aims at obtaining an overview of what has been reported until now in the scientific literature.


To achieve this, we undertook a scoping review. Four databases were searched: PubMed, Embase, Compendex and Scopus. Following a selection process involving different steps, 36 papers were retained. Relevant data, the same for each paper, were recorded. The quality of the selected papers was evaluated using the Critical Review Form for Quantitative Studies (McMaster University). The papers were also classified according to the Canadian Model of Occupational Performance and Engagement (CMOP-E). The CMOP-E allowed us to identify the occupational domains addressed in the retained studies.


Twenty-four papers presented results related to basic activities of daily living, 18 to instrumental activities of daily living, 9 to work activities, 8 to leisure activities, 2 to school and 2 to games. The quality assessment revealed a mean score of 8.8/15, demonstrating that the effects and impacts of robotic arms have to establish in a more rigorous way. The utilisation of a robotic arm has more positive than negative effects and impacts on the various occupational domains.


These assistive devices have the potential to be successfully integrated into the users’ life, but some improvements are desirable to increase the satisfaction related to their utilization.

Source: Effects and impacts of a robotic arm used by individuals with upper limb motor impairment: A scoping review

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[WEB SITE] Stroke Recovery Theories Challenged By New Studies Looking at Brain Lesions, Bionic Arms

July 10, 2013

COLUMBUS, Ohio — Stroke survivors left weakened or partially paralyzed may be able to regain more arm and hand movement than their doctors realize, say experts at The Ohio State University Wexner Medical Center who have just published two new studies evaluating stroke outcomes.

One study analyzed the correlation between long-term arm impairment after stroke and the size of brain lesions caused by patients’ strokes – a visual measure often used by doctors to determine rehabilitation therapy type and duration.  The other study compared the efficacy of a portable robotics-assisted therapy program with a traditional program to improve arm function in patients who had experienced a stroke as long as six years ago.

“These studies were looking at two entirely different aspects of a stroke, yet they both suggest that stroke patients can indeed regain function years and years after the initial event,” said Stephen Page, PhD, OTR/L, author of both studies and associate professor of Health and Rehabilitation Sciences in Ohio State’s College of Medicine. “Unfortunately, we know that this is not a message that many patients and especially their clinicians may be getting, so the patients may not be reaching their true potential for recovery.”

more –> Stroke Recovery Theories Challenged By New Studies Looking at Brain Lesions, Bionic Arms.

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