Posts Tagged Activities of daily living

[Abstract] Electromechanical and robot‐assisted arm training for improving activities of daily living, arm function, and arm muscle strength after stroke

Abstract

Background

Electromechanical and robot‐assisted arm training devices are used in rehabilitation, and may help to improve arm function after stroke.

Objectives

To assess the effectiveness of electromechanical and robot‐assisted arm training for improving activities of daily living, arm function, and arm muscle strength in people after stroke. We also assessed the acceptability and safety of the therapy.

Search methods

We searched the Cochrane Stroke Group’s Trials Register (last searched January 2018), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2018, Issue 1), MEDLINE (1950 to January 2018), Embase (1980 to January 2018), CINAHL (1982 to January 2018), AMED (1985 to January 2018), SPORTDiscus (1949 to January 2018), PEDro (searched February 2018), Compendex (1972 to January 2018), and Inspec (1969 to January 2018). We also handsearched relevant conference proceedings, searched trials and research registers, checked reference lists, and contacted trialists, experts, and researchers in our field, as well as manufacturers of commercial devices.

Selection criteria

Randomised controlled trials comparing electromechanical and robot‐assisted arm training for recovery of arm function with other rehabilitation or placebo interventions, or no treatment, for people after stroke.

Data collection and analysis

Two review authors independently selected trials for inclusion, assessed trial quality and risk of bias, used the GRADE approach to assess the quality of the body of evidence, and extracted data. We contacted trialists for additional information. We analysed the results as standardised mean differences (SMDs) for continuous variables and risk differences (RDs) for dichotomous variables.

Main results

We included 45 trials (involving 1619 participants) in this update of our review. Electromechanical and robot‐assisted arm training improved activities of daily living scores (SMD 0.31, 95% confidence interval (CI) 0.09 to 0.52, P = 0.0005; I² = 59%; 24 studies, 957 participants, high‐quality evidence), arm function (SMD 0.32, 95% CI 0.18 to 0.46, P < 0.0001, I² = 36%, 41 studies, 1452 participants, high‐quality evidence), and arm muscle strength (SMD 0.46, 95% CI 0.16 to 0.77, P = 0.003, I² = 76%, 23 studies, 826 participants, high‐quality evidence). Electromechanical and robot‐assisted arm training did not increase the risk of participant dropout (RD 0.00, 95% CI ‐0.02 to 0.02, P = 0.93, I² = 0%, 45 studies, 1619 participants, high‐quality evidence), and adverse events were rare.

Authors’ conclusions

People who receive electromechanical and robot‐assisted arm training after stroke might improve their activities of daily living, arm function, and arm muscle strength. However, the results must be interpreted with caution although the quality of the evidence was high, because there were variations between the trials in: the intensity, duration, and amount of training; type of treatment; participant characteristics; and measurements used.

Plain language summary

Electromechanical‐assisted training for improving arm function and disability after stroke

Review question

To assess the effects of electromechanical and robot‐assisted arm training for improving arm function in people who have had a stroke.

Background

More than two‐thirds of people who have had a stroke have difficulties with reduced arm function, which can restrict a person’s ability to perform everyday activities, reduce productivity, limit social activities, and lead to economic burden. Electromechanical and robot‐assisted arm training uses specialised machines to assist rehabilitation in supporting shoulder, elbow, or hand movements. However, the role of electromechanical and robot‐assisted arm training for improving arm function after stroke is unclear.

Study characteristics

We identified 45 trials (involving 1619 participants) up to January 2018 and included them in our review. Twenty‐four different electromechanical devices were described in the trials, which compared electromechanical and robot‐assisted arm training with a variety of other interventions. Participants were between 21 to 80 years of age, the duration of the trials ranged from two to 12 weeks, the size of the trials was between eight and 127 participants, and the primary outcome (activities of daily living: the most important target variable measured) differed between the included trials.

Key results

Electromechanical and robot‐assisted arm training improved activities of daily living in people after stroke, and function and muscle strength of the affected arm. As adverse events, such as injuries and pain, were seldom described, these devices can be applied as a rehabilitation tool, but we still do not know when or how often they should be used.

Quality of the evidence

The quality of the evidence was high.

 

via Electromechanical and robot‐assisted arm training for improving activities of daily living, arm function, and arm muscle strength after stroke – Mehrholz, J – 2018 | Cochrane Library

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[Abstract + References] A Wearable Hand Neuroprosthesis for Hand Rehabilitation After Stroke: Preliminary Results of the RETRAINER S2 Randomized Controlled Trial – Conference paper

Abstract

Stroke is the main cause of permanent and complex long-term disability in adults. RETRAINER S2 is a system able to recover and support person’s ability to perform Activities of Daily Living (ADL) in early stage after stroke. The system is based on exercises for hand and wrist performed using Neuro Muscular Electrical Stimulation (NMES). This work describes the preliminary results of a multi-center Randomized Controlled Trial (RCT) aimed at evaluating effectiveness of the system. The preliminary results were calculated on 18 patients who completed the protocol. Data is promising, the RETRANER S2 system seems to be a good tool for stroke rehabilitation. Data confirms also a general good usability of the system.

via A Wearable Hand Neuroprosthesis for Hand Rehabilitation After Stroke: Preliminary Results of the RETRAINER S2 Randomized Controlled Trial | SpringerLink

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[Abstract] Eye Movements Interfere With Limb Motor Control in Stroke Survivors

Background. Humans use voluntary eye movements to actively gather visual information during many activities of daily living, such as driving, walking, and preparing meals. Most stroke survivors have difficulties performing these functional motor tasks, and we recently demonstrated that stroke survivors who require many saccades (rapid eye movements) to plan reaching movements exhibit poor motor performance. However, the nature of this relationship remains unclear.

Objective. Here we investigate if saccades interfere with speed and smoothness of reaching movements in stroke survivors, and if excessive saccades are associated with difficulties performing functional tasks.

Methods. We used a robotic device and eye tracking to examine reaching and saccades in stroke survivors and age-matched controls who performed the Trail Making Test, a visuomotor task that uses organized patterns of saccades to plan reaching movements. We also used the Stroke Impact Scale to examine difficulties performing functional tasks.

Results. Compared with controls, stroke survivors made many saccades during ongoing reaching movements, and most of these saccades closely preceded transient decreases in reaching speed. We also found that the number of saccades that stroke survivors made during ongoing reaching movements was strongly associated with slower reaching speed, decreased reaching smoothness, and greater difficulty performing functional tasks.

Conclusions. Our findings indicate that poststroke interference between eye and limb movements may contribute to difficulties performing functional tasks. This suggests that interventions aimed at treating impaired organization of eye movements may improve functional recovery after stroke.

  

via Eye Movements Interfere With Limb Motor Control in Stroke Survivors – Tarkeshwar Singh, Christopher M. Perry, Stacy L. Fritz, Julius Fridriksson, Troy M. Herter, 2018

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[REVIEW] Moving toward Soft Robotics: A Decade Review of the Design of Hand Exoskeletons – Full Text HTML

Abstract

Soft robotics is a branch of robotics that deals with mechatronics and electromechanical systems primarily made of soft materials. This paper presents a summary of a chronicle study of various soft robotic hand exoskeletons, with different electroencephalography (EEG)- and electromyography (EMG)-based instrumentations and controls, for rehabilitation and assistance in activities of daily living. A total of 45 soft robotic hand exoskeletons are reviewed. The study follows two methodological frameworks: a systematic review and a chronological review of the exoskeletons. The first approach summarizes the designs of different soft robotic hand exoskeletons based on their mechanical, electrical and functional attributes, including the degree of freedom, number of fingers, force transmission, actuation mode and control strategy. The second approach discusses the technological trend of soft robotic hand exoskeletons in the past decade. The timeline analysis demonstrates the transformation of the exoskeletons from rigid ferrous materials to soft elastomeric materials. It uncovers recent research, development and integration of their mechanical and electrical components. It also approximates the future of the soft robotic hand exoskeletons and some of their crucial design attributes.

1. Introduction

The emerging trend of soft robotics has stimulated the interest of engineers and researchers around the world to look into various applications, ranging from biomedical and rehabilitation to grasping and manipulation [1,2]. Biomimetic and bioinspired soft robots have been among the most successful products of soft material robotics. Among others, the inspiration for these soft robots originates from examining invertebrates like caterpillars, worms and fish grubs [2]. The hydrostatic and fluid-like structure motivates researchers to look more into the use of soft materials to develop similar structures.
One of the major lessons learned from these biostructures was the ability to form and adapt to complexly shaped bodies. This led to various developments such as: (1) an octopus-like robot for flexible manipulation [2]; (2) a worm-like robot that uses a thermal shape-memory alloy (SMA) actuator to imitate the motion of its biological counterpart [3]; and (3) a caterpillar-shaped soft robot that imitates the process of translating deformation to locomotor dynamics [4].
Another important development in the emerging field of soft robotics is the use of pneumatic soft grippers for handling fragile objects such as an uncooked egg or an anesthetized mouse [5]. These devices can grip, hold and release certain complexly shaped objects. They have several fingers to hold delicate objects by intelligently adapting themselves to the shape of the object and providing maximum gripping force without damaging it.
This new trend is especially interesting for biomedical and rehabilitation engineering applications as well, with the hand exoskeleton as one of the examples. A major shift from the use of hard to soft materials can be observed in some of the latest designs of hand exoskeletons, such as the Wyss Institute glove [6,7,8], the Magnetic Resonance Compatible (MRC) glove [9,10,11,12], the National University of Singapore (NUS) glove [13,14,15,16,17] and the Seoul National University (SNU) glove [18,19,20,21,22,23]. The hand exoskeleton is an integral part of rehabilitation robotics that provides rehabilitation exercises and assistance in activities of daily living (ADL), such as gripping and grasping [24]. It is commonly recommended for patients with cerebrovascular disease [24], cerebral palsy [25] and rheumatoid arthritis [26].
Unlike a prosthetic hand, a hand exoskeleton is designed and built around the human hand; thus, it has to conform to the hand anatomy and its range of motion to minimize the wearer’s discomfort. More importantly, it has to be light and able to be put on easily so that the wearer can use it daily to perform basic activities. Figure 1a shows the natural skeletal structure of the human finger, the movement of which may be assisted. The structure consists of three joints: distal (DIP), proximal (PIP) and metacarpal (MCP) interphalangeal joints [27,28]. The finger movements are controlled through the activation of extrinsic and intrinsic muscles. The extrinsic muscles are actuated from the forearm and control the flexor and extensor muscle tendons to move the fingers. The intrinsic muscles are located within the finger, and they control the independent motion of the finger [28]. The maximum flexion for the MCP joint ranges from 70° to 95° depending on the finger orientation, while the maximum flexion for the DIP and PIP joints is about 110° and 90°, respectively.
Hand exoskeletons have endured extensive research, primarily in the field of assistive and rehabilitative robotics, and have also been discussed from various perspectives [29,30,31]. Several iterations of different hand exoskeletons indicate the growing need for a better, lighter and more practical solution. Most of the existing hand exoskeletons adopt one of the design approaches depicted in Figure 1. With the rise of soft robotics, there has been a progressive shift from the conventional rigid mechanical structure designs (Figure 1b) to designs with softer actuation (Figure 1c) and designs that closely resemble the natural finger musculoskeletal structure (Figure 1d) [27]. This study aims to review these changes in the recent decade and discuss how the adoption of soft robotics helps in designing a more compliant hand exoskeleton. The design of a hand exoskeleton can be divided into three main components: the mechanical design, the actuation unit and sensory feedback control. This work also examines how soft robotics technology has changed the architectures of these components over the years.[…]

 

Continue —>  Biomimetics | Free Full-Text | Moving toward Soft Robotics: A Decade Review of the Design of Hand Exoskeletons | HTML

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[Abstract] Effects of MOTOmed movement therapy on the mobility and activities of daily living of stroke patients with hemiplegia: a systematic review and meta-analysis

To estimate the effectiveness of MOTOmed® movement therapy in increasing mobility and activities of daily living in stroke patients with hemiplegia.

Systematic review.

English- and Chinese-language articles published from the start of database coverage through 20 June 2018 were retrieved from the Embase, Web of Science, PubMed, OVID, Cochrane Central Register of Controlled Trials, Cochrane Systematic Reviews, Wanfang, Chinese National Knowledge Infrastructure, VIP, and Chinese Biomedicine databases. Articles were also retrieved by manual searches of Rehabilitation Medicine and Chinese journals.

Randomized control trials examining MOTOmed movement therapy interventions for patients with post-stroke hemiplegia were included in this review. The risk of bias assessment tool was utilized in accordance with Cochrane Handbook 5.1.0. All included studies reported mobility effects as primary outcomes. Standardized mean differences or mean differences with the corresponding 95% confidence intervals (CIs) were calculated. Review Manager 5.3 was utilized for meta-analysis.

In total, 19 trials involving a total of 1099 patients were included in the analysis. All studies were of moderate quality, based on the Cochrane Handbook for Systematic Reviews of Intervention: Part 2:8.5. MOTOmed movement therapy resulted in a merged mean difference in the Fugl-Meyer Assessment score of 5.51 (95% CI: 4.03 to 6.98). Comparison of groups treated with and without MOTOmed movement therapy yielded the following mean differences: Modified Ashworth Scale, −1.13 (95% CI: −1.37 to −0.89); Berg Balance Scale, 13.66 (95% CI: 10.47–16.85); Functional Ambulation Category Scale, 0.85 (95% CI: 0.68–1.03); 10-m walk test, 10.15 (95% CI: 5.72–14.58); Barthel Index, 14.82 (95% CI: 12.96–16.68); and Modified Barthel Index, 11.49 (95% CI: 8.96–14.03).

MOTOmed movement therapy combined with standard rehabilitation improves mobility and activities of daily living in stroke patients with hemiplegia.

  

via Effects of MOTOmed movement therapy on the mobility and activities of daily living of stroke patients with hemiplegia: a systematic review and meta-analysis – Cuiling Shen, Fang Liu, Liqun Yao, Zhongyuan Li, Li Qiu, Suzhu Fang, 2018

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[Abstract] Eye Movements Interfere With Limb Motor Control in Stroke Survivors

Background. Humans use voluntary eye movements to actively gather visual information during many activities of daily living, such as driving, walking, and preparing meals. Most stroke survivors have difficulties performing these functional motor tasks, and we recently demonstrated that stroke survivors who require many saccades (rapid eye movements) to plan reaching movements exhibit poor motor performance. However, the nature of this relationship remains unclear.

Objective. Here we investigate if saccades interfere with speed and smoothness of reaching movements in stroke survivors, and if excessive saccades are associated with difficulties performing functional tasks.

Methods. We used a robotic device and eye tracking to examine reaching and saccades in stroke survivors and age-matched controls who performed the Trail Making Test, a visuomotor task that uses organized patterns of saccades to plan reaching movements. We also used the Stroke Impact Scale to examine difficulties performing functional tasks.

Results. Compared with controls, stroke survivors made many saccades during ongoing reaching movements, and most of these saccades closely preceded transient decreases in reaching speed. We also found that the number of saccades that stroke survivors made during ongoing reaching movements was strongly associated with slower reaching speed, decreased reaching smoothness, and greater difficulty performing functional tasks.

Conclusions. Our findings indicate that poststroke interference between eye and limb movements may contribute to difficulties performing functional tasks. This suggests that interventions aimed at treating impaired organization of eye movements may improve functional recovery after stroke.

via Eye Movements Interfere With Limb Motor Control in Stroke Survivors – Tarkeshwar Singh, Christopher M. Perry, Stacy L. Fritz, Julius Fridriksson, Troy M. Herter, 2018

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[ARTICLE] Virtual Reality for Stroke Rehabilitation – Full Text

The use of virtual reality programs specifically designed for stroke rehabilitation is increasing as is the use of commercial video game devices in clinical settings. This review is an update of our review published first in 2011 and then in 2015.1

Objectives

The primary objective of this review was to examine the efficacy of virtual reality compared with an alternative intervention or no intervention on upper limb function and activity. Our secondary objective was to examine the efficacy on gait and balance, global motor function, cognitive function, activity limitation, participation restriction, quality of life, and adverse events.

Methods

We searched the Cochrane Stroke Group Trials Register (April 2017), CENTRAL, MEDLINE, Embase, and 7 additional databases as well as trials registries. We included randomized and quasi-randomized trials of virtual reality in adults after stroke. The primary outcome of interest was upper limb function and activity. Two review authors independently selected trials, extracted data, and assessed risk of bias with input from a third author to moderate disagreements when required.

Main Results

A total of 72 trials (with 2470 participants) were included in the review. This review includes 35 new studies in addition to the studies included in the previous version of this review (published in 2015). Most studies involved small sample sizes and interventions varied in terms of both the goals of treatment and the virtual reality program or device used. Although there are a relatively large number of randomized controlled trials, the evidence remains mostly low quality when rated using the GRADE system because of the risk of bias in the studies and inconsistent findings between studies. Control groups in the included studies usually received either no therapy or conventional therapy which was provided by an occupational therapist or physiotherapist. Primary outcome: when virtual reality was compared with the same dose of conventional therapy the results were not statistically significant for upper limb function (standardized mean difference, 0.07; 95% confidence interval, −0.05–0.20; 22 studies, 1038 participants, low-quality evidence). However, when virtual reality was used to supplement usual care (thereby providing participants in the intervention group with a higher dose of therapy), there was a statistically significant difference between groups (standardized mean difference, 0.49; 95% confidence interval, 0.21–0.77, 10 studies, 210 participants, low-quality evidence). Secondary outcomes: when compared with conventional therapy approaches there were no statistically significant effects for gait speed or balance. Results were statistically significant for the activities of daily living outcome (standardized mean difference, 0.25; 95% confidence interval, 0.06–0.43; 10 studies, 466 participants, moderate-quality evidence); however, we were unable to pool results for cognitive function, participation restriction, or quality of life. There were few adverse events experienced in the 23 studies which reported on this and adverse events were relatively mild. There was a trend suggesting that customized virtual reality programs were preferable to commercial game products, however, these findings were not statistically significant (Figure).

Figure.

Figure. Virtual reality versus conventional therapy: upper limb function: subgroup analyses, specialized, or gaming program. CI indicates confidence interval.

Implications for Practice

We found that virtual reality therapy may not be more effective than conventional therapy for upper limb outcomes, but there is low-quality evidence that virtual reality may be used to improve outcomes in the absence of other therapy interventions after stroke. Clinicians who currently have access to virtual reality programs should be reassured that their use as part of a comprehensive rehabilitation program seems reasonable, taking into account the patient’s goals, abilities, and preferences.

Sources of Funding

Dr Laver is supported by a National Health and Medical Research Council-Australian Research Council fellowship. Dr Saposnik is supported by the 2017 to 2021 Heart and Stroke Foundation of Canada Career Award following an open and peer-reviewed competition. He also served as the Topic Editor for the Emerging Therapies Section (Stroke Journal).

Disclosures

None.

Footnotes

  • This paper is based on a Cochrane Review published in The Cochrane Library 2017, Issue 11 (see www.thecochranelibrary.com for information). Cochrane Reviews are regularly updated as new evidence emerges and in response to feedback, and The Cochrane Library should be consulted for the most recent version of the review.

  • Received December 13, 2017.
  • Revision received December 13, 2017.
  • Accepted December 21, 2017.

Reference

  1. 1.

View Abstract

via Virtual Reality for Stroke Rehabilitation | Stroke

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[Abstract] Additional physical therapy services reduce length of stay and improve health outcomes in people with acute and sub-acute conditions: an updated systematic review and meta-analysis

Abstract

Objective

To update a previous review on whether additional physical therapy services reduce length of stay, improve health outcomes, are safe and cost effective for patients with acute or sub-acute conditions.

Data sources

Electronic database (AMED, CINAHL, EMBASE, MEDLINE, PEDro, PubMed) searches were updated from 2010 through June 2017.

Study selection

Randomized controlled trials evaluating additional physical therapy services on patient health outcomes, length of stay or cost effectiveness were eligible. Searching identified 1524 potentially relevant articles, of which 11 new articles from 8 new randomized controlled trials with 1563 participants were selected. In total, 24 randomized controlled trials with 3262 participants are included in this review.

Data extraction

Data were extracted using the form used in the original systematic review. Methodological quality was assessed using the PEDro scale and The Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach was applied to each meta-analysis.

Data synthesis

Post intervention data were pooled with an inverse variance, random effects model to calculate standardized mean differences (SMDs) and 95% confidence intervals (CIs). There is moderate quality evidence that additional physical therapy services reduced length of stay by 3 days in sub-acute settings (MD-2.8, 95%CI -4.6 to -0.9, I20%) and low quality evidence that it reduced length of stay by 0.6 days in acute settings (MD -0.6, 95%CI -1.1 to 0.0, I2 65%). Additional physical therapy led to small improvements in self-care (SMD 0.11, 95%CI 0.03 to 0.19, I2 0%), activities of daily living (SMD 0.13, 95%CI 0.02 to 0.25, I2 15%) and health-related quality of life (SMD 0.12, 95%CI 0.03 to 0.21, I2 0%), with no increases in adverse events. There was no significant change in walking ability. One trial reported that additional physical therapy was likely to be cost-effective in sub-acute rehabilitation.

Conclusions

Additional physical therapy services improve patient activity and participation outcomes, while reducing hospital length of stay for adults. These benefits are likely safe and there is preliminary evidence to suggest they may be cost effective.

via Additional physical therapy services reduce length of stay and improve health outcomes in people with acute and sub-acute conditions: an updated systematic review and meta-analysis – Archives of Physical Medicine and Rehabilitation

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[Review] Evolution of Cognitive Rehabilitation After Stroke From Traditional Techniques to Smart and Personalized Home-Based Information and Communication Technology Systems: Literature Review – Full Text

ABSTRACT

Background: Neurological patients after stroke usually present cognitive deficits that cause dependencies in their daily living. These deficits mainly affect the performance of some of their daily activities. For that reason, stroke patients need long-term processes for their cognitive rehabilitation. Considering that classical techniques are focused on acting as guides and are dependent on help from therapists, significant efforts are being made to improve current methodologies and to use eHealth and Web-based architectures to implement information and communication technology (ICT) systems that achieve reliable, personalized, and home-based platforms to increase efficiency and level of attractiveness for patients and carers.

Objective: The goal of this work was to provide an overview of the practices implemented for the assessment of stroke patients and cognitive rehabilitation. This study puts together traditional methods and the most recent personalized platforms based on ICT technologies and Internet of Things.

Methods: A literature review has been distributed to a multidisciplinary team of researchers from engineering, psychology, and sport science fields. The systematic review has been focused on published scientific research, other European projects, and the most current innovative large-scale initiatives in the area. A total of 3469 results were retrieved from Web of Science, 284 studies from Journal of Medical Internet Research, and 15 European research projects from Community Research and Development Information Service from the last 15 years were reviewed for classification and selection regarding their relevance.

Results: A total of 7 relevant studies on the screening of stroke patients have been presented with 6 additional methods for the analysis of kinematics and 9 studies on the execution of goal-oriented activities. Meanwhile, the classical methods to provide cognitive rehabilitation have been classified in the 5 main techniques implemented. Finally, the review has been finalized with the selection of 8 different ICT–based approaches found in scientific-technical studies, 9 European projects funded by the European Commission that offer eHealth architectures, and other large-scale activities such as smart houses and the initiative City4Age.

Conclusions: Stroke is one of the main causes that most negatively affect countries in the socioeconomic aspect. The design of new ICT-based systems should provide 4 main features for an efficient and personalized cognitive rehabilitation: support in the execution of complex daily tasks, automatic error detection, home-based performance, and accessibility. Only 33% of the European projects presented fulfilled those requirements at the same time. For this reason, current and future large-scale initiatives focused on eHealth and smart environments should try to solve this situation by providing more complete and sophisticated platforms.[…]

Continue —> JRAT-Evolution of Cognitive Rehabilitation After Stroke From Traditional Techniques to Smart and Personalized Home-Based Information and Communication Technology Systems: Literature Review | Cogollor | JMIR Rehabilitation and Assistive Technologies

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[ARTICLE] Design and Preliminary Feasibility Study of a Soft Robotic Glove for Hand Function Assistance in Stroke Survivors – Full Text

Various robotic exoskeletons have been proposed for hand function assistance during activities of daily living (ADL) of stroke survivors. However, traditional exoskeletons involve the use of complex rigid systems that impede the natural movement of joints, and thus reduce the wearability and cause discomfort to the user. The objective of this paper is to design and evaluate a soft robotic glove that is able to provide hand function assistance using fabric-reinforced soft pneumatic actuators. These actuators are made of silicone rubber which has an elastic modulus similar to human tissues. Thus, they are intrinsically soft and compliant. Upon air pressurization, they are able to support finger range of motion (ROM) and generate the desired actuation of the finger joints. In this work, the soft actuators were characterized in terms of their blocked tip force, normal and frictional grip force outputs. Combining the soft actuators and flexible textile materials, a soft robotic glove was developed for grasping assistance during ADL for stroke survivors. The glove was evaluated on five healthy participants for its assisted ROM and grip strength. Pilot test was performed in two stroke survivors to evaluate the efficacy of the glove in assisting functional grasping activities. Our results demonstrated that the actuators designed in this study could generate desired force output at a low air pressure. The glove had a high kinematic transparency and did not affect the active ROM of the finger joints when it was being worn by the participants. With the assistance of the glove, the participants were able to perform grasping actions with sufficient assisted ROM and grip strength, without any voluntary effort. Additionally, pilot test on stroke survivors demonstrated that the patient’s grasping performance improved with the presence and assistance of the glove. Patient feedback questionnaires also showed high level of patient satisfaction and comfort. In conclusion, this paper has demonstrated the possibility of using soft wearable exoskeletons that are more wearable, lightweight, and suitable to be used on a daily basis for hand function assistance of stroke survivors during activities of daily living.

Introduction

The ability to perform basic activities of daily living (ADL) impacts a person’s quality of life and independence (Katz, 1983Andersen et al., 2004). However, an individual’s independence to perform ADLs is jeopardized due to hand motor impairments, which can be observed in patients with neurological disorders such as stroke. In order to improve hand motor functions in terms of strength and range of motion (ROM) (Kutner et al., 2010), stroke survivors undergo rehabilitation programs comprising repetitive practice of simulated ADL tasks (Michaelsen et al., 2006). Normally, patients undergo rehabilitation exercises in a specialized rehabilitation center under the guidance of physiotherapists or occupational therapists. However, due to increasing patient population, it is foreseen that there will be a shortage of physiotherapists to assist in the rehabilitative process. Thus, there will be comparatively less therapy time, which will eventually lead to a slower recovery process for the patients. Over the past decade, technological developments in robotics have facilitated the rehabilitative process and have shown potential to assist patients in their daily life (Maciejasz et al., 2014). One example of such a device is the hand exoskeleton, which is secured around the hand to guide and assist the movement of the encompassed joints. However, due to the complexity of the hand, designing a hand exoskeleton remains a challenging task.

Traditional hand exoskeletons involve the use of rigid linkage-based mechanisms. In this kind of mechanism, rigid components, such as linear actuators, rotary motors, racks, and pinions as well as rigid linkages are normally involved (Worsnopp et al., 2007Rotella et al., 2009Martinez et al., 2010). To assist hand movements that have high degrees of freedom (DOFs), traditional exoskeletons can be incorporated with a substantial number of actuators to achieve the requirement. However, this means that their application is limited due to the increasing bulkiness for higher DOFs. Therefore, these devices are normally restricted in clinical settings and not suitable for performing home therapy. Additionally, their rigidity, weight and constraint on the non-actuated DOFs of the joints pose complications. As a result, the level of comfort and safety of patients is reduced. In view of this, there is an apparent need for the development of exoskeletons that may be used in both clinical and home settings. A lightweight and wearable exoskeleton may allow patients to bring back home to continue daily therapy or to serve as an assistive device for the ADLs.

The development of wearable robotic exoskeletons serves to provide an alternative approach toward addressing this need. Instead of using rigid linkage as an interface between the hand and the actuators, wearable exoskeletons typically utilize flexible materials such as fabric (Sasaki et al., 2004Yap et al., 2016a) and polymer (Kang et al., 2016), driven by compliant actuators such as cables (Sangwook et al., 2014Xiloyannis et al., 2016) and soft inflatable actuators (Polygerinos et al., 2015dYap et al., 2016c). Therefore, they are more compliant and lightweight compared to the rigid linkage-based mechanism. Cable-driven based exoskeletons involve the use of cables that are connected to actuators in the form of electrical motors situated away from the hand (Nilsson et al., 2012Ying and Agrawal, 2012Sangwook et al., 2014Varalta et al., 2014). By providing actuations on both dorsal and palmar sides of the hand, bi-directional cable-driven movements are possible (Kang et al., 2016). These cables mimic the capability of the tendons of the human hand and they are able to transmit the required pulling force to induce finger flexion and extension. However, the friction of the cable, derailment of the tendon, and inaccurate routing of the cable due to different hand dimensions can affect the efficiency of force transmission in the system.

On the other hand, examples of the soft inflatable actuators are McKibben type muscles (Feifei et al., 2006Tadano et al., 2010), sheet-like rubber muscles (Sasaki et al., 2004Kadowaki et al., 2011), and soft elastomeric actuators (Polygerinos et al., 2015b,cYap et al., 2015); amongst which, soft elastomeric actuators have drawn increasing research interest due to their high compliance (Martinez et al., 2013). This approach typically embeds pneumatic chamber networks in elastomeric constructs to achieve different desired motions with pressurized air or water (Martinez et al., 2012). Soft elastomeric actuators are highly customizable. They are able to achieve multiple DOFs and complex motions with a single input, such as fluid pressurization. The design of a wearable hand exoskeleton that utilizes soft elastomeric actuators is usually simple and does not require precise routing for actuation, compared to the cable-driven mechanism. Thus, the design reduces the possibility of misalignment and the setup time. These properties allow the development of hand exoskeletons that are more compliant and wearable, with the ability to provide safe human-robot interaction. Additionally, several studies have demonstrated that compactness and ease of use of an assistive device critically affect its user acceptance (Scherer et al., 20052007). Thus, these exoskeletons provide a greater chance of user acceptance.

Table 1 summarizes the-state-of-art of soft robotic assistive glove driven by inflatable actuators. Several pioneer studies on inflatable assistive glove have been conducted by Sasaki et al. (2004)Kadowaki et al. (2011) and Polygerinos et al. (2015a,b,c). Sasaki et al. have developed a pneumatically actuated power assist glove that utilizes sheet-like curved rubber muscle for hand grasping applications. Polygerinos et al. have designed a hydraulically actuated grip glove that utilizes fiber-reinforced elastomeric actuators that can be mechanically programmed to generate complex motion paths similar to the kinematics of the human finger and thumb. Fiber reinforcement has been proved to be an effective method to constrain the undesired radial expansion of the actuators that does not contribute to effective motion during pressurization. However, this method limits the bending capability of the actuators (Figure S1); as a result, higher pressure is needed to achieve desired bending.

Table 1. Hand assistive exoskeletons driven by inflatable actuators.

This paper presents the design and preliminary feasibility study of a soft robotic glove that utilizes fabric-reinforced soft pneumatic actuators. The intended use of the device is to support the functional tasks during ADLs, such as grasping, for stroke survivors. The objectives of this study were to characterize the soft actuators in terms of their force output and to evaluate the performance of the glove with healthy participants and stroke survivors. The glove was evaluated on five healthy participants in order to determine the ROM of individual finger joints and grip strength achieved with the assistance of the glove. Pilot testing with two stroke survivors was conducted to evaluate the feasibility of the glove in providing grasping assistance for ADL tasks. We hypothesized that with the assistance of the glove, the grasping performance of stroke patients improved.

Specific contributions of this work are listed as follows:

(a) Presented fabric-reinforcement as an alternative method to reinforce soft actuators, which enhanced the bending capability and reduced the required operating pressure of the actuators,

(b) Utilized the inherence compliance of soft actuators and allowed the actuators to achieve multiple motions to support ROM of the human fingers,

(c) Integrated elastic fabric with soft actuators to enhance the extension force for finger extension,

(d) Designed and characterized a soft robotic glove using fabric-reinforced soft actuators with the combination of textile materials, and

(e) Conducted pilot tests with stroke survivors to evaluate the feasibility of the glove in providing functional assistance for ADL tasks.

Design Requirements and Rationale

The design requirements of the glove presented in this paper are similar to those presented by Polygerinos et al. (2015a,b,c) in terms of design considerations, force requirements, and control requirements. For design considerations, weight is the most important design criterion when designing a hand exoskeleton. Previous studies have identified the threshold for acceptable weight of device on the hand, which is in the range of 400–500 g (Aubin et al., 2013Gasser and Goldfarb, 2015). Cable-driven, hydraulic, and pneumatic driven mechanisms are found to be suitable options to meet the criteria. To develop a fully portable system for practical use in home setting, reduction in the weight of the glove as well as the control system is required. The total weight of the control system should not exceed 3 kg (Polygerinos et al., 2015a,b,c). In this work, the criteria for the weight of the glove and control system are defined as: (a) the weight of the glove should be <200 g, and (b) the weight of the control system should be <1.5 kg.

Considering the weight requirement, hydraulic systems are not ideal for this application, as the requirement of a water reservoir for hydraulic control systems and actuation of the actuators with pressurized water will add extra weight to the hand. The second consideration is that the hand exoskeleton should allow fast setup time. Therefore, it is preferable for the hand exoskeleton to fit the hand anatomy rapidly without precise joint alignment. Compared to cable-driven mechanisms, soft pneumatic actuators are found to be more suitable as they allow rapid customization to different finger length. Additionally, they do not require precise joint alignment and cable routing for actuation as the attachment of the soft pneumatic actuators on the glove is usually simple. Therefore, in this work, pneumatic mechanisms were selected. Using pneumatic mechanism, Connelly et al. and Thielbar et al. have developed a pneumatically actuated glove, PneuGlove that is able to provide active extension assistance to each finger while allowing the wearer to flex the finger voluntarily (Connelly et al., 2010Thielbar et al., 2014). The device consists of five air bladders on the palmar side of the glove. Inflation of the air bladders due to air pressurization created an extension force that extends the fingers. However, due to the placement of the air bladders on the palmar side, grasping activities such as palmar and pincer grasps were more difficult. Additionally, this device is limited to stroke survivors who are able to flex their fingers voluntarily.

In this work, the soft robotic glove is designed to provide functional grasping assistance for stroke survivors with muscle weakness and impairments in grasping by promoting finger flexion. While the stroke survivors still preserve the ability to modulate grip force within their limited force range, the grip release (i.e., hand opening) is normally prolonged (Lindberg et al., 2012). Therefore, the glove should assist with grip release by allowing passive finger extension via reinforced elastic components, similar to Saeboflex (Farrell et al., 2007) and HandSOME (Brokaw et al., 2011). The elastic components of these devices pull the fingers to the open hand state due to increased tension during finger flexion. Additionally, the glove should generate the grasping force required to manipulate and counteract the weight of the objects of daily living, which are typically below 1.07 kg (Smaby et al., 2004). Additionally, the actuators in the glove should be controlled individually in order to achieve different grasping configurations required in simulated ADL tasks, such as palmar grasp, pincer grasp, and tripod pinch. For the speed of actuation, the glove should reach full grasping motion in <4 s during simulated ADL tasks and rehabilitation training.

For the actuators, we have recently developed a new type of soft fabric-reinforced pneumatic actuator with a corrugated top fabric layer (Yap et al., 2016a) that could minimize the excessive budging and provide better bending capability compared to fiber-reinforced soft actuators developed in previous studies (Polygerinos et al., 2015c,d). This corrugated top fabric layer allows a small initial radial expansion to initiate bending and then constrains further undesired radial expansion (Figure 1). The detailed comparison of the fiber-reinforced actuators and fabric-reinforced actuators can be found in the Supplementary Material.

 

 

Figure 1. (A) A fabric-reinforced soft actuators with a corrugated fabric layer and an elastic fabric later [Actuator thickness, T= 12 mm, and length, L = 160 mm (Thumb), 170 mm (Little Finger), 180 mm (Index & Ring Fingers), 185 mm (Middle Finger)]. (B) Upon air pressurization, the corrugated fabric layer unfolds and expands due to the inflation of the embedded pneumatic chamber. Radial budging is constrained when the corrugated fabric layer unfolds fully. The elastic fabric elongates during air pressurization and stores elastic energy. The actuator achieves bending and extending motions at the same time. (C) A bending motion is preferred at the finger joints (II, IV, VI). An extending motion is preferred over the bending motion at the finger segments (I, III, V) and the opisthenar (VII).

Continue —>  Frontiers | Design and Preliminary Feasibility Study of a Soft Robotic Glove for Hand Function Assistance in Stroke Survivors | Neuroscience

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