Quantification of hand functional recovery in spinal cord injury patients

STUDY DESIGN

A prospective cohort study.

OBJECTIVES

To examine the use of a circle-tracing task in quantifying hand functional recovery in cervical spinal cord injury patients.

METHODS

Ten cervical spinal cord injury (SCI) patients and 10 healthy age-matched controls performed a circle-tracing task, using a computerized tablet at the beginning of the study and after 4 weeks. Data relative to performance accuracy as well as pen pressure throughout the performances were collected, and clinical assessment for all patients was performed at the beginning and at the end of the study.

RESULTS

Significant differences were found in pen pressure profiles in the SCI patients between the initial assessment and after 4 weeks of assessment. SCI patients, when compared with controls, apply less pressure during the execution, though no significant differences were found for the other parameters. Examination of pen pressure profiles of both controls and SCI patients reveals that, in addition to the lower pressure registered, SCI patients present a more oscillating pressure profile which is direction-dependent. No significant correlations were found between clinical assessments and pen pressure, both within the initial assessment as well as after 4 weeks.

CONCLUSIONS

This study emphasizes the potential of simple computerized means for quantifying upper limb functions in SCI patients. These results of this study could be helpful for both highlighting specific functional deficits in patients as well tailoring specific interventions.

The effectiveness of therapeutic craft-making activities in treating lower-third forearm fracture: study protocol for a randomized controlled trial

BACKGROUND

Occupational Therapists use craft-making activities as therapeutic interventions to improve physical and psychological functioning of injured people. Despite the therapeutic effects, craft-making is not routinely used in hand rehabilitation as an intervention for patients with upper limb fractures. These patients often experience physical and psychosocial issues; however, without supportive evidence, therapists hesitate to integrate craft-making into upper limb rehabilitation.

PURPOSE

This study aims to determine the effect of a conventional therapy combined with therapeutic craft-making on disability, post-traumatic stress, and physical performance in patients with lower-third forearm fractures.

METHODS

Priori analysis determined that 38 patients will be needed for this superiority randomized controlled trial to be conducted in a hand and upper limb rehabilitation center. Eligible participants must comprehend English, be diagnosed with lower-third forearm fracture(s) stabilized by open reduction internal fixation, and referred to therapy within 2-4 weeks of surgery. Following the CONSORT guidelines, participants will be randomly assigned to a Control (conventional therapy) group or an Intervention (conventional therapy and craft) group. Twice weekly for 6 weeks, Therapist A will provide both groups with 1-h of conventional therapy while the Intervention group will also receive 15 min of craft-making supervised by the Researcher. The primary outcome of disability will be measured with the Quick-Disabilities of Arm, Shoulder and Hand. The secondary outcome measurements include the Patient-Rated-Wrist-Evaluation; Impact of Event Scale-revised and physical performance, i.e., the Purdue Pegboard Test, AROM, and grip strength. All outcome measures will be obtained by Therapist B prior to the 1st therapy visit and after the 12th visit. Descriptive analysis will be done for the categorical and continuous data and a mixed model ANOVA for analysis of the initial and final assessment scores within and between groups.

RESULTS

This study is ongoing.

DISCUSSION

The intent of this study is to determine if therapeutic crafts have value as an intervention when used in combination with conventional therapy for patients with lower-third forearm fractures. If the value of crafts is supported, this evidence may reduce hesitancy of therapists to implement craft-making with patients referred to hand therapy after upper limb fracture.

CONCLUSION

This study is ongoing.

TRIAL REGISTRATION

ANZCTR, ACTRN12622000150741. Retrospectively registered on 28 January 2022 https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382676&isReview=true ..

Assessing hand grasp in patients with systemic sclerosis using the 16-grasp test: Preliminary results from a multidisciplinary study group

BACKGROUND

Reports on hand dysfunction and rehabilitation in SSc are quite scarce in the literature and mainly focus on functional assessment tools, such as the Duruoz Hand Index and the HAMIS test for evaluating hand mobility by simulating specific grasps with nine different objects.

PURPOSE OF THE STUDY

This study aimed to provide an adequate assessment methodology for hand grasp dysfunctions in patients suffering from systemic sclerosis (SSc) through the 16-grasp test.

STUDY DESIGN

Case-control study.

METHODS

Ninety-seven consecutive SSc patients were recruited at our Scleroderma Unit, where a 16-grasp test was performed by all patients and supervised by an experienced hand therapist. Sixteen different patterns of grasp have been divided into power grasps and precision pinch and two more modalities: static and dynamic prehension evaluation on scale from 0 to 4. We also compared previous evaluations on 19 of patients recruited.

RESULTS

The majority of SSc patients (84 females and 13 males; mean age 56.0±12.0 years; mean disease duration 8.0±6.0 years) displayed grasp dysfunctions; in particular 48% and 54% reported slight difficulty in the right and left grasps respectively, 6% medium difficulty in both hands, and only 3% and 1% experienced severe difficulty respectively, while 31.5% had no issues in either hand. Our results showed that the limited cutaneous subset (lcSSc) scored a lower deficit for either grasp compared to diffuse form (dcSSc). No statistically significant differences in total grasp deficit had been noticed when comparing patients having a disease duration < 5 years or longer. In the retrospective study on 19 of these patients, 8 out of 10 lcSSc patients showed no significant changes, while in 2 out of 10, slight improvements were observed in both hands. However, in the dcSSc group, 4 out of 9 worsened bilaterally while the grasp scores for 5 of them remained unchanged.

CONCLUSION

Our study reported hand involvement in both lcSSc and dcSSc forms, more significantly in dcSSc patients. This test is intended to be a more objective means of assessing grasp alterations linked to scleroderma hand deformities. Furthermore, thanks to its intuitiveness, the test may be useful for engineers designing personalized ergonomic assistive devices.

Hand Flexor Tendon Repair: From Biology to Surgery and Rehabilitation

Tendon biology and anatomy are crucial to manage hand flexor tendon injuries, not only for surgical treatment but also for rehabilitation; surgeon and physical therapist have to choose zone by zone the best way to manage and restore the normal function of hand flexor tendons.

Commercial device-based hand rehabilitation systems for stroke patients: State of the art and future prospects

Various hand rehabilitation systems have recently been developed for stroke patients, particularly commercial devices. Articles from 10 electronic databases from 2010 to 2022 were extracted to conduct a systematic review to explore the existing commercial training systems (hardware and software) and evaluate their clinical effectiveness. This review divided the rehabilitation equipment into contact and non-contact types. Game-based training protocols were further classified into two types: immersion and non-immersion. The results of the review indicated that the majority of the devices included were effective in improving hand function. Users who underwent rehabilitation training with these devices reported improvements in their hand function. Game-based training protocols were particularly appealing as they helped reduce boredom during rehabilitation training sessions. However, the review also identified some common technical drawbacks in the devices, particularly in non-contact devices, such as their vulnerability to the effects of light. Additionally, it was found that currently, there is no commercially available game-based training protocol that specifically targets hand rehabilitation. Given the ongoing COVID-19 pandemic, there is a need to develop safer non-contact rehabilitation equipment and more engaging training protocols for community and home-based rehabilitation. Additionally, the review suggests the need for revisions or the development of new clinical scales for hand rehabilitation evaluation that consider the current scenario, where in-person interactions might be limited.

Artificial intelligence in patient-specific hand surgery: a scoping review of literature

PURPOSE

The implementation of artificial intelligence in hand surgery and rehabilitation is gaining popularity. The purpose of this scoping review was to give an overview of implementations of artificial intelligence in hand surgery and rehabilitation and their current significance in clinical practice.

METHODS

A systematic literature search of the MEDLINE/PubMed and Cochrane Collaboration libraries was conducted. The review was conducted according to the framework outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Reviews. A narrative summary of the papers is presented to give an orienting overview of this rapidly evolving topic.

RESULTS

Primary search yielded 435 articles. After application of the inclusion/exclusion criteria and addition of supplementary search, 235 articles were included in the final review. In order to facilitate navigation through this heterogenous field, the articles were clustered into four groups of thematically related publications. The most common applications of artificial intelligence in hand surgery and rehabilitation target automated image analysis of anatomic structures, fracture detection and localization and automated screening for other hand and wrist pathologies such as carpal tunnel syndrome, rheumatoid arthritis or osteoporosis. Compared to other medical subspecialties the number of applications in hand surgery is still small.

CONCLUSION

Although various promising applications of artificial intelligence in hand surgery and rehabilitation show strong performances, their implementation mostly takes place within the context of experimental studies. Therefore, their use in daily clinical routine is still limited.

A systematic review of the measurement properties of the Michigan Hand Outcomes Questionnaire (MHQ)

This systematic review of the literature aimed to identify studies examining the measurement properties of the Michigan Hand Outcomes Questionnaire (MHQ) in various international populations and investigate its use in various diagnoses and health conditions. The search was conducted in MEDLINE (via PubMed), SCOPUS, CINAHL and Web of Science, with no restrictions on publication date, country or patient age. Study quality and risk of bias were assessed using the COnsensus-based Standards to select the health Measurement INstruments (COSMIN) checklist. 312 publications were identified and screened; 55 studies met the inclusion criteria and were critically reviewed. These publications comprised 16 languages and 11 pathologies and mainly investigated the internal consistency, construct validity and reliability of the MHQ. In general, all the measurement properties of the instrument showed good scores. The present review shows that the MHQ is a valid patient-reported outcome measure (PROM) and can be properly used in different clinical and rehabilitative contexts. LEVEL OF EVIDENCE: 2A.

Reducing the number of EMG electrodes during online hand gesture classification with changing wrist positions

Background

Myoelectric control based on hand gesture classification can be used for effective, contactless human–machine interfacing in general applications (e.g., consumer market) as well as in the clinical context. However, the accuracy of hand gesture classification can be impacted by several factors including changing wrist position. The present study aimed at investigating how channel configuration (number and placement of electrode pads) affects performance in hand gesture recognition across wrist positions, with the overall goal of reducing the number of channels without the loss of performance with respect to the benchmark (all channels).

Methods

Matrix electrodes (256 channels) were used to record high-density EMG from the forearm of 13 healthy subjects performing a set of 8 gestures in 3 wrist positions and 2 force levels (low and moderate). A reduced set of channels was chosen by applying sequential forward selection (SFS) and simple circumferential placement (CIRC) and used for gesture classification with linear discriminant analysis. The classification success rate and task completion rate were the main outcome measures for offline analysis across the different number of channels and online control using 8 selected channels, respectively.

Results

The offline analysis demonstrated that good accuracy (> 90%) can be achieved with only a few channels. However, using data from all wrist positions required more channels to reach the same performance. Despite the targeted placement (SFS) performing similarly to CIRC in the offline analysis, the task completion rate [median (lower–upper quartile)] in the online control was significantly higher for SFS [71.4% (64.8–76.2%)] compared to CIRC [57.1% (51.8–64.8%), p < 0.01], especially for low contraction levels [76.2% (66.7–84.5%) for SFS vs. 57.1% (47.6–60.7%) for CIRC, p < 0.01]. For the reduced number of electrodes, the performance with SFS was comparable to that obtained when using the full matrix, while the selected electrodes were highly subject-specific.

Conclusions

The present study demonstrated that the number of channels required for gesture classification with changing wrist positions could be decreased substantially without loss of performance, if those channels are placed strategically along the forearm and individually for each subject. The results also emphasize the importance of online assessment and motivate the development of configurable matrix electrodes with integrated channel selection.

Physiotherapists' Views on the Software Monitoring Application of a Wearable Assistive Glove

The FutureGlove project aims to further develop the CarbonHand system (a wearable assistive glove) by introducing a new software monitoring application. Within this study, we consulted five physiotherapists during online sessions to gain their views on use of data and patients' empowerment. These first insights suggested that more data needs to be collected than it is doing now to monitor the patients' progress, that therapists would like to personalize the amount of freedom they provide to their patients, and that they would like decision support for algorithms, but they do not fully trust them.

Modernising grip dynamometry: Inter-instrument reliability between GripAble and Jamar

INTRODUCTION

Maximum grip strength (MGS) is a reliable biomarker of overall health and physiological well-being. Therefore, an accurate and reliable measurement device is vital for ensuring the validity of the MGS assessment. This paper presents GripAble, a mobile hand grip device for the assessment of MGS. GripAble's performance was evaluated using an inter-instrument reliability test against the widely used Jamar PLUS+ dynamometer.

METHODS

MGS data from sixty-three participants (N = 63, median (IQR) age = 29.0 (29.5) years, 33 M/30 F) from both hands using GripAble and Jamar PLUS+ were collected and compared. Intraclass correlation (ICC), regression, and Bland and Altman analysis were performed to evaluate the inter-instrument reliability and relationship in MGS measurements between GripAble and Jamar PLUS+ .

RESULTS

GripAble demonstrates good-to-excellent inter-instrument reliability to the Jamar PLUS+ with ICC3,1 = 0.906 (95% CI [0.87-0.94]). GripAble's MGS measurement is equivalent to 69% (95% CI [0.67-0.71]%) of Jamar PLUS+'s measurement. There is a proportional difference in mean MGS between the two devices, with the difference in MGS between GripAble and Jamar PLUS+ increasing with MGS.

CONCLUSION

The GripAble is a reliable tool for measuring grip strength. However, the MGS readings from GripAble and Jamar PLUS+ should not be interchanged for serial measurements of the same patient, nor be translated directly from one device to the other. A new normative MGS data using GripAble will be collected and accessed through the software for immediate comparison to age and gender-matched subpopulations.

A Comparative Study Using Electromyography to Assess Hand Exercises For Rehabilitation After Ulnar Nerve Decompression

Ulnar nerve (UN) entrapment is a common peripheral neuropathy and can lead to dysfunction of both sensory and motor function of the hand. Surgical release is the mainstay of treatment, but post-operative rehabilitation of UN innervated intrinsic muscles is lacking evidence. This cohort study utilized surface electromyography (EMG) and assessed the activation of UN innervated intrinsic and extrinsic hand muscles during four exercises in healthy participants. Exercises included rotating baoding balls, squeezing a stress ball or grip device every second, and repetitive finger abduction against a rubber band. Normalized percent activation of each muscle was calculated for each exercise. It was demonstrated that rubber band resistance (RBR) finger abduction showed significantly increased activation in both intrinsic muscles tested, while minimizing activation of the one tested UN innervated extrinsic muscle. Thus, to best target the intrinsic hand muscles without fatiguing extrinsic muscles, the inexpensive and practical RBR exercise is beneficial in post-UN release rehabilitation.

Peak Activation Shifts in the Sensorimotor Cortex of Chronic Stroke Patients Following Robot-assisted Rehabilitation Therapy

Background:

Ischemic stroke is the most common cause of complex chronic disability and the third leading cause of death worldwide. In recovering stroke patients, peak activation within the ipsilesional primary motor cortex (M1) during the performance of a simple motor task has been shown to exhibit an anterior shift in many studies and a posterior shift in other studies.

Objective:

We investigated this discrepancy in chronic stroke patients who completed a robot-assisted rehabilitation therapy program.

Methods:

Eight chronic stroke patients with an intact M1 and 13 Healthy Control (HC) volunteers underwent 300 functional magnetic resonance imaging (fMRI) scans while performing a grip task at different force levels with a robotic device. The patients were trained with the same robotic device over a 10-week intervention period and their progress was evaluated serially with the Fugl-Meyer and Modified Ashworth scales. Repeated measure analyses were used to assess group differences in locations of peak activity in the sensorimotor cortex (SM) and the relationship of such changes with scores on the Fugl-Meyer Upper Extremity (FM UE) scale.

Results:

Patients moving their stroke-affected hand had proportionally more peak activations in the primary motor area and fewer peak activations in the somatosensory cortex than the healthy controls (P=0.009). They also showed an anterior shift of peak activity on average of 5.3-mm (P<0.001). The shift correlated negatively with FM UE scores (P=0.002).

Conclusion:

A stroke rehabilitation grip task with a robotic device was confirmed to be feasible during fMRI scanning and thus amenable to be used to assess plastic changes in neurological motor activity. Location of peak activity in the SM is a promising clinical neuroimaging index for the evaluation and monitoring of chronic stroke patients.

A new visual feedback-based system for the assessment of pinch force, endurance, accuracy and precision. A test-retest reliability study

Introduction

Given that pinch is a precision grip involved in sustained submaximal activities, a Sustained Contraction (SC) task could be associated to Maximal Voluntary Contraction (MVC). To better evaluate the thumb-index system, the test-retest reliability of pinch MVC and SC, measured by a visual feedback-based pinch gauge was assessed.

Methods

26 healthy participants performed MVC and SC in two separate sessions. SC required to maintain 40%MVC as long as possible and it was evaluated in terms of time, accuracy (Mean Distance between force trace and target force, MD), precision (Coefficient of Variability of force trace, CV). MD and CV analyses were conducted dividing the SC task into three equivalent time stages (beginning, middle, exhaustion). Relative Reliability (RR) was measured by Intraclass Correlation Coefficient, and Absolute Reliability (AR) was measured by Standard Error of Measurement and by Bland-Altman plot.

Results

MVC and Time showed high RR and AR in both hands. RR of MD and CV in right hand was excellent in the beginning and middle stages, and fair in the exhaustion one, showing decreasing reliability as fatigue increases. In the left hand RR of MD and CV was generally lower. MD showed excellent reliability in the beginning stage and good reliability in the other stages. CV showed fair relative reliability at both beginning and middle stages, excellent in the last one. Conversely, it was observed high AR of MD and CV in all stages in both hands.

Conclusions

All indices are reliable to assess motor control of thumb-index pinch in both hands.

Active triggering control of pneumatic rehabilitation gloves based on surface electromyography sensors

The portable and inexpensive hand rehabilitation robot has become a practical rehabilitation device for patients with hand dysfunction. A pneumatic rehabilitation glove with an active trigger control system is proposed, which is based on surface electromyography (sEMG) signals. It can trigger the hand movement based on the patient's hand movement trend, which may improve the enthusiasm and efficiency of patient training. Firstly, analysis of sEMG sensor installation position on human's arm and signal acquisition process were carried out. Then, according to the statistical law, three optimal eigenvalues of sEMG signals were selected as the follow-up neural network classification input. Using the back propagation (BP) neural network, the classifier of hand movement is established. Moreover, the mapping relationship between hand sEMG signals and hand actions is built by training and testing. Different patients choose the same optimal eigenvalues, and the calculation formula of eigenvalues' amplitude is unique. Due to the differences among individuals, the weights and thresholds of each node in the BP neural network model corresponding to different patients are not the same. Therefore, the BP neural network model library is established, and the corresponding network is called for operation when different patients are trained. Finally, based on sEMG signal trigger, the pneumatic glove training control algorithm was proposed. The combination of the trigger signal waveform and the motion signal waveform indicates that the pneumatic rehabilitation glove is triggered to drive the patient's hand movement. Preliminary tests have confirmed that the accuracy rate of trend recognition for hand movement is about 90%. In the future, clinical trials of patients will be conducted to prove the effectiveness of this system.

Estimation of spatial-temporal hand motion parameters in rehabilitation using a low-cost noncontact measurement system

Data collection and analysis are commonly used in a rehabilitation process to measure performances of the treatment. There is a lack of studies on the rehabilitation process monitored by a user-friendly interface. A low-cost system is developed in this research to assist users and therapists to measure hand motions and analyse important data of hand joints. The system consists of modules of data capturing, data analysis, and user interface. A Leap Motion sensor is used to capture joint positions of hand motions. Signal processing and wavelet de-noising methods are developed to improve accuracy of the data analysis. The user interface is designed using the Unity software to show graphical information of joint positions and motion parameters. The system has features of noncontact measurements, interactive environment, analysing and recording temporal data of motion parameters of hands. The system is validated by a gold standard motion capturing system. Case studies show effectiveness of the proposed system.

Shape-texture-identification-STI-A test for tactile gnosis: Concurrent validity of STI(2)

STUDY DESIGN

Cross-sectional study.

INTRODUCTION

The shape-texture-identification (STI) test (Össur Nordic AB, Sweden) is used to evaluate one aspect of tactile gnosis in nerve disorders, and it has proven good methodological properties.

PURPOSE OF THE STUDY

A new version of the STI test was recently introduced-STI² (www.sensory-test.com). The purpose of this study was to test the concurrent validity in STI².

METHODS

Using a cross-sectional design, this methodological study compared STI² to the original version based on 2 cohorts; 1 including 20 persons (1 affected finger and corresponding finger on in opposite hand) with affected sensibility after hand injuries and 1 healthy group including 20 persons (digits II and V in both hands). The agreement between the 2 versions of the instrument was calculated statistically by a percentage comparison of the test results and weighted kappa.

RESULTS

The 112 tested fingers showed a complete agreement, or 1-point accepted deviation, between the 2 tests in 92% with weighted kappa of 0.74 and 95% confidence interval of 0.63-0.89. The result showed that there is no significant deviation between the 2 versions of the test.

DISCUSSION

The use of standardizes and evidence based assessment tools in clinical practice is paramount for a patient centered healthcare. Previous research has shown good psychometric proprties in the STI-test. This study contributes to the scientific evidence of the instrument.

CONCLUSION

As the new STI² proved good agreement within the accepted deviation, we conclude that there is evidence to use the new STI² test in assessment of tactile gnosis.

User-centered practicability analysis of two identification strategies in electrode arrays for FES induced hand motion in early stroke rehabilitation

BACKGROUND

Surface electrode arrays have become popular in the application of functional electrical stimulation (FES) on the forearm. Arrays consist of multiple, small elements, which can be activated separately or in groups, forming virtual electrodes (VEs). As technology progress yields rising numbers of possible elements, an effective search strategy for suitable VEs in electrode arrays is of increasing importance. Current methods can be time-consuming, lack user integration, and miss an evaluation regarding clinical acceptance and practicability.

METHODS

Two array identification procedures with different levels of user integration-a semi-automatic and a fully automatic approach-are evaluated. The semi-automatic method allows health professionals to continuously modify VEs via a touchscreen while the stimulation intensities are automatically controlled to maintain sufficient wrist extension. The automatic approach evaluates stimulation responses of various VEs for different intensities using a cost function and joint-angles recordings. Both procedures are compared in a clinical setup with five sub-acute stroke patients with moderate hand disabilities. The task was to find suitable VEs in two arrays with 59 elements in total to generate hand opening and closing for a grasp-and-release task. Practicability and acceptance by patients and health professionals were investigated using questionnaires and interviews.

RESULTS

Both identification methods yield suitable VEs for hand opening and closing in patients who could tolerate the stimulation. However, the resulting VEs differed for both approaches. The average time for a complete search was 25% faster for the semi-automatic approach (semi-automatic: 7.3min, automatic: 10.5min). User acceptance was high for both methods, while no clear preference could be identified.

CONCLUSIONS

The semi-automatic approach should be preferred as the search strategy in arrays on the forearm. The observed faster search duration will further reduce when applying the system repeatedly on a patient as only small position adjustments for VEs are required. However, the setup time will significantly increase for generation of various grasp types and adaptation to different arm postures. We recommend different levels of user integration in FES systems such that the search strategy can be chosen based on the users' preferences and application scenario.

Fear of movement and its effects on hand function after tendon repair

After tendon injuries, it has been observed clinically that patient-reported disability is more severe than the patient's actual performance. This is thought to result from a fear of movement (kinesiophobia) after surgery. The aim of this study was to investigate the presence of kinesiophobia in this patient population and its effects on the clinical outcomes. Patients (n=118) with tendon repairs were included. All the participants received early passive mobilization and were assessed at the end of the 8th week. Grip and pinch strengths were measured and the Nine-Hole Peg Test (9HPT) was conducted. Patients also filled out the Michigan Hand Outcomes Questionnaire (MHOQ) and Tampa Scale for Kinesiophobia (TSK). Patients were divided according to their kinesiophobia: Group 1 with low kinesiophobia (TSK<37) and Group 2 with high kinesiophobia (TSK≥37). The groups were compared on the assessed parameters. Fifty-nine percent of the patients had a high kinesiophobia level. The performance-based test results were similar between the groups (P>0.05). Patient-reported MHOQ and TSK scores were significantly lower in the high kinesiophobic group (P=0.001 and P=0.000, respectively). Patients with tendon repairs often develop kinesiophobia, which may contribute to difficulty when starting to re-use their hand in daily life. None of the objective results were affected by this fear of movement-only patient-reported disability. Clinicians should be aware that clinical outcomes may be affected by the patient's kinesiophobic thinking and must be cautious during treatment.

Fuzzy logic-based mobile computing system for hand rehabilitation after neurological injury

BACKGROUND

Effective neurological rehabilitation requires long term assessment and treatment. The rapid progress of virtual reality-based assistive technologies and tele-rehabilitation has increased the potential for self-rehabilitation of various neurological injuries under clinical supervision.

OBJECTIVE

The objective of this study was to develop a fuzzy inference mechanism for a smart mobile computing system designed to support in-home rehabilitation of patients with neurological injury in the hand by providing an objective means of self-assessment.

METHODS

A commercially available tablet computer equipped with a Bluetooth motion sensor was integrated in a splint to obtain a smart assistive device for collecting hand motion data, including writing performance and the corresponding grasp force. A virtual reality game was also embedded in the smart splint to support hand rehabilitation. Quantitative data obtained during the rehabilitation process were modeled by fuzzy logic. Finally, the improvement in hand function was quantified with a fuzzy rule database of expert opinion and experience.

RESULTS

Experiments in chronic stroke patients showed that the proposed system is applicable for supporting in-home hand rehabilitation.

CONCLUSIONS

The proposed virtual reality system can be customized for specific therapeutic purposes. Commercial development of the system could immediately provide stroke patients with an effective in-home rehabilitation therapy for improving hand problems.

[Hand rehabilitation after distal radius fracture]

Distal radius fractures (DRF) are common. Good outcomes are the result of appropriate initial treatment (immobilization, external fixation, percutaneous pinning or open reduction and internal fixation) and rehabilitation adapted to this treatment. When started immediately, rehabilitation of DRF prevents complications due to immobilization, surgery and a non-controlled healing process. Splints play an important role at all stages of rehabilitation.

Development of a novel haptic glove for improving finger dexterity in poststroke rehabilitation

Almost all stroke patients experience a certain degree of fine motor impairment, and impeded finger movement may limit activities in daily life. Thus, to improve the quality of life of stroke patients, designing an efficient training device for fine motor rehabilitation is crucial. This study aimed to develop a novel fine motor training glove that integrates a virtual-reality based interactive environment with vibrotactile feedback for more effective post stroke hand rehabilitation. The proposed haptic rehabilitation device is equipped with small DC vibration motors for vibrotactile feedback stimulation and piezoresistive thin-film force sensors for motor function evaluation. Two virtual-reality based games ``gopher hitting'' and ``musical note hitting'' were developed as a haptic interface. According to the designed rehabilitation program, patients intuitively push and practice their fingers to improve the finger isolation function. Preliminary tests were conducted to assess the feasibility of the developed haptic rehabilitation system and to identify design concerns regarding the practical use in future clinical testing.

Rehabilitation outcomes in patients with early and two-stage reconstruction of flexor tendon injuries

[Purpose] The primary aim of this study was to assess rehabilitation outcomes for early and two-stage repair of hand flexor tendon injuries. The secondary purpose of this study was to compare the findings between treatment groups. [Subjects and Methods] Twenty-three patients were included in this study. Early repair (n=14) and two-stage repair (n=9) groups were included in a rehabilitation program that used hand splints. This retrospective evaluated patients according to their demographic characteristics, including age, gender, injured hand, dominant hand, cause of injury, zone of injury, number of affected fingers, and accompanying injuries. Pain, range of motion, and grip strength were evaluated using a visual analog scale, goniometer, and dynamometer, respectively. [Results] Both groups showed significant improvements in pain and finger flexion after treatment compared with baseline measurements. However, no significant differences were observed between the two treatment groups. Similar results were obtained for grip strength and pinch grip, whereas gross grip was better in the early tendon repair group. [Conclusion] Early and two-stage reconstruction of patients with flexor tendon injuries can be performed with similarly favorable responses and effective rehabilitation programs.

Proportional estimation of finger movements from high-density surface electromyography

BACKGROUND

The importance to restore the hand function following an injury/disease of the nervous system led to the development of novel rehabilitation interventions. Surface electromyography can be used to create a user-driven control of a rehabilitation robot, in which the subject needs to engage actively, by using spared voluntary activation to trigger the assistance of the robot.

METHODS

The study investigated methods for the selective estimation of individual finger movements from high-density surface electromyographic signals (HD-sEMG) with minimal interference between movements of other fingers. Regression was evaluated in online and offline control tests with nine healthy subjects (per test) using a linear discriminant analysis classifier (LDA), a common spatial patterns proportional estimator (CSP-PE), and a thresholding (THR) algorithm. In all tests, the subjects performed an isometric force tracking task guided by a moving visual marker indicating the contraction type (flexion/extension), desired activation level and the finger that should be moved. The outcome measures were mean square error (nMSE) between the reference and generated trajectories normalized to the peak-to-peak value of the reference, the classification accuracy (CA), the mean amplitude of the false activations (MAFA) and, in the offline tests only, the Pearson correlation coefficient (PCORR).

RESULTS

The offline tests demonstrated that, for the reduced number of electrodes (≤24), the CSP-PE outperformed the LDA with higher precision of proportional estimation and less crosstalk between the movement classes (e.g., 8 electrodes, median MAFA ~ 0.6 vs. 1.1 %, median nMSE ~ 4.3 vs. 5.5 %). The LDA and the CSP-PE performed similarly in the online tests (median nMSE < 3.6 %, median MAFA < 0.7 %), but the CSP-PE provided a more stable performance across the tested conditions (less improvement between different sessions). Furthermore, THR, exploiting topographical information about the single finger activity from HD-sEMG, provided in many cases a regression accuracy similar to that of the pattern recognition techniques, but the performance was not consistent across subjects and fingers.

CONCLUSIONS

The CSP-PE is a method of choice for selective individual finger control with the limited number of electrodes (<24), whereas for the higher resolution of the recording, either method (CPS-PA or LDA) can be used with a similar performance. Despite the abundance of detection points, the simple THR showed to be significantly worse compared to both pattern recognition/regression methods. Nevertheless, THR is a simple method to apply (no training), and it could still give satisfactory performance in some subjects and/or simpler scenarios (e.g., control of selected fingers). These conclusions are important for guiding future developments towards the clinical application of the methods for individual finger control in rehabilitation robotics.

Overall design and implementation of the virtual glove

Post-stroke patients and people suffering from hand diseases often need rehabilitation therapy. The recovery of original skills, when possible, is closely related to the frequency, quality, and duration of rehabilitative therapy. Rehabilitation gloves are tools used both to facilitate rehabilitation and to control improvements by an evaluation system. Mechanical gloves have high cost, are often cumbersome, are not re-usable and, hence, not usable with the healthy hand to collect patient-specific hand mobility information to which rehabilitation should tend. The approach we propose is the virtual glove, a system that, unlike tools based on mechanical haptic interfaces, uses a set of video cameras surrounding the patient hand to collect a set of synchronized videos used to track hand movements. The hand tracking is associated with a numerical hand model that is used to calculate physical, geometrical and mechanical parameters, and to implement some boundary constraints such as joint dimensions, shape, joint angles, and so on. Besides being accurate, the proposed system is aimed to be low cost, not bulky (touch-less), easy to use, and re-usable. Previous works described the virtual glove general concepts, the hand model, and its characterization including system calibration strategy. The present paper provides the virtual glove overall design, both in real-time and in off-line modalities. In particular, the real-time modality is described and implemented and a marker-based hand tracking algorithm, including a marker positioning, coloring, labeling, detection and classification strategy, is presented for the off-line modality. Moreover, model based hand tracking experimental measurements are reported, discussed and compared with the corresponding poses of the real hand. An error estimation strategy is also presented and used for the collected measurements. System limitations and future work for system improvement are also discussed.