Hand Orthosis Research Articles

Modeling and Evaluation of a Novel Hybrid-Driven Compliant Hand Exoskeleton Based on Human-Machine Coupling Model

This paper presents the modeling design method for a novel hybrid-driven compliant hand exoskeleton based on the human-machine coupling model for the patients who have requirements on training and assisting. Firstly, the human-machine coupling model is established based on the kinematics characteristics of human fingers and the Bernoulli beam formula. On this basis, the variable stiffness flexible hinge (VSFH) is used to drive the finger extension and the cable-driven mechanism is used to implement the movement of the finger flexion. Here, a hand orthosis is designed in the proposed hand exoskeleton to act as the base and maintain the function position of the hand for patients with hand dysfunction. Then, a final design prototype is fabricated to evaluate the proposed modeling method. In the end, a series of experiments based on the prototype is proceeded to evaluate its capabilities on stretching force for extension, bio-imitability, finger flexion capability, and fingertip force. The results show that the prototype has a significant improvement in all aspects of the ability mentioned above, and has good bionics. The proposed design method can be utilized to implement the rapid design of the hybrid-driven compliant hand exoskeleton with the changed requirements. The novel modeling method can be easily applied in personalized design in rehabilitation engineering.

Implantable brain-computer interface for neuroprosthetic-enabled volitional hand grasp restoration in spinal cord injury.

Loss of hand function after cervical spinal cord injury severely impairs functional independence. We describe a method for restoring volitional control of hand grasp in one 21-year-old male subject with complete cervical quadriplegia (C5 American Spinal Injury Association Impairment Scale A) using a portable fully implanted brain–computer interface within the home environment. The brain–computer interface consists of subdural surface electrodes placed over the dominant-hand motor cortex and connects to a transmitter implanted subcutaneously below the clavicle, which allows continuous reading of the electrocorticographic activity. Movement-intent was used to trigger functional electrical stimulation of the dominant hand during an initial 29-weeks laboratory study and subsequently via a mechanical hand orthosis during in-home use. Movement-intent information could be decoded consistently throughout the 29-weeks in-laboratory study with a mean accuracy of 89.0% (range 78–93.3%). Improvements were observed in both the speed and accuracy of various upper extremity tasks, including lifting small objects and transferring objects to specific targets. At-home decoding accuracy during open-loop trials reached an accuracy of 91.3% (range 80–98.95%) and an accuracy of 88.3% (range 77.6–95.5%) during closed-loop trials. Importantly, the temporal stability of both the functional outcomes and decoder metrics were not explored in this study. A fully implanted brain–computer interface can be safely used to reliably decode movement-intent from motor cortex, allowing for accurate volitional control of hand grasp.

Implementation of Additive Manufacturing in Designing A Wrist Hand Orthosis to Increase Grasping Time on The Left Hand of Cerebral Palsy Children

Cerebral palsy (CP) is a physical disability in childhood with impaired development of movement and posture due to disorders of the fetal or infant's brain. The measurement results of the spastic HCP children at YPAC Surakarta show that 8 attributes have difficulty grasping the precision type and 9 attributes of the power type. To solve this problem, hand tools called wrist hand orthoses are needed to restore hand function. This study aims to design alternative designs and make prototypes of wrist hand orthoses using the 3D printing process. The research stages began by collecting activity daily living (ADL) data and anthropometric data, taking a participatory approach to produce design alternatives, selecting design alternatives with the PUGH's concept selection method. The chosen design alternative will be printed through the additive manufacturing process. Testing with the 2015 human grasping database showed an increase in grasping time in 13 types of ADL activities from 17 ADLs.

Brain-Computer Interface Coupled to a Robotic Hand Orthosis for Stroke Patients' Neurorehabilitation: A Crossover Feasibility Study.

Brain-Computer Interfaces (BCI) coupled to robotic assistive devices have shown promise for the rehabilitation of stroke patients. However, little has been reported that compares the clinical and physiological effects of a BCI intervention for upper limb stroke rehabilitation with those of conventional therapy. This study assesses the feasibility of an intervention with a BCI based on electroencephalography (EEG) coupled to a robotic hand orthosis for upper limb stroke rehabilitation and compares its outcomes to conventional therapy. Seven subacute and three chronic stroke patients (M = 59.9 ± 12.8) with severe upper limb impairment were recruited in a crossover feasibility study to receive 1 month of BCI therapy and 1 month of conventional therapy in random order. The outcome measures were comprised of: Fugl-Meyer Assessment of the Upper Extremity (FMA-UE), Action Research Arm Test (ARAT), motor evoked potentials elicited by transcranial magnetic stimulation (TMS), hand dynamometry, and EEG. Additionally, BCI performance and user experience were measured. All measurements were acquired before and after each intervention. FMA-UE and ARAT after BCI (23.1 ± 16; 8.4 ± 10) and after conventional therapy (21.9 ± 15; 8.7 ± 11) were significantly higher (p < 0.017) compared to baseline (17.5 ± 15; 4.3 ± 6) but were similar between therapies (p > 0.017). Via TMS, corticospinal tract integrity could be assessed in the affected hemisphere of three patients at baseline, in five after BCI, and four after conventional therapy. While no significant difference (p > 0.05) was found in patients’ affected hand strength, it was higher after the BCI therapy. EEG cortical activations were significantly higher over motor and non-motor regions after both therapies (p < 0.017). System performance increased across BCI sessions, from 54 (50, 70%) to 72% (56, 83%). Patients reported moderate mental workloads and excellent usability with the BCI. Outcome measurements implied that a BCI intervention using a robotic hand orthosis as feedback has the potential to elicit neuroplasticity-related mechanisms, similar to those observed during conventional therapy, even in a group of severely impaired stroke patients. Therefore, the proposed BCI system could be a suitable therapy option and will be further assessed in clinical trials.

The development of low-cost wrist, hand, and finger orthosis for children with cerebral palsy using additive manufacturing

The development of low-cost wrist, hand, and finger orthosis for children with cerebral palsy using additive manufacturing

Investigating the effects of volar wrist cock-up splint and dorsal lock wrist hand orthosis in reducing signs of carpal tunnel syndrome.

Background: Carpal tunnel syndrome (CTS) is the most common compressive neuropathy presenting with sharp pain, parenthesis, dysfunction of the hand in coordination and gripping. Splinting is the most common conservative intervention to improve pain and enological symptom of this Syndrome (CTS). With regard to the importance of these interventions and controversies about different designs of splints, the aim of this study was to compare the therapeutic effects of volar wrist cock-up orthosis and dorsal lock wrist hand orthosis on pain, sensory and motor latency in carpal tunnel syndrome. Methods: In this Randomized controlled trial study, 30 patients diagnosed with mild to moderate CTS were recruited. The subjects were randomly divided into two equal groups. Both groups received one form of splints for three weeks. Before receiving the splints, Electromyography (EMG) and Visual analog scale (VAS) were performed. Then, two different designs of splints were used for a period of three weeks. After that, EMG and Numerical Rating Scale (NRS-11) were repeated to reveal the effects of splints on reducing pain, sensory and motor latency in CTS. Independent t and paired t-tests were done uding SPSS software version 19.0. P-value was set at 0.05. Results: All the variables in both groups showed significant improvement. The NRS-11 test was significantly improved in the dorsal lock wrist hand orthosis group (p<0.05). Conclusion: This study showed that the use of the dorsal lock wrist hand orthosis for about three weeks was significantly improved pain and neurological symptoms of patients with CTS because of maintaining the wrist in the neutral position. Knowing this fact helps us to design and make a less cumbersome and restrictive splint with an accurate position for the wrist and distal joints.

104 A Quality Improvement Project to Reduce Orthoses Complications

Abstract Introduction Anatomical structures of the hand are complex and delicate making hand burns particularly challenging to manage. Orthoses are a cornerstone treatment modality and unsuccessful therapeutic interventions can result in hand contracture and deformities, which can result in up to 95% impairment in upper extremity function. Therapists at our burn center have varying degrees of education and credentials, and we had noticed increased incidence of orthotic induced complications in the hand. The purpose of this QI project was to implement a formal protocol that provided guidelines around fabricating and fitting hand orthoses. Methods The protocol mandated that custom fabricated resting hand orthoses should be fabricated by a single CHT or co-fabricated by two (non-CHT) therapists. Orthoses were fabricated as indicated. Orthosis modifications and orthosis complications, defined as erythema and/or an orthotic induced partial-thickness injury to the volar second metacarpal head (index finger) were documented. For the purposes of our study, breakdown was limited to the index finger. These modifications and complication totals were compared to pre-implementation data. Any patient with missing data points was excluded. Results Seventy-seven patient hands were examined from 2016–2019. Prior to implementation of the protocol, erythema occurred with 23.4% (n=18) of orthoses and orthosis induced partial thickness injury was found in 11.7% (n=9) of cases. Post protocol implementation involved examination of 51 hands. Erythema occurred in just 2.0% of cases (n=1) and partial thickness injury in 3.9% of cases (n=2) This represents a decrease of 94.4% and 77.7%, respectively. Number of modifications was reduced by 40.9%, from 22 to 13. Conclusions Orthosis fabrication is a specialized therapy skill, requiring hands-on training and advanced anatomical knowledge. While orthotic fabrication is part of general therapy education, the depth and breadth of this education is limited by the clinical opportunities presented to each therapist. CHT’s have undergone rigorous study and testing to make them experts in orthosis management and can bolster skills in a burn therapy department. For therapists without this specialty certification, co-fabrication can also lead to improved outcomes, through real time peer review. Data from this QI project showed a statistically significant decrease in erythema and decrease in breakdown and number of modifications needed from utilization of either a CHT or two therapists when managing hand orthoses.

Abstract P205: Rehabilitation With Brain Computer Interface to Improve Hand Function After Stroke

Background: Stroke is the third cause of disability and the first cause of motor impairment of the upper limb, which significantly reduces independence in activities of daily living. Therefore, the development and use of new therapeutic approaches is needed. Brain-computer interfaces (BCI) based on movement intention (MI) have the potential to improve hand function and brain plasticity after stroke. Purpose: Improve hand function after stroke with BCI with MI. Methods: 8 patients with subacute stroke, left or right hemiparesis was divided in two groups. The first received conventional therapy followed by BCI-MI therapy and the second was given BCI-MI therapy and then conventional therapy. The outcome variables were sensory-motor recovery, hand function, spasticity, level of disability, grip strength, change in motor threshold and amplitude of motor evoked potentials (MEP) and changes in desynchronization/synchronization event-related (EDR/EDS). Results: 4 patients were female, the average age 56 ± 12.7 years, and 87% were ischemic stroke. No differences were found between post-conventional therapy and postBCI-MI in the sensorimotor recovery, the spasticity, and the degree of deficiency in the strength. Only in hand function measured with the Action Research Arm Test (ARAT), a statistically significant difference was found in the BCI-MI therapy group (p= 0.0247). Dynamometry grip strength had a tendency to increase the Post-BCI group. A MEP was obtained in the ipsilesional primary motor cortex of 3 patients. A higher EDR was found in the injured hemisphere in favor of the post-BCI group (p= 0.0165). Conclusions: This study shows that BCI-MI rehabilitation, which combines MI with a robotic hand orthosis as feedback, has a significant improvement in hand function and a greater ERD in the ipsilesional primary motor cortex. It is necessary to carry out controlled clinical trials with a larger sample and with a greater frequency and duration of intervention to measure hand motor and functional improvement of patients after stroke.

Investigating the effects of volar wrist cock-up splint and dorsal lock wrist hand orthosis in reducing signs of carpal tunnel syndrome

Investigating the effects of volar wrist cock-up splint and dorsal lock wrist hand orthosis in reducing signs of carpal tunnel syndrome

Production Time and User Satisfaction of 3-Dimensional Printed Orthoses For Chronic Hand Conditions Compared With Conventional Orthoses: A Prospective Case Series.

ObjectiveHand orthoses are often prescribed for persons with chronic hand and wrist impairments. This study assessed the feasibility, in terms of production time and user satisfaction, of 3-dimensional printed hand orthoses compared with conventional hand orthoses for this population.MethodsIn this prospective case series, both a conventional hand orthosis and a 3-dimensional printed hand orthosis were manufactured for 10 participants. Production time (in minutes) of each orthosis was recorded. Each orthosis was worn for one week, after which participants completed a self-designed questionnaire on satisfaction, scored on a 5-point Likert scale. Functionality and orthosis preference were also assessed.ResultsThe mean (standard deviation (SD)) production time for the 3-dimensional printed orthoses, of 112 (11.0) min, was significantly shorter compared with 239 (29.2) min for the conventional orthoses (95% confidence interval (95% CI) 71–182 min, p = 0.001). Satisfaction scores were similar for both orthoses, except for comfort item “fitting method”, which was rated significantly higher for scanning compared with casting (median [IQR] score: 5 [0.0]; 4 [2.0], p = 0.034). Functionality and orthosis preference were rated similar for both orthoses.CONCLUSIONAs the production time was halved, user satisfaction similar, and scanning experienced as slightly more comfortable than casting, 3-dimensional printed hand orthoses seem feasible and potentially beneficial for use in people with chronic hand and wrist impairments.LAY ABSTRACTPersons with chronic hand and wrist impairments often use an orthosis to make it easier to perform daily activities. Three-dimensional scanning and printing can facilitate the manufacturing of hand orthoses. This study compared 3-dimensional printed orthoses with conventional orthoses for persons with chronic hand and wrist impairments, with regard to production time and user satisfaction. Ten participants used a 3-dimensional printed orthosis, as well as a conventional orthosis, each for one week. The results showed that production time of 3-dimensional printed orthoses was half that of conventional orthoses. Satisfaction with both orthoses was similar, except for the “fitting method”, whereby fitting by 3-dimensional scanning was perceived as slightly more comfortable compared with conventional casting. Functionality and orthosis preference were rated similar for both orthoses. In conclusion, 3-dimensional printed orthoses appear to be a potential treatment option for persons with chronic hand and wrist impairments.

A Soft Pressure Sensor Skin to Predict Contact Pressure Limit Under Hand Orthosis.

Customized static orthoses in rehabilitation clinics often cause side effects, such as discomfort and skin damage due to excessive local contact pressure. Currently, clinicians adjust orthoses to reduce high contact pressure based on subjective feedback from patients. However, the adjustment is inefficient and prone to variability due to the unknown contact pressure distribution as well as differences in discomfort due to pressure across patients. This paper proposed a new method to predict a threshold of contact pressure (pressure limit) associated with moderate discomfort at each critical spot under hand orthoses. A new pressure sensor skin with 13 sensing units was configured from FEA results of pressure distribution simulated with hand geometry data of six healthy participants. It was used to measure contact pressure under two types of customized orthoses for 40 patients with bone fractures. Their subjective perception of discomfort was also measured using a 6 scores discomfort scale. Based on these data, five critical spots were identified that correspond to high discomfort scores (>1) or high pressure magnitudes (>0.024 MPa). An artificial neural network was trained to predict contact pressure at each critical spot with orthosis type, gender, height, weight, discomfort scores and pressure measurements as input variables. The neural networks show satisfactory prediction accuracy with R2 values over 0.81 of regression between network outputs and measurements. This new method predicts a set of pressure limits at critical locations under the orthosis that the clinicians can use to make orthosis adjustment decisions.

Combined upper approaches (electrical stimulation, orthotics, robotics, and CI therapy) and the daily use of paralyzed hand under hand orthosis for a sub-acute stroke patient with severe upper limb paralysis:

Combined upper approaches (electrical stimulation, orthotics, robotics, and CI therapy) and the daily use of paralyzed hand under hand orthosis for a sub-acute stroke patient with severe upper limb paralysis:

Development of a Robotic Hand Orthosis for Stroke Patient Rehabilitation

&lt;p class="0abstractCxSpFirst"&gt;This study developed a robotic orthosis capable of detecting the intention of a wearer to move their fingers, thereafter augmenting their muscle force. This was with the aim of producing a device that can be used in post-stroke hand rehabilitation. The design of the orthosis was based on an existing design, which was modified using BLENDER release 2.78 and printed with ABS plastic. An actuator was mounted at the rear end of the orthosis, to provide actuation to perform full range flexion and extension motion for digits. Force sensors were embedded at the fingertips of the orthosis to detect minute finger movements. For severe cases where stroke survivors are incapable of little finger movements, the study employed a brain-computer interface to detect the intent to move. The robotic orthosis achieved an accuracy of 64.1% and 62% in detecting unclench and clench activities respectively and actuating the orthosis digits in response. The results revealed that the design presented here can help provide effective hand rehabilitation. The study concluded that the design incorporated with BCI systems is capable of performing hand rehabilitation in a clinical setting as it obtains some level of accuracy in detecting patient intent to move and actuating in response. This design is low cost, and hence will lessen the economic burden for stroke survivors in a poor-resource country.&lt;/p&gt;&lt;p class="0abstractCxSpLast"&gt;&lt;strong&gt; &lt;/strong&gt;&lt;/p&gt;

Electrode-free visual prosthesis/exoskeleton control using augmented reality glasses in a first proof-of-technical-concept study

In the field of neuroprosthetics, the current state-of-the-art method involves controlling the prosthesis with electromyography (EMG) or electrooculography/electroencephalography (EOG/EEG). However, these systems are both expensive and time consuming to calibrate, susceptible to interference, and require a lengthy learning phase by the patient. Therefore, it is an open challenge to design more robust systems that are suitable for everyday use and meet the needs of patients. In this paper, we present a new concept of complete visual control for a prosthesis, an exoskeleton or another end effector using augmented reality (AR) glasses presented for the first time in a proof-of-concept study. By using AR glasses equipped with a monocular camera, a marker attached to the prosthesis is tracked. Minimal relative movements of the head with respect to the prosthesis are registered by tracking and used for control. Two possible control mechanisms including visual feedback are presented and implemented for both a motorized hand orthosis and a motorized hand prosthesis. Since the grasping process is mainly controlled by vision, the proposed approach appears to be natural and intuitive.

Determination of the Elasticity Modulus of Additively Manufactured Wrist Hand Orthoses.

The article describes the experimental and simulation research on the material properties of the individualized wrist orthoses produced in the additive manufacturing (AM) process by the fused filament fabrication (FFF) method. The authors produced a series of standard (normalized) samples for three-point bending from acrylonitrile butadiene styrene (ABS) filament on a low-budget 3D printer and a series of samples in the shape of a fragment of the orthosis and the entire orthosis. All types of samples were subjected to experimental tests on a universal testing machine, which allowed us to determine the modulus of elasticity of the produced materials by comparing it with finite element method (FEM) simulation models in the ABAQUS environment. The adopted research methodology allowed us to compare the material properties of the material of the entire product—wrist hand orthosis (WHO)—with the material properties of standard bending samples. The obtained values of Young’s modulus are characterized by a large discrepancy between the standard samples and the entire orthosis. On the other hand, the samples with the shape of the middle part of the orthosis were similar in the value of Young’s modulus to the results obtained during the examination of the complete orthosis.

A preliminary study to identify data needs for improving fit of hand and wrist orthosis using verbal protocol analysis

The delayed delivery, poor fitting and discomfort of customised orthoses are reported in rehabilitation clinics as resulting in more invasive interventions. The current practice of orthosis customisation relies heavily upon the experience and fabrication processes of therapists. In order to better understand the current practice, and thus identify data that is required for better comfort moving towards a data-driven customisation, this article describes a study generating working models of therapists. Customisations of hand and wrist orthoses for 18 patients were observed. Verbal protocol analysis was employed to extend the current understanding of fabrication processes. Working models of four therapists were established with quantitative evaluation on major phases, interactive activities and iterations of performing tasks during fabrication, revealing different working models between in- and out-patient departments (e.g. fabrication for in-patients was more complex and focussed on ergonomic fitting whereas fabrication for out-patients paid attention to durability) which were qualitatively explained. Practitioner summary: Fit and comfort are imperative for orthosis design and fabrication, however the current practice of customisation of an orthosis relies upon the experience of individual hand therapist. The article presents working models of hand therapists, and relevant data that would enable customisation of orthosis for better fit. Abbreviations: VPA: verbal protocol analysis; h&w: hand and wrist; LTT: low temperature thermoplastic; ANOVA: analysis of variance

Effectiveness of ultrasound guided ethanol motor points block in reduction of spasticity and improvement of upper limb function in hemiplegic patients: a randomized controlled study

Background: Stroke is the third leading cause of disability in general population commonly causing upper motor neuron syndrome complications like spasticity, which is more common in upper limb. Ethanol injection into spastic muscle is an emerging effective treatment in the spasticity management. Ethanol causes selective destruction of nerve fibers through denaturation of protein.Methods: A randomized controlled study was conducted for a period of 2 years from March 2018 on sixty-eight hemiplegic patients to assess the effectiveness of ethanol muscle block in reduction of spasticity and improvement in functional ability. The patients were allocated into two groups (Group A and B). Group A received ultrasound guided intramuscular ethanol injection along with range of motion (ROM) exercises and wrist hand orthosis (WHO) and Group B received ROM exercises and WHO. The outcomes were measured by modified ashworth scale (MAS) for spasticity and modified version of motor assessment scale for functional improvement.Results: Intervention group showed significant improvement in spasticity shown by reduction of MAS of elbow flexors from 3 at baseline to 1.15±0.3 at 12 weeks as compared to control group with 3 at baseline to 1.76±0.5 at 12 weeks (p&lt;0.05). Upper limb function scale of study group improved from 1.5±0.8 to 3.0±0.6 at 12 weeks compared to control group 1.3±0.8 to 2.8±0.6 (p&lt;0.05).Conclusions: It can thus be concluded that intramuscular injection of ethanol accompanied by wrist hand orthosis have beneficial effect on improvement of spasticity and upper limb function.

Design of a Hand Orthosis for People with Deficiency of the Medial, Radial, and Ulnar Nerves

The reduced mobility in hand is a problem that prevents daily activities such as feeding, bathing, brushing, dressing, grabbing objects, and losing autonomy in everyday situations. The hand disability is mainly due to the deficiency of the ulnar, medial, and radial nerves, which prevents adequate hand movements. In consequence, various assistive technologies are proposed to assist mobility, communication, self-help, and domestic activities. An alternative is the use of active orthosis, which by this proof of concept, the person can perform adequate hand movements. This paper aims to introduce a 3D active orthosis of PLA Plus designed by the Creative Lab in the Universidad Santiago de Cali, which includes an actuator and a low-cost myoelectric signal acquisition system, with two input channels. Finger flexion/extension movements and resting-state were performed. The user’s intention is decoded processing rectified and integrated myoelectric signals. An on-off control algorithm was implemented to generate commands that control orthosis movements. The system is controlled by a person who has a disability due to a C5 and C6 spinal trauma that generated muscular atrophy in the distal level of the hand. Results showed the controlled flexion and extension of the fingers with a good performance. This system assists people with disabilities in the ulnar, medial, and radial nerves to make proper hand movements. The design of the above-mentioned orthosis allows individuals to carry out daily living activities to improve their quality of life.

A Soft Pressure Sensor Skin for Hand and Wrist Orthoses

Side effects caused by excessive contact pressure such as discomfort and pressure sores are commonly complained by patients wearing orthoses. These problems leading to low patient compliance decrease the effectiveness of the device. To mitigate side effects, this study describes the design and fabrication of a soft sensor skin with strategically placed 12 sensor units for static contact pressure measurement beneath a hand and wrist orthosis. A Finite Element Model was built to simulate the pressure on the hand of a subject and sensor specifications were obtained from the result to guide the design. By testing the fabricated soft sensor skin on the subject, contact pressure between 0.012 MPa and 0.046 MPa was detected, revealing the maximum pressure at the thumb metacarpophalangeal joint which was the same location of the highest pressure of simulation. In this letter, a new fabrication method combining etching and multi-material additive manufacture was introduced to produce multiple sensor units as a whole. Furthermore, a novel fish-scale structure as the connection among sensors was introduced to stabilize sensor units and reinforce the soft skin. Experimental analysis reported that the sensor signal is repeatable, and the fish-scale structure facilitates baseline resuming of sensor signal during relaxation.

FAME: Functional Assessment of a Myoelectric Orthosis Hand Orthoses

FAME: Functional Assessment of a Myoelectric Orthosis Hand Orthoses