Hand Paralysis Research Articles

What is the role of hand surgery in plastic surgery? Analysis of hand surgery papers presented in Turkish national congresses of plastic, reconstructive, and aesthetic surgery

Context: Scientific studies are often presented primarily to a group of colleagues at annual scientific meetings. All year rounds are turned into products in congresses. Aims: The aim of the study is to evaluate the extent of the hand surgery in plastic surgery and plastic surgeons' papers related with hand surgery in national congresses; the past eight plastic surgery congresses were classified and presented. Settings and Design: The abstract books of Turkish National Congresses of Plastic, Reconstructive, and Aesthetic Surgery between 2011 and 2018 have been evaluated retrospectively. Subjects and Methods: Distribution of hand surgery according to the topics was evaluated according to the European White Book rules and standards. Distribution of oral and posters and distribution by years were shown. Results: The ratio of hand surgery reports to all reports was 17.3%. Hand and upper extremity surgery topics were presented at 19.7% in the 38th congress, which is the most hand surgery-included congress. The most frequently presented subjects were tumors, flaps, trauma, congenital anomalies, and replantation. Conclusions: Although there are arguments that plastic surgeons have disregarded hand surgery, there is no similar situation for Turkish plastic surgeons in the national platform. It has been found that the most common topics such as tumor excision and repair of the tissue defect were the most presented issues rather than arthroscopy, paralytic hand, and arthritis, which are specific to the hand surgery. Increasing the number of plastic surgery specialists who have been trained with hand surgery as a subspecialty will bring up the subjects that have not been presented in the hand surgery so far, in the future congresses.

Technology, Transaction Costs and Economic Foresight. Developing Tendency-Based Scenarios

Combining historical economic data and positivistic, standard neoclassical economic theories does not give a sufficient nuanced view on different economic futures that address the future inherent uncertainty. Economic history does not repeat itself making economic systems ‘open systems’, and economic laws cannot be regarded as laws in the natural sciences. Therefore, we explore a different approach by taking critical realism as science-philosophical background, using transaction cost theory to cope with the unrealistic full rationality postulate of neoclassical economic theory. In particular, we use the scenario-method from the management sciences and use as the concept of ‘tendencies’, as developed within critical realism, as scenario-framework. To illustrate our approach we use the case of Sense Glove, a light, compact, and modular robotic hand shoe that was originally developed for cost-effective rehabilitation of hand paralysis, but which is now used to get a real sense of feeling objects in virtual and artificial reality.

Clinical and histopathological profile of a patient with localized lepromatous leprosy

Lepromatous leprosy is a polar form of the disease characterized by very low to absent cell mediated immunity, resulting in unrestricted multiplication of the leprosy bacilli. This leads to infiltration and papulo-nodular lesions, which initially favor the cooler areas of the body and later become generalized. However, lepromatous leprosy may rarely be localized to a single or limited sites. Routine skin smears are negative but a skin smear and histopathology from the affected sites are confirmatory. These cases may be misdiagnosed as paucibacillary leprosy with subsequent under-treatment of the patient. Clinicians should be aware of this entity as a simple skin smear from the site can confirm the diagnosis. A 57-year old man presented with an erythematous plaque surrounded by a few satellite papules on the right hand, right ulnar paralysis and partial anaesthesia of the right hand and both feet, for one year. Slit skin smears from routine sites were negative for acid fast bacilli. However, a skin smear from the satellite lesions revealed a bacillary index of 4+. Histopathology of the skin was consistent with lepromatous leprosy. He was initiated on the WHO multibacillary multidrug therapy (MB-MDT).

Sensory Nerve Transfer for Lower Roots Brachial Plexus Injury: Superficial Radial Nerve to the Dorsal Cutaneous Branch and the Superficial Branch of the Ulnar Nerve

In the treatment of brachial plexus injury to lower nerve roots, the priority is to restore motor function to the paralyzed hand. In addition, it is also important to consider sensory reconstruction, which is crucial to the optimal restoration of prehensile function. We report the surgical technique and sensory recovery of a nerve transfer in a case in which the superficial radial nerve was transferred to the dorsal cutaneous branch and the superficial branch of the ulnar nerve in a patient with C7, C8, and T1 roots injury. The nerve transfer successfully restored sensation in the ulnar one and a half digits as well as the ulnar border of the hand, with minimal donor site deficit. This technique provides a useful sensory reconstructive option in patients with brachial plexus injury to lower roots.

Bio-inspired tendon driven mechanism for simultaneous finger joints flexion using a soft hand exoskeleton.

A new tendon driven mechanism, embedded into a soft hand exoskeleton for rehabilitation and assistance, was proposed in this study. The proposed solution was a pulley flexion mechanism inspired by the human musculoskeletal system to enable a natural and comfortable finger flexion. A biomechanical constraint for the finger flexion motion states that the relation between the proximal interphalangeal joint angle of the finger should always be flexed around 1.5 times the distal interphalangeal joint angle. The study aimed to comply with this constraint, by simultaneously distributing the forces over the distal and middle finger phalanges. For evaluation, the voluntary and exoskeleton flexions were compared based on the relation between the proximal and distal interphalangeal joint angles. The results showed that during the exoskeleton flexion the relation between the interphalangeal joints complied with the biomechanical constraint, where the proximal interphalangeal joint angle was 1.5 times larger than the distal interphalangeal joint. This ensures that the mechanism flexes the finger comfortably. The proposed solution is therefore a promising design for a novel soft exoskeleton that will be used for training and assistance of patients with hand paralysis.

Combined endogenous and exogenous disinhibition of intracortical circuits augments plasticity induction in the human motor cortex

BackgroundMotor imagery (MI) engages cortical areas in the human brain similar to motor practice. Corticospinal excitability (CSE) is facilitated during but not after MI practice. We hypothesized that lasting CSE changes could be achieved by associatively pairing this endogenous modulation with exogenous stimulation of the same intracortical circuits. MethodsWe combined MI with a disinhibition protocol (DIS) targeting intracortical circuits by paired-pulse repetitive transcranial magnetic stimulation in one main and three subsequent experiments. The follow-up experiments were applied to increase effects, e.g., by individualizing inter-stimulus intervals, adding neuromuscular stimulation and expanding the intervention period. CSE was captured during (online) and after (offline) the interventions via input-output changes and cortical maps of motor evoked potentials. A total of 35 healthy subjects (mean age 26.1 ± 2.6 years, 20 females) participated in this study. ResultsA short intervention (48 stimuli within ∼90s) increased CSE. This plasticity developed rapidly, was associative (with MIon, but not MIoff or REST) and persisted beyond the intervention period. Follow-up experiments revealed the relevance of individualizing inter-stimulus intervals and of consistent inter-burst periods for online and offline effects, respectively. Expanding this combined MI/DIS intervention to 480 stimuli amplified the sustainability of CSE changes. When concurrent neuromuscular electrical stimulation was applied, the plasticity induction was cancelled. ConclusionsThis novel associative stimulation protocol augmented plasticity induction in the human motor cortex within a remarkably short period of time and in the absence of active movements. The combination of endogenous and exogenous disinhibition of intracortical circuits may provide a therapeutic backdoor when active movements are no longer possible, e.g., for hand paralysis after stroke.

Correlation analysis of motor function improvement and brain structure for upper limb paralysis.

Intervention with combined low-frequency repetitive transcranial magnetic stimulation and intensive occupational therapy can improve brain function in poststroke patients with motor paralysis. We aimed to evaluate the relationship between brain structure at the time of intervention and the degree of motor function improvement using this combination therapy. Twenty-five patients with upper limb paralysis after stroke were hospitalized for 15 days to receive 12 sessions of low-frequency repetitive transcranial magnetic stimulation over the nonlesional hemisphere and occupational therapy. Imaging analysis was carried out using three-dimensional T1-weighted images. Correlation analysis between cortical thickness and upper limb motor function score was carried out using FreeSurfer. Correlation analysis between cortical thickness and motor function improvement was carried out by atlas-based analysis. FreeSurfer showed that significant positive correlations were found between cortical thickness of the postcentral or supramarginal gyrus of the diseased hemisphere and motor function improvements in nondominant hand paralysis (uncorrected P<0.001). Results using the atlas supported these results (P<0.05). The results of the analysis indicated that the effect of our proposed treatment could be related to the cortical thickness. In particular, it is considered that the cortical thickness of the postcentral gyrus or the supramarginal gyrus of the affected hemisphere plays an important role in such recovery in poststroke hemiparetic patients.

Factors predicting independent manipulation of chopsticks in acute stroke patients with dominant hand paralysis using upper extremity evaluations

Factors predicting independent manipulation of chopsticks in acute stroke patients with dominant hand paralysis using upper extremity evaluations

Reflexotherapy of diseases of the musculoskeletal system in children and adolescents. Educational and methodological guide

The training manual is based on many years of experience in the practical application of reflexotherapy in outpatient settings. The article presents a structural analysis of diseases of children and adolescents receiving treatment in the reflexology room of a childrens polyclinic, which revealed a high level of pathology of the musculoskeletal system and connective tissue and a steady growth trend of this group of diseases. Pathogenetic justifications, indications and contraindications for the use of reflexotherapy in Pediatrics and in diseases of the musculoskeletal system in particular are given. Principal therapeutic approaches and treatment regimens for patients with obstetric hand paralysis, spastic torticollis, migraine, Perthes disease and traumatic limb injuries are considered. Recommendations on the organization of outpatient use of reflexotherapy in Pediatrics, the methods used and their instrumental support are formulated. The training manual is intended for doctors who specialize in reflexology, already practicing reflexologists, orthopedic traumatologists and physiotherapists.

Reactivating the Dormant Motor Cortex After Spinal Cord Injury With EEG Neurofeedback: A Case Study With a Chronic, Complete C4 Patient.

Chronic spinal cord injury (SCI) patients present poor motor cortex activation during movement attempts. The reactivation of this brain region can be beneficial for them, for instance, allowing them to use brain-machine interfaces for motor rehabilitation or restoration. These brain-machine interfacess generally use electroencephalography (EEG) to measure the cortical activation during the attempts of movement, quantifying it as the event-related desynchronization (ERD) of the alpha/mu rhythm. Based on previous evidence showing that higher tonic EEG alpha power is associated with higher ERD, we hypothesized that artificially increasing the alpha power over the motor cortex of these patients could enhance their ERD (ie, motor cortical activation) during movement attempts. We used EEG neurofeedback (NF) to enhance the tonic EEG alpha power, providing real-time visual feedback of the alpha oscillations measured over the motor cortex. This approach was evaluated in a C4, ASIA A, SCI patient (9 months after the injury) who did not present ERD during the movement attempts of his paralyzed hands. The patient performed 4 NF sessions (in 4 consecutive days) and screenings of his EEG activity before and after each session. After the intervention, the patient presented a significant increase in the alpha power over the motor cortex, and a significant enhancement of the mu ERD in the contralateral motor cortex when he attempted to close the assessed right hand. As a proof of concept investigation, this article shows how a short NF intervention might be used to enhance the motor cortical activation in patients with chronic tetraplegia.

Self-Calibration Algorithm for a Pressure Sensor with a Real-Time Approach Based on an Artificial Neural Network.

This paper presents a novel approach to predicting self-calibration in a pressure sensor using a proposed Levenberg Marquardt Back Propagation Artificial Neural Network (LMBP-ANN) model. The self-calibration algorithm should be able to fix major problems in the pressure sensor such as hysteresis, variation in gain and lack of linearity with high accuracy. The traditional calibration process for this kind of sensor is a time-consuming task because it is usually done through manual and repetitive identification. Furthermore, a traditional computational method is inadequate for solving the problem since it is extremely difficult to resolve the mathematical formula among multiple confounding pressure variables. Accordingly, this paper describes a new self-calibration methodology for nonlinear pressure sensors based on an LMBP-ANN model. The proposed method was achieved using a collected dataset from pressure sensors in real time. The load cell will be used as a reference for measuring the applied force. The proposed method was validated by comparing the output pressure of the trained network with the experimental target pressure (reference). This paper also shows that the proposed model exhibited a remarkable performance than traditional methods with a max mean square error of 0.17325 and an R-value over 0.99 for the total response of training, testing and validation. To verify the proposed model’s capability to build a self-calibration algorithm, the model was tested using an untrained input data set. As a result, the proposed LMBP-ANN model for self-calibration purposes is able to successfully predict the desired pressure over time, even the uncertain behaviour of the pressure sensors due to its material creep. This means that the proposed model overcomes the problems of hysteresis, variation in gain and lack of linearity over time. In return, this can be used to enhance the durability of the grasping mechanism, leading to a more robust and secure grasp for paralyzed hands. Furthermore, the exposed analysis approach in this paper can be a useful methodology for the user to evaluate the performance of any measurement system in a real-time environment.

Feasibility and safety of shared EEG/EOG and vision-guided autonomous whole-arm exoskeleton control to perform activities of daily living

Arm and finger paralysis, e.g. due to brain stem stroke, often results in the inability to perform activities of daily living (ADLs) such as eating and drinking. Recently, it was shown that a hybrid electroencephalography/electrooculography (EEG/EOG) brain/neural hand exoskeleton can restore hand function to quadriplegics, but it was unknown whether such control paradigm can be also used for fluent, reliable and safe operation of a semi-autonomous whole-arm exoskeleton restoring ADLs. To test this, seven abled-bodied participants (seven right-handed males, mean age 30 ± 8 years) were instructed to use an EEG/EOG-controlled whole-arm exoskeleton attached to their right arm to perform a drinking task comprising multiple sub-tasks (reaching, grasping, drinking, moving back and releasing a cup). Fluent and reliable control was defined as average ‘time to initialize’ (TTI) execution of each sub-task below 3 s with successful initializations of at least 75% of sub-tasks within 5 s. During use of the system, no undesired side effects were reported. All participants were able to fluently and reliably control the vision-guided autonomous whole-arm exoskeleton (average TTI 2.12 ± 0.78 s across modalities with 75% successful initializations reached at 1.9 s for EOG and 4.1 s for EEG control) paving the way for restoring ADLs in severe arm and hand paralysis.

A hybrid EEG-EMG BMI improves the detection of movement intention in cortical stroke patients with complete hand paralysis.

Motor rehabilitation based on brain-machine interfaces (BMI) has been shown as a feasible option for stroke patients with complete paralysis. However, the pathologic EEG activity after a stroke makes the detection of movement intentions in these patients challenging, especially in those with damages involving the motor cortex. Residual electromyographic activity in those patients has been shown to be decodable, even in cases when the movement is not possible. Hybrid BMIs combining EEG and EMG activity have been recently proposed, although there is little evidence about how they work for completely paralyzed stroke patients. In this study we propose a neural interface, relying on EEG, EMG or EEG+EMG features, to detect movement attempts. Twenty patients with a chronic stroke affecting their motor cortex were recruited, and asked to open and close their paralyzed hand while their electrophysiological signals were recorded. We show how EEG and EMG activities provide complementary information for detecting the movement intentions, being the accuracy of the hybrid BMI significantly higher than the EEG-based system. The obtained results encourage the integration of hybrid BMI systems for motor rehabilitation of patients with paralysis due to stroke.

Flex Sensor Based Biofeedback Monitoring for Post-Stroke Fingers Myopathy Patients

Hands are one of the crucial parts of the human body in carrying out daily activities. Accidents on the hands decreasing in motor skills of the hand so that therapy is necessary to restore motor function of the hand. In addition to accidents, hand disabilities can be caused by certain diseases, e.g. stroke. Stroke is a partial destruction of the brain. It occurs if the arteries that drain blood to the brain are blocked, or if torn or leak. The purpose of this study to make biofeedback monitoring equipment for post-stroke hands myopathy patients. Biofeedback is an alternative method of treatment that involves measuring body functions measured subjects such as skin temperature, sweat activity, blood pressure, heart rate and hand paralysis due to stroke. In this study, the sensor used for biofeedback monitoring tool is flex sensor. Flex sensor is a passive resistive device that changes its resistance as the sensor is bent. Flex sensor converts the magnitude of the bend into electrical resistance, the greater the bend the greater the resistance value. The monitoring used in this biofeedback monitoring tool uses Graphical User Interface (GUI) in C# programming language. The motivation of the study is to monitor and record the progressive improvement of the hand therapy. Patients who experienced post-stroke can see the therapy progress quantitatively.

Interactive Design and Development of Real Arm Movements for Application in Rehabilitation

An interactive real arm movements for application in rehabilitation is designed and developed. The aim is to encourage hand paralysis patients performing their physical therapy by introducing games application in replacing conventional hand therapy module and methods. In this project, the accelerometer is used for tracking the orientation of the arm. As the arm moves, the values from x, y and z axis from the accelerometer changes and are being read by the Analog Inputs of the Arduino Board. After being read by the Analog Inputs of the Arduino Board, the 3D model moves as well. Solidworks software was used to modeled the hand in which the data is then transferred to Matlab/Simulink using SimMechanicalLink from Mathworks. Lastly, the sensor glove was programmed to work as a controller of games application in hand rehabilitation thus makes it an enjoyable therapy process.

Recruitment of Additional Corticospinal Pathways in the Human Brain with State-Dependent Paired Associative Stimulation.

Standard brain stimulation protocols modify human motor cortex excitability by modulating the gain of the activated corticospinal pathways. However, the restoration of motor function following lesions of the corticospinal tract requires also the recruitment of additional neurons to increase the net corticospinal output. For this purpose, we investigated a novel protocol based on brain state-dependent paired associative stimulation.Motor imagery (MI)-related electroencephalography was recorded in healthy males and females for brain state-dependent control of both cortical and peripheral stimulation in a brain-machine interface environment. State-dependency was investigated with concurrent, delayed, and independent stimulation relative to the MI task. Specifically, sensorimotor event-related desynchronization (ERD) in the β-band (16-22 Hz) triggered peripheral stimulation through passive hand opening by a robotic orthosis and transcranial magnetic stimulation to the respective cortical motor representation, either synchronously or subsequently. These MI-related paradigms were compared with paired cortical and peripheral input applied independent of the brain state. Cortical stimulation resulted in a significant increase in corticospinal excitability only when applied brain state-dependently and synchronously to peripheral input. These gains were resistant to a depotentiation task, revealed a nonlinear evolution of plasticity, and were mediated via the recruitment of additional corticospinal neurons rather than via synchronization of neuronal firing. Recruitment of additional corticospinal pathways may be achieved when cortical and peripheral inputs are applied concurrently, and during β-ERD. These findings resemble a gating mechanism and are potentially important for developing closed-loop brain stimulation for the treatment of hand paralysis following lesions of the corticospinal tract.SIGNIFICANCE STATEMENT The activity state of the motor system influences the excitability of corticospinal pathways to external input. State-dependent interventions harness this property to increase the connectivity between motor cortex and muscles. These stimulation protocols modulate the gain of the activated pathways, but not the overall corticospinal recruitment. In this study, a brain-machine interface paired peripheral stimulation through passive hand opening with transcranial magnetic stimulation to the respective cortical motor representation during volitional β-band desynchronization. Cortical stimulation resulted in the recruitment of additional corticospinal pathways, but only when applied brain state-dependently and synchronously to peripheral input. These effects resemble a gating mechanism and may be important for the restoration of motor function following lesions of the corticospinal tract.

Cerebral plasticity after contralateral cervical nerve transfer in human by longitudinal PET evaluation

ObjectThe treatment of brachial plexus avulsion injury remains a challenging problem. Admittedly, central nervous mechanisms play a significant role in the motor recovery of the paralyzed hand after peripheral nerve surgery. The present study aimed at investigating the relationship between cerebral reorganization and motor recovery after a unique peripheral crossing nerve transfer surgery in brachial plexus injury patients. MethodsIn the present study, two brachial plexus avulsion injury patients with were followed up for 4 years after contralateral C7 nerve transfer surgery. In the surgery, an intact nerve root from the intact limb was transferred to repair the injured nerves. One patient showed a good motor recovery in the paralyzed hand while the other showed relatively poor outcomes. In the longitudinal follow-up, 9 PET scans of the brain were conducted in both patients at regular intervals of every 6 months. A correlation analysis between cerebral glucose metabolism and flexion power of the paralyzed wrists and fingers was performed to investigate the involvement of brain reorganization during the process of motor recovery. ResultsThe cerebral glucose metabolism in the corpus callosum, premotor cortex (Broadmann Area 6) and the precuneus were found positively correlated with the motor recovery of the paralyzed hand in Patient A (P < .01). Positive correlation between the cerebral glucose metabolism and the motor recovery of the paralyze hand was only present in the corpus callosum in Patient B (P < .01). ConclusionCorpus callosum, premotor cortex and precuneus were related with motor recovery after contralateral cervical nerve transfer surgery. The accumulating activation of these cortical regions potentially represented the recovery of high-order motor networks and may have facilitated the motor recovery.

Drive for Innovative Technologies Leads Industry to Unconventional Sources

Innovation is a hallmark of oil and gas operations. As companies look to survive in the new economy created by the oil price downturn, the need to find new, cost-efficient technology for manufacturing, data processing, or even overall project management, is greater than ever, so much so that the industry is examining other industries for products and processes that may have crossover appeal. That examination was the topic of a panel discussion at the Unconventional Resources Technology Conference in July, where a panel of scientists from firms and laboratories spoke about emerging technologies and new uses for old technologies outside the sphere of traditional petroleum that could have a disruptive impact on the industry. Medical Science Crossovers Olga Koper, oil and gas market leader at Battelle, discussed some of the projects the science research firm has developed in the medical field that could provide significant benefit to operating companies. One such device, the NeuroLife Neural Bypass Technology, helps paralyzed patients regain conscious control of their fingers, hands, and wrists. The system uses a neuroprosthetic microchip that, when implanted in the brain, forms an electronic neural bypass that circumvents disconnected pathways in the nervous system. Battelle applied machine-learning algorithms to decode neuronal activity in the brain and control the use of a person’s forearm muscles. The chip picked up signals from the brain and transmitted the data to a computer with Battelle’s decoding software installed. The decoded data were then transmitted to a proprietary neuromuscular electrical stimulation sys-tem that provided isolated finger movements, essentially allowing a person to control a paralyzed hand by translating his thoughts. Battelle partnered with surgeons at The Ohio State University to implant the system in the brain of a man paralyzed from the chest down. The surgeons implanted a 4×4-mm chip into the motor cortex area of the man’s brain, the area responsible for voluntary movements. Two years into the trial, he is able to transfer objects, stir liquids, and swipe a credit card, among other actions. Koper said the algorithms behind the NeuroLife technology could apply to oil and gas projects, where owners, opera-tors, project managers, and on-site personnel consistently engage in real-time decision making while stringing together large amounts of data. The micro-chip used in the medical case is capable of collecting 30,000 samples/sec across 96 electrodes, producing a total of 2.88 million data points/sec, making it potentially useful hardware for a variety of management systems. “There’s a lot of data, and it has to be filtered, you have to see machine learning of the right data transferred into specific motions,” Koper said. “With big data, the real-time decision making, this is what’s happening right now in the oil and gas industry. We have the technology, but there is not yet that direct type of application. We have to start thinking, how will we do this 10, 20, or even 50 years down the road? Where are some of the new areas where this will be a useful technology?”

Altered modulation of sensorimotor rhythms with chronic paralysis

After paralysis, the disconnection between the cortex and its peripheral targets leads to neuroplasticity throughout the nervous system. However, it is unclear how chronic paralysis specifically impacts cortical oscillations associated with attempted movement of impaired limbs. We hypothesized that μ- (8-13 Hz) and β- (15-30 Hz) event-related desynchronization (ERD) would be less modulated for individuals with hand paralysis due to cervical spinal cord injury (SCI). To test this, we compared the modulation of ERD from magnetoencephalography (MEG) during attempted and imagined grasping performed by participants with cervical SCI (n = 12) and able-bodied controls (n = 13). Seven participants with tetraplegia were able to generate some electromyography (EMG) activity during attempted grasping, whereas the other five were not. The peak and area of ERD were significantly decreased for individuals without volitional muscle activity when they attempted to grasp compared with able-bodied subjects and participants with SCI,with some residual EMG activity. However, no significant differences were found between subject groups during mentally simulated tasks (i.e., motor imagery) where no muscle activity or somatosensory consequences were expected. These findings suggest that individuals who are unable to produce muscle activity are capable of generating ERD when attempting to move, but the characteristics of this ERD are altered. However, for people who maintain volitional muscle activity after SCI, there are no significant differences in ERD characteristics compared with able-bodied controls. These results provide evidence that ERD is dependent on the level of intact muscle activity after SCI.NEW & NOTEWORTHY Source space MEG was used to investigate sensorimotor cortical oscillations in individuals with SCI. This study provides evidence that individuals with cervical SCI exhibit decreased ERD when they attempt to grasp if they are incapable of generating muscle activity. However, there were no significant differences in ERD between paralyzed and able-bodied participants during motor imagery. These results have important implications for the design and evaluation of new therapies, such as motor imagery and neurofeedback interventions.

Towards a wearable hand exoskeleton with embedded synergies.

Numerous hand exoskeletons have been proposed in the literature with the aim of assisting or rehabilitating victims of stroke, brain/spinal cord injury, or other causes of hand paralysis. In this paper a new 3D printed soft hand exoskeleton, HEXOES (Hand Exoskeleton with Embedded Synergies), is introduced and mechanically characterized. Metacarpophalangeal (MCP) and proximal interphalangeal/interphalangeal (PIP/IP) joints had measured maximum flexion angles of 53.7 ± 16.9° and 39.9 ± 13.4°, respectively; and maximum MCP and PIP angular velocities of 94.5 ± 41.9 degrees/s and 74.6 ± 67.3 degrees/s, respectively. These estimates indicate that the mechanical design has range of motion and angular velocity characteristics that meet the requirements for synergy-based control. When coupled with the proposed control loop, HEXOES can be used in the future as a test-bed for synergy-based clinical hand rehabilitation.