Virtual Reality combined with Robotic facilitated movements for pain management and sensory stimulation of the upper limb following a Brachial Plexus injury: A case study

Brachial Plexus injuries are complex in nature caused in large by high impact traffic accidents which can lead to additional complications such as Complex Regional Pain Syndrome and even lead to amputation or the need for further surgical intervention. Treatment options to help repair the brachial plexus initially involve surgical intervention and post-surgery rehabilitation with medication to help with ongoing pain. Pain treatments used for these types of injuries are limited and differ in effectiveness. Paradigms utilising multimodal systems such as the one described in this paper based on virtual reality and robotics could yield results that are non-invasive and provide better rehabilitation outcomes for the sufferers. In this paper we present a single case study exploring whether Virtual Reality plus Haptic feedback have any practical potential for reducing upper limb pain and improving function in patients with brachial plexus injuries. The case study is presented with long standing complex combination of phantom limb and neuropathic pain. A decrease in perceived levels of pain was reported which amounts to a 50% reduction in pain from baseline and an improved range of motion. An examination of the sensory phantom map on the stump seems to indicate an early establishment of the thumb representation on the stump close to the area being stimulated with potential implications for prosthesis use

An AI-Based Model for Texture Classification from Vibrational Feedback: Towards Development of Self-Adapting Sensory Robotic Prosthesis

This paper presents a novel method of tuning vibration parameters to elicit specific perceptions of texture using vibration artefacts detected in EMG signals. Though often used for prosthetic control, sensory feedback modalities like vibration can be used to convey proprioceptive or sensory information. Literature has shown that the presence of sensory feedback in prosthesis can improve embodiment and control of prosthetic devices. However, it is not widely adopted in daily prosthesis use, due in large part to the daily change in perception and interpretation of the sensory modality. This results in daily parameter adjustments so that sensory perception can be maintained over time. A method therefore needs to be established to maintain perception generated by modalities like vibrations. This paper investigates modulating the vibration parameters based on how the vibrations dissipate in the surrounding tissue from the stimuli. This is with the aim of correlating dissipation of vibration to specific perceptions of texture. Participants were asked to control vibration motor parameters to elicit the perception of three different grades of sandpaper, provided to them for reference. Once the vibration parameters were chosen a CNN algorithm identified and categorized the artefact features along equidistantly spaced EMG electrodes. Participants were asked to repeat this experiment on three separate days and on the fourth was asked to complete a texture identification task. The task involved identifying the texture of the sandpaper based on their previously chosen parameters and compared the results to tuning against an AI-based algorithm using the dissipation of the vibration artefacts

An Investigation into the Dissipation of Vibrations Using Electromyography towards the Development of Self-Adapting Robotic Prosthesis

Vibrations can be used to convey positional or sensory information to prosthetic users. However, for the feedback to convey information consistently, daily fine-grained adjustments are required. This paper investigates whether vibration dissipation through the muscle can be tracked using EMG with the aim of providing reliable, long-term sensory feedback. The results of this study showed that the magnitude of vibration artifacts can be measured using EMG and used to create a dissipation trend. This trend varies between participants but shows consistency for individuals when measured across multiple days. This novel way of measuring vibration dissipation can potentially be used as a basis for adaptive sensory control in future prosthesis studies

Brain response to focal vibro-tactile stimulation prior to muscle contraction

This paper presents a single case study of an on-going study evaluating cortical association with facilitation and management of vibro-tactile stimulation applied prior to voluntary muscle contraction. The study consisted of three repetitions of relaxation phase during which vibrations are applied, and a contraction phase. EEG and EMG data was collected to determine muscle and brain activation patterns. The EEG analysis of the mu waves during relaxation + vibration phase seem to indicate sensory cortex activation during focal muscle vibrations. With repetitiveness of vibrations, an increase in maximal calculated mu power was observed that could suggest optimization of the muscle fibers prior to the contraction. When contraction is performed, mu waves are desynchronizing with the movement execution. The analysis of the last relaxation period indicate that the muscle itself facilitates the last contraction locally possibly due to cortical learning

Cortical and Muscle Response to Focal Vibro-Tactile Stimuli

This paper investigates cortical responses to vibro-tactile stimuli. EEG was recorded in two conditions: when vibrations were applied focally on the muscle during relaxation and during muscle contraction. Mu and beta waves analysis of the EEG signals suggest that vibrations applied before the contraction increases the stretch of the muscle, thus improving its output performance. Further analysis of the vibrations applied during the muscle contraction shows cortical activation while modulating vibro-tactile stimuli to stabilise muscle performance

An Optimized Design of a Parallel Robot for Gait Training

The guidelines for enhancing robot-assisted training for post-stroke survivors head towards increasing exercise realism and variability; in particular lower limb rehabilitation needs the patient to feel challenged to adapt his locomotion and dynamic balance capabilities to different virtual ground scenarios. This paper proposes a design for a robot whose end-effector acts as a footplate to be in permanent contact with the user's foot during practice: the structure is such that it enables the user's foot to rotate around three axis, differently from what is currently available in the research for gait training; the parallel kinematic structure and the dimensional synthesis allow a suitable range of motion and aim at limiting device mass, footprint and reaction forces on the actuators when rendering virtual ground. The employed methodology has been validated using ground reaction forces data relative to stroke survivors

VIBROfocus: Design of a focal vibro-tactile robotic-assistive system for spasticity rehabilitation

The main focus of spasticity treatment is to alleviate pain, improve function and reduce risk of additional complications. In this paper the design of a robotic system with enhanced focal vibro-tactile stimulation for the treatment of spasticity in the upper limbs is presented. Building on emerging evidence on the use of vibrations in the treatment of spasticity, we propose a new integrated approach. Our design combines the use of vibro-tactile stimulation of the high tone muscle with robotic movement assistance to augment rehabilitation outcomes in patients with spasticity in the upper limbs

Robotic Therapy for Phantom Limb Pain in Upper Limb Amputees

The system described in this paper combines virtual reality with haptic feedback to increase the level of immersion and invoke the sense of agency in patients with phantom limb pain with the aim of reducing perceived pain. This paper presents three case studies of an on-going clinical study. The initial results suggest an increased sense of embodiment of the virtual limb promotes a decrease in perceived levels of pain. The results strengthen the view that the cortical map does not fully “disappear” yet lays dormant

Performance adaptive training control strategy for recovering wrist movements in stroke patients: a preliminary, feasibility study

<p>Abstract</p> <p>Background</p> <p>In the last two decades robot training in neuromotor rehabilitation was mainly focused on shoulder-elbow movements. Few devices were designed and clinically tested for training coordinated movements of the wrist, which are crucial for achieving even the basic level of motor competence that is necessary for carrying out ADLs (activities of daily life). Moreover, most systems of robot therapy use point-to-point reaching movements which tend to emphasize the pathological tendency of stroke patients to break down goal-directed movements into a number of jerky sub-movements. For this reason we designed a wrist robot with a range of motion comparable to that of normal subjects and implemented a self-adapting training protocol for tracking smoothly moving targets in order to facilitate the emergence of smoothness in the motor control patterns and maximize the recovery of the normal RoM (range of motion) of the different DoFs (degrees of Freedom).</p> <p>Methods</p> <p>The IIT-wrist robot is a 3 DoFs light exoskeleton device, with direct-drive of each DoF and a human-like range of motion for Flexion/Extension (FE), Abduction/Adduction (AA) and Pronation/Supination (PS). Subjects were asked to track a variable-frequency oscillating target using only one wrist DoF at time, in such a way to carry out a progressive splinting therapy. The RoM of each DoF was angularly scanned in a staircase-like fashion, from the "easier" to the "more difficult" angular position. An Adaptive Controller evaluated online performance parameters and modulated both the assistance and the difficulty of the task in order to facilitate smoother and more precise motor command patterns.</p> <p>Results</p> <p>Three stroke subjects volunteered to participate in a preliminary test session aimed at verify the acceptability of the device and the feasibility of the designed protocol. All of them were able to perform the required task. The wrist active RoM of motion was evaluated for each patient at the beginning and at the end of the test therapy session and the results suggest a positive trend.</p> <p>Conclusion</p> <p>The positive outcomes of the preliminary tests motivate the planning of a clinical trial and provide experimental evidence for defining appropriate inclusion/exclusion criteria.</p

Stroke patients' utilisation of extrinsic feedback from computer-based technology in the home: a multiple case study realistic evaluation

Background Evidence indicates that post − stroke rehabilitation improves function, independence and quality of life. A key aspect of rehabilitation is the provision of appropriate information and feedback to the learner. Advances in information and communications technology (ICT) have allowed for the development of various systems to complement stroke rehabilitation that could be used in the home setting. These systems may increase the provision of rehabilitation a stroke survivor receives and carries out, as well as providing a learning platform that facilitates long-term self-managed rehabilitation and behaviour change. This paper describes the application of an innovative evaluative methodology to explore the utilisation of feedback for post-stroke upper-limb rehabilitation in the home. Methods Using the principles of realistic evaluation, this study aimed to test and refine intervention theories by exploring the complex interactions of contexts, mechanisms and outcomes that arise from technology deployment in the home. Methods included focus groups followed by multi-method case studies (n = 5) before, during and after the use of computer-based equipment. Data were analysed in relation to the context-mechanism-outcome hypotheses case by case. This was followed by a synthesis of the findings to answer the question, ‘what works for whom and in what circumstances and respects?’ Results Data analysis reveals that to achieve desired outcomes through the use of ICT, key elements of computer feedback, such as accuracy, measurability, rewarding feedback, adaptability, and knowledge of results feedback, are required to trigger the theory-driven mechanisms underpinning the intervention. In addition, the pre-existing context and the personal and environmental contexts, such as previous experience of service delivery, personal goals, trust in the technology, and social circumstances may also enable or constrain the underpinning theory-driven mechanisms. Conclusions Findings suggest that the theory-driven mechanisms underpinning the utilisation of feedback from computer-based technology for home-based upper-limb post-stroke rehabilitation are dependent on key elements of computer feedback and the personal and environmental context. The identification of these elements may therefore inform the development of technology; therapy education and the subsequent adoption of technology and a self-management paradigm; long-term self-managed rehabilitation; and importantly, improvements in the physical and psychosocial aspects of recovery