A self-aligning end-effector robot for individual joint training of the human arm

Aim: Intense training of arm movements using robotic devices can help reduce impairments in stroke. Recent evidence indicates that independent training of individual joints of the arm with robots can be as effective as coordinated multi-joint arm training. This makes a case for designing and developing robots made for training individual joints, which can be simpler and more compact than the ones for coordinate multi-joint arm training. The design of such a robot is the aim of the work presented in this paper. Methods: An end-effector robot kinematic design was developed and the optimal robot link lengths were estimated using an optimization procedure. A simple algorithm for automatically detecting human limb parameters is proposed and its performance was evaluated through a simulation study. Results: A six-degrees-of-freedom end-effector robot with three actuated degrees-of-freedom and three non-actuated self-aligning degrees-of-freedom for safe assisted training of the individual joints (shoulder or elbow) of the human arm was conceived. The proposed robot has relaxed constraints on the relative positioning of the human limb with respect to the robot. The optimized link lengths chosen for the robot allow it to cover about 80% of the human limb’s workspace, and possess good overall manipulability. The simple estimation procedure was demonstrated to estimate human limb parameters with low bias and variance. Discussion: The proposed robot with three actuated and three non-actuated degrees-of-freedom has a compact structure suitable for both the left and right arms without any change to its structure. The proposed automatic estimation procedure allows the robot to safely apply forces and impose movements to the human limb, without the need for any manual measurements. Such compact robots have the highest potential for clinical translation

Trends and developments in hip and knee arthroplasty technology

The developments in hip and knee arthroplasty over recent years have aimed to improve outcomes, reduce complications and improve implant survival. This review describes some of the most interesting trends and developments in this important and fast-moving field. Notable developments have included ceramic hip resurfacing, mini hip stems, cementless knee replacement and the wider adoption of the dual mobility articulation for hip arthroplasty. Advances in additive manufacturing and the surface modification of joint replacements offer increasing options for more challenging arthroplasty cases. Robotic assisted surgery is one of the most interesting developments in hip and knee surgery. The recent growth in the use of this technology is providing data that will help determine whether this approach should become the standard of care for hip and knee arthroplasty in the future.

The design of Lil’Flo, a socially assistive robot for upper extremity motor assessment and rehabilitation in the community via telepresence

Introduction We present Lil’Flo, a socially assistive robotic telerehabilitation system for deployment in the community. As shortages in rehabilitation professionals increase, especially in rural areas, there is a growing need to deliver care in the communities where patients live, work, learn, and play. Traditional telepresence, while useful, fails to deliver the rich interactions and data needed for motor rehabilitation and assessment. Methods We designed Lil’Flo, targeted towards pediatric patients with cerebral palsy and brachial plexus injuries using results from prior usability studies. The system combines traditional telepresence and computer vision with a humanoid, who can play games with patients and guide them in a present and engaging way under the supervision of a remote clinician. We surveyed 13 rehabilitation clinicians in a virtual usability test to evaluate the system. Results The system is more portable, extensible, and cheaper than our prior iteration, with an expressive humanoid. The virtual usability testing shows that clinicians believe Lil’Flo could be deployed in rural and elder care facilities and is more capable of remote stretching, strength building, and motor assessments than traditional video only telepresence. Conclusions Lil’Flo represents a novel approach to delivering rehabilitation care in the community while maintaining the clinician-patient connection.

Reliability and validity of a computer game-based tool of upper extremity assessment for object manipulation tasks in children with cerebral palsy

Introduction A computer game-based upper extremity (CUE) assessment tool is developed to quantify manual dexterity of children with Cerebral Palsy (CP). The purpose of this study was to determine test-retest reliability of the CUE performance measures (success rate, movement onset time, movement error, and movement variation) and convergent validity with the Peabody Developmental Motor Scale version 2 (PDMS-2) and the Quality of Upper Extremity Skills Test (QUEST). Methods Thirty-five children with CP aged four to ten years were tested on two occasions two weeks apart. Results CUE performance measures of five chosen object manipulation tasks exhibited high to moderate intra-class correlation coefficient (ICC) values. There was no significant difference in the CUE performance measures between test periods. With few exceptions, there was no significant correlation between the CUE performance measures and the PDMS-2 or the QUEST test scores. Conclusions The high to moderate ICC values and lack of systematic errors indicate that the CUE assessment tool has the ability to repeatedly record reliable performance measures of different object manipulation tasks. The lack of a correlation between the CUE and the PDMS-2 or QUEST scores indicates that performance measures of these assessment tools represent distinct attributes of manual dexterity.

Case study assessing the feasibility of using a wearable haptic device or humanoid robot to facilitate transitions in occupational therapy sessions for children with autism spectrum disorder

Introduction Some children with autism spectrum disorder (ASD) have difficulties with transitions that may lead to problem behaviours. Although the use of technologies with children with ASD is receiving increasing attention, no study has looked at their effect on transitions in activities of daily living. This study aimed to document the feasibility of (1) using two intervention technologies (NAO humanoid robot or wearable haptic device) separately to facilitate transitions in occupational therapy sessions for children with ASD and (2) the method used to document changes. Methods Using a single case reversal (ABA) design, two children with ASD were randomly assigned to one of the intervention technologies (humanoid robot or haptic bracelet). Each technology was used as an antecedent to stimulate the start of transitions in eight intervention sessions at a private occupational therapy clinic. Data concerning the time required for transitions, child’s behaviours during transitions at the clinic and mother’s perception of the child’s performance in transitions at home were analysed graphically. Results When using technology, both children’s behaviours were appropriate, quick and relatively stable. Also, both mothers reported improved perceptions of their child’s performance in transitions. Conclusions This exploratory study suggests no detrimental effect of using these technologies.

Usability, functionality, and efficacy of a custom myoelectric elbow-wrist-hand orthosis to assist elbow function in individuals with stroke

Introduction After stroke, upper limb impairment affects independent performance of activities of daily living. We evaluated the usability, functionality, and efficacy of a myoelectric elbow-wrist-hand orthosis to provide support, limit unsafe motion, and enhance the functional motion of paralyzed or weak upper limbs. Methods Individuals with stroke participated in a single-session study to evaluate the device. Ability to activate the device was tested in supported and unsupported shoulder position, as well as the elbow range of motion, ability to maintain elbow position, and ability to lift and hold a range of weights while using the device. Results No adverse events were reported. 71% of users were able to operate the device in all three active myoelectric activation modes (Biceps, Triceps, Dual) during testing. Users were able to hold a range of wrist weights (0.5–2 lbs) for 10–120 seconds, with the largest percentage of participants able to hold weights with the device in Biceps Mode. Conclusions The myoelectric elbow-wrist-hand orthosis improved range of motion during use and was efficacious at remediating upper extremity impairment after stroke. All users could operate the device in at least one mode, and most could lift and hold weights representative of some everyday objects using the device.

Virtual Hand Illusion in younger and older adults

Introduction Embodiment involves experiencing ownership over our body and localizing it in space and is informed by multiple senses (visual, proprioceptive and tactile). Evidence suggests that embodiment and multisensory integration may change with older age. The Virtual Hand Illusion (VHI) has been used to investigate multisensory contributions to embodiment, but has never been evaluated in older adults. Spatio-temporal factors unique to virtual environments may differentially affect the embodied perceptions of older and younger adults. Methods Twenty-one younger (18–35 years) and 19 older (65+ years) adults completed the VHI paradigm. Body localization was measured at baseline and again, with subjective ownership ratings, following synchronous and asynchronous visual-tactile interactions. Results Higher ownership ratings were observed in the synchronous relative to the asynchronous condition, but no effects on localization/drift were found. No age differences were observed. Localization accuracy was biased in both age groups when the virtual hand was aligned with the real hand, indicating a visual mislocalization of the virtual hand. Conclusions No age-related differences in the VHI were observed. Mislocalization of the hand in VR occurred for both groups, even when congruent and aligned; however, tactile feedback reduced localization biases. Our results expand the current understanding of age-related changes in multisensory embodiment within virtual environments.

Effect of 8-week treadmill running with peroneal muscle functional electrical stimulation on laterally deviated centre of plantar pressure position and star excursion balance test performance

Introduction Ankle sprain is a common injury that can have long-term sequelae resulting in pain, swelling and a reduction of physical activity participation. Previous research has shown a laterally deviated centre of pressure (COP) during running gait increases the risk of lateral ankle sprain. As a method of altering COP, electrical stimulation has been considered. Method A group of 14 healthy males were randomly allocated to case control groups which were single blinded. The intervention involved an 8-week training programme of functional electrical stimulation to the peroneal muscles during treadmill running, with a sham control group. Outcomes were COP position and star excursion balance test. Statistical analysis was through SPSS using a combination of MANOVA, T-tests and Wilcoxon signed rank Results There was a significant difference in the results post intervention at max pressure for intervention M = 0.7(±0.7) and control M = −6.0 (±4.6) conditions; t(6) = −2.9, p < 0.05 Conclusion It has been demonstrated that FES can alter COP during max pressure in running gait after an 8-week training programme, although carry over effect appears limited and further testing is required.