Towards automation of dynamic-gaze video analysis taking functional upper-limb tasks as a case study.

BACKGROUND AND OBJECTIVE: Previous studies in motor control have yielded clear evidence that gaze behavior (where someone looks) quantifies the attention paid to perform actions. However, eliciting clinically meaningful results from the gaze data has been done manually, rendering it incredibly tedious, time-consuming, and highly subjective. This paper aims to study the feasibility of automating the coding process of the gaze data taking functional upper-limb tasks as a case study. METHODS: This is achieved by developing a new algorithm capable of coding the collected gaze data through three main stages; data preparation, data processing, and output generation. The input data in the form of a crosshair and a gaze video are converted into a 25 Hz frame rate sequence. Keyframes and non-key frames are then obtained and processed using a combination of image processing techniques and a fuzzy logic controller. In each trial, the location and duration of gaze fixation at the areas of interest (AOIs) are obtained. Once the gaze data is coded, it can be presented in different forms and formats, including the stacked color bar. RESULTS: The obtained results showed that the developed coding algorithm highly agrees with the manual coding method but significantly faster and less prone to unsystematic errors. Statistical analysis showed that Cohen's Kappa ranges from 0.705 to 1.0. Moreover, based on the intra-class correlation coefficient (ICC), the agreement index between computerized and manual coding methods is found to be (i) 0.908 with 95% confidence intervals (0.867, 0.937) for the anatomical hand and (ii) 0.923 with 95% confidence intervals (0.888, 0.948) for the prosthetic hand. A Bland-Altman plot also showed that all data points are closely scattered around the mean. These findings confirm the validity and effectiveness of the developed coding algorithm. CONCLUSION: The developed algorithm demonstrated that it is feasible to automate the coding of the gaze data, reduce the coding time, and improve the coding process's reliability.

Technology for monitoring everyday prosthesis use: a systematic review.

BACKGROUND: Understanding how prostheses are used in everyday life is central to the design, provision and evaluation of prosthetic devices and associated services. This paper reviews the scientific literature on methodologies and technologies that have been used to assess the daily use of both upper- and lower-limb prostheses. It discusses the types of studies that have been undertaken, the technologies used to monitor physical activity, the benefits of monitoring daily living and the barriers to long-term monitoring, with particular focus on low-resource settings. METHODS: A systematic literature search was conducted in PubMed, Web of Science, Scopus, CINAHL and EMBASE of studies that monitored the activity of prosthesis users during daily-living. RESULTS: Sixty lower-limb studies and 9 upper-limb studies were identified for inclusion in the review. The first studies in the lower-limb field date from the 1990s and the number has increased steadily since the early 2000s. In contrast, the studies in the upper-limb field have only begun to emerge over the past few years. The early lower-limb studies focused on the development or validation of actimeters, algorithms and/or scores for activity classification. However, most of the recent lower-limb studies used activity monitoring to compare prosthetic components. The lower-limb studies mainly used step-counts as their only measure of activity, focusing on the amount of activity, not the type and quality of movements. In comparison, the small number of upper-limb studies were fairly evenly spread between development of algorithms, comparison of everyday activity to clinical scores, and comparison of different prosthesis user populations. Most upper-limb papers reported the degree of symmetry in activity levels between the arm with the prosthesis and the intact arm. CONCLUSIONS: Activity monitoring technology used in conjunction with clinical scores and user feedback, offers significant insights into how prostheses are used and whether they meet the user's requirements. However, the cost, limited battery-life and lack of availability in many countries mean that using sensors to understand the daily use of prostheses and the types of activity being performed has not yet become a feasible standard clinical practice. This review provides recommendations for the research and clinical communities to advance this area for the benefit of prosthesis users.

Skill assessment in upper limb myoelectric prosthesis users: Validation of a clinically feasible method for characterising upper limb temporal and amplitude variability during the performance of functional tasks.

Upper limb myoelectric prostheses remain challenging to use and are often abandoned. A proficient user must be able to plan/execute arm movements while activating the residual muscle(s), accounting for delays and unpredictability in prosthesis response. There is no validated, low cost measure of skill in performing such actions. Trial-trial variability of joint angle trajectories measured during functional task performance, linearly normalised by time, shows promise. However, linear normalisation of time introduces errors, and expensive camera systems are required for joint angle measurements. This study investigated whether trial-trial variability, assessed using dynamic time warping (DTW) of limb segment acceleration measured during functional task performance, is a valid measure of user skill. Temporal and amplitude variability of forearm accelerations were determined in (1) seven myoelectric prosthesis users and six anatomically-intact controls and (2) seven anatomically-intact subjects learning to use a prosthesis simulator over repeated sessions. (1): temporal variability showed clear group differences (p<0.05). (2): temporal variability considerably increased on first use of a prosthesis simulator, then declined with training (both p<0.05). Amplitude variability showed less obvious differences. Analysing forearm accelerations using DTW appears to be a valid low-cost method for quantifying movement quality of upper limb prosthesis use during goal-oriented task performance.

Does integrating research into the prosthetics and orthotics undergraduate curriculum enhance students' clinical practice? An interview study on students' perception.

BACKGROUND: Problem-based learning (where rather than feeding students the knowledge, they look for it themselves) has long been thought of as an ideal approach in teaching because it would encourage students to acquire knowledge from an undetermined medium of wrong and right answers. However, the effect of such approach in the learning experience of prosthetics and orthotics students has never been investigated. OBJECTIVES: This study explores the implications of integrating problem-based learning into teaching on the students' learning experience via implementing a research-informed clinical practice module into the curriculum of last year prosthetics and orthotics undergraduate students at the University of Jordan (Amman, Jordan). STUDY DESIGN: Qualitative research pilot study. METHODS: Grounded theory approach was used based on the data collected from interviewing a focus group of four students. RESULTS: Students have identified a number of arguments from their experience in the research-informed clinical practice where, generally speaking, students described research-informed clinical practice as a very good method of education. CONCLUSION: Integrating problem-based learning into teaching has many positive implications. In particular, students pointed out that their learning experience and clinical practice have much improved after the research-informed clinical practice. CLINICAL RELEVANCE: Findings from this investigation demonstrate that embedding problem-based learning into prosthetics and orthotics students' curriculum has the potential to enhance students' learning experience, particularly students' evidence-based practice. This may lead to graduates who are more knowledgeable and thus who can offer the optimal patient care (i.e. clinical practice).

Feasibility study of a take-home array-based functional electrical stimulation system with automated setup for current functional electrical stimulation users with foot-drop.

OBJECTIVE: To investigate the feasibility of unsupervised community use of an array-based automated setup functional electrical stimulator for current foot-drop functional electrical stimulation (FES) users. DESIGN: Feasibility study. SETTING: Gait laboratory and community use. PARTICIPANTS: Participants (N=7) with diagnosis of unilateral foot-drop of central neurologic origin (>6mo) who were regular users of a foot-drop FES system (>3mo). INTERVENTION: Array-based automated setup FES system for foot-drop (ShefStim). MAIN OUTCOME MEASURES: Logged usage, logged automated setup times for the array-based automated setup FES system and diary recording of problems experienced, all collected in the community environment. Walking speed, ankle angles at initial contact, foot clearance during swing, and the Quebec User Evaluation of Satisfaction with Assistive Technology version 2.0 (QUEST version 2.0) questionnaire, all collected in the gait laboratory. RESULTS: All participants were able to use the array-based automated setup FES system. Total setup time took longer than participants' own FES systems, and automated setup time was longer than in a previous study of a similar system. Some problems were experienced, but overall, participants were as satisfied with this system as their own FES system. The increase in walking speed (N=7) relative to no stimulation was comparable between both systems, and appropriate ankle angles at initial contact (N=7) and foot clearance during swing (n=5) were greater with the array-based automated setup FES system. CONCLUSIONS: This study demonstrates that an array-based automated setup FES system for foot-drop can be successfully used unsupervised. Despite setup's taking longer and some problems, users are satisfied with the system and it would appear as effective, if not better, at addressing the foot-drop impairment. Further product development of this unique system, followed by a larger-scale and longer-term study, is required before firm conclusions about its efficacy can be reached.

Visuomotor behaviours when using a myoelectric prosthesis.

BACKGROUND: A recent study showed that the gaze patterns of amputee users of myoelectric prostheses differ markedly from those seen in anatomically intact subjects. Gaze behaviour is a promising outcome measures for prosthesis designers, as it appears to reflect the strategies adopted by amputees to compensate for the absence of proprioceptive feedback and uncertainty/delays in the control system, factors believed to be central to the difficulty in using prostheses. The primary aim of our study was to characterise visuomotor behaviours over learning to use a trans-radial myoelectric prosthesis. Secondly, as there are logistical advantages to using anatomically intact subjects in prosthesis evaluation studies, we investigated similarities in visuomotor behaviours between anatomically intact users of a trans-radial prosthesis simulator and experienced trans-radial myoelectric prosthesis users. METHODS: In part 1 of the study, we investigated visuomotor behaviours during performance of a functional task (reaching, grasping and manipulating a carton) in a group of seven anatomically intact subjects over learning to use a trans-radial myoelectric prosthesis simulator (Dataset 1). Secondly, we compared their patterns of visuomotor behaviour with those of four experienced trans-radial myoelectric prosthesis users (Dataset 2). We recorded task movement time, performance on the SHAP test of hand function and gaze behaviour. RESULTS: Dataset 1 showed that while reaching and grasping the object, anatomically intact subjects using the prosthesis simulator devoted around 90% of their visual attention to either the hand or the area of the object to be grasped. This pattern of behaviour did not change with training, and similar patterns were seen in Dataset 2. Anatomically intact subjects exhibited significant increases in task duration at their first attempts to use the prosthesis simulator. At the end of training, the values had decreased and were similar to those seen in Dataset 2. CONCLUSIONS: The study provides the first functional description of the gaze behaviours seen during use of a myoelectric prosthesis. Gaze behaviours were found to be relatively insensitive to practice. In addition, encouraging similarities were seen between the amputee group and the prosthesis simulator group.