A real-time algorithm for the detection of compensatory movements during reaching.

Introduction: Interactive game systems can motivate stroke survivors to engage with their rehabilitation exercises. However, it is crucial that systems are in place to detect if exercises are performed correctly as stroke survivors often perform compensatory movements which can be detrimental to recovery. Very few game systems integrate motion tracking algorithms to monitor performance and detect such movements. This paper describes the development of algorithms which monitor for compensatory movements during upper limb reaching movements in real-time and provides quantitative metrics for health professionals to monitor performance and progress over time. Methods: A real-time algorithm was developed to analyse reaching motions in real-time through a low-cost depth camera. The algorithm segments cyclical reaching motions into component parts, including compensatory movement, and provides a graphical representation of task performance. Healthy participants (n = 10) performed reaching motions facing the camera. The real-time accuracy of the algorithm was assessed by comparing offline analysis to real-time collection of data. Results: The algorithm's ability to segment cyclical reaching motions and detect the component parts in real-time was assessed. Results show that movement types can be detected in real time with accuracy, showing a maximum error of 1.71%. Conclusions: Using the methods outlined, the real-time detection and quantification of compensatory movements is feasible for integration within home-based, repetitive task practice game systems for people with stroke.

Making music after stroke: using musical activities to enhance arm function.

A common long-term consequence of stroke is impaired arm function, which affects independence and quality of life in a considerable proportion of stroke survivors. There is a growing need for self-management strategies that enable stroke survivors to continue their recovery after rehabilitation has ceased. Interventions with high-intensity, repetitive task training and feedback are most likely to improve function. Achieving the required amount of self-practice is challenging, however. Innovative approaches are required to translate therapies into rewarding activities that can be undertaken independently. This paper describes the key principles and development of a novel intervention that integrates individuals' preferred music with game technology in upper limb rehabilitation. The "tap tempo" paradigm, which uses rhythmic auditory cueing, provides repetitive upper limb task training, which can be tailored to individual goals and progress (e.g., in terms of movement range and complexity), while providing sensitive quantitative feedback to promote skill acquisition and enhance self-management.

Acoustic analysis and mood classification of pain-relieving music.

Listening to preferred music (that which is chosen by the participant) has been shown to be effective in mitigating the effects of pain when compared to silence and a variety of distraction techniques. The wide range of genre, tempo, and structure in music chosen by participants in studies utilizing experimentally induced pain has led to the assertion that structure does not play a significant role, rather listening to preferred music renders the music "functionally equivalent" as regards its effect upon pain perception. This study addresses this assumption and performs detailed analysis of a selection of music chosen from three pain studies. Music analysis showed significant correlation between timbral and tonal aspects of music and measurements of pain tolerance and perceived pain intensity. Mood classification was performed using a hierarchical Gaussian Mixture Model, which indicated the majority of the chosen music expressed contentment. The results suggest that in addition to personal preference, associations with music and the listening context, emotion expressed by music, as defined by its acoustical content, is important to enhancing emotional engagement with music and therefore enhances the level of pain reduction and tolerance.