Design and development of a unique six degrees of freedom prototype virtual reality mirror therapy system tool for upper limb stroke rehabilitation (MINERVA)

Abstract

Brain damage via stroke causes significant disability affecting one’s quality of life. Improving impaired limb mobility and the specific motor skills affected involves strengthening muscles and brain retraining. A common theme in rehabilitation research is engaging the patient and having them adhere to the physiotherapist’s rehabilitation programme. As rehabilitees tend to underperform concerning the recommended exercise amount guidelines, it is imperative to pursue an engaging way to allow rehabilitees to meet the targets. Such achievement would satisfy the personal goals of those participants, relieve strain on post-stroke care facilities and allow anticipated economic savings for the Health Service. MINERVA is a prototype VRMT system which has developed two original features, the first feature is the 6DoF and the second is the asymmetric mirroring mode. Due to external circumstances further development and the original experiments that focused on user factors, perceived presence and patient performance could not be conducted. A technological test was conducted instead to see current state of MINERVA by measuring the FPS of the game developed. FPS is related to cybersickness which is also related to perceived presence and presence is required for the MT illusion to work for a VRMT system. When MINERVA used the VR hardware the mean FPS was 63 which is satisfactory. MINERVA is exploring concepts and was not at the stage of refactoring for optimisation, FPS value can be improved.

Methods
A novel Virtual Reality Mirror Therapy (VRMT) system MINERVA to explore the potential for upper limb stroke rehabilitation was developed within a multidisciplinary approach involving neuropsychology, physiotherapy, and technology, being developed from a user-centred approach. A prototype of the system constructed underwent iterative progression.

Results
Literature suggests both Mirror Therapy (MT) and Virtual Reality (VR) as separate interventions show promise in this area. Perception and attitude are key factors for success. The vividness of the illusion presented must be high in MT for success, and the VR demands for the sense of presence must remain unbroken. The implementation here is unique in comparison to other Virtual Reality Mirror Therapy (VRMT) solutions published in the literature. A unique mirror mode to develop exclusive to VR and impossible to implement in traditional MT.

Conclusion
This research hypothesises the potential of MINERVA and the feasibility of VRMT as an effective rehabilitative tool which encourages neuroplasticity and increases strength through tasks performed when using it. Combining into VR and MT into a single intervention to take advantage of their rehabilitative strengths has been done, though very few studies documented and the variance in implementation is high.

Date of Award	Dec 2023
Original language	English
Supervisor	Karl Mc Creadie (Supervisor) & Darryl Charles (Supervisor)