Immersive Virtual Reality for the Cognitive Rehabilitation of Stroke Survivors
In recent years, Virtual Reality (VR) technology has become increasingly common, with related hardware becoming more affordable. For example, current head-mounted displays (HMDs) on the market not only offer high-resolution displays but also feature precise head and handheld controller tracking. Initially, these technologies were mostly used in the entertainment industry, but more and more fields are starting to use this technology for serious games, especially in the rehabilitation of traumatic events, including stroke patients.
Background and Objective
A stroke occurs when the brain’s blood supply is cut off or there is bleeding in and around the brain, causing brain cell damage. Depending on the area of the brain affected, a stroke can lead to different symptoms, such as weakness on one side of the body (hemiparesis), visual disturbances, and aphasia. Notably, Post-Stroke Cognitive Impairment (PSCI) is also common, affecting problem-solving abilities, memory, and task sequencing abilities.
Although the brain has a certain degree of neuroplasticity, i.e., the ability to form and reorganize synaptic connections, which helps in long-term recovery, cognitive rehabilitation after a stroke remains a relatively neglected yet important area. This study, conducted by researchers from the University of Chester and Chester NHS Foundation Trust, funded by Innovate UK, aims to explore the potential of VR technology in cognitive rehabilitation for stroke patients.
Research Source and Methods
The paper, written by Kausik Chatterjee, Alastair Buchanan, Katy Cottrell, Sara Hughes, Thomas W. Day, and Nigel W. John, was published in 2022 in the journal IEEE Transactions on Neural Systems and Rehabilitation Engineering. It describes the development process of a VR application called VIRTUE and reports its effectiveness in a randomized controlled trial.
Research Process and Methods
The study includes several major steps:
Development of the VR System
The VIRTUE application was developed collaboratively by a medical device company, a university research team, and a stroke unit at a large hospital. It uses a modular architecture, partitioning tasks between the PC and VR headset. The team employed the Scrum framework from Agile software development, creating and improving the application in short, two-week iterations.
The design and implementation of the game scenarios fully incorporated feedback from clinical experts and patient representatives. For example, in a virtual kitchen scenario, patients wear an HMD and immerse themselves in a virtual environment interacting with objects to complete a series of household tasks like making toast. During these interactions, the system collects various data to allow clinicians to assess patient performance and gradually increase task difficulty. This personalized design not only improves actual rehabilitation effects but also ensures the application’s flexibility.
Hardware Selection and Improvement
The VIRTUE system currently uses the Oculus Rift S, which is relatively affordable at approximately £300 each. The Rift S offers a 2560 x 1440 pixel resolution and an 80Hz refresh rate and is equipped with two six-degrees-of-freedom (6DoF) touch controllers to support hand and position tracking, facilitating interactions between virtual hands and the virtual environment.
System Scenario Design
VIRTUE system has designed multiple scenes for selection, such as a bedroom (making the bed, choosing clothes), a bathroom (brushing teeth, running a bath), a kitchen (making toast, making coffee), a dining room, and a garden. These tasks can be completed while sitting and with one-hand operation, allowing patients to complete tasks without moving from the scene.
Key Experimental Results
From October 2019 to February 2021, the research team conducted a double-blind Phase IIb randomized controlled trial over 12 months (with a pause due to the pandemic) in a large hospital’s stroke ward, recruiting 40 patients for VIRTUE VR rehabilitation treatment.
The trial, with medical ethics review number 19/NW/0419, demonstrated good safety and acceptability of the VR treatment program. Although there were some initial discomforts with the equipment and technical issues with the software, these were effectively resolved through gradual improvements. Among the three patient groups, the severe cognitive impairment group (MOCA scores <15) showed significantly greater cognitive function improvement at the end of the treatment compared to other groups.
Research Conclusions and Significance
The study demonstrates that VR technology has significant potential in cognitive rehabilitation treatment in the acute phase following a stroke. The main advantages include: 1. Personalized Treatment: Task difficulty can be freely adjusted according to patient needs, reflecting personalized healthcare. 2. Safe and Effective: No serious adverse events were found; patients had a high acceptance of this new technology, with some showing significant cognitive function improvement after completing simple tasks. 3. Cost-Saving: Due to the effective treatment, hospital stay time is reduced, showing great potential in saving medical resources compared to traditional methods.
This study also provides a reference for subsequent Phase III large-scale multi-center trials and suggests setting the lower MOCA score limit of future study subjects at 19 to maximize the benefits of the VR treatment program.
Future Prospects
The VIRTUE system plans to expand to more daily life scenarios and develop standalone headsets independent of PCs so that patients can continue VR treatment at home. AI technology will be further integrated to achieve personalized automated management and treatment, reducing reliance on traditional treatment resources.
Overall, this study demonstrates the pioneering application of VR technology in the field of stroke cognitive rehabilitation, promoting the development of this emerging field and bringing numerous potential benefits to patients, doctors, and the entire healthcare system.