Stroke patients and therapists in Otago and Germany have given the thumbs up to a fascinating new augmented reality technology developed in Dunedin.
“The main idea is that we fool the brain about what we see,” says Professor Holger Regenbrecht. He’s the Co-leader of the Human Computer Interaction Lab at the University of Otago.
When utilising this technology during rehabilitation, stroke patients use their functioning hand to carry out recommended exercises, such as gripping or holding up a certain number of fingers.
Augmented reality (AR) technology provides a reflection of this functioning hand working, mirroring its movement and presenting this to the patient, so that it looks as if their impaired hand is carrying out the movements.
PhD student Chris Heinrich, who is developing this technology, says that during a stroke, the part of the brain that controls movement to a functioning limb is destroyed.
So, when the brain sees the impaired hand moving, the brain reorganises itself and accounts for this movement.
It’s about the patient seeing this illusion and these brain areas being successfully stimulated,” Chris explains.
The prototype technology has been used at Dunedin’s Wakari Hospital and the MEDIAN Klinik Berlin-Kladow in Berlin, Germany – with positive effects.
A research associate and occupational therapist at the German clinic, Nadine Morkisch, says the technology has been used with stroke patients who are paralysed on one side of the body.
Both therapists and patients gave positive feedback; and all the patients would repeat the therapy in future and recommend it to others, she says.
“Furthermore, the patients strongly proposed that this system should be used in rehabilitation.”
Mirror therapy limitations
Professor Regenbrecht explains that for years, therapists have utilised mirror therapy with stroke patients, using actual mirrors. However, these may constrain the body’s position and patients don’t always fully believe their impaired limb is moving.
Seven or eight years ago, the university’s Information Science Department started to collaborate with the Department of Psychology and a local psychotherapist to research the use of AR in stroke rehabilitation.
The Oxford Dictionary defines AR as “a technology that superimposes a computer-generated image on a user’s view of the real world.”
Professor Regenbrecht says a number of students built a couple of systems, resulting in the Augmented Reflection technology clinical version.
Using this, a patient puts each hand into a separate black box and sees the resulting mirrored illusion on a nearby computer screen.
For the past three years, Chris has been developing a more advanced version using virtual reality (VR), so patients are immersed in a three-dimensional environment. They wear a head-mounted display and move their functioning hand, yet in front of their eyes within the goggles, they see their impaired limb performing exercises.
“You’re completely immersed in the augmented reality,” Chris says.
This more advanced, immersive version was finished last month and it is hoped to trial it with stroke patients at Wakari and in Berlin.
While the systems already being used at these hospitals are too complex to be widely replicated, Chris and Professor Regenbrecht hope this latest, more advanced version will be different.
Its headset with tracking camera can be bought off the shelf for about $1,000 and can be used with most new home desktop computers.
Patients could use this more advanced version at home or community centres.
The goal of this project is to bring it to the patient’s home,” Chris says.
“It’s not to replace the therapist but allow the patient to practice their therapist-guided rehabilitation at home.”
Brain Research New Zealand is funding this immersive project, which focuses on the upper body.
Below is a video showing the stroke rehabilitation virtual reality mirror therapy. On the top left is the patient’s functioning hand and, on the right, the illusion the patient sees of his or her impaired hand working. Video: University of Otago.
If you liked this story, join up to our Daily Encourager Media Facebook page by clicking here