PARREHA headset allows Parkinsonians to move around their home without any external assistance

Oxford 21 October 2003More than 700.000 people in the European Union alone suffer from Parkinson's disease, a number forecast to increase as the population ages. But IST project PARREHA is utilising the development of wearable virtual reality technology to allow some people stricken with this disease to walk where before they were paralysed, as has been reported by the European IST Results news service.


Two in 1000 people are afflicted with Parkinson's disease, which is a disorder of the central nervous system. Parkinson's results from the loss of dopamine-producing brain cells. Dopamine is a chemical messenger responsible for transmitting signals within the brain. Loss of dopamine causes loss of function in brain cells, leaving patients unable to direct or control their movement in a normal manner. As a result, many people with Parkinson's have difficulty initiating and sustaining walking in conditions that would normally present no problems, such as an unobstructed corridor.

Paradoxically, scientists have discovered that when visual "obstructions" are placed in their way, some people with Parkinson's can walk normally. This little understood effect is called kinesia paradoxa. These "obstructions" can be as simple as pieces of paper set down on the floor and so are usually referred to as visual "cues".

Virtual reality technology has now evolved to the point where a user, wearing a light headset, could see virtual visual cues wherever they looked. The user could continue to see the world if the display is either very small or is part of a semi-transparent visor. One of the three results developed by PARREHA, a three-year IST programme funded e-Health project that ended in 2002, was to design such a wearable headset device that enables a small proportion of people with Parkinson's to move freely and more safely in their normal environment, a major achievement given that falling is the second greatest cause of death in people with Parkinson's disease. Such a mobile walking aid is of special interest to people with vascular Parkinson's, for which no drug therapy exists.

In a series of trials and exhibitions during the three-year project, consortium manager Oxford Computer Consultants, who developed the prototype, demonstrated subjects walking with and without the mobile walking aid, known as the "Portable PARREHA". After trying to walk unaided in an unobstructed corridor, the user put on a semi-transparent virtual reality headset. Through the headset he could see both the corridor and a series of brightly coloured stripes that scroll slowly towards the viewer as if they are walking down a tunnel. Working with the Parkinson's group, Europark, Parreha showed this device was highly effective for a certain group of people with Parkinson's.

"You just put one on your head and walk down the street", stated project leader Reynold Greenlaw. Dr. Greenlaw went on to explain the evolution of the equipment, noting that at first the virtual reality technology was very complex. "Now we've got it down to just a few visual patterns that trigger walking in about 5 percent of those with Parkinson's", he stated, adding that, for those that it treats "it has an enormous effect on their quality of life and does not rely on any drugs or surgery".

The consortium has already received attention for its results. Following demonstrations at the IST 2002 event in Copenhagen in November 2002, PARREHA was evaluated as one of the most impressing projects in the IST 2002 event, classified as a "You just gotta see this" project. PARREHA was also short-listed for an e-Health prize ahead of the e-Health ministerial conference in Brussels in May of this year.

The commercial partners in PARREHA have formed a company based in Italy called ParkAid. Recently, ParkAid met manufacturers of wearable computer displays at Europe's largest Parkinson's clinic, at Bad Nauheim in Germany with the aim of developing a PDA-based headset for commercial release that will assist walking. Among these were Xybernaut, a United States-based specialist in wearable and mobile computing, which looks poised to become one of the main manufacturers of the headsets.

Dr. Greenlaw noted that the equipment should be certified in 2004, and although exact pricing has yet to be set, he estimated that the equipment, including the headset, PDA and special software, will cost between 2000 to 2500 euros. Such a product on the market will be good news for the 35.000 estimated Europeans and thousands of others worldwide facing this debilitating disease at the end of their lives.

Commercial exploitation of the other two results of the project - a virtual reality exercise and training environment and a videoconferencing system designed to link people with Parkinson's to their doctors - are on hold as ParkAid focuses on the headset. However, the virtual room is set up at the Bad Nauheim clinic and is attracting interest from researchers at the clinic and elsewhere such as the Centre for Movement Analysis and Therapy in Brussels.

More news on the PARREHA project is available in the VMW May 2003 article Two European projects tackling Parkinson's disease present promising results. For direct information, you can contact Dr. Greenlaw.

Leslie Versweyveld

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