09 March 2009

Robots give helping hand

Robot technology is giving debilitated stroke patients a helping hand - literally.


Robot technology is giving debilitated stroke patients a helping hand - literally.

Researchers at the University of California, Irvine, say a robotic hand is helping patients regain strength and movement so they can perform simple acts such as grasping and releasing objects.

"Robots may help patients reduce disability after stroke," said lead researcher Dr Steven C. Cramer, an associate professor of neurology, anatomy and neurobiology. "People who had weakness months to years after stroke were able to have better movement in their arm and hand as a result of the robot therapy."

Cramer was scheduled to describe the new device, called the Hand-Wrist Assisting Robotic Device (HOWARD), on Wednesday at the American Stroke Association's annual meeting, in San Francisco.

How the study was conducted
In the study, Cramer and colleagues worked with seven women and six men, averaging 63 years of age, who had suffered a stroke.

More than three months after their stroke, all the patients had moderate weakness and reduced function in their right hand, although the hand was not totally paralysed or unable to feel.

The researchers first tested the remaining strength in the right hand and how well patients could squeeze. "We also looked at things people would care about - things like picking up a cup and holding it without spilling it," Cramer explained.

During the sessions, the patient's hand was strapped to the robot. "As they moved their hand, these metal brackets, Velcro-ed to the back of the hand, measured how well they were moving," Cramer said. "If they couldn't finish the movement, the robot would finish the movement for them," he explained.

The movement coupled squeezing the hand and extending the wrist, Cramer said. "The patients practised both grasping and releasing everyday objects," he said.

Each patient received training using HOWARD in 15 two-hour therapy sessions spread over three weeks.

Improvements across the board
At the end of three weeks, all patients had improved their ability to grasp and release objects, the researchers said.

All the patients showed improvement in the ability to perform real-world tasks, such as grasping a block, gripping a drinking glass, pinching to pick up a small marble or ball bearing, and putting their hand on their head. They also showed significant improvement on tests of dexterity.

In addition, after three weeks, patients developed a significantly greater range of motion in their hands and wrists and were rated as less disabled on a standard occupational therapy test.

During another month of follow-up, many of the improvements in movement were sustained, but others deteriorated, Cramer said. It is possible that more work with the robot would further improve movement, he noted.

Cramer believes the robot can become a valuable part of rehabilitation after stroke.

"Robots offer certain advantages for therapy after stroke," Cramer said. "There is consistency, accuracy, durability and the potential for tele-rehab," he said. "You could treat 10 patients in their homes from a single location."

Could be of real help
One expert agreed that the technique could be of real help to patients.

"The implementation of robotics coupled with virtual reality training holds promise for motor recovery and, hopefully, functional recovery for chronic stroke patients," said Dr Ira G. Rashbaum, chief of stroke rehabilitation at New York University Medical Centre in New York City. "I'm pleased to see the researchers combined these modalities with the potential for synergy."

Stroke patients and their loved ones must understand, however, that there must be sufficient residual motor power in their arm and hand to initiate some movement for this therapy to work, said Rashbaum, who is also clinical associate professor of rehabilitation medicine at New York University School of Medicine.

"As is the case with constrained-movement therapy, one size does not fit all for stroke rehabilitation patients," he said.

"The other point to bear in mind is that motor recovery, while exciting to obtain, does not necessarily translate into functional recovery," Rashbaum said. "The question is, did these patients improve many of their upper extremity activities of daily living, such as grooming, hygiene, dressing, undressing and toileting?" – (HealthDayNews)

Read more:
Stroke Centre
Robotic system for paralysed

February 2007


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