THURSDAY, July 3 (HealthDay News) -- A tongue drive system that enables severely disabled people to operate powered wheelchairs and to perform other tasks has been developed by engineers at the Georgia Institute of Technology.

"This device could revolutionize the field of assistive technologies by helping individuals with severe disabilities, such as those with high-level spinal cord injuries, return to rich, active, independent and productive lives," Maysam Ghovanloo, an assistant professor in the School of Electrical and Computer Engineering, said in a prepared statement.

Users of the Tongue Drive system have a small magnet (the size of a grain of rice) attached to their tongue by implantation, piercing or tissue adhesive. The movement of the magnetic tracer attached to the tongue is detected by magnetic field sensors mounted on a headset outside the mouth or on an orthodontic brace inside the mouth. This movement data is transmitted to a portable computer carried on the user's clothing or wheelchair.

"We chose the tongue to operate the system, because unlike hands and feet, which are controlled by the brain through the spinal cord, the tongue is directly connected to the brain by a cranial nerve that generally escapes damage in severe spinal cord injuries or neuromuscular diseases," Ghovanloo said. "Tongue movements are also fast, accurate and do not require much thinking, concentration or effort."

The system can be programmed to recognize a user's specific tongue movements based on their abilities, oral anatomy, personal preferences and lifestyles.

"An individual could potentially train our system to recognize touching each tooth as a different command. The ability to train our system with as many commands as an individual can comfortably remember is a significant advantage over the common sip-n-puff device that acts as a simple switch controlled by sucking or blowing through a straw," Ghovanloo said.

The Tongue Drive system was described June 29 at the annual conference of the Rehabilitation Engineering and Assistive Technology Society of North America, in Washington, D.C. An article about the system was expected to be published in an upcoming issue of the Journal of Rehabilitation Research and Development.

More information

The Alliance for Technology Access has more about assistive devices.

MONDAY, June 30 (HealthDay News) -- Researchers have identified 21 new genetic regions implicated in Crohn's disease, bringing to 32 the total number of genes and loci -- regions of the genome typically including one or more genes that are known to increase susceptibility to the disease.

For this study, published in the journal Nature Genetics, the international team of scientists and clinicians analyzed DNA samples from almost 12,000 people in Europe and North America.

"We now know of more than 30 genetic regions that affect susceptibility to Crohn's disease. These explain only about a fifth of the genetic risk, which implies that there may be hundreds of genes implicated in the disease, each increasing susceptibility by a small amount," lead author Dr. Jeffery Barrett, of the Wellcome Trust Centre for Human Genetics at the University of Oxford, said in a prepared statement.

"Whilst this study shows the power of genome-wide association studies to reveal the genetics behind common diseases, it also highlights the complexity of diseases such as Crohn's," Barrett noted.

Crohn's disease causes inflammation of the gastrointestinal tract, resulting in pain, ulcers and diarrhea. Onset of the disease typically occurs between the ages of 15 and 40, but it can strike at any age. As many as 80 percent of people with Crohn's disease will require surgery.

Along with identifying potential new targets for the development of drugs to treat Crohn's, this study found that loci with genes associated with Crohn's are also implicated in a number of other diseases such as asthma, diabetes, rheumatoid arthritis and psoriasis.

"It's too early for us to say how Crohn's disease and many of these other diseases, including asthma, are linked at a biological level," study co-author Dr. Miles Parkes, consultant gastroenterologist at Addenbrooke's Hospital and the University of Cambridge, said in a prepared statement. "However, we are building up a picture of the biology underlying Crohn's disease, and the more we understand about the underlying biology of these diseases, the better equipped we will be to treat them."

"Genetics, and particularly the large scale approach of genome-wide association studies, offers much hope for understanding the biological causes of complex diseases," Dr. Mark Walport, director of the Wellcome Trust, said in a prepared statement. "Studies such as this also highlight the important relationships between different diseases, and, as such, may offer valuable insights into the pathways that lead to common symptoms such as inflammation."

The Wellcome Trust is a charity that funds biomedical research.

More information

The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about Crohn's disease.

MONDAY, June 30 (HealthDay News) -- The risk of rheumatoid arthritis is twice as high in women who had a heavy birth weight (more than 10 pounds) than those with an average birth weight (7 to 8.5 lbs), a new study finds.

Researchers at the Hospital for Special Surgery, New York City, analyzed data from more than 87,000 women who took part in the U.S. Nurses' Health Study between 1976 and 2002. The women were aged 30 to 55 at the start of the study.

During the study period, 619 women were diagnosed with rheumatoid arthritis. Those with heavy birth weights were more likely to develop rheumatoid arthritis than those with average birth weights. This association held true even after the researchers took into account factors likely to influence birth weight, such as parental smoking, socioeconomic status, maternal diabetes, age at first period, use of oral contraceptives or HRT, breast-feeding and weight.

There is no obvious biological explanation for the finding, said the researchers. But they noted adults with rheumatoid arthritis have abnormal hormone regulation and this process may be triggered while in the womb.

The study, published in the current issue of the Annals of Rheumatic Diseases, supports the fetal origin of disease theory, which states that certain conditions and diseases in adulthood are programmed by factors during pregnancy.

More information

The American Academy of Family Physicians has more about rheumatoid arthritis.