Neural implant silk brings hope for epilepsy and spine injuries

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Neural implant silk brings hope for epilepsy and spine injuries

Posted by: Vera (Deficient mindful) | Category (s): Science, Technology | Posted: Friday, May 21, 2010 0
Scientists have created a new type of electrode for brain implants that practically melts in place, fitting perfectly with the irregular surface of the brain.

Made from a blend of a polymer needs, metal and silk, ultra implant is less than the traditional invasive needle electrodes, causing virtually no damage to the brain.

A piece of silk - or fibroin, the protein from which silk is made - are designed to dissolve after the electrodes are implanted in the brain, ensuring a perfect contact and more accurate readings of electrical impulses from the brain.

Brain Electrode
The technology can boost the field of brain-machine interfaces and allow the creation of practical devices for monitoring and controlling the epileptic seizures and even to transmit signals from the brain to specific body parts, skipping damaged parts by fractures in the spine.

"These implants have the potential to maximize the contact between the electrodes and brain tissue, minimizing damage to the brain. They can provide a platform for a wide variety of medical devices, with applications in epilepsy, in spinal cord injuries and other neurological disorders , "says Dr. Walter Koroshetz of the National Institute of Neurological Disorders, the United States.

The experiments showed that the implants thin and flexible, covered with silk, capture the brain activity more accurately than the thicker implants used today, even when used in conjunction with the same electronic circuit support.

Neural Electrodes
The first generation of neural electrodes, used for recording of brain signals - and yet the most widely used - consists of small metallic needles that penetrate deep into the brain tissue.

The second generation brought calls microelectrode arrays consisting of tens of electrode wire semi-flexible. Although less invasive, these arrays are essentially ultraminiaturizados chips, and its silicon-based hard not allow them to conform to the irregular surface of the brain.

Already the new electrodes to the neural basis of silk can literally "hug" the brain, adapted to the grooves and extending their rounded surfaces, sticking up like a tape.

The flexibility also allows them to adapt to normal movements, or even abnormal brain inside the skull.

Silk, metal and plastic
Besides its flexibility, the silk was chosen as the electrode base material because it is sturdy enough to withstand the insertion of thin metallic pathways responsible for capturing brain signals and send them to the processing equipment.

Silk also allows the implants are designed to prevent inflammatory reactions and to dissolve into predetermined time, which can range from almost immediately after implantation until years later.

The arrays of metal electrodes - with about 500 micrometers thick - can be printed in layers of polyimide (a type of plastic) and silk, and then positioned on the brain.

The electronics of the implant was obtained in collaboration with the team of Professor John Rogers of the University of Illinois, who developed electronic circuits superflexíveis used, for example, a digital camera that mimics the human retina.

Brain implants
Brain implants were tested on objects of complex geometry and malleable, and ultimately the brain of live animals under anesthesia.


The experiments led to development of a matrix that is based on a grid of polyamide and silk dissolves so it makes contact with the brain, allowing the array of electrodes "hold" strongly brains, picking up more precise that much thicker electrodes used today.

Now that the operation proved the technique, the researchers plan to thicken the electrodes on the base of silk and plastic in order to obtain readings of brain signals with a higher resolution - the prototypes used to date are formed by 30 electrodes in a pattern 5x6.

"It is also possible to compress the implants silk and send them to the brain through a catheter in formats defined and already exploited with high-performance electronic components," Dr. Rogers envisions.

Epilepsy and spinal injury
In patients with epilepsy, cerebral arrays of electrodes can be used to detect when a seizure is starting, and send back to the brain electrical pulses which cancel out attacks.

In people with spinal injuries, the technology has the potential to directly read the complex signals in the brain controlling movement and forward these signals directly to muscles healthy or prostheses, skipping the damaged portion.

Source: http://www.diariodasaude.com.br/