Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Artificial muscles restore ability to blink, save eyesight

Surgeons from UC Davis Medical Center have demonstrated that artificial muscles can restore the ability of patients with facial paralysis to blink, a development that could benefit the thousands of people each year who no longer are able to close their eyelids due to combat-related injuries, stroke, nerve injury or facial surgery.

In addition, the technique, which uses a combination of electrode leads and silicon polymers, could be used to develop synthetic muscles to control other parts of the body. The new procedure is described in an article in the January-February issue of the Archives of Facial Plastic Surgery.

"This is the first-wave use of artificial muscle in any biological system," said Travis Tollefson, a facial plastic surgeon in the UC Davis Department of Otolaryngology – Head and Neck Surgery. "But there are many ideas and concepts where this technology may play a role."

In their study, Tollefson and his colleagues were seeking to develop the protocol and device design for human implantation of electroactive polymer artificial muscle (EPAM) to reproducibly create a long-lasting eyelid blink that will protect the eye and improve facial appearance. EPAM is an emerging technology that has the potential for use in rehabilitating facial movement in patients with paralysis. Electroactive polymers act like human muscles by expanding and contracting, based on variable voltage input levels.

For people with other types of paralysis, the use of artificial muscles could someday mean regaining the ability to smile or control the bladder. Reanimating faces is a natural first step in developing synthetic muscles to control other parts of the body, said UC Davis otolaryngologist Craig Senders.

"Facial muscles require relatively low forces, much less than required to move the fingers or flex an arm," said Senders.

Blinking is an essential part of maintaining a healthy eye. The lid wipes the surface of the eye clean and spreads tears across the cornea. Without this lubrication, the eye is soon at risk of developing corneal ulcers that eventually can cause blindness.

Involuntary eye blinking is controlled by a cranial nerve. In most patients with permanent eyelid paralysis, this nerve has been injured due to an accident, stroke, or surgery to remove a facial tumor. Many have no other functioning nerves nearby that can be rerouted to close the eyelid. Others were born with Mobius syndrome, characterized by underdeveloped facial nerves. These patients are expressionless and can neither blink nor smile.

Eyelid paralysis currently is treated by one of two approaches. One is to transfer a muscle from the leg into face. However, this option requires six to10 hours of surgery, creates a second wound, and is not always suitable for elderly or medically fragile patients.

The other treatment involves suturing a small gold weight inside the eyelid. The weight closes the eye with the help of gravity. Though successful in more than 90 percent of patients, the resulting eye blink is slower than normal and cannot be synchronized with the opposite eye. Some patients also have difficulty keeping the weighted lid closed when lying down to sleep. In the United States, an estimated 3,000 to 5,000 patients undergo this surgery every year and therefore might benefit from an alternative treatment.

For their study, Senders and Tollefson used a novel alternative method for eyelid rehabilitation in permanent facial paralysis. They used an eyelid sling mechanism to create an eyelid blink when actuated by an artificial muscle. Using cadavers, the surgeons inserted a sling made of muscle fascia or implantable fabric around the eye. Small titanium screws secured the eyelid sling to the small bones of the eye. The sling was attached to a battery-operated artificial muscle. The artificial muscle device and battery were into a natural hollow or fossa at the temple to disguise its presence.

Senders and Tollefson found that the force and stroke required to close the eyelid with the sling were well within the attainable range of the artificial muscle. This capability may allow the creation of a realistic and functional eyelid blink that is symmetric and synchronous with the normal, functioning blink. A similar system also could give children born with facial paralysis a smile.

The three-layered artificial muscle was developed by engineers at SRI International of Palo Alto, Calif., in the 1990s. Inside is a piece of soft acrylic or silicon layered with carbon grease. When a current is applied, electrostatic attractions causes the outer layers to pull together and squash the soft center. This motion expands the artificial muscle. The muscle contracts when the charge is removed and flattens the shape of the sling, blinking the eye. When the charge is reactivated, the muscle relaxes and the soft center reverts back to its original shape.

"The amount of force and movement the artificial muscle generates is very similar to natural muscle," Tollefson said. An implanted battery source similar to those used in cochlear implants would power the artificial muscle.

For patients who have one functioning eyelid, a sensor wire threaded over the normal eyelid could detect the natural blink impulse and fire the artificial muscle at the same time. Among patients lacking control of either eyelid, an electronic pacemaker similar to those used to regulate heartbeats could blink the eye at a steady rate, and be deactivated by a magnetic switch.

The researchers are now refining the technique on cadavers and animal modes. They estimate the technology will be available for patients within the next five years.

The study was funded by a grant from the American Academy of Facial Plastic and Reconstructive Surgery.

UC Davis School of Medicine is among the nation's leading medical schools, recognized for its specialty-and primary-care programs.The school offers combined medical and master's degree programs in public health, business administration, and rural health, as well as a combined medical and doctoral degree for physician scientists interested in addressing specific scientific, social, ethical and political challenges of health care. Along with being a leader in health-care research, the school is known for its commitment to people from underserved communities and a passion for clinical care. For more information, visit UC Davis School of Medicine.

David Ong | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

nachricht New potential cancer treatment using microwaves to target deep tumors
12.10.2016 | University of Texas at Arlington

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>