Military science's gift to medicine: ARL, MIT development of the "perfect mirror" revolutionizes approaches to neurosurgery
August 23, 2012
- 1997 ARL basic science research evolved into a surgical tool that today is saving and improving lives.
- Research in low-loss reflective materials led to the development of "the perfect mirror" which was based on the omni-directional aspects of metallic mirrors, or mirrors commonly found in household bathrooms, with dielectric mirrors which are commonly used in devices such as lasers.
- ARL's Institute for Soldier Nanotechnologies at MIT in Boston is home to the development of the CO2 laser fiber.
Last November, Alex Foley was about six months outside of graduating from the U.S. Naval Academy when an officer's medical review revealed a tumor growing on the nerve that connected his ear to his brain.
It's a fairly rare condition; national studies report only 20 or so of every million are diagnosed a year with it. Most people don't realize they have it until their equilibrium turns a smooth gait into a staccato step or a medical exam uncovers the benign condition. But if left untreated, the pressure from a growing tumor on the brain can be fatal.
Foley turned to the Walter Reed National Military Medical Center in Bethesda for his operation where surgeons use a medical tool – a laser fiber – that started in 1997 at the U.S. Army Research Laboratory's (ARL) Institute for Soldier Nanotechnologies at Massachusetts Institute of Technology as a basic science research project intended to advance next-generation military uniforms and telecommunication devices.
Instead, the researchers' work in low-loss reflective materials led to the development of "the perfect mirror" which was based on the omni-directional aspects of metallic mirrors, or mirrors commonly found in household bathrooms, with dielectric mirrors which are commonly used in devices such as lasers. This technology resulted in lasers with reflective properties from every angle, and it's a critical building block for a revolutionary approach to neurosurgery.
Today, surgeons in military and civilian hospitals around the world turn to the CO2 laser fiber to perform the most delicate surgeries.
"The advantage of the CO2 laser is it adds safety to a lot of the surgeries that I do to remove benign and malignant tumors of the middle ear and the skull base as well as other pathologies," said Dr. Arnaldo L. Rivera, a Navy commander who heads the Ear, Nose and Throat Clinic at Walter Reed. Rivera, who started using the laser fiber in surgeries in 2007, performed Foley's surgery.
"The way the CO2 laser interacts with tissue allows me to be very precise in dissecting tumors from structures that we want to preserve."
Laser surgery involves cutting or treating tissue with an intense, concentrated beam of light. Laser beams vaporize target tissue by evaporating the water inside its cells.
"There's always been a fundamental tradeoff in surgery, in particular, in the treatment of tumors between doing things invasively or minimally invasively and precision," said Dr. Yoel Fink, one of the initial Army researchers who later founded OmniGuide, Inc., which marketed the first hand-held CO2 laser scalpel system that has been used at hundreds of hospitals in over 25,000 surgeries including the removal of cancerous tumors in sensitive tissues in the airway, ear, brain and spine, and other areas where precision is critical.
"If you really want to be precise, you work with a steel scalpel and in that case, you need to open up the body in order to remove a tumor. So at that limit, you're very precise but you're also highly invasive."
He said doctors often turn to radiation to excise tumors because radiation is less invasive, "but what happens then is your radiation damages a much larger region in your body than the tumor itself."
The fiber's size and functionality help make it an ideal surgical solution, but getting both right wasn't easy, Fink said.
"One of the big challenges we had when we got started was that the technology for making very thin layers on the inner part of the fiber didn't exist. So many people, when they heard about our original concept dismissed it because they said, 'hey, you can never manufacture such a fiber."
So they came up with a new way of making such a fiber.
"We start off with what we call a pre-form. It's a macroscopic, scaled up model of the fiber."
The pre-form has a hollow core, multiple layers of the reflective materials, and even a cladding on the outside to protect the fiber. The pre-form is then heated and drawn down – pulled almost like taffy candy – into a fiber, keeping intact the 'technology' that makes the fiber work.
"Upon receiving notice that I had this tumor, I had done extensive research on the tumor. I had joined the Acoustic Neuroma Association, which is a global organization that survivors and personnel that have that condition developed a forum and advise each other and give guidance on how to intertwine that part into their life, and overcome it," recalled Foley.
"So I was reaching out to the Mayo Clinic in Los Angeles which is world renowned as well. And I had done some research in contacting them, but I contacted Bethesda because they're very close and all of the surgeons that I had heard about were phenomenal people here, and upon meeting Commander Rivera, I could tell from his persona that the medical staff here - although they may operate with their intellect and their hands - I think they really operate from their hearts.
"I decided to stay within the scope of the military for the medical operation because I want to serve my country and I think that I have faith and put trust in the country to serve me when I need it too."
Dr. Robert Kokoska, program manager at the U.S. Army Research Office in Research Triangle Park, N.C., said "the whole idea behind standing up a center like [the Institute for Soldier Nanotechnologies] was to exploit the growing field of nanotechnology on a very fundamental level." He said the Army was looking to create "a focused, concentrated set of researchers at one institution who can provide know-how in the area of nanotechnology looking at materials that are studied, synthesized, theorized at the nano scale to provide capabilities that you may otherwise not be able to provide through the Army."
"Who knew that this theory and really ground-level materials development that was in many ways focused toward transmitting information could be used to transmit some forms of laser that could be used to melt tumors," Kokoska said. "It's a great deal of satisfaction knowing that the basic research the Army has funded here has been put to an important medical use that is saving lives."