« Washington Engineer - May 2005
Faculty and students create surgeon's assistants of the future
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On the battlefield of the future, medical personnel won’t be on the front lines dodging bullets and shrapnel as they try to reach fallen soldiers to render aid.
Instead, tough, high-tech robotic pods will be in the thick of battle with human soldiers, acting as the eyes, ears and hands of surgeons situated hundreds or even thousands of miles away. From that distance, the doctors can practice their life-saving arts through the precise, remotely controlled machines. The practice will not only safeguard skilled surgeons and put fewer medics on the dangerous front lines, but could save soldiers’ lives by getting them the expert care they need sooner after being hit.
That’s the vision of researchers at the University of Washington, facilitated by a multidisciplinary collaboration between the departments of electrical engineering and surgery.
Professor Blake Hannaford and research Assistant Professor Jacob Rosen, both in electrical engineering, with Professor Mika Sinanan, in surgery, are leading a group of students in the UW’s Biorobotics Lab in an cooperative liaison with partner universities and companies to create a “trauma pod” for the military. The Pentagon recently gave the consortium $12 million over two years to help make that vision a reality.
In practice, the pod would essentially be a portable, unmanned surgical bay, just large enough for the patient to fit inside and operated by a single remote surgeon. Here’s the envisioned scenario:
A soldier is hit, and his comrades call for medical aid. Helper robots move the patient into a trauma pod, which is built into an armored vehicle. Once moved inside the pod, the soldier first gets a full-body scan. That’s compared to a previous scan, stored in the soldier’s dog tags, to pinpoint the injury. Then the cyber-surgery unit, guided by a telesurgeon miles away, whirs into action. Sensors in the soldier’s armor monitor vital signs throughout the procedure. After being treated and stabilized, the patient is evacuated via air to a medical facility.
The current plan for the pod is to replace the traditional human surgery team with four robotic surgical arms, and a mechanized tool changer and equipment dispenser to service them.
That’s the UW’s role in the first phase of the project: building the tool changer, a device that changes various implements scalpels, sutures, syringes, retractors, sponges – on the surgical arms at the appropriate time.
“Essentially, this is replacing the sterile nurse who hands tools to the surgeon,” Rosen said. “There will be a magazine full of tools, and the tool changer will keep track of which tools occupy which point in space. The tool changer’s arm will pick a tool and bring it to the appropriate surgical arm.”
The test for that stage will be in two years, at the end of the first phase. But Rosen and his team are already busily working on technology that could apply to the second phase, where the goal is to make the machinery as small and robust as possible.
For the past three years, students and lab staff members from bio, mechanical and electrical engineering and surgery have labored on an operating room of the future, designing and fabricating new surgical robotic arms so precise and efficient that a surgeon could operate on a patient via remote control.
The system is significantly smaller than a commercially available unit, now in use at the UW Medical Center. Researchers are working on incorporating force feedback into the system, which would allow surgeons to “feel” resistance as the robot touches and probes tissue. The design of the surgical arms mimics the workings of a human arm, where shoulder and elbow joins are used for gross positioning while the hands perform finer manipulations.
“It’s an ambitious project,” said Rosen, standing next to a new prototype of the surgical table in the lab, located on the fourth floor of the New Electrical Engineering Building. Behind him, two surgical arms reach upward, one fitted on each side of the table along a sliding track. “The scientific foundations for this surgical robot design derive from work we’ve been doing for more than 10 years in the UW Medical Center, recording the kinematics and dynamics of surgeons’ tools while they perform surgery – what precise movements they make and the magnitudes of force they apply to tissues during surgical procedures.”
A trial of the new surgical robot is tentatively scheduled for sometime this summer. Part of the crew will pack the robot up a mountainside in Hawaii and set it up in the wilds, using a pig carcass as a practice patient.
Then a surgeon in Seattle will attempt to control the robot remotely to perform surgical procedures on the pig. If successful, that will be a big step forward, the researchers say. But significant problems still need to be solved before soldiers will see a fully functional trauma pod.
“The challenge here is to automate tasks that for us as
humans seem very easy,” Rosen said. “Replacing a tool on the robotic arm, for example, is simple. It turns out that you can break that task down to about 100 mini tasks, which must be executed by an automatic tool changer.”
Another task will involve getting the arms to work cooperatively in a tight space.
“We as humans are very good at avoiding collisions” Rosen said. “The robotic arms have to have help with that. Each has to ‘know” where the others are so they can perform their tasks without hitting each other.”
That’s a software problem, according to Mitchell Lum, an electrical engineering grad student and lab research assistant. And one that he and other student researchers are having fun grappling with.
“This is novel research – it’s not stuff that’s been done before,” Lum said. “Being in on designing and building something like this is a real privilege. It’s not the kind of thing you can do in the classroom.”
The overall trauma pod project is led by SRI International, a research and development company. Other partners include General Dynamics Robotic Systems, the Oak Ridge National Laboratory, University of Texas, University of Maryland and Robotic Surgical Tech Inc.
Discovery of cooperative RNA switches hint at evolutionary past
Two University of Washington computer scientists are part of a team that has discovered a pair of rare, naturally occurring RNA “switches” in a class of bacteria that work cooperatively to manage the amino acid glycine.
The finding, reported in a recent issue of the journal Science, could support the notion of an “RNA world,” or an evolutionary period when RNA played a much greater role in metabolic processes.
RNA stands for ribonucleic acid, a chemical that is found in cells. Its main role lies in transmitting genetic instructions from DNA to the rest of the cell and controlling certain chemical reactions.
The newest riboswitch, as it’s called, is unique because of its cooperative nature, representing a complex mechanism previously found only in protein enzymes.
“The current world has a combination of proteins and nucleic acids, including RNA, playing a role in life, and there is an immense chicken-and-egg problem because you can’t have one without the other,” said Walter Ruzzo, a professor in the UW’s Department of Computer Science & Engineering with an adjunct appointment in the Department of Genome Sciences. “One theory, and it’s still controversial, is that RNA played both roles at one point.”
Ruzzo and Zasha Weinberg, a CSE graduate student, have been working with a group of biochemists from Yale University since February, looking for RNA switches in nature. The Yale researchers had already identified the switch in question, but hadnt yet realized what they had.
That’s where computer science came in. The use of computing technology to examine and compare the RNA structures is critical to the work, Ruzzo said.
“The key to understanding these things is to find more examples of them, and Zasha has developed some terrific computational tools that speed up the search for these structures,” he said. “Because Zasha had a much more sensitive searching tool, he found that these switches usually appear in tandem. They have the same structure, but they are significantly different at the nucleotide level. The biochemists simply didn't see that they came in pairs.”
The net effect of having the pair working together is that it provides a much more efficient switch in detecting glycine.
Glycine is a building block for protein, but it can also be used for energy. The double switch is able to strike the right balance between having enough glycine for protein synthesis and being able to readily use any extra for energy production.
“The cooperation means that the switch turns more sharply from off to on when an excess of glycine is created,” Ruzzo said.
The senior author of the paper is Ronald Breaker, professor in the Department of Molecular, Cellular and Developmental Biology at Yale. Other authors, also from Yale, include Maumita Mandal, Mark Lee, Jeffrey Barrick and Gail Mitchell Emilsson.