Despite advances in technology and technique, there will always be one limiting factor in the operating room: the surgeon. Hours of exacting work can tire anybody, especially someone navigating the delicate intricacies of the human brain. The solution is as old as science fiction, but the technology has only recently caught up to the concept. The Robot-Assisted Microsurgery (RAMS) prototype is a robotic surgical tool first developed for space use and later refined as a precision instrument for microsurgery. Peter D. LeRoux, MD, a neurosurgeon at the University of Pennsylvania Medical Center, reports on the feasibility of RAMS in brain surgery in the March issue of Neurosurgery. "The RAMS system works like an extension of the surgeon's hands," said LeRoux. In essence, the system consists of a set of robotic arms: a master arm, which functions like a joystick; and an operating arm, which actually performs the surgery. The surgeon manipulates the master arm just as they would hold a surgical instrument, and the operating arms mimic the surgeon's movements on the patient. "Robotic surgery is not about replacing surgeons, but enhancing their abilities in the operating room," explained LeRoux. The concept is simple, RAMS serves as an intermediary between the surgeon's hands and the surgical instruments. In effect, it allows the surgeon to filter out the slight tremors that are present in even the most skilled surgical hands. The advantage of a robotic surgical system is that it could remove some of the random factors that affect surgery. "A surgeon's performance can vary throughout a lifetime - or even during a procedure," explained LeRoux. "Automation can compensate for these variables and lead to better results for patients." According to LeRoux, RAMS also represents a change in the way surgical tools are created. Typically, surgeons are the ones who recognize the need of a particular tool, and then call upon the expertise of engineers to develop it. Here, however, the engineers developed the surgical tool to solve a particular problem. At the behest of NASA, the Jet Propulsion Laboratory first developed the RAMS prototype as a means of conducting emergency surgery via remote control. They envisioned, for example, surgeons on earth performing robotic surgery on an astronaut in space. The limitations of remote controlled surgery are obvious, since the further the surgeon is from the patient, the longer the signal takes to get between the two. "It gets to a point when a 'real-time' operation just couldn't work in real time," said LeRoux. Long distance surgery is not the only application of the technology. With the help of MicroDexterity Systems, Inc., JPL further developed the system to assist microsurgery. LeRoux and his colleagues were granted use of RAMS to see how well the system would apply to the demands of precise surgical operations. The researchers first experimented with the technology in trials with nonanimal models, getting a feel for the controls while they practiced their techniques. Impressed with their results, they began trials in 10 rats, repairing blood vessels that supply the brain, a common microsurgical procedure. Although the procedures using RAMS took longer than average - which LeRoux attributes in part to the learning curve - the researchers were able to demonstrate that the concept was sound. Still, RAMS is not perfect, and the system would need further development for it to be useful in human surgery. LeRoux notes the lack of tactile feedback - the sense that your hands are pushing against real objects - and the limited degrees of freedom the prototype robot hand has in comparison with that of a human hand. However, the researchers remain optimistic that engineers can overcome many of the technical hurdles with the help of feedback from surgeons. "In many ways, this technology is just a crude prologue to some of the amazing things that are ahead," said LeRoux. "There is clearly a lot of work to be done, but the potential is enormous."