A gentle touch is one of the most important attributes of a skilled surgeon and one of the most difficult skills to transfer. Researchers at the University of Illinois Metropolitan Group Hospitals (MGH) in Chicago have designed a training device to help residents learn the gentle art of manipulating tissue with minimal force.
   "We all recognize that it is important to handle tissue gently," said MGH surgical resident Joseph Talarico, MD. "The gentle touch can be learned, but we need feedback to learn it. With today's training, there is a complete lack of touch feedback in training outside the operating room. Inside the OR, robots and other technologies allow significant use of force with little or no feedback."
   Dr. Talarico and a group of researchers under the direction of Illinois Masonic Medical Center surgery chief Vijay Maker, MD, set out to create a feedback device that can teach gentle touch.
   The group attached a small piezoresistive touch sensor to a standard set of laparoscopic forceps. The forceps are used to move a small object, simulating a typical laparoscopic manipulation. The sensor directly translates the amount of force used into voltage, which is measured and graphed on a screen the size of a typical PDA. Changes in the graph trace provide real-time visual feedback on the amount of force being applied.
   "The visual display is highly useful," Dr. Talarico told the American College of Surgeons Clinical Congress meeting in San Francisco. "It allows the resident to directly correlate the physical action and force of manipulation to what is shown on screen. We found a very quick learning response."
   In a baseline test of 25 surgical residents, the force used to manipulate the test object produced an average of 10.1 volts over three separate movements. When asked to use less force, a second set of three manipulations produced an average of 4.6 volts, indicating that residents used less than half as much force to accomplish the same task. A third set of manipulations produced 2.7 volts, a further 40% reduction in force.
   "This is an inexpensive instrument that is robust and easy to use," Dr. Talarico said. "As a training tool, it really adds to the simulators that are already out there without adding significant cost of complication."