SAN FRANCISCO, Oct. 20 /U.S. Newswire/ -- Researchers from the Metropolitan Group Hospitals Residency in General Surgery, Chicago, Ill., have created the first device of its kind to teach surgical residents the most difficult aspect of the art of surgery -- the surgeon's gentle touch. Even when surgeons performed predominantly open operations and inserted their hands into the human body, gentleness was the hardest skill to teach, according to Vijay Maker, MD, FACS, chair of the department of surgery at Illinois Masonic Medical Center. "How do you teach something when the impact is not totally visible, and the patients cannot respond because they are under anesthesia," he said. That process took years of careful observation of and tutelage by experienced surgical educators.
The situation has become more complicated now that so many surgical procedures are minimally invasive and involve inserting surgical instruments through tiny incisions in the body. "With minimally invasive surgery, we are not touching patients with our hands anymore.

We touch them with instruments that are 12 to 18 inches long, so the feel of gentleness is gone altogether," Dr. Maker said as he reported findings from a study presented at the 2005 Clinical Congress of the American College of Surgeons.

Although surgical residents use simulators to learn how to perform minimally invasive operative techniques, the devices are goal-oriented and drill students in performing specific tasks, such as moving an object from one place to another, sewing tissues together, or stanching blood flow. None of the simulators available today reinforce for surgical residents the need to accomplish every task as gently as they can, Dr. Maker said.

The device, developed in Dr. Maker's surgical laboratory at Advocate Illinois Masonic Medical Center, Chicago, teaches gentleness by providing a visible gauge of the degree of force exerted when grasping and manipulating a piece of tissue. It records the amount of voltage produced when surgical residents use a minimally invasive tool to pick up and transport an object from one place to another and produces a graph, much like an electrocardiograph strip, of the changes in voltage in real time. As a result, surgical residents can see how much strength they are applying during the entire time they are doing a specific task, explained Joseph A. Talarico, MD, a resident in general surgery who designed the device under the direction of Dr. Maker.

According to the researchers' findings, the device not only records gentleness, it also helps surgical residents improve their gentle touch. In the study, 25 residents in general surgery used the touch device to pick up, move, and release an object three times using their normal amount of force. After the residents were shown a graph of their performance, they were asked to perform the task a second time using less force. The third time, the surgical residents were asked to perform the task in their most gentle manner.

The average amount of force declined significantly over the course of the three tasks. For all the residents, the average voltage was 10.1 millivolts the first time, 4.6 millivolts the second time, and 2.7 millivolts the third time they performed the task. The degree of gentleness used by the residents the third time was significantly higher than the first time they performed the task.

The device is simple, inexpensive, and highly sensitive. It has three elements that are available commercially. The device consists of a piezoresistive (having the capability of altering resistance through physical or mechanical pressure) touch sensor that is similar to the technology in electric toothbrushes or touch-tone telephones. While electric toothbrushes and touch-tone phones initiate action by touch, the piezoresistive surgical training device measures the amount of action initiated by touch.

The sensor releases a voltage signal every time force is applied, and it measures voltage signals down to one one-millionth of a volt. The device also includes an analog to digital converter, which translates the voltage signal into information that can be stored and displayed electronically on a monitor, and software that generates graphs of the voltage signals.

The researchers have developed a prototype of the device that may be included in a standard minimally invasive surgery simulator. Dr. Maker envisions a simulator that implants sensors in artificial reconstructions of human tissue and quantifies the amount of force used when a surgical instrument is applied. "This is where the science and art of surgery meet.

We are measuring the art of surgery and then training surgical residents to reach that level," Dr. Maker said.

Also participating in the study were Douglas Rathburn, MS, MBA; Azam Jan, MD; and Marek Rudnicki, MD, PhD, FACS.