Tiny capsule adds a sense of touch to laparoscopic surgery
October 28, 2013
Researchers at Nashville's Vanderbilt University have developed a wireless capsule that can restore a sense of touch for surgeons. Keyhole surgeries or other minimally invasive procedures could benefit greatly from this new technology, as the capsule provides haptic feedback to help doctors maneuver and make important conclusions during surgery.
Surgeons are utilizing less invasive methods of surgery with increasing frequency, although these methods do have some limitations. During open surgery, for instance, doctors traditionally use a technique known as palpation, in which they use their fingers to feel for and locate hidden tumors, blood vessels, and other structures. With minimally invasive surgeries, this technique isn’t feasible, since doctors use smaller points of entry and tiny tools to navigate a patient's insides.
That's where the capsule comes in. Containing a pressure sensor, an accelerometer, a wireless transmitter, a magnetic field sensor and a small battery, it's just 0.6 inches (15.2 mm) wide by 2.4 inches (61 mm) long.
Using surgical tools, doctors can handle the wireless capsule and press it against targeted tissues. The pressure sensor records the information while an accelerometer records the movements. The transmitter then sends haptic information back to a computer analysis system, which gives the surgeon a color-defined layout of the tissue stiffness. This information can help the doctor determine if they are approaching a hidden tumor or some other biological structure.
Desktop testing, using silicone gel to simulate tissue, indicated that “the capsule can measure the local stiffness of the tissue with a relative error less than five percent.” As the researchers strive to get a haptic resolution that is the same or better than human touch, they have achieved a relative error of eight percent in large animal tests.
The researchers admit that the current output is limited to computer screen feedback, but they have already suggested using the capsule technology with a haptic glove to provide a literal sense of touch for surgeons.
The capsule was designed at the Science and Technology of Robotics in Medicine (STORM) Lab at Vanderbilt University. Additional testing and biomechanical analysis has taken place at the University of Colorado, Boulder.
The hope is to make the already more than two million minimally invasive surgeries done annually in the US safer and easier for both the patient and the surgeon. The research team aims to get approval to test the capsule in clinical trials in the next five years.
An overview of the capsule’s functionality can be seen in the video below.
Source: Vanderbilt University