Integrated imaging system provides new focus for laparoscopy

The system is said to take advantage of variable focal length microlens systems pioneered by Hongrui Jiang, the Lynn H. Matthias and Vilas Distinguished Achievement Professor of electrical and computer engineering at UW-Madison.

Laparoscopy (or keyhole surgery) is a minimally invasive technique used for procedures in the abdominal area, including surgery on the colon, stomach, oesophagus or reproductive organs. Surgeons conduct the procedure with the assistance of a video camera and long, thin instruments fed through three to five ports, or trocars, placed in small incisions in the abdomen.

In most current laparoscopic procedures, the camera presents several challenges - one of which is that the surgeon can’t operate it independently, said Charles Heise, a UW-Madison professor of surgery. “Another person must hold the camera, manipulate it, focus it, and move it in and out to clean it,” he says. “It has a limited field of view and it ties up one of the ports.”

The new system centres around retractable microlens arrays integrated onto the end of each port. When a port is inserted into the body, these cameras will flare out in a ring, allowing the surgeon to use the port simultaneously for imaging and operating.

Using software or voice commands, the surgeon can tune the focus of each camera to adjust the depth of field, which improves the image quality. Multiple cameras on each port will provide an immersive, three-dimensional view of the procedure, yet their location near the abdominal wall will help to minimise spatter that ordinarily would accumulate on a traditional camera placed right at the site of the procedure.

Jiang said in a statement that the new system is a holistic solution that addresses most of the drawbacks in the current technology. He has been fine-tuning the microlens technology for more than a decade and sought to transform his technology into clinically relevant applications. For the past several years, Jiang has collaborated with laparoscopic surgeons at UW-Madison on ways to do that.

“This whole project was generated and driven by both sides - from the pursuit to address engineering challenges to the pursuit to solve clinical and medical problems,” he said. “The advantage of our approach is that we gave the clinical requirements and disadvantages a lot of thought so that we could come up with a comprehensive solution to address all of the problems.”

Jiang received a four-year, $1.6 million grant from the National Institutes of Health to fund the effort. In addition to Jiang and Heise, the UW-Madison research team includes Jacob Greenberg, an assistant professor of surgery; and Yu Hen Hu, a professor of electrical and computer engineering.

While the researchers have made significant strides, they will continue to refine the lens and camera technology. They also will focus on developing algorithms for processing the images from multiple cameras and stitching them seamlessly into a single, 3D view, as well as developing prototypes for laparoscopic simulators that will allow them to gauge how surgeons use the system.