Light-Based Surgical Mapping System to Shorten OR Times

A light-based surgical guidance system said to be "10 to 100 times faster than other guidance systems" is under development by Toronto-based start-up 7D Surgical Inc.

The new system compares imaging data derived from the surgical site with preoperative MRI or CT scans to generate a 3-D map of the patient's anatomy to guide surgeons in performing the procedure. Its inventor, Victor Yang, MD, a Canada Research Chair in bioengineering and biophotonics at Ryerson University and a neurosurgeon at Sunnybrook Health Sciences Centre, likens his device to a GPS system for surgeons.

"We know we have a fantastic application," says Yang. "There's a clinical demand for it." An additional advntage is that Yang's technology, being light-based, minimizes the use of intraoperative X-rays.

Yang says his system projects a series of binary patterns like the stripes of a barcode onto the patient. The system's software analyzes deformations of the pattern and mathematically reconstructs the surface of the patient's anatomy, creating a 3-D "map" of the anatomy. When combined with the preoperative imaging data, this surface map can be used to guide surgeons as they work and show them what lies beyond the existing incision.

"The 7D Surgical navigation system performs at least 10 times faster than existing systems," according to a Ryerson University press release. "The device takes 1-2 minutes to capture and compute the information needed to begin surgery, while similar products take 20 minutes or more."

The key to its speed is the  way in which it matches preoperative imaging to the patient's anatomy, a process called coregistration. With existing systems, surgeons match points on MRI or CT scans taken beforehand to points on the patient's body, one by one. Yang's system does this automatically and delivers coregistered points by the hundreds in less than a second.

"With existing systems, if you lose  your tracking, it's a big headache because now you have to reacquire [the points]; you need to 'relock' on. That process takes a long time. With 7D Surgical navigation, if you lose your tracking, it's not a big deal because in less than a second you're back on lock," says Yang.

Yang, along with neurosurgeons and orthopedic spinal surgeons at Sunnybrook, has formed 7D Surgical Inc. and is leading initial clinical feasibility studies of the device. While currently only one prototype unit is in use at Sunnybrook, by virtue of a new partnership with contract manufacturer Celestica, Yang and the 7D Surgical team predict that five additional units will be built and placed at additional clinical sites within the year. The goal, 7D Surgical says, is to have the system available for sale by 2016.

Yang's research is funded by Brain Canada, the Canada Foundation for Innovation, the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council of Canada, and the Ontario Ministry of Research and Innovation.

Stephen Levy  is a contributor to Qmed and MPMN.