By: 31 August 2015
Tiny mechanical wrist gives new dexterity to needlescopic surgery

Tiny mechanical wrist gives new dexterity to needlescopic surgery

A surgical robot with steerable needles with wrists less than two millimetres thick has been developed by a team of engineers and doctors at Vanderbilt University in Nashville, USA. The tiny mechanical wrist could improve minimally invasive surgery

Although it’s been around since the 1990s, needlescopic surgery is only used regularly by a handful of surgeons around the world, and is largely limited to scraping away diseased tissue with curettes or burning it away with tiny lasers or heated wires.

The new device, developed by a research team headed by associate professor of mechanical engineering Robert Webster will allow surgeon-operators to perform procedures that haven’t been possible before, and will allow the use of needles in places that have previously been beyond their reach.

The effort to adapt robotic technology to minimally invasive surgery (MIS) has been dominated by Intuitive Surgical’s da Vinci Surgical System. Depending on the type of surgery, it requires incisions that are 8mm or 5mm in size.

The ‘steerable needles’ developed by Webster and his team are a system of telescoping tubes that are made out of nitinol, a ‘memory metal’ that retains it shape. Each tube has a different intrinsic curvature. By precisely rotating, extending and retracting the tubes, an operator can steer the tip in different directions, allowing it to follow a curving path through the body.

The design allows the needles to operate in areas of the body that neither manual endoscopic instruments nor the da Vinci robot can reach, but its usefulness was limited by the fact that the needles didn’t have a wrist.

“Adding the wrists to the steerable needles greatly expands the system’s usefulness,” said co-author Herrell. “There are a myriad of potential applications in some really exciting areas such as endoscopic neurosurgery. This would allow us to do surgeries that at present require much larger incisions and may even enable us to perform operations that are not feasible at present.”

By the end of the summer, the team hopes to have completed the control software and the interface that allows the surgeons to operate the device. They are actively looking for a commercial partner who will take the new instrument through the FDA approval process including initial clinical trials. “Our best case scenario is that the system could be available to surgeons in four to five years,” said Webster.

Source: Vanderbilt University