Surgical tool inspired by ovipositor of parasitic wasps

The prototype, developed by researchers at Delft University of Technology in the Netherlands and described in Frontiers in Bioengineering and Biotechnology, could allow MIS techniques to be used in previously hard-to-reach areas of the body.

Medical sting

The ovipositor is an ultra-thin organ, shaped like a flexible hollow needle, used by parasitic wasps to lay their eggs in trees or live hosts. Inside this delicate organ is a series of blades that join with a tongue-and-groove mechanism. The blades can slide independently of each other to create friction forces by using their mechanical movement, and these friction forces were used by the researchers in the implementation of their design.

"The wasp ovipositor is so thin that it can't actually fit any muscles within it, so we knew it was a clever mechanical solution worth studying to see if we could recreate it," said lead author Dr Aimée Sakes of the Bio-Inspired Technology Group at Delft University of Technology, led by Prof Dr Paul Breedveld.

"The ovipositor-inspired transport system uses friction generated between the blades and the tissues to transport those tissues, in the same way the wasp ovipositor works to transport wasp eggs."

Applying these friction-based techniques in the design of new surgery devices may allow researchers to surpass the boundaries faced by current tools, which work by suction.

"We already see challenges arise with current devices, as they often get clogged when removing things like blood clots," Dr Sakes said in a statement. "We also currently can't reach remote locations in the human body or perform surgery in miniature structures, such as parts of the brain, due to the relatively large size of MIS instruments. However, our system could potentially enable the removal of tumorous tissues deep inside the human body through miniature incisions in future."

According to TU Delft, the main drawback of the newly developed tool is that the speed at which it transports tissues is still substantially slower than current suction-based devices, so further research is still needed before the system is ready to be used in surgery. However, the research offers promising potential for treating diseases currently not treatable and reachable with existing equipment.