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A robotic arm that can bend, stretch and squeeze through the body to perform delicate surgical operations has been developed in Italy.
The device, which was inspired by the way an Octopus' arm moves, has been designed to enable surgeons to more easily access remote, confined regions of the body and manipulate soft organs without damaging them.
While part of the arm would be used to manipulate organs, another part would operate, reducing the number of instruments and entry incisions needed during operations, the researchers believe.
Although no surgical tasks have been performed yet, the robot arm has been successfully demonstrated in simulated scenarios where organs were represented by water-filled balloons.
The device, which is featured in the journal Bioinspiration & Biomimetics, published today, can quickly transform from a bending, flexible instrument into a stiff and rigid state.
Engineers were inspired by the flexible arms of the octopus, which have no rigid skeletal support and adapt to their environment by twisting, changing their length or bending in any direction at any point along the arm. An octopus varies the stiffness of its arms in segments to move and interact with objects.
The device is made from two interconnecting, identical modules. Each module moves by the inflation of three cylindrical chambers equally spaced inside the module. By alternating and combining the inflation of the three chambers, the module could be made to bend and stretch in various directions.
The stiffness of the two modules is also controlled by exploiting a “granular jamming phenomenon” in which a flexible membrane inside the module is filled with a granular media. When a vacuum is applied to the membrane, its density increases and the whole membrane becomes rigid.
Dr Tommaso Ranzani, lead author of the study from the Sant'Anna School of Advanced Studies in Italy, said: “The human body represents a highly challenging and non-structured environment, where the capabilities of the octopus can provide several advantages with respect to traditional surgical tools.
“Generally, the octopus has no rigid structures and can thus adapt the shape of its body to its environment. Taking advantage of the lack of rigid skeletal support, the eight highly flexible and long arms can twist, change their length, or bend in any direction at any point along the arm.”
In their study, the researchers performed a number of characterization tests on the robotic device, showing that it could bend to angles of up to 255° and stretch to up to 62% of its initial length. The stiffening mechanism was able to provide stiffness increases from 60% up to 200%.
Traditional surgical tasks often require the use of multiple specialized instruments such as graspers, retractors, vision systems and dissectors, to carry out a single procedure.
“We believe our device is the first step to creating an instrument that is able to perform all of these tasks, as well as reach remote areas of the body and safely support organs around the target site,” Ranzani added.