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Miniaturising surgical robotics – building a model ship inside a very small bottle

One reason that surgery is exciting is its interface with technology. Surgical robots, becoming more common in well-resourced healthcare settings, are one example. However, as with all new technologies, there is a balance to be struck: wholeheartedly embracing an innovation versus enthusiasm tempered by objective assessment of efficacy and economy.

What does a robot have that a human does not? Robotic technology promises more precise manipulation of tissues, potentially enabling surgery through smaller corridors. Ever since humans began operating, we have always strived to make our interventions less invasive. Surgical robots are no doubt a part of that evolution.

Behind every surgical robot, there is (for now) a human driver. Intra-operative decision-making is constant, dynamic and multi-faceted. Current computer AI is a long way from having the capacity to analyse and integrate all the relevant information and so supplant the need for a human surgeon and the wider surgical team. Of course, being a good surgeon is much more than the act of surgery itself. Human-to-human communication is fundamental to making a diagnosis and coming to a joint decision about the best care for a patient. Robots, or computer avatars, are a long way from being able to build a therapeutic relationship and replicate this facet of medicine.

Another very pragmatic issue is the current size and cost of surgical robots. Human surgeons are relatively cheap and, compared with bulky surgical robots, have a small footprint in the operating theatre. Surgical robots will need to miniaturise significantly in order to become a standard part of surgical equipment.  

Miniaturisation brings interesting engineering challenges. Robots need to counteract the forces exerted by the end of the instrument on the tissue and must be able to support their own weight; both are factors that demand a sizeable robot. Traditional lever arm mechanisms often require a large range of movement outside the body in order to achieve the required, smaller range of movement within it. Moving away from lever arm mechanisms and towards cable-driven (or other flexible) instruments can facilitate the required range of movement more elegantly. As the movement occurs within the body, there is no need for large movements outside. Moreover, there is a lesser need to counteract body wall forces that are exerted with a lever arm.

Creating such minimally invasive instruments is a challenge, both in terms of design and manufacturing. As miniaturisation proceeds, the challenge becomes reminiscent of building a detailed model ship inside a very small glass bottle. 3D printing, nanotechnology, and self-assembling components may all serve a purpose. Given the accelerating pace of technological development, it is inevitable however that surgical robots will take on a larger role in the coming decade.

Mark Hughes

Director, eoSurgical

Skull-base neurosurgery fellow, Leeds General Infirmary


Email: mark.hughes@eosurgical.com

Twitter: @eosurgical