Smart, flexible and steerable surgical needles

Extremely accurate cancer detection? Treatment of inoperable patients? The robot-controlled flexible needles being developed by UT scientist Sarthak Misra are making all that and more possible. Needles are commonly used in surgery, as they cause the patient minimal pain and tissue damage. Smart, flexible needles take this minimally invasive surgery to the next level, enabling access to otherwise inaccessible parts of the body.

Flexible robot needles can carry out ‘impossible’ tasks

The use of needles in surgery is quite common. For instance, needles are often used in prostate cancer diagnosis and treatment (biopsy and brachytherapy), brain surgery and surgery babies still in the mother’s womb. One of the disadvantages of conventional surgical needles is their rigidity, which sometime causes them to miss their target, for example, if the patient’s body, or an organ in the body, moves. This can lead to misdiagnosis and incomplete treatment. And that, in turn, can have traumatic, sometimes even fatal, consequences.

Self-navigating robot

With his robotically guided, flexible needles, UT scientist Sarthak Misra hopes to tackle these problems. Flexible needles can circumnavigate healthy tissue or other obstacles in the body, reaching parts of the body that would otherwise be difficult to access. They offer much higher precision and less damage and discomfort for patients.

Misra’s needles are also smart: thanks to a unique combination of technologies, they can carry out medical tasks that would otherwise be difficult or impossible to perform. ‘For example, the needles are equipped with sensors that can transmit detailed information on tissue rigidity to the surgeon,’ explains Misra. A recent addition is optical shape sensing, which enables the flexible needles, while moving through the patient’s body, to send the surgeon detailed location information without the use of imaging.

Flexible micro- or nano-robotic devices

By integrating more and better functionalities in the robot needles, Misra hopes to open up more and more medical possibilities. ‘In the coming years we hope to keep developing flexible needles, gearing them to a number of selected high-impact areas of medical application. Two fields could be oncology and neurosurgery, for example.’ One of Misra’s dreams for the future: flexible, self-navigating micro- or nano-robotic devices equipped to autonomously perform monitoring, preventive and curative tasks in the human body.

In 2014, Misra, who previously worked on space robots for the International Space Station, received the ERC grant of 1.5 million euros for his work in the field of flexible needles. At the end of 2017 he received a further 150.000 euros for a follow up project, INSPIRE, with which he hopes to make flexible needles applicable to tumour ablation and other minimally invasive surgery procedures.

‘What I did in space robotics at macro level is the same as what we do with surgical robots at micro level: using robotics to tackle seemingly unsolvable problems. For me, another thing the two fields have in common is the fact that you cannot make mistakes in either area. This makes my work really challenging. The ability to cope with the pressure comes with time. I have learnt to sit quietly, think deeply and wait for the solution to present itself – even if weeks and months go by without anything visibly happening. Staying motivated is not always easy, but as the years go by you learn, and you grow in confidence that the process will eventually bear fruit.’
prof.dr. S. Misra (Sarthak)
Professor in the Department of Biomechanical Engineering and head of the Surgical Robotics Laboratory, University of Twente | Adjunct professor, Rijksuniversiteit Groningen

Studied Mechanical Engineering at the John Hopkins University, United States

Field of interest: applied mechanics at macro, micro and nano level, formerly in space robotics and now in the field of surgical robotics