Using DLR technology for robot-assisted surgery
21 June 2016
The surgeon sits at a console, while robotic arms perform his commands with high precision – making exact incisions or stitching severed veins in a tiny space.
During the operation, the doctor can feel through the controls exactly what the instrument tips on the robot are doing, just as if he were holding them in his own hands. Robot and human are working together hand in hand. "Our robot MIRO makes the surgeon's work easier, for example by filtering out the slight irregularities in human hand movements or executing the surgeon's movements with high precision on a reduced scale, and thus optimising surgeries," emphasises Alin Albu-Schäffer from the German Aerospace Centre (Deutsches Zentrum für Luft- und Raumfahrt; DLR). The licence for the MIRO medical robot developed by DLR was sold to Medtronic, the largest Medical Device company in the world, who plans to incorporate many technologies from MIRO into the robot it is developing and launching in the next few years. It will be part of their portfolio that focuses on moving surgeries from open surgery to minimally invasive surgeries.
Accurate and with a sense of touch
The MIRO robotic arm is lightweight and it has flexible joints and sensitivity like DLR's space robot, Justin. Numerous sensors in its interior ensure that all of the robotic arm's contacts with the environment is relayed to the operator's input device in real time. In minimally invasive surgery – during which the doctor needs to introduce long clamps into the 'operation area' of the human body through the smallest possible incision – the MIRO robot's technology supports the surgeon. The doctor carries out the operation at a console and, while doing so, watches the 3D endoscope images on a monitor and controls the tips of his tool as if doing it himself – and not with the complicated but essential extensions of the instruments. For the surgeon, this means a more intuitive procedure that is felt more directly. "In this way, malignant tissue can be removed with greater precision and healthy tissue left undamaged."
Space technology for medicine
The foundations for the medical robot originate from spaceflight. The engineers at the DLR Institute for Robotics and Mechatronics are successfully working on operating robots remotely from the ground or from the International Space Station (ISS) and giving the operator the impression of being there – telepresence. A cosmonaut on the ISS was able to use DLR's Kontur-2 joystick to move a robotic arm on the ground for the first time in August 2015 and feel, for example, whether he was encountering resistance. "Our Institute has been carrying out research in the field of telepresence for several years, says the Head of the DLR Institute Albu-Schäffer. The experience acquired is now being put to use in the MIRO medical robot as well. "However, in medicine it is not about the large distance between the robot and the operator, but about overcoming the barriers of the human body – that is, the operating site is often difficult to access during the intervention, so delicate movements need to be performed with great precision."
The DLR engineers have repeatedly sat experienced surgeons at their console to test typical surgical procedures on artificial silicone hearts and plastic tissue with the medical robot. Spinal column experts have put MIRO to the test with repairs of vertebrae and the setting of small screws into bone material. With these practice runs, the engineers are a step closer to meeting the requirements of the users. The MIRO technology is now being adapted as the basis for a market-ready product and designed for special applications in a Bavarian development centre by the licensee Medtronic. Hence, the German site is continuing to profit directly from this development.
Ideas for the medical robotics of the future
The project has been partly financed by the Helmholtz Validation Fund, with the intention of filling the gaps between scientific knowledge on the one hand and the requirements of industry for commercially viable research results on the other. "With MIRO, we have been able to develop a major research project that is being launched on the market by a licensee and hence is moving from research to commercial use for the benefit of patients," stresses Robert Klarner from DLR Technology Marketing, which has been a partner in the process and has co-financed the development.
But the research work into medical robotics at DLR has not come to an end with the issuing of the licence. The engineers at the DLR Institute of Robotics and Mechatronics already have more ideas on how the robot can support humans. "In the MIRO Innovation Lab, we are developing more applications and software concepts that give the robot greater autonomy," explains Albu-Schäffer. So a robotic arm might in future be able to perform the surgeon’s commands partly autonomously – i.e. not just highly precise incisions, for example, or treating larger areas of tissue, but independently tying knots for the surgeon with high sensitivity and precision when stitching.