by John R. Fischer
, Senior Reporter | April 25, 2022
Surgeons in the near future may only need to maneuver a joystick to quickly treat a patient with a stroke or aneurysm, even if the patient is in an entirely different location.
Engineers at the Massachusetts Institute of Technology have developed a telerobotic system that allows surgeons to remotely control a robotic arm to safely operate on a patient during the “golden hour” of time to save their life and preserve brain function.
Controlled by magnets, the doctor can use the solution to insert and guide a thin wire to the source of a blood clot that causes the stroke. The primary purpose is to target locations for clots quickly so that microcatheters and other standard devices can be used to deliver therapeutics. Treating patients in the critical “golden hour” after a stroke occurs is difficult for patients in remote areas, as neurovascular surgeons are often miles away at major medical institutions. This increases the risks of death and brain damage.
Xuanhe Zhao, a professor of mechanical engineering and of civil and environmental engineering at MIT, and his colleagues see the solution being available in smaller hospitals, with trained surgeons at larger medical centers remotely guiding it. This would reduce the need to transport patients from rural areas to large cities. "We are in the process of forming a startup company to translate this technology for clinical trials and approvals with support from the MIT Deshpande Center. We estimate that it will take two-to-three years before the device will be tested in humans and three-to-five years before it will be commercially available to hospitals," Zhao told HCB News.
The system has a medical-grade robotic arm with a magnet attached to its wrist. Using a joystick and live imaging, an operator can adjust the orientation of the magnet and maneuver the arm as it inserts a soft, thin magnetic wire through arteries and vessels.
In a phantom model of the brain, neurosurgeons were able to guide the robot’s arm through vessels and around sharp corners to the target location after just one hour of training. Once there, they threaded a microcatheter along the wire to the site and then retracted the wire and left the microcatheter to remove simulated clots. They were also able to navigate complex vessels that are difficult to access with a manual guidewire.
The system is based on work the researchers conducted in 2019 to steer a magnetically-controlled thread through a life-sized silicone model of the brain’s blood vessels using a handheld magnet. The joystick enables users to tilt the magnet in an orientation that the magnetic wire can follow and buttons on the mouse control a set of motorized linear drives to make the wire move forward and back. The wire used is as thin and flexible as a neurovascular guidewire, but with a soft, magnetically responsive tip that follows and bends in the direction of a magnetic field.
In addition to providing time-critical treatment, the solution spares surgeons from being exposed to radiation from X-ray imaging and allows for quicker training compared to the years required to manually learn how to perform endovascular surgery.
Zhao does not see the solution being used in point-of-care settings for neuro interventions due to the complex nature of the task, but says that "telerobotic treatments of certain diseases may be possibly made into point-of-care solutions in the far future."
The findings were published in Science Robotics