The University of Utah has revealed a new robotic drill system for greatly speeding up surgical procedures. One type of complex cranial surgery could be done in a fiftieth of the normal time, decreasing from two hours to just two and a half minutes.
A computer-driven automated drill, similar to those used to machine auto parts, could play a pivotal role in future surgical procedures. The new machine can make one type of complex cranial surgery 50 times faster than standard procedures, decreasing from two hours to two and a half minutes. Researchers at the University of Utah developed a drill that produces fast, clean and safe cuts – reducing the time the wound is open and the patient is anesthetised, thereby decreasing the incidence of infection, human error, and surgical cost. The findings are reported in Neurosurgical Focus.
To perform complex surgeries – especially cranial surgeries – surgeons typically use hand drills to make intricate openings, adding hours to a procedure: “It was like doing archaeology,” said William Couldwell, study author and neurosurgeon at the University of Utah Health. “We had to slowly take away the bone to avoid sensitive structures.”
Couldwell saw a need for a device that could alleviate this burden and make the process more efficient: “We knew the technology was already available in the machine world, but no one ever applied it to medical applications.”
“My expertise is dealing with the removal of metal quickly, so a neurosurgical drill was a new concept for me,” explained A. K. Balaji, associate professor in mechanical engineering. “I was interested in developing a low-cost drill that could do a lot of the grunt work to reduce surgeon fatigue.”
The team developed the drill from scratch, as well as new software to calculate the safest cutting path. First, the patient is imaged using CT scans to gather bone data and identify the exact location of sensitive structures, such as nerves, veins and arteries that must be avoided. Surgeons then use this information to program a cutting path for the drill: “The software lets the surgeon choose the optimum path from point A to point B, like Google Maps,” says Balaji. In addition, the surgeon can program safety barriers along the cutting path within 1 mm of sensitive structures. “Think of the barriers like a construction zone,” says Balaji. “You slow down to navigate it safety.”
The translabyrinthine surgery is performed thousands of times a year to expose slow-growing, benign tumours that can form at auditory nerves. This cut must avoid several sensitive features, including facial nerves and the venous sinus, a large vein that drains blood from the brain. Risks of this surgery include loss of facial movement. The system developed at Utah has an automatic emergency shut-off switch. During surgery, facial nerves are monitored for any signs of irritation: “If the drill gets too close to the facial nerve and irritation is monitored, the drill automatically turns off,” says Couldwell.
The new drill could reduce the duration of this complex procedure from two hours for hand-drilling by an experienced surgeon to two and a half minutes. The shorter surgery is expected to lower the chance of infection and improve post-operative recovery. It also has potential to substantially reduce the cost of surgery, because it shaves hours from operating room time.
The team has now demonstrated the safety and speed of the drill by performing this complex cut – but Couldwell stresses that it can be applied to many other procedures: “This drill can be used for a variety of surgeries, like machining the perfect receptacle opening in the bone for a hip implant,” he said.
The varied application of the drill highlights another factor that drew Balaji to the project: “I was motivated by the fact that this technology could democratise health care by levelling the playing field so more people can receive quality care,” he said. The team is now examining opportunities to commercialise the drill to ensure that it is more widely available for other surgical procedures.