UAE scientists have developed soft sensors to help give surgeons a sense of touch during keyhole surgery.
As more operations are carried out using keyhole or minimally invasive methods, the technology could prove increasingly useful. It could also be adapted for telesurgery, which enables surgeons to operate on patients on the other side of the world.
The researchers at New York University Abu Dhabi have applied for a patent and hope to set up a spin-off company to commercialise the technology.
Typically, with minimally invasive surgery, a small incision is made and a long, thin tube called a laparoscope is used to carry out the operation. In other procedures, endoscopes – tubes with cameras – examine areas inside the body and treat conditions.
Minimally invasive surgery offers faster recovery times and less scarring than traditional open surgery and has become popular for hernia operations and gallbladder or appendix removal.
Why is the innovation important?
However, according to Dr Mohammad Qasaimeh, an associate professor of mechanical engineering and bioengineering at NYU Abu Dhabi, it may provide surgeons with less tactile feedback, making it difficult to judge how much force is being applied.
“With experience they can gain knowledge, but the main problem is with trainees, surgical trainees, or people with less experience,” he told The National.
“Can we develop devices – the laparoscopic tools, the endoscopic tools, all tools associated with minimally invasive surgery as well as robotic surgery – to have force sensing, to know how much we are grasping?
“Are we harming that tissue we are grasping inside the patient’s body? Can we estimate the stiffness of this tissue? Is it very soft, is it very stiff?”
Soft silicone sensors developed by Dr Qasaimeh and his colleagues aim to help surgeons answer these questions.
The sensors contain multiple channels filled with liquid metal, and when pressure is applied, the metal’s movement causes the channels to deform, creating the sense of touch.
The researchers have used their sensors on a laparoscopic grasper, with one sensor placed on the handle to measure the force applied by the surgeon, and another on the tool’s jaw to measure interactions with the tissue.
Details of the technology have been published in Microsystems and Nanoengineering.
The first author of the study, Dr Wael Othman, who was previously a postdoctoral associate in Dr Qasaimeh’s laboratory and, since January, an assistant professor at Khalifa University in Abu Dhabi, said in a statement that the aim was “to create sensors that are both sensitive and practical for real surgical environments”.
“This design allows us to measure both gentle and strong forces within the same small device, and to place sensors where they are most useful on surgical tools,” he said. In a previous study, Dr Qasaimeh and his colleagues bought commercially available sensors but found they “were not good enough”.
Either they were not flexible – they are rigid – or their integration was hard, they are not reliable, they need to be recalibrated each time, he said.
In earlier work, the researchers invited surgeons to use surgical tools on raw or cooked pieces of meat and asked them to indicate which pieces were softer and which were harder.
They discovered that when the surgeons had basic sensory feedback, they were better able to tell how firm samples were, highlighting the importance of touch.
What next?
The technology could be used with existing laparoscopic tools, with new tools that the researchers develop, or even with high-tech surgical robots.
“These surgical robots are amazing. You can do microsurgery – when it comes to brain, eye surgery, this kind of microsurgery – with great precision and accuracy. But yet you will be surprised that those surgical robots, worth more than $1 million, do not have active feedback sensors,” Dr Qasaimeh said.
“It would be straightforward if we can collaborate with these [robotics] companies, to bring that kind of integration and sensation to their robots.”
Dr Qasaimeh said the technology could also be used with telesurgery. The internet-enabled practice uses remote control to carry out operations on patients who can be thousands of miles away.
“In that scenario, definitely as a surgeon you need some sensation,” he said. “Surgeons need some sort of feedback, other than a camera.”
Commercialisation of the technology would require the sensors to be produced more quickly.
“We need larger scale production so that you can produce perhaps 100 sensors per day,” Dr Qasaimeh said.
“As of now every sensor will take us a day to produce because we are doing it manually, not automated or semi-automated. When you go to the market you need to think of scaling that up.”
