- Title: Mini robot delicate enough to perform cataract surgery
- Date: 29th November 2016
- Summary: CAMBRIDGE, ENGLAND, UK (NOVEMBER 24, 2016) (REUTERS) (SOUNDBITE) (English) CHRIS WAGNER, HEAD OF ADVANCED SURGICAL SYSTEMS AT CAMBRIDGE CONSULTANTS, SAYING: "I think the fact that it's a 1.8 millimetre diameter robot that's operating on the size scale of the eye, it's exciting. This just opens the door to a number of different types of procedures that you can do that previously weren't possible. So I think it's just exciting that the fidelity of motion is so good; the delay that we've got between the interface and the robot motion; it's great." MORE OF SCIENTISTS OPERATING AXSIS PINCERS MOVING WITH SCIENTISTS OPERATING IN BACKGROUND
- Embargoed: 14th December 2016 14:50
- Keywords: Cambridge Consultants cataracts robot robotic sugery robot surgeon University College London
- Location: CAMBRIDGE, ENGLAND, UK / FILE LOCATIONS
- City: CAMBRIDGE, ENGLAND, UK / FILE LOCATIONS
- Country: Cambodia
- Reuters ID: LVA0035AI1E8R
- Aspect Ratio: 16:9
- Story Text: Two tiny robotic arms fitted with surgical instruments measuring just 1.8 millimetres in diameter could help surgeons perform delicate procedures like cataract surgery with greater precision and safety than human hands alone.
Axsis, from technology developers Cambridge Consultants, has flexible instruments built in to an external body the size of a drinks can. The company says this allows the overall size to be reduced significantly compared to other robotic systems already in use.
"All the articulation has been moved to inside of the body, and so on the outside of the body nothing is moving, so no arm is swinging around that you have to avoid and no arm motion has to conflict with another robot arm," said Chris Wagner, head of advanced surgical systems. "By designing the robot in this way you still get full performance of the robot on the inside of the body but it makes the design of the robot on the outside much smaller."
The surgeon teleoperates the robot using two haptic joysticks, which give instantaneous feedback, while they see the progress of the work on a video monitor with the image enlarged. The extra dexterity afforded by Axsis, said Wagner, could be a particular benefit when operating on small bodily structures, such as the eye.
Cataracts -- the clouding of the lens of the eye which blocks out light eventually causing blindness -- are currently corrected by a surgeon using micro tweezers about 2 millimetres in diameter under a microscope to remove the cloudy lens and replace it with an artificial one.
"One of the difficult parts of cataract surgery is getting close to the lens of the eye, getting close to the capsule of the lens of the eye without breaking it. And so, this is an extremely sensitive part of the operation currently. But with something like robotics, paired with intraoperative guidance, so intraoperative imaging; you can see where the robot is, see where the lens is, see where the relevant anatomy is," Wagner told Reuters.
"By having a computer in the loop between when the surgeon's moving their hands and the robot moving, that computer can recognise when the surgeon's about to make a motion that can go outside and actually puncture the lens, for example, and stop that motion."
However, some experts have questioned whether Axsis would provide any real benefit to modern cataract surgery.
University College London ophthalmologist Ian Murdoch told Reuters: "If the complication rate is less then this would be obviously great. Routine cataract surgery is done the world over with relatively low complication rates and, in some units, the speed is already remarkable."
He added that damaging the posterior capsule during cataract surgery "happens at present in about 0.1-0.7% cases in different reports, thus proving a lower complication rate would require a very large comparative study".
Traditional surgical robotics, such as Intuitive Surgical's da Vinci robot-assisted system, are large by design because of the need to operate long, straight instruments that pass through small holes into the patient.
The motor and control configuration in Axsis eliminates the need for a large range of motions around the patient. Each tiny robotic arm is controlled by an actuator with tendon-like cables controlling the movement of the arms.
"These cables are 110 microns in diameter, going through 150 micron hole. So that means the cable is the same size as a human hair. And yet this material is gel-spun polyethylene which is stronger than kevlar, stronger than steel by volume and it's what NASA uses in some of their solar sails. So it's an extremely efficient material, extremely strong for making this high performance actuator," added Wagner.
Robotics is already transforming surgery. Surgical robots are used in hernia repair, bariatric surgery, hysterectomies and the vast majority of prostate removals in the United States, according to Intuitive Surgical, which has more than 3,600 of its da Vinci machines in hospitals world-wide.
Cambridge Consultants believes, however, the cumbersome size of current surgical robots could be reduced to improve the way medical professionals approach a variety of procedures and allow surgeons to get closer to the patient without the barrier of large equipment.
"I think the fact that it's a 1.8 millimetre diameter robot that's operating on the size scale of the eye, it's exciting. This just opens the door to a number of different types of procedures that you can do that previously weren't possible," said Wagner.
The Axsis prototype was developed as a technology demonstrator to show how precision surgical robots could be miniaturised. Wagner added that it would still take significant investment to turn the prototype into a viable tool for surgeons, but said it typically takes 2-4 years of development for a new product like this to make it to market.
Cataract surgery is one of the most common surgeries globally, with around 20 million such operations each year.
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