WebZine
2016.9
What's New
The Future of Robotic Surgery: Snake-Like Bots That Glide Into Orifices
Posted 26 Jul 2016 | 17:00 GMT
Letting a snake-like robot glide into your mouth and down your throat may sound a bit alarming. Letting such a robot glide into any of your other orifices may sound more alarming still.
But the Flex Robotic System from Medrobotics, in Raynham, Mass., has earned high praise from a head and neck surgeon who has sent it snaking down 19 of his patients’ throats as of today. “It really is changing the way I do business,” says David Goldenberg, director of otolaryngology surgery at the Penn State Hershey Medical Center. “It is the future of head and neck surgery.” His surgical colleagues in the colorectal and OB-GYN departments are also planning clinical trials using the Flex, Goldenberg told IEEE Spectrum.
The Cancer Surgeon’s Latest Tool: Quantum Dot
By Imad Naasani
Posted 21 Sep 2016 | 15:00 GMT
The bits of semiconducting material that are lately brightening the colors on television screens hold a much greater promise—that they will extend lives. These tiny crystals are far too small to be seen with the naked eye, measuring just one ten-thousandth the width of a human hair, which is one reason they’re called quantum dots. When you shine a suitable light on such a dot, it becomes luminous, emitting a very pure color that is determined by its size.
My colleagues and I at Nanoco Technologies, in Manchester, England, have been working with a team of researchers led by Sandy MacRobert at University College London to explore quantum-dot technology for various medical treatments. While there are many exciting possibilities to be explored, the most important one we’re pursuing aims to help delineate malignant tumors and the pathways along which they spread, which could improve the safety and effectiveness of cancer surgery.
The Flex entered the U.S. market just last year (and the European market the year before that), and getting it approved by regulators was no easy task, Medrobotics executives told Spectrum. Interestingly, the biggest hassle was ensuring that the robot was dumb enough to meet the U.S. Food and Drug Administration’s (FDA’s) requirements.
“When we approached the FDA, almost the first question out of their mouth was about the autonomous nature of the robot. They raised it as a serious red flag,” says Medrobotics CEO Samuel Straface. “We had to show that the surgeon has complete and absolute control at all times. If it was any other way, we’d still be a science project,” he says.
This conjunction of statements from surgeon and CEO neatly sums up the current state of robotic surgery. The new “robots” coming out are giving surgeons new capabilities, but really they’re still just tools in the hands of the all-powerful human. That’s because the FDA has barred anything resembling an autonomous robotic assistant from the operation room.
Roboticists may see autonomous surgical bots as a grand research goal, as Spectrum explored recently in a feature article [Would You Trust a Robot Surgeon to Operate on You?]. And recent triumphs, like an autonomous system that stitched up pig intestines more effectively than human surgeons, have demonstrated their progress. But it’s a long way from the lab to the clinic, as Medrobotics discovered. “We’re injecting some reality,” says Straface. “Just because you can build these things doesn’t mean you can sell them.”
The quantum dots we’re discussing are engineered from a blend of elements drawn from groups III and V, or II and VI, of the periodic table—elements like cadmium, lead, zinc, arsenic, indium, tellurium, selenium, sulfur, and phosphorus, which are used in pairs or as alloys. In that way quantum dots are similar to various optoelectronic devices. When exposed to a relatively shortwave light source, quantum dots absorb some of its energy and reemit light of a longer wavelength (which is to say, a different color), a process known as fluorescence. The size of the dots can be finely tuned so that they will give off any color of the spectrum you might want: The bigger the dot, the longer the wavelength it emits.
The most common commercial use of quantum dots by far has been in the backlights for LCD television screens, where they help produce two of the three colors needed. Blue comes directly from an LED, which illuminates quantum dots that in turn produce red and green light. Because quantum dots emit very pure colors, the television pictures they create are particularly vivid, showing upwards of 50 percent more color range than the average display. Their use in TVs also lowers power consumption, because less of the backlight’s energy is absorbed by the color filters in the LCD screen.