When Chinese president Xi Jinping visited Britain last October, one of the more unusual gifts he received was one he couldn’t actually see – a model of the Great Wall of China which was the same width as a human hair.
Researchers at Imperial College had used advanced 3D printing techniques to make the model. But the more practical use of the technology is for the development of advanced surgical instruments. The detail of these precision surgery instruments cannot be seen by the human eye, but they are expected to replace the large robotic instruments used in operating theatres at present.
At the cutting edge of work being carried out at the Hamlyn Centre in Imperial College, a lab which develops technologies for use in healthcare, is a clasping hand which is little more than half the breadth of a hair. As well as being used in surgery, the device could be applied to the more efficient delivery of cancer drugs.
According to the centre’s director, Prof Guang-Zhong Yang, the new smart surgical instruments, effectively handheld robots, will improve efficiency and cut costs. At present, robots in operating theatres are large imposing machines which can be operated by surgeons, be they present or remote. The new smaller handheld instruments allow a surgeon more room to work. Yang explains that instead of having a large robot towering over the patient, surgeons instead use handheld robotic instruments allowing them to operate as normal.
In the Hamlyn Centre on the Kensington campus of Imperial College lies a room which Yang refers to as “the museum”. Inside there are past and present generations of robots used for general surgery and procedures used in urology and gynaecology.
The robot’s arms make incisions and relay camera images to the surgeon who controls them. There are about 3,000 such machines in use around the world, each with a multimillion-pound price tag.
Across the corridor from “the museum” sits the lab where Yang’s team is developing the new handheld devices, the polar opposite of the large machines utilised at present. Using 3D printing at nanoscale, they have developed a clasping hand that fits on top of a minute piece of fibre which can be used for precise drug delivery and surgery.
The device measures just 60 microns across – a human hair is 100 microns wide, a red blood cell about 10 microns. It is produced by using a technique called two photon polymerisation, where a controlled point of pulsed laser is used to join together molecules to solidify a light-sensitive material.
This tiny device enables surgeons to carry out procedures at human cell level, says Yang. “At the very tip of the fibre we are able to put very small manipulators,” he says. “At the moment, for surgical procedures we still need to make incisions for the instruments but in the future we will probably just use a small needle.”
Other uses include the better targeted delivery of drugs for cancer care, says Yang. Chemotherapy drugs can affect cells in the body other than the cancer cells – causing tiredness and sickness – but the new implements will be able to carry tiny “payloads” of drugs for more precise delivery.
“Surgery is a different game altogether in the future. [It is] not about manipulating and stitching up tissue,” he says. “Our aim is … to do things with bare hands that you cannot do, to do things that are more accurate and more informative and then you do things that the other alternative techniques cannot do.”
Yang says he expects this new generation of surgical instruments to be in general use within a decade. Fibres with the manipulative hands on top will likely come in sterile packaging and be disposed of after one use. It is hoped the implements will be made available to a whole new group of surgeons, because they will be far cheaper than the multimillion-pound robots used today.
Yang makes it clear that the new smart instruments are not intended to replace surgeons but to let them continue to do what they do well and improve upon what they can’t.
Rather than having a very small minority of super-surgeons, there will be more doctors able to carry out procedures. Says Yang: “You improve the consistency, you improve the safety, you have more people able to do complex procedures and therefore the healthcare provision for everyone will be better.”
A 3D printed future
It was more than 30 years ago when a method of manufacturing called stereolithography, now known as 3D printing, was discovered.
Chuck Hull, who was back then working for a company which used UV light to put thin layers of plastic veneers on tabletops and furniture, was frustrated that the production of small plastic parts for prototyping new product designs could take up to two months.
He developed a system in which light was shone into a vat of photopolymer – a material which changes from liquid to a plastic-like solid when light shines upon it – and traces the shape of one level of the object. Subsequent layers are then printed until it is complete. The technology used at Imperial College works in a similar manner, whereby a structure is built layer upon layer but at a minute scale.
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