Solving the puzzle: a small scanner for suspicious moles
Researcher Aleksandar Jovic is working on a pen-shaped device that your doctor can use to scan suspicious moles for skin cancer. It promises to be much cheaper and easier than the current method that can only be used by dermatologists.
If you find a suspicious spot on your skin or have a mole that suddenly starts itching or bleeding, you obviously want to have it examined as quickly as possible. In that case, your doctor will often refer you to a hospital or a clinic. There, dermatologists with special equipment called Optical Coherence Tomography (OCT) scanners, will determine whether the moles require further examination.
But this equipment is slow and expensive, costs between EUR 50,000 and 100,000 and takes up a lot of space. This is why this equipment can only be found in hospitals. But an alternative method is possible. “We are developing a handy portable device, a miniature version of the hospital equipment, that is also less expensive,” says PhD candidate Aleksandar Jovic from the EEMCS faculty.
Reduced healthcare costs
Your own doctor can use a device like this to scan moles in his or her own office. “The scan is then sent to a dermatologist, who decides if further investigation is necessary,” says Jovic. This has a number of advantages. It clarifies the situation for the patient more quickly and there is no need to visit the hospital or clinic. It also takes less time for the dermatologist, which reduces healthcare costs. “The aim is that this device should be as easy to use as taking a photo with your camera,” says Jovic.
But this is still the future, because the device is currently being developed. However, Jovic recently presented a prototype, a microelectromechanical system (MEMS) silicon chip, several millimetres in size, that can scan the skin. His research is part of a broader trend in remote healthcare known as telemedicine. It involves data being collected from different places and shared with a specialist. The idea for the research came from the Spanish company MedLumics, whose founders include someone who was awarded his PhD at TU Delft. They were convinced that the technology found in the sluggish equipment used by dermatologists could be made within a much smaller device. This became the starting point of Jovic's research, which is being fully-funded by the European Union.
In recent years, he has been working closely with the Spanish company to refine the technology. It has not been an easy process. “The large-scale OCT scanner works in a similar way to a paper scanner that many people have at home or at work. Imagine you want to scan a document. You place it on a glass plate. Light goes across the paper and the scanner creates an image. The standard OCT using mirrors and lenses works in the similar way, but with much more precision. This is why they are more expensive,” says Jovic. But how do you make it so small that it fits into a pen? That was the difficult part of Jovic's work. In a scanner, you use a mirror and separate lenses. “But what happens if we combine them? And create a device in which all the components are completely integrated into a small silicon chip? It not only saves space, but also a lot of time and money. That's what we have been working on.”
Making a lens and mirror in one is a new approach. Jovic says it was like reinventing the wheel. “Thanks to the potential of the MEMS technology, the silicon chip can do the same as the large-scale equipment. The trick is how a light waveguide, a micro meter-scale mirror and a lens are connected into one single block which is then connected to the rest of the silicon chip. Therefore, they do not have to move relative to each other like in standard OCT scanners. Instead they move all together thus moving the light beam as well.”
His research is part of a broader trend in remote healthcare known as telemedicine. It involves data being collected from different places and shared with a specialist.
Making a lens and mirror in one is a new approach. Thanks to the potential of the MEMS technology, the silicon chip can do the same as the large-scale equipment.
Jovic takes the chip out of the cabinet with pride. The chip was completely fabricated in Else Kooi Laboratory at TU Delft. He recently presented it at a conference. “We have not yet tested it on skin. But we have demonstrated that you can use it to scan,” he says. “We do eventually aim to test it on skin, which is definitely possible.”
Jovic has made important progress in the development of a pen-shaped device that may soon be available at your doctor's practice. He has demonstrated that you can conduct the scanning process in a machine that fits into your hand.
Because the device is so small, the layout design of the MEMS chip was crucial. Which component should be placed in which precise location on the chip and how do you connect it to other components? Like an architect, Jovic was continually developing the design and layout. “In the mornings, I often went straight to my whiteboard to work on the layout. I was continually working to find the smartest way of building and connecting everything to each other. My colleagues helped me a lot. I was able to brainstorm with them and they gave me advices. In the last few years, I have continually been consulting with other researchers and colleagues from TU Delft and MedLumics.”
It was one big puzzle to solve, he says. Everything needed to fit perfectly, and now it finally does. He hopes to see the research continue. If there is new funding for the project, an improved prototype should be possible within a year, Jovic believes. It should be able to reach the market within three to five years. “Then doctors will soon be able to use it in their practice and make a rapid diagnosis with this device, simply by holding it above a suspicious mole.”
Text: Robert Visscher | Image: Mark Prins | November 2017