CMOS and ultra-high speed imaging in medicine
Ahead of the inaugural MediSens clinical imaging technology conference in London (12-14 December), we interview our guest speakers and advisory board members, industry professionals with profound experience of the technologies deployed in medical imaging.
Dr Renato Turchetta obtained his PhD from Strasbourg University (France) in 1991. He was Associated Professor in Electronics at the University there until he joined the Rutherford Appleton Laboratory (UK) in 1999 as a Senior Designer. In 2016, Renato left STFC and is now CEO of wegapixel, a CIS design center and division of Specialised Imaging Ltd.
His session, “How CMOS can be further leveraged to advance medical imaging” takes place on the second day of the conference, on Wednesday 14 December.
What would you say is your career highlight so far?
I started my career working on detectors in particle physics. That was in the 90’s and at that time, specialised detectors were used. In 1999 I had the idea that one could use a standard CMOS image sensor to directly detect particles. If it could work, it would greatly simplify the way charged particle detectors were built. I patented this idea, first demonstrated on a small prototype and then applied to transmission electron microscopy.
There I developed the first 16 megapixel sensor for direct detection of electrons. This sensor is now a product, which is very popular in that field. The whole concept of direct detection of electrons with a CMOS image sensor has revolutionised the field and nowadays CMOS have become the reference sensor in this field, displacing technologies like CCDs or films, which were formerly used in the field. Also, it is since then that I have started working on CMOS image sensors.
That brought me to another highlight of my career which is working on wafer scale CMOS image sensors. I did when working at the Rutherford Appleton Laboratory. A spin-off, vivaMOS was created around this.
The other highlight of my career is the ultra-fast sensor I developed for Specialised Imaging. When I started about 5 years ago, it looked totally crazy. We wanted to do a megapixel sensor working at 5 million frames per second. Together with my team, I managed to achieve this. The sensor won a Queen’s Award for Innovation this year and took me to my new enterprise, the creation of wegapixel.
What innovations have you worked on in the past decade that you hope will be most influential in the future?
I mentioned above the direct detection of electrons with a CMOS image sensor. This has already proved to be influential, and scientists in the field talk about a ‘revolution’ (they are not my words!). Somehow this is already there, and already shaping the field.
If there are things that have not yet fully achieved their potential, I hope that wafer-scale CMOS image sensing technology will revolutionise the field of medical imaging.
Despite CMOS being a well established technology in many fields, including imaging, it is fighting to be adopted as the mainstream technology in X-ray medical imaging. The potential is enormous as with CMOS you can add functionalities which cannot be implemented with other technologies.
For example, one can detect single photons and then process them. At a first level, just counting photons could virtually eliminate noise from images. Then one could add the measurement of the energy of every photon, achieving the equivalent of ‘colour’ imaging. Other types of processing would be possible, e.g. measuring the time of arrival of photons, which could be interesting for time-resolved applications
Are there any topics you’d like to revisit?
Fairly early on in my career I designed the first X-ray photon counting chip. At that time it was coupled to a separate silicon detector. It was designed for a medical beam line on a synchrotron. This prototype demonstrated how beneficial photon counting could be to image quality, but didn’t make it to the market.
The main reason was that the technology we chose was still too complicated so not suitable for large volume manufacturing. Now that CMOS image sensors are around and starting being used for X-ray medical imaging as well, I would like to revisit the whole concept of photon counting and energy measurement and apply to wafer-scale CMOS image sensor technology.
Why does ultra-high speed imaging matter?
Ultra-high speed is imaging at or beyond 1 million frames per second. The main field of application is material science, but there is an interest now in using it for looking at the way bubbles can be popped open and deliver drugs locally to cancerous cells. In order to understand how bubbles behave, ultra-high speed imaging is necessary. Using bubbles to deliver drugs would be much less invasive than other ways.
Which companies do you admire and why? Can you give us an example inside and outside your field?
Difficult to be impartial on the first part of the question! After many years working in publicly funded research, I decided to join Specialised Imaging Ltd. This is a small UK company which has been able through the years to continuously innovate in the field of ultra-high speed imaging. My admiration for them is part of the reason to joined them and founded their CMOS image sensor design spin-off, wegapixel.
Moving away from my personal experience, I also admire Aspect Systems Gmbh. This is another small company, based in Germany. They provide image sensor testing service and product and have managed to grow over the years in an organic and sustainable way. They are passionate about what they do and very customer-focused.
What are you looking forward to most at MediSens?
I have attended other conferences organised by the same people who are now behind MediSens. So I look forward to the same mix of high-quality talks and great networking opportunities. As I mentioned above, X-ray medical imaging is a kind of new frontier for CMOS image sensors. I hope this conference will help move us forward into this new exciting territory and I want to be one of those that make this happen.
Find out more
Built by medical practitioners and the world’s foremost digital imaging experts, this conference addresses the need for a more integrated approach to developing medical imaging systems for clinical use. Topics discussed will cover a range of sensor technologies including CCD, CMOS and fibre-based systems from macro to micro, connected by photonics technologies and the requirement for high quality, reliable imaging.
By bringing together medical professionals and the imaging technology supply chain, the audience can gain a better understanding of the challenges and capabilities of today’s advanced medical imagers.