Ton van der Steen receives highest international recognition for ultrasound

The figurehead of ultrasound in the Netherlands, is how colleagues call Prof. Dr. Ton van der Steen of Erasmus MC. On Oct. 11, 2022, he received the highest international recognition in his field, the Lord Rayleigh Award. "I just love sound tremendously," he said.

The Medical Delta professor and former president of Medical Delta was standing at the entrance of the Kruger Park in South Africa, ready to go on safari with his son, when the email arrived. He was the recipient of the 2022 Lord Rayleigh Award, presented by the world's largest engineering society: the Institute of Electrical and Electronics Engineers (IEEE). "It made me quiet for a moment, I could hardly believe it. It is the most important award in my field: ultrasound. For me, it is the ultimate recognition of my scientific work at the frontier of technology and clinic."

In the vein

Van der Steen receives the prize for the technological innovations he brought to patients with cardiovascular diseases. He developed several methods to image constrictions in the coronary arteries of the heart not from the outside, but from inside the vessel. With his team from the Biomedical Engineering Department at Erasmus MC's Thorax Center, Van der Steen designed and built catheters that use light and sound waves to map the plaque in the vein. "The light is in there to determine the chemical composition of the plaque and with the sound we map the anatomy," he said.

In fact, how the plaque is composed is crucial for treatment, Van der Steen says. A plaque composed of connective tissue can be very uncomfortable and cause chest pain, but is not fatal. But does the plaque contain a fat globule with a membrane over it? Then it's a different story: if the fat globules shoot loose, the patient may develop thrombosis and suffer from a brain or heart attack.

So before the interventional cardiologist gets to work with balloons and stents to fix the narrowing, these days he or she can use an intravascular catheter to determine if and how fragile the plaque is. "This allows the interventional cardiologist to see if and where to place a stent. For example, you don't want the edges of the stent to land exactly in a fat globule," Van der Steen explains.

No straightforward process

Designing and making the intravascular catheter is not a straightforward process, Van der Steen explains. "To do it is not so difficult, but to do it in such a way that it is technically reproducible and can be used in patients is. For our latest catheter - a photoacoustic catheter - a 0.8-millimeter diameter tube contains two coaxial cables, a light fiber and on the tip a mirror, two echo elements, a preamplifier and a chip. All that has to be controlled from outside the body through that tube. And the whole thing has to rotate 3000 times a minute, so that the whole inside of the vessel is viewed. Because to get it done we have been busy for quite some time, with the help of the Experimental Medical Instrumentation Department and colleagues from TU Delft."

Van der Steen is not only praised for his technical feats. According to his peers, he also often succeeds in getting his discoveries to the patient. To do so, he seeks cooperation with what he calls the "golden triangle": engineers, doctors and industry. One of the highlights was the first time the imaging catheter designed by Van der Steen and his team was used on a patient. "I had stipulated that the first ten patients were treated in Rotterdam. We broadcast that moment live from the catheterization room at an international congress for cardiologists attended by more than 10,000 people." This catheter is now commercially available.

Circulation of bone

Van der Steen is the first Dutch and the youngest recipient ever of the Lord Rayleigh Award. Usually the award goes to someone nearing the end of his career. That moment is not yet in sight for him, Van der Steen laughs. "I hope this is not the end. There's still so much I'm looking forward to in my field."

As an example, he cites high frame rate imaging. This is a technique in which 5,000 images per second are made. "In my department, we use this to do research into early detection of heart failure. Meanwhile, at Erasmus MC, the technique is also used for guidance of awake brain surgery. Recently, someone from TU Delft in collaboration with my department managed to use high frame rate imaging to measure the blood flow in bone."

What is its clinical application? "I have no idea, but it will exist. The moment it becomes technically possible to measure an organ's anatomy, elasticity or blood flow, you can sit down with clinicians and the application will come naturally."

This article appeared on Amazing Erasmus MC.

BNR Nieuwsradio broadcast an interview with Ton van der Steen on the occasion of the Lord Rayleigh Award. You can listen to that item here.