Sergio Maldonado-Ortega – smalort@upv.es
Instagram: @i3m_upvcsic

Instituto de Instrumentación para Imagen Molecular (i3M), Universitat Politècnica de València (UPV) – Consejo Superior de Investigaciones Científicas (CSIC), València, València, 46022, Spain

Enrique González-Mateo
Alejandro Cebrecos
Brenda Morant-Ferrando
César D. Vera-Donoso
Alicia Carrión
Francisco Camarena
Noé Jiménez

Popular version of 3aBAa5 – Preliminary results of kidney stone comminution using acoustic vortices
Presented at the 190th ASA Meeting
Read the abstract at https://eppro01.ativ.me/web/index.php?page=Session&project=ASASPRING2026&id=531062

–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–

Kidney stones are a painful reality for millions of people worldwide. When these small, hard mineral deposits get too big to pass naturally, doctors often turn to non-invasive treatments that use ultrasound waves to break them into tiny pieces from outside the body. The current gold standard, extracorporeal shock wave lithotripsy (ESWL), works, but it can sometimes be slow or less effective on particularly stubborn stones. In recent years burst wave lithotripsy (BWL) has emerged as a new and promising alternative. If ESWL was a big hammer hitting the stones to break them, BWL would be a tiny hammer hitting them with lower pressure but much faster.

We’ve got a new technique for breaking kidney stones that’s both efficient and effective. It uses something called acoustic vortices.

The Efficacy of the Vortices
Standard ultrasound treatments work like a hammer, hitting the stone with pulses of pressure until it cracks. But our research brings a new approach to the table. By shaping the sound waves into a vortex — kind of like a whirlpool or a tornado — we can do more than just “hit” the stone; we can also twist it. The twisting motion of an acoustic vortex creates unique stresses that pull and twist the stone’s structure at the same time. This “rotational stress” makes the fragmentation process much more efficient, tearing the stone apart from the inside out in ways that standard pulses cannot.

Testing the Technology
To test this theory, we developed a functional portable prototype shown in Fig. 1, featuring a robotic arm equipped with two specialized ultrasound transducers. One therapeutic transducer of 1.1 MHz and 128 elements, which acts as the “breaker,” sending out the vortex waves. One imaging probe with 128 elements, basically an “eye” that let us see the stone and keep an eye on how it is breaking down in real-time.

Figure 1: Here you can see our portable prototype, with all the equipment mentioned previously, such as the robotic arm and the transducers attached to it (a). Schematic explaining how this technique would work in a real scenario (b).

We put our vortices to test by comparing them against the best emerging ultrasound technique (conventional BWL) under the same conditions. We tested them on two types of targets:

• Artificial stones: Lab-made models of BegoStone designed to mimic the properties of different human stones.
• Real stones: Challenging samples donated by patients that were so tough they had already survived previous conventional hospital treatments without breaking. We tested different types of stones, like uric acid, brushite, apatite, and calcium oxalate monohydrate (COM).

Twice as Fast, Twice as Effective
The results were clear. When using acoustic vortices, the artificial stones broke twice as fast as they did with conventional BWL. Video 1 illustrate the fragmentation speed difference between both techniques in experiments conducted with artificial stones.

We conducted a total of 16 experiments for this type of artificial stone. Figure 2 illustrates the average fragmentation speed across all these experiments, comparing both techniques. More importantly, the success carried over to real-world cases. The human stones we tested were “unbreakable” by current techniques, yet our vortex technology successfully crumbled them, as Fig. 2 shows.

Figure 2: Average fragmentation process of artificial stones with conventional BWL and Vortex (a). Average fragmentation process of real kidney stones with conventional BWL and Vortex (b).

Why It Matters
This breakthrough could lead to faster medical procedures, meaning less time on the operating table for patients and a higher success rate for treating those stubborn stones that current technology struggles to crack. By adding a “twist” to traditional physics, we are opening the door to a more efficient and potentially safer non-invasive future for kidney stone treatment.