3D acoustic holograms to treat diseases like Alzheimer’s or Parkinson’s

Nervous system diseases caused a total of 27,508 deaths during 2020 in our country, according to Dice of the INE. Within this category, we find well-known pathologies such as Alzheimer’sThe from parkinsonschizophrenia or multiple sclerosis.

Using a new technology, a team from the Polytechnic University of Valencia (UPV), the Higher Council for Scientific Research (CSIC) and the columbia university (USA) created acoustic holograms 3D printed to improve the treatment of this type of disease.

The technique makes it possible to cross, for the first time, the blood brain barrier in both hemispheres simultaneously. This barrier is a protective system that controls and restricts the entry of foreign substances between the bloodstream and brain fluid. With this control, the administration of therapeutic drugs to combat pathologies that affect the central nervous system is facilitated.

as explained Francisco Camara, researcher at the Institute of Instrumentation for Molecular Imaging (I3M), a ultrasound Focused treatments allow the treatment of neurological diseases thanks to their ability to generate therapeutic effects in a precise and non-invasive way.

“However, applying them to the structures of the central nervous system is complicated. This is due to the aberration and attenuation effects of the bones of the skull and the complex and extensive spatial distribution of the deep structures of the brain”, says Camarena.

Acoustic holograms are an improvement over previous ultrasound treatments and can correct these aberrations introduced by the skull. “The ultrasound beam is focused and adapted bilaterally and very precisely in parts of the brain of great therapeutic interest, such as, for example, the two nuclei that make up the hippocampus, related to Alzheimer’s disease, and which has a whimsical three-fold shape. dimensions”, he adds. Noé Jimenez, researcher Juan de la Cierva from the UPV.

3D acoustic hologram. / UPV

How it works?

The ultrasound emitter is like a loudspeaker that vibrates at 500,000 oscillations per second (a conventional one can reach 250/s). The hologram is placed in front of the emitter and is traversed by the wave. At the same time, a cone filled with water is placed in contact with the skull, through which the wave propagates before reaching the patient. Then the wave travels through the skull, finally focusing on the area of ​​the brain of therapeutic interest.

At the same time, microbubbles – contrast agents – are introduced into the bloodstream, which, when they reach the capillaries of the brain and coincide with the ultrasound, begin to vibrate. The blood-brain barrier skin starts to sag and that’s when ‘small cracks’ open through which drug molecules pass for the treatment of pathology that affects the central nervous system.

3D hologram operation. / UPV

Custom, low-cost holograms

The hologram, customized for each case, is created with a 3D printer. “Let’s say the doctor needs to sonify a patient’s amygdala. To do this, he would provide us with a CT scan and an MRI, in which he would identify and segment the treatment area. With this information, we design the hologram we need to achieve the sonification of the region in question”, explains Sergio Jiménez, from the UPV.

Jiménez also highlights the low cost of holograms, which between 40 and 300 euros depending on the medical application.

Currently, the team of researchers from UPV, CSIC and Columbia University is working to test this new technology in monkeys. They are also designing the first protocols for human experimentation. with the aim of treating brain tumors and developing brain neurostimulation studies.