This wearable ultrasound device uses a miniaturized transducer and bio-adhesive hydrogel to non-invasively stimulate the brain for long durations, potentially treating neurological disorders.
Transcranial focused ultrasound (tFUS) has emerged as a promising non-invasive technique for neuromodulation, offering advantages over existing methods like TMS and tDCS in terms of spatial resolution and penetration depth. This technology holds potential for treating various neurological and psychiatric disorders by modulating brain activity in a targeted manner.
Current tFUS systems face significant limitations hindering their widespread adoption and clinical translation. The bulky size of existing transducers, coupled with the rapid dehydration of conventional ultrasound gels used for acoustic coupling, makes long-term and wearable applications challenging. This necessitates frequent reapplication of the gel and limits the practicality of tFUS for continuous neuromodulation, which is often required for sustained therapeutic effects.
This technology describes a wearable ultrasound device for long-term cortical neuromodulation. It features a miniaturized ultrasound transducer called SFAT (Self-Focusing Acoustic Transducer) that uses an ACFAL (Air-Cavity Fresnel Acoustic Lens) to focus ultrasound waves with high spatial resolution and intensity for effective brain stimulation through the skull.
The device also incorporates a bio-adhesive hydrogel made of AMPS and glycerol, which acts as a coupling medium between the transducer and the skin. This hydrogel maintains hydration and adhesion for extended periods, eliminating the need for traditional ultrasound gels that dry out quickly. The system has been shown to suppress somatosensory evoked potentials, demonstrating its potential for non-invasive neuromodulation.
This technology differentiates itself from existing neuromodulation methods in several ways. First, it offers a non-invasive approach for long-term cortical neuromodulation, unlike invasive techniques like deep brain stimulation. Second, the miniaturized SFAT, coupled with the bio-adhesive hydrogel, allows for a wearable design that does not require handheld operation or bulky setups. This is a significant improvement over traditional transcranial focused ultrasound (tFUS) systems, which are large and require skilled operators. Third, the bio-adhesive hydrogel provides a long-term stable coupling solution compared to conventional ultrasound gels, enabling continuous treatment over extended periods.
These features make this technology a promising platform for various applications, including the treatment of neurological and psychiatric disorders.
https://www.biorxiv.org/content/10.1101/2024.07.17.603650v1