We have proposed and demonstrated a non-contact method for generating in-vivo ultrasound by irradiating the body surface with modulated terahertz waves. Unlike traditional ultrasound imaging, this approach allows for the creation of in-vivo ultrasound without the need to attach a transducer to the skin using gel. While terahertz waves are generally thought to be unsuitable for in-vivo applications due to their strong absorption by water, we are actively leveraging this absorptive property for a photoacoustic effect. Looking ahead, we aim to develop in-vivo ultrasound technologies that can seamlessly integrate into daily life and sports activities, with the goal of contributing to preventive medicine and enhancing physical skills.
Natsumi Ichikawa and Yasuaki Monnai. “Generating in vivo continuous ultrasound based on sub-terahertz photoacoustic effect,” APL Photonics. 8, 086105 , 2023.