BackgroundFundamental researches
We have discovered that ultrasound irradiation generates electricity and magnetism in biological tissues and materials. We are commercializing a technology for sensing the electromagnetic signals induced by ultrasound (acoustically stimulated electromagnetic signals: ASEM signals).
(Left) Comparison between Echo and ASEM methods. (Right) Echo and ASEM images of a rat femur.
ref.) K. Ikushima, Progress Review, Jpn. J. Appl. Phys. 62, SJ0802 (2023)
The Acoustically Stimulated ElectroMagnetic method (ASEM method) is based on the basic researches of IKUSHIMA Group at Tokyo University of Agriculture and Technology. For details, please visit IKUSHIMA Group's website.
Biomedical sensingMedical and healthcare
In fibrous biological tissues such as bones, tendons, ligaments, aortic walls, and aortic valves, ultrasound pressure produces electrical polarization (ASEM signal). Our technique visualises the crystallinity and orientation of collagen and elastin based on the size and orientation of this polarisation. In particular, we aim to assess the quality (crystallinity) of locomotory organs, to evaluate healing of fractures and tendon ruptures and to visualise/quantify the effects of exercise.
ASEM signals (shown in green) of tendon superimposed on the standard echo image.
ref.) Nature Research Highlights " The body electric: soft tissue makes electricity under stress" APS Physics: Soft Biological Tissues Can Be Piezoelectric. "Electric Polarization of Soft Biological Tissues Induced by Ultrasound Waves", Phys. Rev. Lett.123, 238101 (2019) (Original manuscript, Supplemental material)
Collagen, which makes up approximately 60% of the body's protein, plays a role in shaping our bodies, including the locomotor organs, internal organs and blood vessels. One of the main factors leading to the need for care and support is "disorders of the locomotor organs" such as fractures, falls and joint diseases. In the context of the global ageing population, maintaining one's own mobility of one's own volition is extremely important for independent living. In the working-age population, an early return to society after a fracture or tendon rupture has economic value for both the individual and society. This project aims to develop support for rehabilitation and everyday health management, as well as medical treatment, including diagnosis and treatment decisions. Through this project, we hope to realise a society in which each individual can maintain and manage his or her own health condition, enjoy appropriate exercise and lead a lively life.
Acoustomagnetic sensing and industrial inspectionIndustrial sensing
In magnetic materials such as steel, ultrasound pressure produces magnetic polarization (ASEM signal). The magnitude and direction of the polarization depend on the magnetic domain structure in the ultrasonic irradiated area.
The ASEM method allows magnetic imaging and local magnetic hysteresis measurements via ultrasonic scanning.
The acoustomagnetic sensing is used for nondestructive testing and evaluation of steel products and infrastructures.
(Left) Stress embrittlement of austenitic stainless steel. (Right) Visualization of residual stress distribution in a welded specimen.
ref.) "Evaluation of Tensile Residual Stress in Welded Steel Plates Using Acoustically Stimulated Electromagnetic Response", IEEE T-UFFC 68, 1478 (2022) "Magnetic hysteresis and magnetic flux patterns measured by acoustically stimulated electromagnetic response", Jpn. J. Appl. Phys. 54, 086601 (2015). "Magnetic sensing via ultrasonic excitation" Rev. Sci. Instrum. 84, 044903 (2013)
HistoryASEM technology
