Innovative Detachable Acoustic Lens Enhances Ultrasound Imaging Precision

Researchers at the Korea Research Institute of Standards and Science (KRISS) have unveiled a groundbreaking detachable acoustic lens designed to facilitate precise focal adjustments in ultrasound imaging systems. This advancement promises to significantly improve the accuracy of ultrasonic inspections, akin to how photographers switch camera lenses to optimize image quality.

The study detailing this innovation has been published in the journal Measurement Science and Technology. Ultrasound imaging functions by emitting sound waves into various objects or the human body and capturing the echoes to visualize internal structures. Among the various methods, the C-scan technique is particularly notable for its ability to produce high-resolution images, making it invaluable in both medical diagnostics, such as cancer detection, and in industrial applications like nondestructive testing (NDT) of components in aircraft and pipelines.

To achieve high-resolution ultrasound images, it is crucial to enhance the intensity of emitted and reflected sound waves while also controlling the focal length with precision. Typically, focused ultrasound transducers are employed in C-scan ultrasound inspection systems to direct the dispersed ultrasound energy onto specific target areas, thereby improving image quality.

However, a significant drawback exists in that standard focused ultrasound transducers come with a fixed focal length. This limitation necessitates the acquisition of multiple transducers, each with a different focal length, leading to increased costs. Additionally, it complicates the fine-tuning of focus to align with the characteristics of the object being examined, hindering optimal resolution.

To address this challenge, the Acoustics, Ultrasound, and Vibration Metrology Group at KRISS has developed a novel design for a detachable acoustic lens. By integrating this newly engineered lens with a fixed-focus ultrasound transducer, users can readily adjust the focal distance to match the inspection target without needing to purchase additional equipment. This flexibility allows for tailored image resolution specific to each examination.

The KRISS team's acoustic lens features an aspheric shape, which provides a sharper focus and enhanced resolution compared to traditional spherical lenses. Conventional acoustic lenses often suffer from spherical aberration, resulting in a blurry image at the edges due to the lens configuration. The researchers have also created a foldable design for the lens, enabling size adjustments to fit various attachment areas.

In tests involving a C-scan ultrasound imaging device applied to a phantom model simulating human anatomy, the KRISS lens successfully visualized fine structures as small as 25 micrometers (um), achieving a resolution approximately 1.5 times greater than that of a similar device without the lens at the same focal distance.

According to Dr. Kim Yong Tae, a principal research scientist at KRISS, there are plans to extend the application of this lens design technology beyond C-scan systems to encompass a broader range of ultrasound imaging applications.

For further reading, the complete study is accessible in Measurement Science and Technology with the DOI: 10.1088/1361-6501/ad9ecc.