Scientists in Austria and France have developed a new imaging method that can reveal objects hidden behind opaque materials such as sand, fog, or even human tissue, potentially opening new frontiers in medical diagnostics and sensing technologies.<\/p>\n
The breakthrough, published this week in Nature Physics, was achieved by researchers at the Institut Langevin in Paris and TU Wien in Vienna.\u00a0<\/p>\n
Their approach uses what they call a \u201cfingerprint matrix,\u201d a mathematical description of the unique way each object scatters waves such as light or ultrasound.<\/p>\n
Fingerprint matrix<\/p>\n
Ordinary imaging methods, whether photographs, sonar, or ultrasound scans, rely on sending a wave toward an object and analyzing the portion that bounces back.\u00a0<\/p>\n
But this becomes nearly impossible when a dense medium obscures the object. In such cases, waves scatter off the target and repeatedly off the surrounding material, creating a noisy signal.<\/p>\n
\u201cInstead of the object, all you see is a diffuse fog; this is a fundamental problem of imaging techniques, from sonar in submarines to imaging in medicine,\u201d said Lukas Rachbauer, a study co-author.<\/p>\n
The team first studied objects in a clear environment to solve this, recording how they scatter waves under ideal conditions.\u00a0<\/p>\n
That pattern, or fingerprint, is stored in a matrix. Later, the researchers send in ultrasonic waves when the same object is hidden in a complex environment, such as a steel ball buried in sand.\u00a0<\/p>\n
Although most of the waves scatter chaotically, some still interact with the buried object and carry traces of its fingerprint.<\/p>\n
By comparing the measured signals with the stored fingerprint, the team\u2019s algorithm can pinpoint the object\u2019s location even though it cannot be seen directly.<\/p>\n
\u201cFrom the correlations between the measured reflected wave and the unaltered fingerprint matrix, it is possible to deduce where the object is most likely to be located, even if the object is buried,\u201d said Stefan Rotter, professor at TU Wien\u2019s Institute of Theoretical Physics.<\/p>\n
Detecting hidden objects<\/p>\n
The researchers tested the system with steel balls buried in sand and extended it to medical scenarios.\u00a0<\/p>\n
In one application, they successfully identified lesion markers used to monitor breast cancer, which are often obscured by scattered signals in traditional scans.\u00a0<\/p>\n
They also used the technique to detect muscle fibers, a capability that could advance the diagnosis of heart and muscular diseases.<\/p>\n
Beyond medicine, the fingerprint matrix could<\/a> apply to optical imaging and other wave-based detection systems.\u00a0<\/p>\n