Portable ultrasound scanner identifies underage victims, border-crossers

“The use of our portable scanner as a rapid screening device is comparable with that of the breathalysers used to test drivers’ alcohol levels,” explains Hewener. “While the results of the test are not accepted as legal evidence per se, they can at least confirm initial suspicions and provide grounds for further testing – which in the case of driving under the influence would mean giving a blood sample for blood-alcohol analysis.” The handheld ultrasound scanner developed by the Fraunhofer scientists could thus give authorities an additional tool for confirming suspected cases of forced prostitution of minors, so they may more easily obtain a court order for an X-ray examination to determine the victim’s exact age.

From a technical point of view, the solution consists of a low-cost, handheld, single-channel ultrasound device that is wrapped around the person’s wrist to perform the test. It transmits the measured data via a wireless interface directly to a connected mobile device, such as a smartphone or tablet, for processing and analysis. The results of the analysis are displayed on the screen of the user’s mobile device in an easy-to-read graphical format. Traffic-light colours indicate whether the data corroborates or weakens suspicion of crime. This simplified measurement and display system facilitates use of the technology on-site, in situations typically encountered by law enforcement agents. No special training is required to operate the device and evaluate the measurement results. Smart algorithms derived from machine learning combined with knowledge from practical experience perform the analysis and interpretation of the measured data, and are integrated into the corresponding app.

Embedded in an overall project that includes clinical, social and psychological aspects
“Conventional ultrasound measuring systems, such as those used in diagnostic imaging, are unsuitable for this type of application because the ultrasound wave frequencies they employ are too high,” says Hewener, describing the technological challenges of this project. “The electronics we developed for our compact mobile scanner support the necessary transmission and reflection measurements using low-frequency ultrasound, and wirelessly transmit the raw data to a terminal device for processing and output. And because that device is a consumer electronics device such as a smartphone, i.e. containing standard components, there is no need for the ultrasound scanner hardware to have expensive, customized electronics. This reduces the device’s development costs and results in a particularly low purchase price for the authorities.”

As part of the overall PRIMSA initiative funded by the German Federal Ministry of Education and Research (BMBF), the design and use of the scanner system is also being evaluated by project partners from a social and psychological perspective, accompanied by in-depth reflections on its clinical implications. The system is currently being tested by Saarland University in a clinical study at the university’s medical center in Homburg, Germany, in collaboration with the non-profit association Hope for Freedom. In the altogether difficult and delicate context of the trafficking of children, one of the best possible scenarios would be one in which the border control authorities were able to apprehend minors at their first point of entry into the EU. With a suitably reliable method of identifying underage victims, they could be immediately handed over into the care of the prevention and intervention program.

On the technical development side of the program, Fraunhofer IBMT is collaborating with an industry partner: CEMEC – Intelligente Mechanik GmbH. After completing the evaluation phase, they will develop a prototype based on the existing technology demonstrator, ultimately culminating in the ready-to-use product. This phase too involves ongoing collaboration with government agencies to ensure that the product meets the specific needs and requirements of the real environment in which it will be used. Further studies will also be carried out to verify the reliability of the measurement system and the accuracy of its results. Taking the long view, the new scanning device may open up many other medical applications, for example when diagnosing osteoporosis patients in residential care facilities or at home.