Rilemo’s portable and battery-powered devices are based on Electromagnetic Radar Spectroscopy Imaging (ERSI), a safer alternative to X-rays and CT, based on transmitting electromagnetic waves towards a patient and receiving their reflections to generate images.
ERSI uses non-ionising waves, which do not cause DNA damage as X-rays can. These waves propagate and reflect inside patients depending on the dielectric permittivity of their tissues, a property closely related to fluid content.
Illustration of the EM spectrum.
This relationship between the high sensitivity of ERSI to dielectric permittivity and the link between dielectric permittivity and fluid content is what makes it possible to build a device capable of detecting the multiple pathologies described in the Product Overview section.
ERSI is built on three steps: signal transmission, reflection reception, and image generation.
The device is secured on the anatomical area of interest with a soft pressure comparable to a sweatband. Because ERSI is not sensitive to most clothing or hair, the patient can remain dressed without complex preparation.
Once in position, the antennas inside the device emit electromagnetic waves at low power towards the patient. These waves operate in the 0.5–4 GHz range, technically classified as microwaves and similar in frequency to Wi-Fi and Bluetooth signals. At these frequencies, electromagnetic waves are non-ionising and do not pose a health risk even with long-term exposure.
After emission, signals reflect off body tissues depending on the dielectric permittivity of each region and travel back to the device, where they are captured and processed into an image. The entire acquisition completes in under 5 seconds, with a Specific Absorption Rate (SAR) below 200 mW/kg, which is 8x lower than a typical smartphone and 16x lower than an MRI.
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This imaging method was developed at the Italian National Institute for Nuclear Physics (INFN) and the European Organisation for Nuclear Research (CERN), derived from Microwave Imaging (MWI) with three fundamental advantages:
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Once the electromagnetic waves interact with the body, the dielectric permittivity of tissues introduces distortions in the reflections. These reflected waves are captured by the system and processed by Rilemo's proprietary AI pipeline, producing three complementary image modalities simultaneously for every acquisition:
These three modalities are produced simultaneously for every acquisition, allowing the clinician to interpret anatomy, structural change, and quantitative tissue composition side by side.