DE-102024003678-A1 - Method and device for preventing detection with bio-radars

Abstract

A method for preventing detection with bio-radars is presented, in which the respiratory and heart rate of a living target subject, as well as the frequency and bandwidth of the bio-radar, are recorded, a control signal is generated from the respiratory and heart rate and the frequency analysis of the bio-radar for a metamaterial, the metamaterial is subjected to the control signal, so that the detection of the movement of the metamaterial and the living target subject due to its respiratory and heart rate in successive reflected radar wave pulses of the bio-radar is prevented by compensating the phase profile of the reflected bio-radar pulses.

Inventors

• Martin Schwarz

Assignees

• Bundesrepublik Deutschland (Amt für Ausrüstung, Informationstechnik und Nutzung der Bundeswehr)

Dates

Publication Date

20260513

Application Date

20241108

Claims (2)

1. Method for preventing detection by bio-radar, wherein - the respiratory and heart rate of a living target subject, as well as - the frequency and bandwidth of the bio-radar are recorded, - a control signal is generated from the respiratory and heart rate and the frequency analysis of the bio-radar for a metamaterial, - the metamaterial is subjected to the control signal, so that the - detection of the movement of the metamaterial and the living target subject based on its respiratory and heart rate, - in successive reflected radar wave pulses of the bio-radar is prevented by - compensation of the phase profile of the reflected bio-radar pulses.
2. Procedure according to Claim 1 characterized by the fact that the metamaterial is incorporated into uniform clothing

Description

The invention relates to a method for preventing the contactless, distance-effective detection of vital parameters by bio-radars. Solutions for the contactless detection of heartbeat and/or respiratory rate in living beings (Greek "bios"), so-called bio-radars, are known. They are used not only for the contactless, remotely effective determination of these vital parameters in medicine, but also, among other things, in the search for buried persons, i.e., in locating living individuals under inaccessible piles of rubble during rescue operations. Such systems are also being researched for relieving the burden on nursing staff in care homes, as well as for monitoring suicidal individuals in psychiatric hospitals and prisons. From the European Disclosure Notice EP 2 626 845 A1 A method for the sensor-based monitoring of a room is known, characterized in that the room is monitored with a bioradar sensor for recording vital parameters when at least one person is present, wherein recorded vital parameters are compared with stored normal parameters and a signal is triggered in the event of certain deviations. The German patent specification further reveals DE 11 2015 001 807 B4 A driver fatigue sensor device with millimeter-wave radar and operating method, wherein the operating method comprises: transmitting millimeter-wave signals generated in the integrated millimeter-wave radio input section; receiving millimeter-wave signals reflected from the driver's body; amplifying the reflected signal in the integrated millimeter-wave radio input section; down-converting the signals by mixing them with the same signal of the same frequency as the transmitted signal in the integrated millimeter-wave radio input section; amplifying a converted signal after the mixer in the integrated millimeter-wave radio input section; analog filtering of the signals after amplification in the integrated millimeter-wave radio input section; conditioning the signals in the integrated millimeter-wave radio input section for subsequent analog-to-digital conversion, which is performed by the analog-to-digital conversion unit; digital processing of the signal in the digital processing functionality by: extracting a heart rate from the previously processed signal; Extracting a rate of change of heart rate from the previously processed signal; extracting a respiratory rate from the previously processed signal; extracting a rate of change of respiratory rate from the previously processed signal; digital processing in a driver fatigue event decision functionality. Since radar technology is generally widespread in the military sector, applications in this area are conceivable in the near future. In addition to its already known ability to see through walls, such radars can also be used where optical/visual and/or thermal/infrared concealment measures ("stealth/camouflage") prevent detection in these spectral ranges. This makes it possible to detect living but stationary enemy personnel or infantry units using bio-radar deployed on autonomous vehicles (e.g., drones) or by special forces in combat. (For example, detecting stationary snipers or special forces units, who typically employ very effective optical/thermal-infrared concealment.) Recent publications suggest that bio-radar technology will soon be used for military purposes. This is supported by the fact that there are currently no suitable (passive and tolerable) countermeasures, particularly at the individual level, to protect oneself against bio-radar detection – and that the movements of the living body, specifically the chest, induced by breathing and heartbeat are unavoidable. Since the integration of radar systems into surveillance systems, concealing objects from detection has become a primary objective. Numerous approaches exist for passively protecting objects from detection (e.g., RCS minimization: geometry optimization, coating). More recently, in addition to these approaches, methods have emerged to envelop moving objects with metamaterials, thus protecting them from radar detection. Metamaterials are artificially produced materials with optical, electrical, or magnetic properties that do not occur naturally. For example, the Chinese patent application CN 110011060 A An electromagnetic stealth metamaterial and its application are known. The metamaterial comprises a metallic The electromagnetic camouflage metamaterial consists of a base layer and a dielectric layer arranged sequentially from bottom to top. A multitude of metal spots are arranged on the dielectric layer, with each spot comprising 3 to 6% of the surface area of the dielectric layer's upper surface. This simple structure allows it to be sprayed directly onto a target surface (unless manufactured using three-dimensional printing technology) and offers a wide range of applications. For targets of varying sizes, the unit distribution does not need to be rearranged; only the lengths and area ratios of the metal spots are re