Anti-Sensing: Defense against Unauthorized Radar-based Human Vital Sign Sensing with Physically Realizable Wearable Oscillators

TL;DR

This paper introduces Anti-Sensing, a wearable device-based method that uses physically realistic oscillations to disrupt unauthorized radar sensing of vital signs, enhancing privacy in healthcare and human-robot interaction.

Contribution

It proposes a novel, physically realizable perturbation technique using wearable oscillators to defend against radar-based vital sign sensing, with an optimization algorithm for effective disruption.

Findings

Significantly reduces radar-based heart rate estimation accuracy

Effective in both simulated and real-world experiments

Provides a practical privacy-preserving solution for radar sensing systems

Abstract

Recent advancements in Ultra-Wideband (UWB) radar technology have enabled contactless, non-line-of-sight vital sign monitoring, making it a valuable tool for healthcare. However, UWB radar's ability to capture sensitive physiological data, even through walls, raises significant privacy concerns, particularly in human-robot interactions and autonomous systems that rely on radar for sensing human presence and physiological functions. In this paper, we present Anti-Sensing, a novel defense mechanism designed to prevent unauthorized radar-based sensing. Our approach introduces physically realizable perturbations, such as oscillatory motion from wearable devices, to disrupt radar sensing by mimicking natural cardiac motion, thereby misleading heart rate (HR) estimations. We develop a gradient-based algorithm to optimize the frequency and spatial amplitude of these oscillations for maximal disruption while ensuring physiological plausibility. Through both simulations and real-world experiments with radar data and neural network-based HR sensing models, we demonstrate the effectiveness of Anti-Sensing in significantly degrading model accuracy, offering a practical solution for privacy preservation.