7 research outputs found
H2B: Heartbeat-based Secret Key Generation Using Piezo Vibration Sensors
We present Heartbeats-2-Bits (H2B), which is a system for securely pairing
wearable devices by generating a shared secret key from the skin vibrations
caused by heartbeat. This work is motivated by potential power saving
opportunity arising from the fact that heartbeat intervals can be detected
energy-efficiently using inexpensive and power-efficient piezo sensors, which
obviates the need to employ complex heartbeat monitors such as
Electrocardiogram or Photoplethysmogram. Indeed, our experiments show that
piezo sensors can measure heartbeat intervals on many different body locations
including chest, wrist, waist, neck and ankle. Unfortunately, we also discover
that the heartbeat interval signal captured by piezo vibration sensors has low
Signal-to-Noise Ratio (SNR) because they are not designed as precision
heartbeat monitors, which becomes the key challenge for H2B. To overcome this
problem, we first apply a quantile function-based quantization method to fully
extract the useful entropy from the noisy piezo measurements. We then propose a
novel Compressive Sensing-based reconciliation method to correct the high bit
mismatch rates between the two independently generated keys caused by low SNR.
We prototype H2B using off-the-shelf piezo sensors and evaluate its performance
on a dataset collected from different body positions of 23 participants. Our
results show that H2B has an overwhelming pairing success rate of 95.6%. We
also analyze and demonstrate H2B's robustness against three types of attacks.
Finally, our power measurements show that H2B is very power-efficient
OCHID-Fi: Occlusion-Robust Hand Pose Estimation in 3D via RF-Vision
Hand Pose Estimation (HPE) is crucial to many applications, but conventional
cameras-based CM-HPE methods are completely subject to Line-of-Sight (LoS), as
cameras cannot capture occluded objects. In this paper, we propose to exploit
Radio-Frequency-Vision (RF-vision) capable of bypassing obstacles for achieving
occluded HPE, and we introduce OCHID-Fi as the first RF-HPE method with 3D pose
estimation capability. OCHID-Fi employs wideband RF sensors widely available on
smart devices (e.g., iPhones) to probe 3D human hand pose and extract their
skeletons behind obstacles. To overcome the challenge in labeling RF imaging
given its human incomprehensible nature, OCHID-Fi employs a cross-modality and
cross-domain training process. It uses a pre-trained CM-HPE network and a
synchronized CM/RF dataset, to guide the training of its complex-valued RF-HPE
network under LoS conditions. It further transfers knowledge learned from
labeled LoS domain to unlabeled occluded domain via adversarial learning,
enabling OCHID-Fi to generalize to unseen occluded scenarios. Experimental
results demonstrate the superiority of OCHID-Fi: it achieves comparable
accuracy to CM-HPE under normal conditions while maintaining such accuracy even
in occluded scenarios, with empirical evidence for its generalizability to new
domains.Comment: Accepted to ICCV 202
Wireless Sensing for Medical Applications
A transmitted wireless signal travelling at the speed of light in indoor spaces goes on an intriguing journey inwhich it reflects off ambient objects and gets modulated by human motion before reaching the receiver.Leveraging this fundamental principle, this thesis exploits radio signals from commercial wireless devices toenable novel health sensing applications. The practical outcomes of this work range from wireless-basedphysiological vital sign monitoring to the first system for automatic tracking of Hand Hygiene practices ofhealthcare workers.To deliver this, we introduced techniques and algorithms to analyse human motions form reflected radiosignals while addressing the practical challenges associated with the noise presence in Radio Frequency (RF)signal and the requirements of the sensing applications themselves. By relying purely on RF signals forsensing, these systems operate in a contact-less manner, agnostic to lighting conditions and can fit inresidential and clinical environments without invading the privacy of the inhabitants. In effect, we show howthe capabilities of commercially available RF devices can be harnessed for health and well-being sensingwhile addressing the downsides of alternative modalities (e.g., wearables and camera-based systems)
ICML 2023 Topological Deep Learning Challenge:Design and Results
This paper presents the computational challenge on topological deep learning that was hosted within the ICML 2023 Workshop on Topology and Geometry in Machine Learning. The competition asked participants to provide open-source implementations of topological neural networks from the literature by contributing to the python packages TopoNetX (data processing) and TopoModelX (deep learning). The challenge attracted twenty-eight qualifying submissions in its two month duration. This paper describes the design of the challenge and summarizes its main findings.</p
ICML 2023 topological deep learning challenge. Design and results
This paper presents the computational challenge on topological deep learning that was hosted within the ICML 2023 Workshop on Topology and Geometry in Machine Learning. The competition asked participants to provide open-source implementations of topological neural networks from the literature by contributing to the python packages TopoNetX (data processing) and TopoModelX (deep learning). The challenge attracted twenty-eight qualifying submissions in its two-month duration. This paper describes the design of the challenge and summarizes its main finding