21 Aug 10:15 Po-Hsiang Lai: Laser Doppler Vibrometry Measurements as a New Biometric

HIIT seminar, Friday Aug 21, 10:15 a.m. (coffee from 10), Exactum C222

Po-Hsiang Lai
Washington University in Saint Louis
Electrical and Systems Engineering

Laser Doppler Vibrometry Measurements as a New Biometric

Abstract:
A novel approach of remotely sensing mechanical cardiovascular activity as a biometric marker is proposed. Laser Doppler Vibrometry (LDV) is used to sense vibration on the surface of the skin above the carotid artery. This motion is related to arterial wall movements associated with the central blood pressure pulse. The non-contact basis of the LDV method has several potential benefits related non-intrusiveness. Several recognition methods are proposed that use the temporal and/or spectral information in the signal to assess biometric performance both on an intra-session basis, and on an inter-session basis involving testing repeated after delays of 1 week to 6 months. Authentication testing performance reaches an equal-error rate of 0.5% for intra-session testing. However, performance degrades substantially for inter-session testing, requiring a more robust approach to modeling. Improved performance is obtained using techniques based on time-frequency decomposition, incorporating a method for extracting informative components. Biometric fusion methods are applied to train models using data from multiple sessions. As currently implemented, this approach yields an inter-session equal-error rate of 6.3%. LDV biometric performance under the effect of physical exercise is tested. An equal error rate of 2.8% for inter-state tests indicates that the LDV pulse signal is stable after moderate physical exercise. The performance degrades during exercise, but improves within 30 seconds as the heart rate recovers during the resting period. The results suggest that the variability caused by heart rate fluctuations and respiration changes decreases within a short time.

Bio:
Po-Hsiang Lai is working on his Doctor of Science degree in Electrical and Systems Engineering at Washington University in Saint Louis. He works with his advisor Professor Joseph A. O'Sullivan on pattern recognition, biometrics and clustering problems using information theoretic methods. He received his Bachelor of Science degree in Applied Science Major in Electrical Engineering in 2006 from Washington University.

Email: skyhsiang@gmail.com