Vascular Wall Stiffness Indices Detection Using an Accelerometer-Based System

The measure of arterial stiffness is significant for the diagnosis of the cardiovascular health. A prototype accelerometer- based system for vascular stiffness indices detection is proposed and experimentally validated. The developed accelerometer-based system could continuously capture the accelerations related to the displacement of the carotid arterial walls. The measured accelerometric waveforms are recorded by a data acquisition card for signal processing and analysis in real-time. The recorded accelerometric signals from the carotid skin surface are double- integrated and calibrated linearly using our clinically validated ARTSENS® (ARTerial Stiffness Evaluation for Noninvasive Screening) device to estimate the subject-specific one-time calibration coefficients. The acquired accelerometric signal with these calibration coefficients was used to estimate the diameter parameters such as arterial distension (Δ D), end-diastolic diameter (Dd), and systolic diameter (D s). 12 subjects (7 males, 5 females, age =25.42± 2.5 years) with no prior history of cardiovascular diseases were enrolled for the in-vivo validation study. The accelerometer-based system could capture continuous distension waveforms for all the recruited subjects. Arterial stiffness indices such as stiffness index (β), arterial compliance (AC) and Peterson's elastic modulus (Ep) were calculated using the obtained diameter parameters from the accelerometer-based system. The correlation (R2) for β, AC and Ep observed between ARTSENS reference device and accelerometric system were 0.93, 0.95 and 0.94 respectively. Bland-Altman plots of β, AC, and Ep of ARTSENS reference device and the accelerometric system shows a small mean bias of 0.07, -0.001 and 0.81 respectively. The preliminary results suggest the potential of the accelerometer- based system for vascular wall stiffness indices detection.