Automatic Measurement of End-Diastolic Arterial Lumen Diameter in ARTSENS

Abstract

Over past few years, we are developing a system for facilitating large scale screening of patients for cardiovascular risk—arterial stiffness evaluation for noninvasive screening (ARTSENS). ARTSENS is an image-free device that uses a single element ultrasound transducer to obtain noninvasive measurements of arterial stiffness (AS) in a fully automated manner. AS is directly proportional to end-diastolic lumen diameter (Dd). Multilayered structure of the arterial walls and indistinct characteristics of intima-lumen interface (ILI) makes it quite difficult to accurately estimate Dd in A-mode radio-frequency (RF) frames obtained from ARTSENS. In this paper, we propose a few methods based on fitting simple mathematical models to the echoes from arterial walls, followed by a novel method to fuse the information from curve fitting error and distension curve to arrive at an accurate measure of Dd. To bring down the curve fitting time and facilitate processing on low-end processors, a novel approach using the autocorrelation of echoes from opposite walls of the artery has been discussed. The methods were analyzed for their comparative accuracy against reference Dd obtained from 85 human volunteers using Hitachi-Aloka eTRACKING system. Dd from all reported methods show strong and statistically significant positive correlation with eTRACKING and mean error of less than 7% could be achieved. As expected, Dd from all methods show significant positive correlation with age.

Intra- and inter-operator reproducibility of automated cloud-based carotid lumen diameter ultrasound measurement

“…The study indicated that the reproducibility was sufficient for in vivo studies if the width of the ROI is 1.0 mm or wider. Sahani 30 et al in 2015 propose a novel method to fuse the information from (a) curve fitting error and (b) distension curve to arrive at an accurate measure of LD computation from a low axial-resolution ultrasound system such as ARTSENS in 85 human volunteers. The study was based on the fusion of information from more accurate distension waveforms with less reliable waveforms to obtain higher accuracy for LD estimation.…”

“…Fourth, due to multifocal 12 nature of calcium in the carotid arteries in both near and far walls (double sided), a decrease in LD can predict the stenosis severity. Fifth, an accurate end-diastolic LD is an essential parameter in measuring arterial elasticity 13 …”

“…Recent innovations19, [20], 21, 22, 23 have enabled us to automate the LD computations. Previous automated LD measurement systems24, 25, 26, 27, 28, 29, 30 lack an “anytime-anywhere” solution and telemedicine-based model 31 . A detailed literature survey is presented in the Discussion section.…”

Arterial compliance probe for cuffless evaluation of carotid pulse pressure

“…The acquired ultrasound echo frames and dual channel MPG signals were processed simultaneously, but independently in the digital domain. Construction of the arterial lumen diameter waveform from the ultrasound echo frames was performed using the fully automated algorithm of our clinically validated ARTSENS ® technology, demonstrated in a series of publications [ 27 – 29 , 33 – 35 ]. Briefly, in this technology locations of arterial near and far wall in the filtered ultrasound echoes were identified using wall detection algorithm [ 28 ].…”

Assessment of Carotid Arterial Stiffness in Community Settings With ARTSENS®

“…These continuous echoes are displayed in real-time to provide a visual (video-graphic) effect, which helps the operator precisely orienting the probe along the diameter of the vessel by ensuring out-of-phase moving echoes from both the proximal and distal walls [14]. A set of automated algorithms identify and continuously track echoes originating from the walls and perform an online evaluation of the arterial lumen diameter and distension waveforms [14], [15], [17].…”