The overall goal of the proposed research program is to design and develop a noninvasive device foraccurately measuring arterial compliance. Arterial compliance has been shown to be a strong indicator of manytypes of vascular disease, including cardiovascular disease, peripheral vascular occlusive disease, diabetes,renal failure, and aging. However, current imaging modalities and non-invasive methods of compliancemeasurement are limited by poor resolution, sensitivity and robustness.The proposed arterial elasticity imaging (AEI) device overcomes these limitations, producing real-time imagesof local arterial strain and near-real time elastic modulus results. High precision, direct measurements of vesseltissue motion using ultrasound tissue tracking will be combined with lumen pressure equalization. Usingspeckle tracking techniques, sub-micron precision measurements of tissue motion will be produced with fine,sub-millimeter, spatial resolution in a localized region, allowing direct intramural strain estimation of targetedvessels. In addition, external preloading will significantly improve sensitivity over measurements atphysiological pressure conditions, by increasing the strain induced by the vessel pressure pulse. By combiningpulse wave velocity (PWV) measurements using speckle tracking with intramural strain estimates, the vesselelastic modulus will be reconstructed with significantly reduced error from geometrical uncertainties andboundary conditions. Real-time display of tissue strain images and tracking metrics will provide 'as needed'assessment and valuable feedback information to the user. This technology will fully characterize nonlinearelastic properties in a highly localized region, and provide vascular compliance assessment over a large straindynamic range with very high precision.The main technical challenge facing device development is providing real-time tissue tracking, which is neededfor intramural strain and PWV measurement. Cross correlation based speckle tracking methods requiresignificant computational power, historically limiting them to off-line (i.e., not real-time) processing. PixelVelocity Incorporated has developed algorithms and methods that combined with modern multi-processingcomputer hardware will provide computational power and flexibility needed for real-time arterial elasticitymeasurements in a portable ultrasound device.
Artery hardness, or elasticity, has been shown to be a strong indicator of cardiovascular disease, peripheral vascular occlusive disease, diabetes, renal failure, and aging. The proposed imaging device will directly visualize and quantify vessel elasticity, providing diagnostic and monitoring capabilities for vascular diseases.
| Park, Dae Woo; Kruger, Grant H; Rubin, Jonathan M et al. (2013) In vivo vascular wall shear rate and circumferential strain of renal disease patients. Ultrasound Med Biol 39:241-52 |
| Park, Dae Woo; Kruger, Grant H; Rubin, Jonathan M et al. (2013) Quantification of ultrasound correlation-based flow velocity mapping and edge velocity gradient measurement. J Ultrasound Med 32:1815-30 |
