High frame rate vector flow imaging of stenotic carotid bifurcation: computational modeling and analysis

Poster Session Session P1Aa. Beam Formation: Computational Aspects And Artifact Reduction: no. P1Ab-1Analysis of the complex blood flow pattern in the carotid bifurcation is clinically important to the diagnosis of carotid stenoses. We hypothesize that the use of high frame rate imaging methods such as plane wave excitation, together with vector flow estimators like block matching, may potentially be a suitable imaging problem to this problem. This paper presents our team’s initial efforts in developing a high frame rate vector flow imaging framework that is based on plane wave excitation principles and a high dynamic range block matching algorithm that incorporates least squares fitting principles. We have conducted a series of Field II simulations on straight tubes and carotid bifurcation to evaluate the estimation accuracy and imaging performance of our framework. Results indicate that high-frame-rate vector flow imaging is capable of visualizing complex blood flow. It has potential to be further developed into a new clinical technique for vascular diagnoses.published_or_final_versionThe 2011 IEEE International Ultrasonics Symposium (IUS), Orlando, FL., 18-21 October 2011. In IEEE International Ultrasonics Symposium Proceedings, 2011, p. 409-41

Scalability support for multiparty multimedia communications

In this paper, we propose a new communication abstraction known as the group channel which facilitates and supports the implementation of multiparty interactive multimedia (MIM) applications such as video conferencing. The group channel is a high-level abstraction for group communication. The credit scheme and the dynamic bandwidth calibration scheme are provided as an integral part of the group channel service for allocating network bandwidth dynamically as participants join and leave the group channel. The multimedia transport protocol (MTP) is proposed as a realization of the group channel service in the ATM network. Its prototype implementation and a simple multiparty videoconferencing application built on top of the MTP prototype are described in this paper. Our results show that the group channel is capable of guaranteeing the performance of MIM applications irrespective of the group size and differences in workstation speeds