Measurement of flow-mediated vasodilatation using Kalman filtering

Brachial artery flow-mediated vasodilation (FMD) is increasingly used as a measure of endothelial function. High resolution ultrasound provides a noninvasive method to observe this flow-mediated vasodilation by monitoring the diameter of the artery over time. In the past, the diameter had to be measured in tedious postprocessing routines, usually by the examiner himself. We present a system, which is able to process ultrasound rf-data in realtime. On that system, we implemented a Kalman filter, which makes the tracking of both vessel walls possible. The diameter can be calculated accurately, taking into account process noise as well as measurement noise.