Abstract: The invention relates to a method of segmenting an image of a structure stored as a set of spatially related data points representing variations in a predetermined parameter, said method comprising the steps of selecting a seed point within the structure to be segmented, assigning to each of the data points a value of connectivity indicative of the confidence that respective areas of the data points are part of the same structure as said seed point, said value of connectivity including a function of the distance of the respective point from said seed point, establishing a threshold value for said level of connectivity and selecting for display data points meeting said threshold value.

Abstract: An intravascular ultrasound imaging system in which data from an ultrasonic transducer array is digitized and processed in a pipeline, the latter having means to divert/extract data from the pipeline and reintroduce it into the pipeline to enable images to be displayed retrospectively.

Abstract: A method of overcoming the ring down problem comprises the steps of generating a reference scan and updating it on the basis of a long term running average and then subtracting that running average from the current A-scan to remove the ring down.

Abstract: A catheter (1a, 1b) is provided with an ultrasonic transducer array at its tip (3), the transducer array having been manufactured from an annulus of piezoelectric material (10) by making longitudinal mutually parallel slots (18) in the material.

Abstract: A digital transmission system in which bursts of digital signals are transmitted in opposite directions over a two wire telephone loop at fixed frame intervals. Each signal burst is bounded by initial and final synchronization bits at its beginning and ending respectively. Synchronization is established by determining coincidence of the final bit of one burst, the initial bit of the following burst, and two gating signals having an equivalent time interval therebetween.