High frame rate imaging using parallel transmission of focused coded fields

Misaridis, T; Munk, P

dc.contributor.author	Misaridis, T	en
dc.contributor.author	Munk, P	en
dc.date.accessioned	2014-03-01T02:49:46Z
dc.date.available	2014-03-01T02:49:46Z
dc.date.issued	2004	en
dc.identifier.issn	10510117	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/34735
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-21644433658&partnerID=40&md5=7a73d86d372d52f96f0007afe394270a	en
dc.subject.other	Algorithms	en
dc.subject.other	Backpropagation	en
dc.subject.other	Computer simulation	en
dc.subject.other	Data acquisition	en
dc.subject.other	Matrix algebra	en
dc.subject.other	Phase shift	en
dc.subject.other	Transducers	en
dc.subject.other	Beamformers	en
dc.subject.other	High frame rate imaging	en
dc.subject.other	Medical ultrasound systems	en
dc.subject.other	Multi-focussed pulsed beams	en
dc.subject.other	Ultrasonic imaging	en
dc.title	High frame rate imaging using parallel transmission of focused coded fields	en
heal.type	conferenceItem	en
heal.publicationDate	2004	en
heal.abstract	We have previously presented a numerical method for calculating the excitation signals on individual elements, in order to transmit multi-focused pulsed beams in parallel. The algorithm is based on a modified directivity spectrum method, where local fields are decomposed into plane waves, which are then back-propagated to the transducer elements. In order to form the received beams in parallel, the receiver is a matched filter-and-sum beamformer that uses the calculated transmitted pulses reversed in time, Such an architecture eliminates the need of delay calculations and apodization values on the beamformer, since both are incorporated in the filters. The output of the beamformer is a correlation both in axial and lateral (beam) directions, and this can be used advantageously by generating correlation-based coded focused beams with no need for additional temporalonly compression filtering. This paper shows the design of FM-coded focused fields and how these fields can yield more strongly focused fields or higher frame rate. Simulated images show the implementation of the method using only 4 emissions. Neighboring beams to be formed in parallel use different codes with a cross-correlation of 20 dB. Such a cross-correlation would be insufficient using a conventional delay-and-sum beamformer. In the proposed system, the worst-case beam interference is -46 dB, making it possible to obtain images of similar resolution to conventional imaging at very high frame rates. Additionally, coding partially compensates for the SNR loss that is due to multi-focusing using only few emissions. ©2004 IEEE.	en
heal.journalName	Proceedings - IEEE Ultrasonics Symposium	en
dc.identifier.volume	2	en
dc.identifier.spage	1417	en
dc.identifier.epage	1420	en