Measurement of a 2D electric dipole field using the acousto-electric effect

Ragnar Olafsson, Russell S Witte, Matthew O'Donnell

Research output: Chapter in Book/Report/Conference proceedingConference contribution

8 Citations (Scopus)

Abstract

Conventional methods for mapping cardiac current fields have either poor spatial resolution (e.g. ECG) or are time consuming (e.g., intra-cardiac catheter electrode mapping). We present a method based on the acousto-electric effect (AEE) and lead field theory for minimally-invasive mapping of 2D current distributions. The AEE is a pressure-induced conductivity modulation in which focused ultrasound can be used as a spatially-localized pressure source. As a proof of principle we generated a 2D dipole field in a thin bath of 0.9% NaCl solution by injecting 28 mA through a pair of electrodes. A 7.5 MHz transducer was focused on the bath from below. A recording electrode was rotated along the boundary of the bath in 20° steps. For each angle, the transducer was swept over the bath in a raster scan. A pulse-echo and an AEE voltage trace were acquired at each point. The AEE traces were combined in post-processing as if coming from a multi-electrode circular array. The direction and magnitude of the current field at each point in the plane was estimated from the AEE and compared to simulation. The potential field was independently mapped using a roving monopolar electrode. The correlation coefficient between this map and the simulated field was 0.9957. A current source density analysis located the current source and sink to within 1±2 mm of their true position. This method can be extended to 3 dimensions and has potential for use in rapid mapping of current fields in the heart with high spatial resolution.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume6513
DOIs
StatePublished - 2007
Externally publishedYes
EventMedical Imaging 2007: Ultrasonic Imaging and Signal Processing - San Diego, CA, United States
Duration: Feb 18 2007Feb 19 2007

Other

OtherMedical Imaging 2007: Ultrasonic Imaging and Signal Processing
CountryUnited States
CitySan Diego, CA
Period2/18/072/19/07

Fingerprint

Electrodes
Transducers
Catheters
Electrocardiography
Ultrasonics
Modulation
Electric potential
Processing

Keywords

  • Acousto-electric
  • Cardiac
  • Conductivity
  • Current
  • Dipole
  • Distribution
  • Electrocardiography
  • Mapping
  • Ultrasound

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Olafsson, R., Witte, R. S., & O'Donnell, M. (2007). Measurement of a 2D electric dipole field using the acousto-electric effect. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE (Vol. 6513). [65130S] https://doi.org/10.1117/12.712448

Measurement of a 2D electric dipole field using the acousto-electric effect. / Olafsson, Ragnar; Witte, Russell S; O'Donnell, Matthew.

Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 6513 2007. 65130S.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Olafsson, R, Witte, RS & O'Donnell, M 2007, Measurement of a 2D electric dipole field using the acousto-electric effect. in Progress in Biomedical Optics and Imaging - Proceedings of SPIE. vol. 6513, 65130S, Medical Imaging 2007: Ultrasonic Imaging and Signal Processing, San Diego, CA, United States, 2/18/07. https://doi.org/10.1117/12.712448
Olafsson R, Witte RS, O'Donnell M. Measurement of a 2D electric dipole field using the acousto-electric effect. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 6513. 2007. 65130S https://doi.org/10.1117/12.712448
Olafsson, Ragnar ; Witte, Russell S ; O'Donnell, Matthew. / Measurement of a 2D electric dipole field using the acousto-electric effect. Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 6513 2007.
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