Walsh function current patterns and data synthesis for electrical impedance tomography

Author

Woo, Eung Je ; Hua, Ping ; Webster, John G. ; Tompkins, Willis J. ; Pallás-Areny, Ramón

Author_Institution

Dept. of Biomed. Eng., Kon Kuk Univ., Choongbuk, South Korea

Volume

11

Issue

4

fYear

1992

fDate

12/1/1992 12:00:00 AM

Firstpage

554

Lastpage

559

Abstract

A data collection method which uses Walsh functions as injection current patterns is presented. This method can satisfy two conditions: the optimality of current patterns in every iteration and the single-time data measurement condition. The use of Walsh functions simplifies the design of current sources since only two levels of current (+1 and -1) are required, whereas sinusoidal injection requires a digital-to-analog converter to produce many different values of currents. Compared to diagonal or neighboring type of pulses as injection current patterns, Walsh injection current patterns provide more information about the interior of the subject since Walsh function simulate low and high spatial frequency patterns. Therefore, Walsh function injection uses the simplicity of pulse type injection and yields the better distinguishability or SNR of sinusoidal injection,

Keywords

Walsh functions; computerised tomography; Walsh function current patterns; current patterns optimality; data synthesis; digital-to-analog converter; electrical impedance tomography; high spatial frequency patterns; injection current patterns; low spatial frequency patterns; pulse type injection; sinusoidal injection; Biomedical measurements; Computational modeling; Computer errors; Conductivity; Image reconstruction; Impedance; Iterative algorithms; Time measurement; Tomography; Voltage measurement;

fLanguage

English

Journal_Title

Medical Imaging, IEEE Transactions on

Publisher

ieee

ISSN

0278-0062

Type

jour

DOI

10.1109/42.192691

Filename

192691