Waveform generator for electrical impedance tomography (EIT) using linear interpolation with multiplying D/A converters.
This paper describes the implementation of a multiplying digital-to-analogue (D/A) converter as a programmable waveform generator to be used in an electrical impedance tomography (EIT) system. Different digital techniques of generation waveforms are considered and the advantages and disadvantages of the chosen slope-plus-pedestal technique are presented. A wire-wrapped prototype system has been designed, and from measured frequency spectra the total harmonic distortion can be calculated to values between 1.1 and 2.9% depending on frequency.
Blad
B
B
Radiation Physics Department, University Hospital, Lund, Sweden.
Johannesson
J
J
Johnsson
G
G
Bachman
B
B
Lindström
K
K
D000703:Analog-Digital Conversion; D017097:Electric Impedance; D004582:Electronics, Medical / Q000295:instrumentation; D004867:Equipment Design; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation; D009991:Oscillometry / Q000295:instrumentation; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D014054:Tomography / Q000295:instrumentation* / Q000379:methods