title: FFT analysis of the X-ray tube voltage waveforms of high-frequency generators for radiographic systems.
abstract: OBJECTIVE
  To present a novel method for analyzing the voltage waveform from high-frequency X-ray generators for radiographic systems.
  
  
  METHODS
  The output signal of the actual voltage across the tube of a high-frequency generator was measured using the built-in voltage sense taps that are used for voltage regulation feedback in X-ray generators. The output signal was stored in an analyzing recorder, and the waveforms were analyzed using FFT analysis. The FFT analysis of high-frequency generators consisted of obtaining the power spectrum, comparing the major frequency components in the tube voltage waveforms, and examining the intensity of each frequency component.
  
  
  RESULTS
  FFT analysis enables an objective comparison of the complex tube voltage waveforms in high-frequency X-ray generators. FFT analysis detected the change in the X-ray tube voltage waveform that occurred when there were problems with the high-frequency generator.
  
  
  CONCLUSIONS
  High-frequency X-ray generators are becoming the universal choice for radiographic systems. The X-ray tube voltage and its waveform are important features of an X-ray generator, and quality assurance (QA) is important, too. As a tool for engineers involved in the design and development of X-ray generators, we can see that our methods (FFT analysis) might have some value as a means of describing generator performance under varying conditions. Furthermore, since the X-ray tube voltage waveform of a high-frequency generator is complex, FFT analysis may be useful for QA of the waveform.
authors.affiliation: Department of Radiological Technology, Tohoku University School of Health Sciences, Aobaku, Sendai, Japan. chida@mail.tains.tohoku.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Chida
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: D
authors.initials: D
authors.lastname: Ito
authors.forename: H
authors.initials: H
authors.lastname: Shimura
authors.forename: M
authors.initials: M
authors.lastname: Zuguchi
authors.forename: Y
authors.initials: Y
authors.lastname: Takai
mesh_terms: D000465:Algorithms; D004560:Electricity; D005583:Fourier Analysis; D006801:Humans; D011785:Quality Assurance, Health Care / Q000379:methods; D011859:Radiography / Q000295:instrumentation*; D011874:Radiometry / Q000379:methods*; D015203:Reproducibility of Results