title: Medical ultrasound imager based on time delay spectrometry.
abstract: A reflection mode proof-of-concept medical ultrasound imager based on time delay spectrometry has been developed and tested. The system uses a broad band swept-frequency signal operating up to 10 MHz. Signal processing using a fast Fourier transform (FFT) permits extraction of range information. The imager has a higher signal-to-noise ratio than pulse-echo systems which allows high resolution at greater depths. The time delay spectrometry (TDS) spread spectrum operates at lower peak intensities than pulse-echo and permits more control of the spectral content and amplitude of the signal. At present, the system is non-real time which degrades in vivo imaging because of averaging over several cardiac cycles and tissue movement.
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena 91109.
authors.forename: R C
authors.initials: RC
authors.lastname: Heyser
authors.forename: J D
authors.initials: JD
authors.lastname: Hestenes
authors.forename: J A
authors.initials: JA
authors.lastname: Rooney
authors.forename: P M
authors.initials: PM
authors.lastname: Gammell
authors.forename: D H
authors.initials: DH
authors.lastname: Le Croissette
mesh_terms: D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods