oelze - ece 571 lecture 4 biological measurement 1 bioe 571
DESCRIPTION
Oelze - ECE 571 Lecture 4 Doppler Circle f S Assume a sound source emitting sound with frequency f S is moving with respect to the observerTRANSCRIPT
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Biological Measurement 1Biological Measurement 1
BIOE 571BIOE 571
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
I. Topics Covered TodayI. Topics Covered Today
• Detecting the envelope of a signalDetecting the envelope of a signal• B-mode image construction: a recipeB-mode image construction: a recipe• Characterizing B-mode image qualityCharacterizing B-mode image quality
• Methods for improving B-mode imagingMethods for improving B-mode imaging
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Doppler CircleDoppler Circle
ffS S
Assume a sound source emitting sound with frequency fAssume a sound source emitting sound with frequency fSS is is moving with respect to the observer moving with respect to the observer
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Doppler CircleDoppler Circle
ffS S
Assume a sound source emitting sound with frequency fAssume a sound source emitting sound with frequency fSS is is moving with respect to the observer moving with respect to the observer
x x ΔΔf = ff = fssccss/c/c00 ΔΔf = -ff = -fssccss/c/c00
ΔΔf = 0 f = 0
ΔΔf = ff = fssccsscoscosθθ/c/c00
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Ultrasound DopplerUltrasound Doppler
Doppler shift in ultrasound is in audible ranges Doppler shift in ultrasound is in audible ranges
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Ultrasound Doppler: CWUltrasound Doppler: CW
Blood velocity Blood velocity
θθ
Observation on Observation on overlap of beams overlap of beams
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Ultrasound Doppler: PWUltrasound Doppler: PW
Blood velocity Blood velocity
θθ
Range Cell Range Cell
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Ultrasound PW DopplerUltrasound PW Doppler
Time signals from scatterer moving through range gate Time signals from scatterer moving through range gate 2 MHz tone burst - 1.5 kHz Doppler shift2 MHz tone burst - 1.5 kHz Doppler shift
ffPRFPRF = 10 kHz = 10 kHz
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Ultrasound PW DopplerUltrasound PW Doppler
Amplitude of “in phase” Doppler signal at each sampleAmplitude of “in phase” Doppler signal at each sample2 MHz tone burst - 1.5 kHz Doppler shift2 MHz tone burst - 1.5 kHz Doppler shift
ffPRFPRF = 10 kHz = 10 kHz
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Ultrasound PW DopplerUltrasound PW Doppler
Doppler signal sampled at TDoppler signal sampled at TPRFPRF
2 MHz tone burst - 1.5 kHz Doppler shift2 MHz tone burst - 1.5 kHz Doppler shift
ffPRFPRF = 10 kHz = 10 kHz
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Ultrasound PW DopplerUltrasound PW Doppler
Frequency of Doppler spectrumFrequency of Doppler spectrum2 MHz tone burst - 1.5 kHz Doppler shift2 MHz tone burst - 1.5 kHz Doppler shift
ffPRFPRF = 10 kHz = 10 kHz
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Ultrasound PW DopplerUltrasound PW Doppler
Doppler signal - UndersampledDoppler signal - Undersampled2 MHz tone burst - 6 kHz Doppler shift2 MHz tone burst - 6 kHz Doppler shift
ffPRFPRF = 10 kHz = 10 kHz
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Ultrasound PW DopplerUltrasound PW Doppler
Doppler spectrumDoppler spectrum2 MHz tone burst - 6 kHz Doppler shift2 MHz tone burst - 6 kHz Doppler shift
ffPRFPRF = 10 kHz = 10 kHz
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Ultrasound PW DopplerUltrasound PW Doppler
1.5 kHz Doppler shift 1.5 kHz Doppler shift -1.5 kHz Doppler shift -1.5 kHz Doppler shift
DDII (t) (t)
DDQQ (t) (t)
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Doppler Velocity and CFI (Duplex)Doppler Velocity and CFI (Duplex)
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Doppler Velocity and CFI (Duplex)Doppler Velocity and CFI (Duplex)
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
CFICFI
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
CFICFI
Mitral valve regurgitation (jet)Mitral valve regurgitation (jet)
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Power DopplerPower Doppler
Power Doppler – thyroid nodulePower Doppler – thyroid nodule
Oelze - ECE 571 Lecture 4Oelze - ECE 571 Lecture 4
Power DopplerPower Doppler
Power Doppler – 3D renderingPower Doppler – 3D rendering