1. Oelze - ECE 571 Lecture 4 Biological Measurement 1 BIOE 571

2. Oelze - ECE 571 Lecture 4 I. 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

3. 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 observer

4. 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 observer x Δf = f s c s /c 0 Δf = -f s c s /c 0 Δf = 0 Δf = f s c s cosθ/c 0

5. Oelze - ECE 571 Lecture 4 Ultrasound Doppler Doppler shift in ultrasound is in audible ranges

6. Oelze - ECE 571 Lecture 4 Ultrasound Doppler: CW  Blood velocity θ Observation on overlap of beams

7. Oelze - ECE 571 Lecture 4 Ultrasound Doppler: PW  Blood velocity θ Range Cell

8. Oelze - ECE 571 Lecture 4 Ultrasound PW Doppler Time signals from scatterer moving through range gate 2 MHz tone burst - 1.5 kHz Doppler shift f PRF = 10 kHz

9. Oelze - ECE 571 Lecture 4 Ultrasound PW Doppler Amplitude of “in phase” Doppler signal at each sample 2 MHz tone burst - 1.5 kHz Doppler shift f PRF = 10 kHz

10. Oelze - ECE 571 Lecture 4 Ultrasound PW Doppler Doppler signal sampled at T PRF 2 MHz tone burst - 1.5 kHz Doppler shift f PRF = 10 kHz

11. Oelze - ECE 571 Lecture 4 Ultrasound PW Doppler Frequency of Doppler spectrum 2 MHz tone burst - 1.5 kHz Doppler shift f PRF = 10 kHz

12. Oelze - ECE 571 Lecture 4 Ultrasound PW Doppler Doppler signal - Undersampled 2 MHz tone burst - 6 kHz Doppler shift f PRF = 10 kHz

13. Oelze - ECE 571 Lecture 4 Ultrasound PW Doppler Doppler spectrum 2 MHz tone burst - 6 kHz Doppler shift f PRF = 10 kHz

14. Oelze - ECE 571 Lecture 4 Ultrasound PW Doppler 1.5 kHz Doppler shift -1.5 kHz Doppler shift D I (t) D Q (t)

15. Oelze - ECE 571 Lecture 4 Doppler Velocity and CFI (Duplex)

16. Oelze - ECE 571 Lecture 4 Doppler Velocity and CFI (Duplex)

17. Oelze - ECE 571 Lecture 4 CFI

18. CFI Mitral valve regurgitation (jet)

19. Oelze - ECE 571 Lecture 4 Power Doppler Power Doppler – thyroid nodule

20. Oelze - ECE 571 Lecture 4 Power Doppler Power Doppler – 3D rendering