Ultrasound permit the assessment of a broad range of cardiovascular function, both healthy and pathological. The main method by which ultrasound measures flow is through a velocity estimate, which is conducted by comparing the phase differences of successive pulse-echo signals from moving tissue or blood.

1. ULTRASONIC BLOOD FLOW METER
Learning Points
Classification : Transit Type & Doppler Type
Applications.
Principle & Mathematical Expressions.
Role of Lead Zirconate Titanate transducer.
Presented By
Gaurav Pandey

2. Ultrasonic Vibrations
• Frequency above 20 kHz- above the hearing range is called
as ultrasound.
• By far the most popular and versatile type of ultrasonic
transducer is the piezoelectric crystal, which converts an
oscillating electric field applied to the crystal into a
mechanical vibration.
• Piezoelectric crystals include quartz, Rochelle salt, and
certain types of ceramic.
• Shorter wavelength have higher generating power can be
transmitted over a long distance without loss of energy.

3. Application : Biomedical
Measurement of blood velocity.
Volume Flow.
Flow Direction.
Flow Profile.
Visualize the lumen of blood vessel.

4. Classification
1.Transit type velocity
flow meter.
2.Doppler Shift Type.

5. Transit Time Velocity Meter

6. Mathematical Equations with respect to upstream and downstream

7. Doppler Shift Method

9. Block Diagram-Doppler Shift Flowmeter