1. What is Rate of Blood Flow?

Definition: The rate of blood flow (Q_b) is the volume of blood passing through a vessel per unit time, measured in mL/min.

Purpose: This calculation is essential in cardiovascular physiology to assess circulation efficiency and diagnose vascular conditions.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q_b \) — Blood flow rate (mL/min)
• \( V_b \) — Blood velocity (cm/s)
• \( A_v \) — Vessel cross-sectional area (cm²)

Explanation: The product of blood velocity and vessel cross-sectional area gives the volumetric flow rate.

3. Importance of Blood Flow Calculation

Details: Measuring blood flow helps evaluate cardiac output, assess vascular resistance, and diagnose conditions like stenosis or aneurysms.

4. Using the Calculator

Tips: Enter the blood velocity in cm/s and vessel cross-sectional area in cm². Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a normal blood flow rate?
A: Varies by vessel: ~5000 mL/min in aorta, ~250 mL/min in renal arteries, ~5 mL/min in capillaries.

Q2: How is blood velocity measured?
A: Clinically measured using Doppler ultrasound or calculated from pressure gradients.

Q3: What affects cross-sectional area?
A: Vessel diameter (A = πr²) and any pathological changes like atherosclerosis.

Q4: Why mL/min instead of cm³/s?
A: mL/min is clinically more relevant, but you can convert (1 mL/min = 0.0167 cm³/s).

Q5: Does this account for pulsatile flow?
A: No, this gives mean flow. For pulsatile analysis, more complex calculations are needed.