Flow Rates Using Nuclear or Electron Paramagnetic Resonance Techniques with Applications to Biological and Chemical Processes

The equations for measuring flow rates are derived using NMR and EPR relaxation time determinations. Several experimental procedures are discussed. One method of measurement depends upon the difference between static relaxation times and the apparent relaxation time of materials flowing through the observation region. Another procedure utilizes saturated or inverted spins as a ``tracer'' to measure flow rates. These schemes may readily be applied to blood flow velocity measurements in humans or animals, or to mineral and chemical flow rate determinations. The advantage of this spin resonance flowmeter is that the flow channel is not disturbed. Thus blood flow velocities are readily measured without the necessity of breaking the skin.