Laser-doppler evaluation of the human tympanic membrane by measuring blood flow, volume, and velocity.

From a hospital setting, a sample base of 50 people with normal hearing, was used to study the otoacoustic phenomenon of the ear. Human volunteers were taken into an acoustic room and allowed to rest for 5 minutes. Each volunteer inserted a probe as close to the tympanic membrane as possible. The objective of the study was to determine the pattern of distribution of blood flow, volume, and velocity of erythrocytes circulating in blood vessels of the tympanic membrane. This was achieved by recording numerical values for the flow, volume, and velocity of erythrocytes using the laser-Doppler flowmeter. Analysis of the results showed two distinct relationships, a negative exponential curve in the blood flow for the right and left ear, and a Gaussian distribution for the velocity and volume of erythrocytes for both ears.