Variation in human semen viscoelastic properties with respect to time post ejaculation and frequency of ejaculation.

The present study concerns the rheological characterization of the coagulation-liquefaction process of human semen. Results obtained using a multiple point capillary viscometer reveal marked variations in the elasticity and viscosity of an individual's semen with time immediately following ejaculation and frequency of ejaculation. Similarity among all cases examined for each material property is revealed by relating times post ejaculation to semen liquefaction time, thereby coupling liquefaction time with specific material property values. Further, the final state of liquefied semen is found to be characterized by Newtonian behavior (mean absolute viscosity = 3.37 centipoise). The semen's liquefaction time and ejaculate volume are determined to be functions of the frequency of ejaculation. Steady state ejaculate volume is found to decrease linearly with increasing ejaculation frequency, thereby providing a measure of glandular secretory rate. When collectively considered, these findings provide possible means for monitoring an individual's glandular behavior over an extended period of time and comparing such behavior to established standards.