F. Mazzilli et al., A new objective method for scoring human sperm hyperactivation based on head axis angle deviation, INT J ANDR, 24(4), 2001, pp. 189-196
The aims of the present study were, first to develop a new method for evalu
ating sperm hyperactivation (HA) based on sperm head axis angle deviation,
and second to apply this method in scoring selected sperm populations durin
g capacitation. This was made possible by improving our original superimpos
ed image analysis system (SIAS). The new option on the system enables us to
determine the real angular deviation of the entire head in successive supe
rimposed frames. The entire procedure for each spermatozoon requires 10-20
sec, according to the frame/rate utilized. A clear cut-off between the valu
es of hyperactivated, transitional and non-hyperactivated spermatozoa was f
ound at 11 and 21 frames/sec. However, at 6 frames/sec, a partial overlap b
etween the three classes was found. We defined sperm activity as follows. A
t 11 frames/sec, hyperactivated: angle sum greater than or equal to 405 deg
rees; transitional: 200 degrees less than or equal to angle sum < 405 degre
es. At 21 frames/sec, hyperactivated: angle sum greater than or equal to 76
0 degrees; transitional: 350 degrees less than or equal to angle sum < 760
degrees. The results, in agreement with previous research, show the peaks o
f activity at 3 h, dropping to a minimum at 6 h. This phenomenon was signif
icantly more evident in fertile compared with subfertile semen samples.