For the first time, three American scientists have successfully shown the three-dimensional (3D) paths of human sperm. They saw the generally straight paths, sometimes corkscrew-like paths, and rarely hyperactive paths taken by the multitude of sperm as they travel to the egg.
The technology used by these scientists is based on a sensor chip. They call is "a lensfree on-chip imaging technique".
The technique is able to see the 3-D trajectories of over 1,500 individual human sperms within an observation volume of approximately 8 to 17 cubic millimeters.
The study by these researchers was published on Wednesday, September 19, 2012, in the journal Proceedings of the National Academy of Sciences.
The researchers state within their abstract: "This computational imaging platform relies on holographic lensfree shadows of sperms that are simultaneously acquired at two different wavelengths, emanating from two partially-coherent sources that are placed at 45° with respect to each other."
And, "This multiangle and multicolor illumination scheme permits us to dynamically track the 3D motion of human sperms across a field-of-view of > 17 mm2 and depth-of-field of approximately 0.5–1 mm with submicron positioning accuracy."
What happened was that the researchers shot red and blue LED (light-emitting diode) lights from different directions onto the human sperm as they traveled on their journeys.
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