High-throughput lensfree 3D tracking of human sperms reveals rare statistics of helical trajectories.

Electrical Engineering Department, University of California, Los Angeles, CA 90095.
Proceedings of the National Academy of Sciences (Impact Factor: 9.81). 09/2012; 109(40):16018-22. DOI: 10.1073/pnas.1212506109
Source: PubMed

ABSTRACT Dynamic tracking of human sperms across a large volume is a challenging task. To provide a high-throughput solution to this important need, here we describe a lensfree on-chip imaging technique that can track the three-dimensional (3D) trajectories of > 1,500 individual human sperms within an observation volume of approximately 8-17 mm(3). 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. This multiangle and multicolor illumination scheme permits us to dynamically track the 3D motion of human sperms across a field-of-view of > 17 mm(2) and depth-of-field of approximately 0.5-1 mm with submicron positioning accuracy. The large statistics provided by this lensfree imaging platform revealed that only approximately 4-5% of the motile human sperms swim along well-defined helices and that this percentage can be significantly suppressed under seminal plasma. Furthermore, among these observed helical human sperms, a significant majority (approximately 90%) preferred right-handed helices over left-handed ones, with a helix radius of approximately 0.5-3 μm, a helical rotation speed of approximately 3-20 rotations/s and a linear speed of approximately 20-100 μm/s. This high-throughput 3D imaging platform could in general be quite valuable for observing the statistical swimming patterns of various other microorganisms, leading to new insights in their 3D motion and the underlying biophysics.

  • [Show abstract] [Hide abstract]
    ABSTRACT: We review our progress on the development of computational lensfree on-chip microscopy and tomography techniques for biomedical imaging, microanalysis and telemedicine applications.
    SPIE Optical Metrology 2013; 05/2013
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Sperm quality assessment plays an essential role in human fertility and animal breeding. Manual analysis is time-consuming and subject to intra- and inter-observer variability. To automate the analysis process, as well as to offer a means of statistical analysis that may not be achieved by visual inspection, we present a computational framework that tracks the heads and traces the tails for analyzing sperm motility, one of the most important attributes in semen quality evaluation. Our framework consists of 3 modules: head detection, head tracking, and flagellum tracing. The head detection module detects the sperm heads from the image data, and the detected heads are the inputs to the head tracking module for obtaining the head trajectories. Finally, a flagellum tracing algorithm is proposed to obtain the flagellar beat patterns. Our framework aims at providing both the head trajectories and the flagellar beat patterns for quantitatively assessing sperm motility. This distinguishes our work from other existing methods that analyze sperm motility based merely on the head trajectories. We validate our framework using two confo-cal microscopy image sequences of ram semen samples that were imaged at two different conditions, at which the sperms behave differently. The results show the effectiveness of our framework.
    2014 IEEE 11th International Symposium on Biomedical Imaging (ISBI 2014); 04/2014
  • [Show abstract] [Hide abstract]
    ABSTRACT: Analyzed some shortages of the existing one-time password (OTP) authentication schemes, a new OTP authentication scheme is designed. This scheme used the SM2 cryptographic algorithm and Hash function to ensure data transmission security, provided the mutual authentication between client and server, resisted different kinds of attacks, and protected the user's identity information effectively. Analysis showed that compared with the existing schemes, the new designed scheme had higher security, small system overhead and easy to implement.
    2013 2nd International Symposium on Instrumentation & Measurement, Sensor Network and Automation (IMSNA); 12/2013


1 Download
Available from