KPICS SpermFinder™ Benefits and Technology

Benefits of Automated Sperm-Finding

The presence and identification of sperm has been and remains the single most accurate confirmatory test for the determination of sexual activity. Unfortunately, microscopic examination of slides to identify sperm cells is one of the most tedious and time-consuming activities in the forensic biology laboratory.

One of the primary reasons for the huge backlog in DNA cases awaiting analysis in forensic laboratories across the U.S. and around the world is that the initial step in DNA analysis is manual microscopic identification of the sperm cells found in the smears taken in each rape case.

When few sperm are present it is not unusual for an analyst to spend an hour or more searching each of multiple individual slides for identifiable sperm cells. In addition, it is a great deal more difficult to identify sperm cells when the slide also includes a high density of debris that is similar in appearance to sperm cells such as white blood cells or dense layers of epithelial cells.

Cases in which there is an allegation of rape but in which no sperm are immediately found are even more time-consuming for the technician. A highly skilled technician may spend as much as two hours searching a slide for a single sperm head, often stopping the search far earlier because of the backlog of casework. A two-hour time limit is a common lab policy, however those limits vary in different laboratory settings.

Forensic laboratories can benefit greatly from an automated system that significantly reduces the time required for lab analysts to search for sperm cells on smeared slides, without sacrificing accuracy or changing lab protocol.

KPICS SpermFinder™ – How It Works

The KPICS SpermFinder™ includes a system of software and hardware used to scan microscope slides to identify the locations of probable sperm cells on the slide.

The system excels due to its unique patent-pending method for analyzing microscopic images taken from a sample slide, including its ability to identify suspected spermatozoa, with or without tail intact, regardless of the amount of surrounding debris, as well as its ability to allow for normal over- and under-staining variations.

Steps In The Process

A digital color image is captured from a microscope slide. The captured color image is then split into multiple images representing individual components of multiple color spaces including: hue, saturation, and intensity (HSV); red, green, and blue (RGB); and cyan, magenta, yellow, and black (CMYK).

A processing algorithm is then applied to the various images split from the original color image. Additional image-processing algorithms enable the system to sort out other non-sperm cells and debris on the slides, such as bacteria, epithelial and white blood cells.

Each suspected sperm cell is assigned a location based on a universal coordinate system. The universal coordinate system allows the locations to be replicated on a different microscope system from a different manufacturer, a different design or with a different automated stage. The universal coordinate system measures the location of suspected sperm cells from a fixed physical feature on the microscope slide and assigns each location an X, Y value based on a selected unit or a polar coordinate value based on a selected unit.

Any object found in an image from the sample slide possessing certain criteria is then mapped based on the X center of gravity, Y center of gravity and Z position. These coordinates are cross-calculated to the current universal position and stored in a log file for each slide. Locations of suspected sperm cells are saved, and after automated scanning is complete the analyst can review the results through the microscope.

Each probable sperm cell that was identified is moved to the center of the analysis field of view by the computer, and the analyst can then confirm identification of each individual sperm cell. Saved coordinates that are created may also be used with other devices such as laser microdysection for DNA extraction directly from the slide.