Introduction
Commercially available computer-aided sperm analysis (CASA) was introduced to research laboratories and laboratory medicine nearly 10 years ago. The first instruments were CellSoft (Cryo Resources, Montgomery, NY) and ExpertVision (later called CellTrak, Motion Analysis Corp., Santa Rosa, CA). There soon followed the HTM-2000 (Hamilton Thorn Research, Beverly, MA), the SM-CMA instrument from Europe (Stromberg-Mika, Bad Feilnbach, Germany), and others. There are now over 120 papers which verify CASA technology for semen analysis or apply it in basic and clinical studies. However, despite this enormous body of work, and the considerable time since its introduction, CASA's potential has not been realized for two basic reasons. First, manufacturers have been unwilling or unable to address a fundamental limitation of the technology, namely the inability of CASA instruments to obtain accurate counts and percent motilities when the concentration of a specimen is greater than about 50 x 106 sperm/ml or less than about 20 x 106 sperm/ml, or when a specimen is laden with debris. These common conditions require laboratories to either dilute, concentrate, or wash specimens, significantly limiting routine clinical application of the technology. Second, professional societies and organizations have been slow to develop and recommend performance and operating standards for CASA instruments. Appeals have been made by industry spokesmen and individual scientists (Schrader et al., 1992; Chapin et al., 1992) to achieve this end, but no stance has been taken by any professional group on the performance, use, calibration, or standardization of CASA technology.
The application of CASA in clinical laboratory medicine is hindered by these continuing technical limitations and the lack of involvement by professional organizations.