BACKGROUND: Most current commercial flow cytometers employ analog circuitry to provide feature values describing the pulse waveforms produced from suspended cells and particles. This restricts the type of features that can be extracted (typically pulse height, width, and integral) and consequently places a limit on classification performance. In previous work, we described a first-generation digital data acquisition and processing system that was used to demonstrate the classification advantages provided by the extraction of additional waveform features. An improved version of the system is discussed in this paper, focusing on dual-buffering to ensure increased pulse capture. A mathematical model of the system is also presented for performance analysis. METHODS: The second-generation system incorporates fast digitization of analog pulse waveforms, instantaneous pulse detection hardware, and a novel dual-buffering scheme. A mathematical model of the system was developed to theoretically compute the capture-rate performance. RESULTS: The capture rate of the system was theoretically analyzed and empirically measured. Under typical conditions, a capture rate of 8,000 pulses/s was experimentally achieved. CONCLUSIONS: Based on these results, the dual-buffer architecture shows great potential for use in flow cytometry. (c) 2005 Wiley-Liss, Inc.
BACKGROUND: Most current commercial flow cytometers employ analog circuitry to provide feature values describing the pulse waveforms produced from suspended cells and particles. This restricts the type of features that can be extracted (typically pulse height, width, and integral) and consequently places a limit on classification performance. In previous work, we described a first-generation digital data acquisition and processing system that was used to demonstrate the classification advantages provided by the extraction of additional waveform features. An improved version of the system is discussed in this paper, focusing on dual-buffering to ensure increased pulse capture. A mathematical model of the system is also presented for performance analysis. METHODS: The second-generation system incorporates fast digitization of analog pulse waveforms, instantaneous pulse detection hardware, and a novel dual-buffering scheme. A mathematical model of the system was developed to theoretically compute the capture-rate performance. RESULTS: The capture rate of the system was theoretically analyzed and empirically measured. Under typical conditions, a capture rate of 8,000 pulses/s was experimentally achieved. CONCLUSIONS: Based on these results, the dual-buffer architecture shows great potential for use in flow cytometry. (c) 2005 Wiley-Liss, Inc.