Table 1.

Minimal design criteria

Performance Parameter	Performance Target	Justification	Microcontroller Specs
Detector type	PMTs, photodiodes, current mode APDs	Most common detector formats in flow cytometers	Integrated Analog to Digital Converter (ADC)
Detector count	4	Can perform CD4 and other cellular immunophenotyping	≥ 4 signal inputs to the ADC
Minimal pulse width	>50 μs	Anticipated initial use of the system is with a cytometer using acoustic focusing, which provides high analysis rates at extended transit times.	Per channel ADC sample rate must be at least 0.1-0.2 MSPS
Dynamic range and sensitivity	Accurately measure all 8 beads of the Spherotech Rainbow Microspheres, signifying 3 decades of dynamic range	Demonstrate 3.5 to 4 decades of dynamic range, supporting most flow cytometry applications	The effective number of bits (ENOB) and effective sampling rate of the ADC must provide at least 13-bit results
Interrogation points	1	Initial target application was CD4+ cellular assays, which only requires one interrogation point	No extra memory required to support delayed signals
Event Rate	>1000/s	Analyze >100,000 events in <2 minutes to provide excellent statistics for most applications	20 KB/sec data transfer rate to computer
Reported parameters	Peak, Area, Width	Conventional parameters useful for most analysis	Sufficient processing power and bit depth to calculate these.
Cost	Path to <$100.00/system	Minimize component cost and assembly cost	Microcontroller provides inexpensive, single chip solution
Power	5 watt limit on system power	Potential for battery operation	Require less than 1 W to allow room for all system components
Size	Single circuit board	Minimize the footprint in a small system	Microcontroller minimizes part count
User interface	Laptop computer	Simplify user interaction and generate FCS 3.0 compliant data files.	Support a common communication protocol