Patent ID: 8723140

Claim:
An apparatus for analyzing a sample, comprising: a flow channel through which the sample can pass; a first light source adapted to illuminate one or more first excitation region(s) of the flow channel with first excitation light, the first excitation light adapted to stimulate a first light emission from particles of a first particle type, the first light emission having a characteristic first response time τ 1 ; a detector disposed to receive light from a plurality of first detection regions of the flow channel, the detector adapted to provide a detector output based on the received light; and a spatial filter disposed between the flow channel and the detector, the spatial filter having a pattern of variable transmission such that (a) the first light emission from a given first particle of the first particle type is transmitted to the detector when the given first particle is disposed in any of the first detection regions of the flow channel, and (b) the first light emission from the given first particle is at least partially blocked from reaching the detector when the given first particle is disposed in any of a plurality of first shielded regions of the flow channel, the first shielded regions being interspersed with the first detection regions; wherein the first detection regions are spatially separated from the first excitation region(s) by a gap having a first gap dimension; wherein the apparatus is configured to isolate the first light emission from a second light emission emitted by a component in the sample when exposed to the first excitation light, the second light emission characterized by a second response time τ 2 ; and wherein the gap dimension is a function of τ 1 and τ 2 .