Patent ID: 8373860

Claim:
An article of manufacture, comprising: a fluid-engaging structure, wherein the fluid-engaging structure includes (a) a channel that in use can contain fluid and through which objects can move; (b) one or more bounding parts that bound the channel, and wherein at least one of the one or more bounding parts include one or more light transmissive portions, wherein at least one of the one or more light transmissive portions is configured to receive excitation light and provide the received excitation light, and wherein excitation light enters the channel and interacts with an object resulting in emanating light; and (c) one or more mask arrangements configured to receive at least part of the emanating light and in response, provide encoded emanating light, wherein the one or more mask arrangements and the channel are further configured so that the encoded emanating light includes time variation resulting from relative movement between the one or more mask arrangements and the object, the time variation including information about the object; wherein the fluid-engaging structure further comprises: a first of the one or more mask arrangements configured to receive at least part of the emanating light and in response provide encoded emanating light to received emanating light, and is located on a first portion of the bounding parts; one or more mirrors, at least one of the one or more mirrors configured to substantially reflect the excitation light through the one or more light transmissive portions; and an internal reflecting surface, wherein the internal reflecting surface is configured to retransmit the reflected excitation light into the channel with the fluid and objects, and wherein the article of manufacturing is configured for use with a host structure, and wherein the host structure includes: at least one excitation light source; a filter configured to receive and filter the encoded emanating light; and a photo-sensor configured to receive the filtered encoded emanating light and detect time variation resulting from relative movement between the one or more mask arrangements and the objects, the time variation including information about the objects, and wherein the photosensor is further configured to provide an electrical signal indicating one or more sensed time-varying waveforms.