Apparatus and method for discriminating among lateral flow assay test indicators
An apparatus for analyzing a lateral flow test strip having a plurality of types of markers for binding to analytes corresponding, respectively, to the types of markers. The apparatus includes a plurality of emitters corresponding, respectively, to the plurality types of markers on the lateral flow test strip. Each emitter emits light in a predetermined range near an optimum absorption wavelength for the corresponding type of marker to excite the marker.
1 . An apparatus for analyzing a lateral flow test strip having a plurality of types of markers for binding to analytes corresponding, respectively, to the types of markers, the apparatus comprising:
a plurality of emitters corresponding, respectively, to the plurality of types of markers on the lateral flow test strip, each emitter emitting light in a predetermined range near an optimum absorption wavelength for the corresponding type of marker to excite the marker.
2 . An apparatus as in claim 1 , further comprising:
a detector to detect a presence, absence or concentration of an analyte in accordance with movement of an excited marker into or out of a detection zone of the lateral flow test strip.
3 . An apparatus as in claim 1 , wherein the markers are fluorescent dyes.
4 . An apparatus as in claim 1 , wherein the emitters are light emitting diodes (LEDs).
5 . An apparatus as in claim 2 , wherein the detector is one or more photodiodes.
6 . An apparatus as in claim 2 , further comprising:
an optical guide between the detector and the lateral flow test strip which guide optical signals emitted by the excited markers to the detector.
7 . An apparatus as in claim 2 , further comprising:
a filter between the detector and the lateral flow test strip which attenuates optical signals outside of a wavelength range for the types of markers to be detected by the detector.
8 . An apparatus for analyzing a lateral flow test strip having a plurality of types of markers for binding to analytes corresponding, respectively, to the types of markers, the apparatus comprising:
a tunable optical source tunable to emit light in a predetermined range near an optimum absorption wavelength for each of the types of markers to excite the markers; and
at least one detector to detect a presence, absence or concentration of each analyte in accordance with movement of an excited marker into or out of a detection zone of the lateral flow test strip.
9 . An apparatus as in claim 8 , wherein the markers are fluorescent dyes.
10 . An apparatus as in claim 8 , wherein the detector is one or more photodiodes.
11 . An apparatus as in claim 8 , further comprising:
an optical guide between the detector and the lateral flow test strip which guides optical signals emitted by the excited markers to the detector.
12 . An apparatus as in claim 8 , further comprising:
a filter between the detector and the lateral flow test strip which attenuates optical signals outside of a wavelength range for the types of markers to be detected by the detector.
13 . A method for discerning among markers, comprising:
independently pulsing an emitter to create a pulse train to excite a marker; and
detecting the response of the excited marker.
14 . A method as in claim 13 , further comprising modulating the intensity of the pulse train emitted.
15 . A method as in claim 13 , wherein the emitter is pulsed in a pseudo random pulse sequence.
16 . A method as in claim 13 , wherein the response of the excited marker is filtered.
17 . A method comprising:
emitting a light to excite a marker on a lateral flow test strip to produce an optical signal from the excited marker;
stopping emission of the light; and
monitoring the optical signal produced by the excited marker after stopping emission of the light.
18 . A method according to claim 17 , wherein said monitoring comprises
measuring a time delay between stopping emission of the light and an onset of decay of the optical signal produced by the excited marker.
19 . A method according to claim 17 , wherein said stopping emission of the light causes a decay of the produced optical signal and said monitoring comprises
analyzing trailing edges of decay times of the produced optical signals.
20 . A method according to claim 17 , wherein said stopping emission of the light causes a decay of the produced optical signal and said monitoring comprises determining decay information of the produced optical signal, said decay information being used to determine peak intensity levels.
21 . A method according to claim 17 , wherein said monitoring comprises measuring the produced optical signal at its peak.
22 . A method according to claim 17 , wherein the light emitted is pulsed.