PARTICLE MANIPULATION SYSTEM WITH CYTOMETRIC CAPABILITY AND FEEDBACK LOOP AND VARIABLE GAIN DETECTOR
A MEMS-based particle manipulation system which uses a particle manipulation stage and a plurality of laser interrogation regions. The laser interrogation regions may be used to assess the effectiveness or accuracy of the particle manipulation stage. In one exemplary embodiment, the particle manipulation stage is a microfabricated, flap-type fluid valve, which sorts a target particle from non-target particles in a fluid stream. The laser interrogation stages are disposed in the microfabricated fluid channels at the input and output of the flap-type sorting valve. The laser interrogation regions may be used to assess the effectiveness or accuracy of the sorting, and to control or adjust sort parameters during the sorting process. One or more feedback loops may be used to improve the particle manipulation process, based on data acquired during the first interrogation and/or during a downstream confirmation. Artificial intelligence techniques may be used to good effect. A variable gain detector may improve the speed and sensitivity of the system.
1 . A variable gain detector, comprising:
at least one of a circuit that varies the gain applied to a sensor between at least two values, a higher value and a lower value, and a detector having a plurality of independently controllable sensors with variable gain.
2 . The variable gain detector of claim 1 , further comprising:
a wavelength separating device which separates a multiwavelength signal from a sample according to the wavelengths of the multiwavelength signal.
3 . The variable gain detector of claim 1 , further comprising:
a sampling circuit that samples the higher value and the lower value, and digitizes these samples.
4 . The variable gain detector of claim 1 , wherein the wavelength separating device forms a spatial intensity profile on a first spatial axis.
5 . The detector of claim 3 , wherein the wavelength separating device may be implemented using refractive or diffractive optics, a graded optical filter, filters of different attenuations.
6 . The detector of claim 3 , wherein the intensity profile is projected onto one or a plurality of sensors, wherein the same or different light intensities are incident onto the plurality of independently controllable sensors.
7 . The detector of claim 3 , wherein the emitted light from the sample is spectrally separated into its wavelength components along a second spectral axis.
8 . The variable gain detector of claim 1 , wherein the independently controllable sensors are programmable.
9 . The variable gain detector of claim 1 , wherein the independently controllable sensors are remotely programmable.
10 . The variable gain detector of claim 1 , wherein the independently controllable sensors are arranged to detect four spectrally dispersed wavelengths.
11 . The variable gain detector of claim 2 , further comprising:
a demultiplexer that separates the digitized higher value and digitized lower value.
12 . The variable gain detector of claim 1 , further comprising:
at least two signal conditioning circuits that separately condition the digitized higher value and the digitized lower value.
13 . The variable gain detector of claim 4 , wherein the at least two signal conditioning circuits apply a first gain to the digitized higher value and a second gain to the digitized lower value.
14 . A system for manipulating particles, comprising:
a microfabricated cell sorting system, which distinguishes target cells from non-target material, wherein the target cells are distinguished by a laser-induced fluorescent signal, and wherein this laser-induced fluorescent signal is detected by the variable gain detector of claim 1 .
15 . The system for manipulating particles of claim 13 , wherein the cell sorting system includes a microfabricated valve that separates the target particle from non-target material.
16 . The system for manipulating particles of claim 14 , wherein the valve moves in a plane parallel to a fabrication plane, and uses electromagnetic actuation.