A method of selecting a type of particle for use in standardisation and/or calibration of a flow cytometer. The method includes determining the location of two or more particle focal points of particles flowing through a cross section of a channel in the flow cytometer; for each type of particle, determining for each particle focal point, for a beam of light directed at a type of particle at said particle focal point from a first direction, the total intensity of light scattered along a second direction; determining the difference between the highest and lowest determined light intensities of the light intensities determined at the two or more particle focal points; and selecting a type of particle for which the difference between the highest and lowest determined light intensities at the two or more particle focal points is below a predetermined threshold.

Holograms of colloidal dispersions encode comprehensive information about individual particles' three-dimensional positions, sizes and optical properties. Extracting that information typically is computation-ally intensive, and thus slow. Machine-learning techniques based on support vector machines (SVMs) can analyze holographic video microscopy data in real time on low-power computers. The resulting stream of precise particle-resolved tracking and characterization data provides unparalleled insights into the composition and dynamics of colloidal dispersions and enables applications ranging from basic research to process control and quality assurance.

A system for determining a vehicle operating state is provided. The system includes at least two particle detectors, a controller and a memory. A sample volume used by each particle detector of the at least two particle detectors configured to be collected in a different location relative to the vehicle than another sample volume used by another particle detector of the at least two particle detectors and at least one sample volume is configured to be collected in an environment where particles are disturbed by the vehicle. The controller is configured to determine at least one operating state of the vehicle based at least in part on a comparison of output signals of the at least two particle detectors. The at least one memory is used to store at least operating instructions implemented by the controller in determining the at least one operating state of the vehicle.

A particulate matter sensor device comprising an enclosure (21) that comprises a flow inlet (11), a flow outlet (12) and a flow channel (2) extending therebetween, a radiation source for emitting radiation into the flow channel (2) for interaction of the radiation with the particulate matter in the flow (20) of an aerosol sample when guided through the flow channel (2), a radiation detector (4) for detecting at least part of said radiation after interaction with the particulate matter. The sensor device comprises a flow modifying device (511) arranged upstream of the radiation detector (4) and/or of the radiation source (3) for modifying the flow (20) for reducing particulate matter precipitation onto the radiation detector (4) and/or onto the radiation source (3) and/or the channel wall sections in close proximity to the detector (4) and/or source (3). The invention also relates to a method of determining parameters of particulate matter in an aerosol sample by using such a particulate matter sensor device.

A method for characterizing particle objects comprises generating a radiation beam, illuminating with the radiation beam an observation region transited by a particle object, collecting an interference image determined by an interference between a transmitted fraction and a part of the scattered fraction of the radiation beam that propagates around the direction of the optical axis, collecting a part of the scattered fraction that propagates at the scattering angle, and measuring at least one scattered radiation intensity value determined by the part of the scattered fraction, calculating, from the interference image, a pair of independent quantities that define the complex field of the first part of the scattered fraction, calculating, starting from the pair of independent quantities, a theoretical value of scattered radiation intensity, and comparing the measured value with the theoretical scattered radiation intensity value.

Device and method for detecting dispersed extracellular vesicles in a liquid dispersion sample, said method using an electronic data processor for classifying the sample as having, or not having, extracellular vesicles present, the method comprising the use of the electronic data processor for pre-training a machine learning classifier with a plurality of extracellular vesicle liquid dispersion specimens comprising the steps of: emitting a laser modulated by a modulation frequency onto each specimen; capturing a temporal signal from laser light backscattered by each specimen for a plurality of temporal periods of a predetermined duration for each specimen; calculating specimen DCT or Wavelet transform coefficients from the captured signal for each of the temporal periods; using the calculated coefficients to pre-train the machine learning classifier; wherein the method further comprises the steps of: using a laser emitter having a focusing optical system coupled to the emitter to emit a laser modulated by a modulation frequency onto the sample; using a light receiver to capture a signal from laser light backscattered by the sample for a plurality of temporal periods of a predetermined duration; calculating sample DCT or Wavelet transform coefficients from the captured signal for each of the temporal periods; using the pre-trained machine learning classifier to classify the calculated sample coefficients as having, or not having, extracellular vesicles present.

Examples disclosed herein generally relate to systems and methods for detecting the size of a particle in a fluid. In one example, a system for imaging a particle includes a first imaging device. The first imaging device includes a lens and a digital detector. The system further includes a laser source. He laser source is configured to emit a first laser beam and a second laser beam. The digital detector is configured to accumulate a metric of an intensity of an accumulated light that passes through the lens. The accumulated light is scattered from the particle. The accumulated light includes light from the first laser beam and the second laser beam.

Presented herein are compositions, systems, and methods related to optical substrates that simultaneous (1) enhance a fluorescence signal emitted by a fluorophore and (2) enhance “contrast” signal that comprises scattered signal intensity over substrate reflectivity at a non-fluorescent wavelength. In certain embodiments, the optical substrate comprises a thin, transparent, dielectric layer. In alternative embodiments, the optical substrate comprises a stack of thin, transparent dielectric layers, for example, that is designed for both specific scattering enhancement and fluorescence enhancement.

A method of optically characterizing individual molecules/molecular complexes, or other particles, in solution. The method comprises flowing a solution comprising the molecules/molecular complexes into an imaging region of a microfluidic channel, wherein the imaging region of the microfluidic channel has a first lateral dimension of greater than 1 μm in an x-direction wherein the x-direction is perpendicular to a direction of the flow; capturing a succession of images of the individual molecules/molecular complexes in the imaging region; tracking movement of the individual molecules/molecular complexes in at least the x-direction in the imaging region using the succession of images; and characterizing the individual molecules/molecular complexes from the tracked movement. In some implementations the characterizing comprises determining a diffusion coefficient of the molecules/molecular complexes from the tracked movement.

The invention relates to a method and system for characterizing particles using a flow cytometer comprising detecting radiated light from the particles using two or more detectors positioned to allow for the detection in two or more angular directions and generating a waveform, as a digital representation for the detected radiated light for each of said angulation direction. The waveforms are transformed using one or more basis functions to obtain one or more coefficients characterizing the waveform. The one or more coefficients characterizing the waveform preferably correspond to properties of the particle(s), thereby enabling analysis of physical properties of the particles (such as size, shape, refractive index) or biological properties of the particles (such as cell type, cell cycle state or localization or distribution of molecules within the cell and/or on the cell surface). In preferred embodiments the method and system are used for a label-free sorting of particles, in particular biological cells.