Disclosed herein are systems, methods, and devices for calibrating contrast measurements from laser speckle imaging systems to accurately determine unknown particle motion characteristics, such as flow rate. The calibration stores to memory calibration data, which may include a set of measurements from samples with known particle characteristics and/or estimates of noise, including the effects on contrast arising from undesired signals unrelated to the unknown particle motion characteristics. The calibration data may be accessed and used to correct an empirical measurement of contrast and/or interpolate a value of the unknown particle motion characteristic. The system may include a light source, photodetector, processor, and memory, which can be combined into a single device, such as a wearable device, for providing calibrated flow measurements. The device may be used, for example, to measure blood flow, cardiac output, and heart rate, and can be used to amplify the pulsatile signal.

Disclosed herein are systems, methods, and devices for calibrating contrast measurements from laser speckle imaging systems to accurately determine unknown particle motion characteristics, such as flow rate. The calibration stores to memory calibration data, which may include a set of measurements from samples with known particle characteristics and/or estimates of noise, including the effects on contrast arising from undesired signals unrelated to the unknown particle motion characteristics. The calibration data may be accessed and used to correct an empirical measurement of contrast and/or interpolate a value of the unknown particle motion characteristic. The system may include a light source, photodetector, processor, and memory, which can be combined into a single device, such as a wearable device, for providing calibrated flow measurements. The device may be used, for example, to measure blood flow, cardiac output, and heart rate, and can be used to amplify the pulsatile signal.

Devices, systems, and methods are disclosed for improved laser speckle imaging of samples, such as vascularized tissue, for the determination of the rate of movement of light scattering particles within the sample. The system includes a structure adjoining a light source and a photo-sensitive detector. The structure can be positioned adjacent the sample (e.g., coupled to the sample) and configured to orient the light source and detector relative the sample such that surface reflections, including specular reflections and diffuse reflections, are discouraged from entering the detection field of the detector. The separation distance along the structure between the light source and the detector may further enable selective depth penetration into the sample and biased sampling of multiply scattered photons. The system includes an operably coupled processor programmed to derive contrast metrics from the detector and to relate the contrast metrics to a rate of movement of the light scattering particles.

Devices, systems, and methods are disclosed for improved laser speckle imaging of samples, such as vascularized tissue, for the determination of the rate of movement of light scattering particles within the sample. The system includes a structure adjoining a light source and a photo-sensitive detector. The structure can be positioned adjacent the sample (e.g., coupled to the sample) and configured to orient the light source and detector relative the sample such that surface reflections, including specular reflections and diffuse reflections, are discouraged from entering the detection field of the detector. The separation distance along the structure between the light source and the detector may further enable selective depth penetration into the sample and biased sampling of multiply scattered photons. The system includes an operably coupled processor programmed to derive contrast metrics from the detector and to relate the contrast metrics to a rate of movement of the light scattering particles.

A device which: optically detects the presence of, measures the flow rate of, and identifies the characteristics of venting fugitive gas emissions. Specifically the device provides a spectral analysis of emission gas constituents; selective detection of the presence of venting hydrocarbons; measurement of venting emissions flow rates, the measurement of shut-in and flowing venting system pressures and the venting system temperatures. The flow rates are corrected, relative to the detection of the gas constituents and standard temperature and pressure (STP). These devices are configured to collect such data electronically and transmit via various telemetry systems, to a secure remote data network for reporting, access, evaluation, real-time monitoring and archiving as required.

A device which: optically detects the presence of, measures the flow rate of, and identifies the characteristics of venting fugitive gas emissions. Specifically the device provides a spectral analysis of emission gas constituents; selective detection of the presence of venting hydrocarbons; measurement of venting emissions flow rates, the measurement of shut-in and flowing venting system pressures and the venting system temperatures. The flow rates are corrected, relative to the detection of the gas constituents and standard temperature and pressure (STP). These devices are configured to collect such data electronically and transmit via various telemetry systems, to a secure remote data network for reporting, access, evaluation, real-time monitoring and archiving as required.

A system for measuring fluid flow in a wellbore is provided. A probe includes at least a heater. A fiber optic cable is connected to the probe. The system is programmed to perform operations including: changing an output of the heater to thereby change a temperature of drilling fluid moving over a fiber optic cable; measuring a strain on the fiber optic cable caused by changing the temperature of the drilling fluid; preliminarily determining a velocity of the drilling fluid from the measured strain; measuring at least a second parameter of the drilling fluid; adjusting the preliminary determined velocity based on the measured at least a second parameter to yield an adjusted velocity; and determining a flow rate of the drilling fluid based on the adjusted velocity.

An optical sensor includes: a sensor portion, having a transmitter and at least one receiver, configured to couple to a wettable component having a fluid flow channel, wherein the transmitter is disposed to emit a light that travels from the sensor portion to the wettable component where a majority of the light is directed towards the fluid flow channel at an angle between a first critical angle and a second critical angle; wherein with liquid filling the fluid flow channel, the majority of the light refracts at a liquid interface and travels through the entirety of the fluid flow channel; wherein with gas in the fluid flow channel, the majority of the light reflects at a gas interface and does not travel through the entirety of the fluid flow channel; wherein the amount of the light refracted and/or reflected and received by the at least one receiver, is used to determine if there is liquid or gas in the fluid flow channel.

An optical sensor includes: a sensor portion, having a transmitter and at least one receiver, configured to couple to a wettable component having a fluid flow channel, wherein the transmitter is disposed to emit a light that travels from the sensor portion to the wettable component where a majority of the light is directed towards the fluid flow channel at an angle between a first critical angle and a second critical angle; wherein with liquid filling the fluid flow channel, the majority of the light refracts at a liquid interface and travels through the entirety of the fluid flow channel; wherein with gas in the fluid flow channel, the majority of the light reflects at a gas interface and does not travel through the entirety of the fluid flow channel; wherein the amount of the light refracted and/or reflected and received by the at least one receiver, is used to determine if there is liquid or gas in the fluid flow channel.

An example method to perform optical measurements involves: emitting a first light beam via a first light source; performing first measurements by detecting the first light beam via a first optical sensor; emitting a second light beam via a second light source; performing second measurements by detecting the second light beam via a second optical sensor, the first and second measurements comprising variable components; performing third measurements by detecting a third light beam emitted from the second light source via a third optical sensor, the third measurements comprising a first steady state component representative of light intensities of the first and second light sources; and compensating a first light output of the first light beam and a second light output of the second light beam by controlling one or more currents to the first and second light sources based on the first steady state component of the third measurements.