A system (100) for detecting tissue inflammation, and gingivitis specifically, including a light emitter (102) configured to emit light at a tissue region (104) within a user's mouth; a light detector (106) configured to detect optical signals diffusely reflected through the tissue region over a period of time; a controller (130) configured to: determine a slope signal (Q) based on at least two signals (R(λ.sub.1), R(λ.sub.2)) from the optical signals, the at least two signals including at least one signal from a hemoglobin-dominated wavelength range; determine one or more characteristics of the slope signal; and select a best measurement signal based on the one or more characteristics of the slope signal. The system further includes a user interface (116) configured to provide information regarding a position of a probe for accurate detection of tissue inflammation based on the one or more characteristics of the slope signal.

A method of determining an absorption or turbidity coefficient of a liquid involves storing a set of data describing a plurality of droplets or other discrete bodies of liquid of different shapes, sizes and absorption or turbidity coefficients. Each body is captured as a combination of a measurable transmission parameter obtained by modelling the interaction of light with a drop, and of one or more dimensional measurements selected from lengths, areas and volumes. The absorption or turbidity coefficient is indicated also. By measuring the transmission of light through a real body of liquid, and making measurements allowing the droplet to be specified, the absorption or turbidity coefficient associated with a droplet giving rise to the same behaviour in transmitting light can be identified from the data set.

Provided is a gas sensor comprising first and second light emitting parts, first and second light receiving parts, a first optical path region and a second optical path region, wherein the optical path regions have a common region, an optical path length of the first optical path region is longer than that of the second optical path region, a rate of change of an output signal with respect to a gas to be measured of the first light receiving part is larger than that of the second light receiving part, a rate of change of an output signal with respect to an interference gas of the second light receiving part is larger than that of the first light receiving part, and a sensitivity peak wavelength of the second light receiving part overlaps with an absorption wavelength of water vapor.

A method for detecting one or more predetermined materials, includes receiving sensor data from an optical sensor system, wherein the sensor data indicates a plurality of wavelengths, processing, in real time, the sensor data using a recurrent neural network to correlate the sensor data with one or more predetermined materials, detecting the presence of the one or more predetermined materials based on the correlated sensor data, and outputting a correlation signal indicating whether the one or more predetermined materials have been detected. The method can further include receiving feedback from an operator indicating whether the correlation signal is accurate, and modifying a correlation model of the recurrent neural network based on the feedback to enhance correlating the sensor data to the one or more predetermined materials.

In a measurement apparatus or a measurement method, an information processing apparatus executes: a process of specifying a bunch of grapes to be measured on the basis of detection of grasping of the bunch of grapes by a gripper; and a process of starting to measure the number of pieces of the specified bunch of grapes.

A material analytical sensor includes an emitter that irradiates a material with irradiation light including a wavelength region related to estimation of an amount of a component of the material, a controller that controls an irradiation cycle of the irradiation light, a receiver that receives reflected light from the material to output as a pulse signal and receives disturbance light to output as a noise signal, an integrator that samples N pulse signals during a predetermined period and integrates the sampled N pulse signals to obtain a first integrated value, and samples N noise signals during a same period as the predetermined period with a same cycle as the irradiation cycle and integrates the sampled N noise signals to obtain a second integrated value, and an extractor that deducts the second integrated value from the first integrated value to extract an amount of the reflected light.

Systems and methods disclosed herein, in accordance with one or more embodiments provide for imaging gas in a scene, the scene having a background and a possible occurrence of gas. In one embodiment, a method and a system adapted to perform the method includes: controlling a thermal imaging system to capture a gas IR image representing the temperature of a gas and a background IR image representing the temperature of a background based on a predetermined absorption spectrum of the gas, on an estimated gas temperature and on an estimated background temperature; and generating a gas-absorption-path-length image, representing the length of the path of radiation from the background through the gas, based on the gas image and the background IR image. The system and method may include generating a gas visualization image based on the gas-absorption-path-length image to display an output image visualizing a gas occurrence in the scene.

Aspects of the embodiments are directed to compact and non-contact systems, methods, and devices for optical detection of target chemicals on/in samples are disclosed. Light of at least two different wavelengths, or different bands of wavelengths, interacts with a target chemical, and at least some of the light that has interacted with the target chemical is incident on at least two photodetectors. Each of the photodetectors is configured to detect light of a different wavelength, or a different band of wavelengths, that has interacted with the target chemical. A processing logic is configured to compute a ratio between a parameter indicative of the intensity of light detected by one photodetector and a parameter indicative of the intensity of light detected by the other photodetector, and to determine the presence and/or the amount of the target chemical based on the computed ratio.

A gas sensor (2) distinguishes between a target gas and a contaminant and includes a light source (8), a measurement volume (4), a detector (22), and an adaptable filter system (20) with a first optical filter and a second optical filter. The filter system switches between a first composite state, with both filters in a reference state, a second composite state, with the first filter in a first reference state and the second filter in a second measurement state, a third composite state with the first filter in a first measurement state and the second filter in a second reference state, and a fourth composite state, with both filters in a measurement state. The gas sensor detects a target gas and makes a determination as to a presence of the contaminant by comparing the respective detector signals, generated during at least three of the composite states, with each other.

A method of determining the concentration of a species in a portion of a furnace atmosphere is described. The method comprises the steps of measuring first, second and third intensities of electromagnetic radiation in the furnace at first, second and third wavelengths respectively. The third wavelength is selected to be representative of absorption of electromagnetic radiation by the species. A fourth intensity of electromagnetic radiation is calculated, being an estimate of the intensity of electromagnetic radiation in the furnace at the third wavelength absent any absorbing species in the furnace atmosphere. The third intensity and the fourth intensities are used to determine a parameter that is proportional to the concentration of absorbing species in the portion of the furnace atmosphere. Apparatus for carrying out the method is also described.