40 results about "Beer–Lambert law" patented technology

Methods and apparatus for measuring cerebral O₂ saturation and detecting cerebral hypoxia-ischemia using multi-wavelength near infrared spectroscopy (NIRS). Near-infrared light produced by an emitter is directed through brain tissue. The intensity of the light that passes through the brain tissue is measured using photodiode detectors positioned at distinct distances from the emitter. This process is conducted for at least three wavelengths of near-infrared light. One of the wavelengths used is substantially at an isobestic point for oxy-hemoglobin and deoxy-hemoglobin, but the other two may be any wavelengths within the near-infrared spectrum (700 nm to 900 nm), so long as one of the additional wavelengths is greater than the isobestic point and the other is less than the isobestic point. Tissue oxygenation is calculated using an algorithm derived from the Beer-Lambert law. Cerebral hypoxia-ischemia may be diagnosed using the calculated tissue oxygenation value.

The invention discloses a method for obtaining the leaf area index and the average leaf inclination of rice canopy by using a hemisphere photographic process. The method comprises the following steps of: collecting a hemisphere image of rice canopy from bottom to top inside the rice canopy by using a digital hemisphere shooting system based on a fisheye lens; after performing gray conversion and binaryzation on the hemisphere image, obtaining the canopy porosity under the zenith angle at a viewing angle of 57 degrees, and calculating the rice canopies LAI and ALIA under the condition of the single zenith angle at the viewing angle of 57 degrees based on the Beer-Lambert law and a poisson model as well as the two characteristics of the blade projection function of the rice canopy; simulating the leaf inclination distribution of the rice canopy by an elliptic function and optimizing the rice canopies LAI and ALIA calculated by using the single-angle method so as to rapidly acquire the rice canopies LAI and ALIA. The rice canopies LAI and ALIA can be obtained in real time without picking up rice blade outdoors for destructive artificial measurement, and basic parameters for monitoring the rice growth in real time and remotely estimating the yield of rice are provided.

The invention discloses a VCSEL (vertical cavity surface emitting laser)-based low-power-consumption gas detection method and device. The method comprises the following steps that: a microprocessor controls a sawtooth wave current driving circuit to drive a VCSEL to generate light with specified wavelength in the first step; the light emitted from the VCSEL reaches an optical fiber sensing probe and a reference air chamber through a light path; and an optical signal with concentration information enters a photoelectric conversion circuit and is converted into a corresponding analog voltage signal by the photoelectric conversion circuit, the analog voltage signal is converted into a digital voltage signal which can be identified by the microprocessor through an analog/digital (A/D) conversion circuit, a temperature measurement circuit transmits a measured environment temperature value to the microprocessor, and thus the microprocessor obtains the wavelength of the light emitted from the VCSEL in case of a given driving current and calculates a field gas concentration signal according to a Beer-Lambert law. The method has the advantage of implementing the gas concentration detection at low power consumption.

A method and apparatus for measuring and calibrating the measurement of small volumes of liquids. The small volumes of liquid are typically dispensed from liquid delivery devices, the delivery device often having multiple channels to analyze many samples at once. The liquid samples are delivered to one or more cells, typically in a multi-well plate, and positioned in a spectrophotometer for determining an absorbance of a chromophore in the liquid sample. Based upon an absorbance measurement and the concentration of the chromophore, a path length of the liquid sample is determined, from which a volume of the sample may be calculated. The method and apparatus provide various means for correcting for differences in the dimensions and/or other factors causing a non-linear deviation from the Beer-Lambert law. A system or kit may be provided including sets of sample solutions of varying dilution ranges for calibrating different liquid volumes. The kit may further include software code for storing and analyzing the various sample solutions.

A method, apparatus and kit for precisely and accurately determining the volume of a liquid aliquot which can be used to calibrate a liquid delivery device. Two dye-containing solutions, a sample solution and a diluent solution, are prepared such that each solution contains a different dye, with the solutions having different absorbance values at a first wavelength and at a second wavelength. The absorbance value of a known volume of diluent solution is measured at both wavelengths. Either one aliquot of sample solution is added to the diluent solution and then absorbance measurements are made at both wavelengths, or multiple aliquots of sample solution are mixed serially into the diluent solution and then absorbance measurements are made at both wavelengths after each aliquot is added. The volume of any single aliquot is calculated by using a two-step formula which is based on the Beer-Lambert law.

A method, an apparatus, and a kit including the apparatus and a fluorescence agent are provided for measuring a time-varying change in an amount of blood in a tissue volume, and include exciting a fluorescence agent in the blood, acquiring a time-varying light intensity signal during a pulsatile flow of the blood through the tissue volume, the pulsatile flow having a systolic and a diastolic phase resembling a conventional photoplethysmogram, and processing the acquired signal by applying a modified Beer-Lambert law to obtain a measurement of the time-varying change in the amount of blood in the tissue volume. The instantaneous molar concentration of the fluorescence agent is determined by utilizing a concentration-mediated change in a fluorescence emission spectrum of the fluorescence agent. There is further provided a fluorescence agent for use in the method.

The invention discloses a high-speed passive distance measuring method based on oxygen absorption and a multiple regression, mainly relating to a distance measuring method. The method comprises the following steps: receiving a target radiation signal which is subjected to atmospheric attenuation by using an infrared spectrometer; estimating the distance value of a target to be measured by using a Beer-Lambert law in combination with a multiple linear regression algorithm. The advantages of a Fourier transform multichannel are utilized fully, target distance information can be calculated by only measuring target radiation once without specifically assuming a target moving state or continuously tracking and repeatedly sampling the target, a the measuring process can be finished instantly, the detection distance is long, and high measuring reliability is realized. Moreover, selected oxygen adsorbs wave bands around 762 nm, thereby well eliminating the weather influences, ensuring the measuring accuracy. Furthermore, the high-speed passive distance measuring method has a significant application prospect on the aspects of infrared search tracking system and electro-optical countermeasure.

The invention discloses a method for detecting remaining trace tween 80 in water, and aims to provide the method for detecting the remaining trace tween 80 in the water, which has the advantages of directly determining by using an ultraviolet visible spectrophotometer, along with low analysis cost, easiness, convenience and fastness in operation and accurate analysis result. The method comprises the following steps of: dissolving a tween 80 sample in distilled water to prepare sample solutions of different concentrations; detecting the sample solutions of different concentrations by using the ultraviolet visible spectrophotometer at the detection wavelength of 232nm, drawing the obtained absorbency into a standard curve and acquiring a linear regression equation based on the standard curve according to a Beer-Lambert law; detecting the absorbency of the water sample with unknown tween 80 content by using the ultraviolet visible spectrophotometer at the wavelength of 232nm; and calculating the content of the tween 80 in the unknown water sample based on the linear regression equation. In the method, the ultraviolet visible spectrophotometer is used for direct determination; and a specific measure is provided for scientifically and quantitatively monitoring the content of the tween 80 in the water body.

The invention provides a device for measuring an optical absorption coefficient of a large-caliber crystalline material. According to the measurement device, stable collimated laser beams are formed by utilizing a tunable laser light source and a stable laser power system, the stable laser beams irradiate a measured large-caliber crystal, the perpendicularity between incident laser and the surface of the large-caliber crystal and the perpendicularity between the o-axis or e-axis of the large-caliber crystal and the table board are monitored by utilizing an optical autocollimating method, the laser polarization direction is adjusted and output to be parallel to the o-axis or e-axis of the large-caliber crystal by utilizing a polarizer and an analyzer, a transmission ratio of the o-light or e-light of the large-caliber crystal in a specific polarization state is measured, and a single-point absorption coefficient formula of the crystalline material on o-light or e-light is deduced by utilizing a Beer-Lambert law, so that the absorption coefficient of the large-caliber crystal can be measured, and finally, the large-caliber crystalline material is subjected to scanning and splicing measurement through a high-precision scanning sample platform deck mechanism, and precision measurement of the large-caliber crystalline material on the optical absorption coefficient of the o-light or e-light is realized.

The invention relates to a dual-PPG (Photoplethysmography)-based blood pressure measuring method and device. The method comprises the following steps: penetrating human tissues by using projection light, wherein the influence factor of the light absorption of the human tissues can be obtained according to a Beer-Lambert law: log(I0/I)=epsilonCl; reflecting the change of blood volume through a PPG signal; calculating the blood pressure by using PTT (Push to Talk). The method and the device have the advantages that self-detection can be realized through the blood pressure measurement based on PPG, and the all-day blood pressure can be better monitored based on continuous blood pressure monitoring of PPG in order to reflect the diurnal change situation of the blood pressure. The method and the device have important significance to the prevention of sudden cardiovascular diseases. Through the continuous blood pressure measurement based on PPG, the treatment of hypotensive drugs can be well monitored. Compared with other continuous blood pressure measurement, the continuous blood pressure measurement way based on PPG has remarkable advantages.

The invention is suitable for the technical field of medical image processing and applying, and provides a method and system for obtaining the value of the bone mineral density of the human body. The method includes the following steps: obtaining the high-low-energy image X ray injection strength, obtaining calibration parameters, collecting low-energy X ray images and high-energy X ray images of the bone area, preprocessing the collected images, receiving an interested area which is selected by a user and requires calculation of the value of the bone mineral density, locating an accurate area of the interested area which requires the calculation of the value of the bone mineral density, and calculating the value of the bone mineral density according to the Beer-Lambert law. By means of the method and system, dependence on hardware of a bone mineral density instrument can be reduced while the value of the bone mineral density is calculated; on the basis of a common digital X ray machine, the scheme of the method and system is applied, measurement and calculation of the bone mineral density of the human body can be achieved, the problem in the hardware is not required to be considered, and the production cost of the bone mineral density instrument is reduced to a certain degree. In addition, when the scheme is adopted for collecting the bone images, a standard body is not required, and the image collecting process is accordingly simplified.

The invention discloses an under-forest illumination intensity estimation method based on remote sensing, and the method comprises the following steps: 1, determining a to-be-detected region and illumination-related parameters, wherein the illumination-related parameters comprise the total time ht of the possible solar radiation in one day and the position parameters of the sun; 2, calculating the total solar radiation above a canopy, wherein the total solar radiation above the canopy in a to-be-detected region comprises the solar direct solar radiation in the direction of a local incidence angle, the scattered radiation and the reflected radiation of the ground surface, i.e., Gi=Bi+Di+Ri; 3, carrying out the inversion of a leaf area index through a remote sensing image, and calculating and obtaining the under-forest illumination intensity based on the Beer-Lambert law according to the total solar radiation above the canopy. The method provided by the invention is easy to implement, is low in cost, and is high in accuracy.

The invention discloses a non-invasive portable blood glucose meter based on an array CCD, comprising an LED light source, a lens, an optical fiber distance sensor, a finger groove, a driving circuit, an array CCD sensor, an ARM chip, a memory, a bluetooth chip and a power supply module. The invention is based on Beer-Lambert's law, uses an array CCD sensor to record the image data of the transmitted light of the finger under two conditions of the test light source and the reference light source, and obtains the influence of glucose on the absorbance through data processing. Use the optical fiber distance sensor to measure the size of the optical path length, and obtain the expression between the glucose concentration, absorbance, and optical path length through the curve fitting method. blood sugar concentration, display and save the results through the mobile device. The invention has the advantages of portability, low cost and simplicity.

The invention discloses an optical non-invasive detection method of mixed venous oxygen saturation. The optical non-invasive detection method comprises the following steps: light intensity signals are obtained through transmitting devices with different wavelengths and receiving devices at corresponding parts, then absorption coefficients are obtained by an improved beer-lambert law, after a series of treatments such as fast Fourier transform of the absorption coefficients, the mixed venous oxygen saturation is finally calculated out, the mixed venous oxygen saturation is monitored in a real-time, non-invasive and non-intrusive manner, and the method can be used for monitoring conditions such as physiological change of a shock patient. The method is reliable, high in flexibility, simple to operate, and favorable for popularization and application. The invention puts forward a non-invasive venous oxygen saturation measurement method for the first time, and the non-invasive venous oxygen saturation measurement method has the advantages of being high in safety, high in measurement precision and the like by adopting an optical technology.

The invention discloses a near-infrared diffusion correlation spectroscope based on a brand-new software correlator. The time resolution can be flexibly arranged, and the time resolution of being smaller than 1 ms is achieved; delay times and the number of the delay times can also be flexibly arranged. When the number of the delay times is small, the correction Beer-Lambert law [8] provided by W. B. Baker and the like and used for measurement of the blood flow volume is adopted. When the number of the delay times is large, the biological tissue blood flow volume is obtained through the theoretical fitting method. A plurality of counters are adopted, and the near-infrared diffusion correlation spectroscope can be expanded into a multi-channel near-infrared diffusion correlation spectroscope easily. Hence, the near-infrared diffusion correlation spectroscope is fast, cheap and flexible.

The invention relates to the field of atmospheric optics, and specifically relates to an optical initial radiation intensity calibration method, device and system. The method comprises the steps: obtaining an earth-sun distance correction factor and relative air mass at a moment of measurement, and a voltage value of light, with a given wavelength, outputted through a measurer when the relative air mass is within at least one measurement section, wherein the maximum difference between the maximum value and the minimum value of the relative air mass in the measurement section is two; carrying out reciprocal transformation of the relative air mass corresponding to the voltage value outputted by the measurer; and employing a least square regression algorithm to calculate a calibrated voltage value in each measurement section according to the Beer-Lambert law, the voltage value of light, outputted through a measurer, with the given wavelength, the relative air mass after reciprocal transformation and the earth-sun distance correction factor at the moment of measurement. The method can reduce the measurement requirements of calibration, can complete measurement in a short time, reduces the measurement errors, and improves the practicability of measurement.

The invention discloses a dexamethasone sodium phosphate injection intermediate testing method. The dexamethasone sodium phosphate injection intermediate testing method comprises following steps: a dexamethasone sodium phosphate injection intermediate sample is dissolved in a 0.06-0.15% dimethyl sulfoxide unsaturated organic solution so as to prepare sample solutions of different concentration, wherein the concentration of the sample solutions ranges from 1000 to 3000mg/L; the sample solutions are delivered into an ultraviolet spectrophotometer for detection, a standard curve is drawn based on obtained absorbance values, and a linear regression equation is obtained according to the standard curve based on Beer-Lambert law; a sample to be tested is prepared into a solution according to the step 1, and then is subjected to absorbance value detection at a wavelength ranging from 200 to 300nm, and then the content of the dexamethasone sodium phosphate injection intermediate is calculated based on the linear regression equation. With equal labor and environment investment, yield of each batch is increased by 20%, production cost is reduced, and at the same time product yield is improved.

The invention belongs to the technical field of photoelectricity and micro electro mechanical systems, and relates to an air chamber structure, in particular to an air chamber structure of a nondispersive spectrum gas analyser. The air chamber structure comprises an air chamber inner shell, a filter core, an air chamber outer shell, a front cover, a rear cover, a transmitting end and a receiving end; the air chamber inner shell and the air chamber outer shell are of ring body structures, small holes are uniformly distributed on a circumference surface of the air chamber inner shell, and an inner diameter of the air chamber outer shell is larger than an outer diameter of the air chamber inner shell; through holes are opened on the front cover and the rear cover; and according to the novel straight air chamber structure provided by the invention, the affect on a calculating result of air concentration caused by pollution from extremely small number of dusts is greatly reduced, parallel light coincides with the empirical equation stated in the Beer-Lambert law, and the difficulty on norm algorithm of air concentration is reduced.

The invention discloses a diet oil fume VOCs precision automatic monitor. The monitor comprises an absorption liquid box, an absorption tank, an absorption tube, a first liquid discharge valve, a pump, a waste liquid box, a reaction chamber, a color developing agent chamber, a colorimetric chamber, a data processing system, a data window, a first liquid inlet valve, a second liquid inlet valve, a second liquid discharge valve, a third liquid discharge valve, a visual window, a stirring motor and a stirrer. The monitor has an advantage that through adding a novel high-efficiency catalyst load nano-silver metal organic framework ZIF-8 and a targeted color developing agent, chemical reaction with aldehydes and ketones in oil fume VOCs is performed, and a Beer-Lambert law is used to convert into an aldehyde ketone content so as to obtain an accurate oil fume VOCs concentration. By using the technology, detection of an existing traditional infrared spectrophotometry to oil fume is subverted, and the oil fume VOCs is quantified in a real sense.

The invention discloses a non-invasive spine marrow lesion detector. According to the invention, optical signals carrying marrow information are converted into electric signals by detecting units through near infrared technology; data is obtained through signal processing; hemodynamic parameters of the marrow can be obtained according to the modified Beer-Lambert law; and therefore spine marrow lesions can be diagnosed. The detector is noninvasive, can continuously and rapidly diagnose lesions, is low in cost and quite high in reliability, is suitable for diagnosing spine marrow lesions, and can effectively avoid a phenomena that patients are in pain when the patients are diagnosed through other methods.