摘要:
A method determines an analyte concentration in a sample including the analyte and a substance. The method includes providing an absorption spectrum of the sample. The absorption spectrum has an absorption baseline. The method further includes shifting the absorption spectrum so that the absorption baseline approximately equals a selected absorption value in a selected absorption wavelength range. The method further includes subtracting a substance contribution from the absorption spectrum. Thus, the method provides a corrected absorption spectrum substantially free of a contribution from the substance.
摘要:
A calibration standard for calibrating a thermal gradient spectrometer. The calibration standard is a structure having a particular glucose concentration which a thermal gradient spectrometer reads for determining whether the spectrometer is in calibration. The structure of the calibration standard properly mimics the physiology of human tissue. A number of such standards, each containing a different concentration of glucose are provided in kit form with a thermal gradient spectrometer for use in calibrating the spectrometer. The spectrometer is provided with a display and internal circuitry for performing self-calibrating adjustments and a communications port for electronically coupling to a remote computer and database for supplying external calibration commands to said spectrometer.
摘要:
A method and apparatus for monitoring glucose, ethyl alcohol and other blood constituents in a noninvasive manner. The measurements are made by monitoring infrared absorption of the desired blood constituent in the long infrared wavelength range where the blood constituent has a strong and distinguishable absorption spectrum. The long wavelength infrared energy emitted by the person as heat is monitored and the infrared absorption of particular constituents in the blood (such as glucose or blood alcohol) is measured at characteristic infrared absorption wavelengths for those constituents. The measurements are preferably synchronized with systole and diastole of the cardiac cycle so that the signal contribution caused by veins and tissues (which do not pulse) may be cancelled when a ratio of the detected signals is taken. The concentration of the blood constituents are then determined in accordance with a polynomial equation.
摘要:
A method and apparatus are described that permit an analyte concentration to be estimated from a measurement in the presence of compounds that interfere with the measurement. The method reduces the error in the analyte concentration in the presence of interferents. The method includes the use of a set of measurements obtained for a large population having a range of known analyte and interfering compound concentrations. From a sample measurement, which may or may not be one of the population, likely present interferents are identified, and a calibration vector is calculated.
摘要:
An ingestible gastric device comprising a formed body that is adapted to expand upon exposure to a hydration medium and then degrade after a first residence time in the stomach cavity, allowing the device to be passed by the patient's normal digestive process, and monitoring means for monitoring the gastric device. In some embodiments, the monitoring means comprises a biocompatible RFID tag.
摘要:
A physiological sensor apparatus, system and method for determining a physiological characteristic, comprising providing at least one physiological sensor that is adapted to measure at least one physiological characteristic at a target measurement site on a subject's body, heating an extended tissue region on the subject's body, whereby blood perfusion of the tissue region is enhanced, and measuring at least one physiological characteristic at the target measurement site with the physiological sensor during or within a predetermined period after heating the extended tissue region. In one embodiment, the sensor system includes at least one temperature algorithm that is adapted to adjust the heat applied to the extended tissue region based on the body's response to the heat stimuli.
摘要:
A method for determining a physiologic characteristic associated with cardiac function in a subject comprising the steps of providing at least one electromagnetic radiation absorption measurement, providing demographic information reflecting the subject's physical condition, determining a temporal plethysmographic value from the electromagnetic radiation absorption measurement, and determining at least one physiologic characteristic from the temporal plethysmographic value and demographic information by using a predetermined phenomenological model that is adapted to provide an estimate of a blood volume-time relationship proximate the heart and compute at least one physiologic characteristic associated with cardiac function based on the estimated blood volume-time relationship.
摘要:
Methods and associated algorithms for determining cardiac and/or cardiovascular performance that are based on at least one cardiac function determinant associated with or at least in part, reflective of preload, contractility and afterload.
摘要:
The invention comprises a method and apparatus for processing signals reflecting a physiological characteristic by detecting the intensity of light following tissue absorption at two wavelengths and subtracting the best estimate of the desired signal from the difference between the signals. Corrected first and second intensity signals are determined by applying a residual derived from a combination of the first and second intensity signals as multiplied by a residual factor and subtracted from a difference between the first and second intensity signals to the first and second intensity signals. In one embodiment, the method and apparatus are used to determine arterial oxygen saturation.
摘要:
The invention is method and apparatus for determining a physiological characteristic by detecting the intensity of light following tissue absorption at two wavelengths, estimating the pulse amplitude and indexing a calculated physiological characteristic to the estimated pulse amplitude. In one embodiment, the ratio of logarithms of absorbance signal amplitude is indexed to the pulse amplitude to improve the accuracy of arterial oxygen saturation as determined by a pulse oximeter.