Topic
Calibration curve
About: Calibration curve is a research topic. Over the lifetime, 6552 publications have been published within this topic receiving 95128 citations.
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TL;DR: In this article, the degree of N-deacetylation of chitosan samples was determined by using the absorption ratios [A1655/A3450] in the equation of the calibration curve.
Abstract: Various infrared spectroscopic techniques for the analysis of degree of N-deacetylation of chitosan were evaluated for accuracy. A new method was proposed which involved development of a calibration curve using the absorbance intensities of the chitosan infrared spectrum at 1655 and 3450 cm−1. The degree of N-deacetylation of various chitosan samples was then determined by using the absorption ratios [A1655/A3450] in the equation of the calibration curve. This method yielded results which were superior to those of any of the previously reported infrared spectroscopic methods tested herein.
163 citations
TL;DR: It is recommended that investigators design their own calibration curves not only to improve accuracy but also to understand the range(s) of highest error and to choose the optimal points within the expected sensing range for calibration.
Abstract: Tekscan pressure sensors are used in biomechanics research to measure joint contact loads. While the overall accuracy of these sensors has been reported previously, the effects of different calibration algorithms on sensor accuracy have not been compared. The objectives of this validation study were to determine the most appropriate calibration method supplied in the Tekscan program software and to compare its accuracy to the accuracy obtained with two user-defined calibration protocols. We evaluated the calibration accuracies for test loads within the low range, high range, and full range of the sensor. Our experimental setup used materials representing those found in standard prosthetic joints, i.e., metal against plastic. The Tekscan power calibration was the most accurate of the algorithms provided with the system software, with an overall rms error of 2.7% of the tested sensor range, whereas the linear calibrations resulted in an overall rms error of up to 24% of the tested range. The user-defined ten-point cubic calibration was almost five times more accurate, on average, than the power calibration over the full range, with an overall rms error of 0.6% of the tested range. The user-defined three-point quadratic calibration was almost twice as accurate as the Tekscan power calibration, but was sensitive to the calibration loads used. We recommend that investigators design their own calibration curves not only to improve accuracy but also to understand the range(s) of highest error and to choose the optimal points within the expected sensing range for calibration. Since output and sensor nonlinearity depend on the experimental protocol (sensor type, interface shape and materials, sensor range in use, loading method, etc.), sensor behavior should be investigated for each different application.
161 citations
Patent•
27 Sep 2010
TL;DR: In this article, the authors describe features, systems and methods for customizing calibration curves, parameter algorithms, and the like to individual users, among other features, system and methods.
Abstract: This disclosure describes, among other features, systems and methods for customizing calibration curves, parameter algorithms, and the like to individual users. An initial calibration curve generated based on a population can be used as a starting point in an algorithm for measuring a physiological parameter such as glucose. The measurement algorithm can determine one or more initial measurement values for a user based on the initial calibration curve. In certain embodiments, one or more alternative measurements, such as invasive or minimally invasive measurements, can periodically or sporadically be input into the measurement algorithm. The algorithm can use the alternative measurements to adapt the calibration curve to the individual. As a result, measurements for the individual can more accurately reflect the individual's actual parameter values.
160 citations
TL;DR: It is shown that the difference between the average lengths of the paths traveled by red and infrared photons makes the calibration curve of oximeters sensitive to the total attenuation coefficients of the tissue in the two wavelength bands, as well as to absorption by the pulsating arterial blood.
Abstract: Photon diffusion theory is used to derive analytical expressions that relate the AC-DC intensity ratios measured by transmission-mode and reflectance-mode pulse oximeters to arterial oxygen saturation (S/sub a/O/sub 2/). The effects of multiple scattering are examined by comparing the results of the photon diffusion analysis with those obtained using an analysis is based on the Beer-Lambert law which neglects scattering. It is shown that the difference between the average lengths of the paths traveled by red and infrared photons makes the calibration curve of oximeters sensitive to the total attenuation coefficients of the tissue in the two wavelength bands, as well as to absorption by the pulsating arterial blood. Therefore, the shape of the calibration curve is affected by tissue blood volume, source-detector placement, and other variables that change the wavelength dependence of the attenuation coefficient of the tissue. After evaluating the relationship between S/sub a/O/sub 2/ and the red/IR AC-DC ratio under a variety of physiological conditions, it is concluded that for oximeters utilizing fixed calibration curves based on measurements obtained from normal subjects, errors introduced by interfering variables should be less than a few percent when S/sub a/O/sub 2/ exceeds 70%. >
155 citations
TL;DR: The paper summarizes critically the current approaches for the calculation of the limits of detection and quantification based on the calibration line and the explicit formulas relevant to the use of straight line and quadratic models are reported.
Abstract: The paper summarizes critically the current approaches for the calculation of the limits of detection and quantification. In the context of the description of the method based on the calibration line, the arguments concerning the underlying experimental design, the choice of the appropriate model in the univariate regression, the effects of the dispersion characteristics of the data are deeply discussed. The effects of the scedasticity of the experimental data are taken into account in the obtainment of the calibration curve and in its utilization. To gain transparency, adaptability, and tutorial effectiveness the explicit formulas relevant to the use of straight line and quadratic models are reported. An application of the described procedures to GC-MS data is reported as an illustrative example. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 26:1–18, 2007
154 citations