Detector arrangement for blood culture bottles with colorimetric sensors
First Claim
1. A detection system comprising:
- a blood culture bottle comprising a sample medium;
a colorimetric sensor positioned in the blood culture bottle and subject to change of color due to change in pH or CO2 of the sample medium;
a sensor LED illuminating the colorimetric sensor;
a reference LED illuminating the colorimetric sensor;
a control circuit configured to selectively and alternately activating the sensor LED and the reference LED; and
a photodetector, the photodetector configured to measure reflectance from the colorimetric sensor during the selective and alternating illumination of the colorimetric sensor with the sensor LED and the reference LED and configured to generate intensity signals;
a computer receiving the intensity signals, the computer including a memory storing a calibration relationship between intensity signals for the reference LED as a function of distance of the bottle from a home position in relation to the detection arrangement;
wherein the reference LED has a peak wavelength of illumination between 750 and 900 nm.
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Accused Products
Abstract
A detector arrangement for a blood culture bottle incorporating a colorimetric sensor which is subject to change of color due to change in pH or CO2 of a sample medium within the blood culture bottle. The detector arrangement includes a sensor LED illuminating the colorimetric sensor, a reference LED illuminating the colorimetric sensor, a control circuit for selectively and alternately activating the sensor LED and the reference LED, and a photodetector. The photodetector measures reflectance from the colorimetric sensor during the selective and alternating illumination of the colorimetric sensor with the sensor LED and the reference LED and generates intensity signals. The reference LED is selected to have a peak wavelength of illumination such that the intensity signals of the photodetector from illumination by the reference LED are not substantially affected by changes in the color of the colorimetric sensor.
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Citations
10 Claims
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1. A detection system comprising:
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a blood culture bottle comprising a sample medium; a colorimetric sensor positioned in the blood culture bottle and subject to change of color due to change in pH or CO2 of the sample medium; a sensor LED illuminating the colorimetric sensor; a reference LED illuminating the colorimetric sensor; a control circuit configured to selectively and alternately activating the sensor LED and the reference LED; and a photodetector, the photodetector configured to measure reflectance from the colorimetric sensor during the selective and alternating illumination of the colorimetric sensor with the sensor LED and the reference LED and configured to generate intensity signals; a computer receiving the intensity signals, the computer including a memory storing a calibration relationship between intensity signals for the reference LED as a function of distance of the bottle from a home position in relation to the detection arrangement; wherein the reference LED has a peak wavelength of illumination between 750 and 900 nm. - View Dependent Claims (2)
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3. A method comprising the steps of:
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providing a blood culture bottle comprising a sample medium and a colorimetric sensor positioned in the blood culture bottle, the colorimetric sensor subject to change of color due to change in pH or CO2 of the sample medium; alternately and repeatedly illuminating the colorimetric sensor with a sensor LED and a reference LED; measuring reflectance from the colorimetric sensor due to the illumination of the colorimetric sensor by the sensor LED and reference LED with a photodetector, the photodetector responsively generating intensity signals; receiving the intensity signals at a computer, the computer including a memory storing a calibration relationship between intensity signals for the reference LED as a function of distance of the bottle from a home position in relation to the detection arrangement; wherein the reference LED has a peak wavelength of illumination of between 750 and 900 nm. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10)
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Specification