Patents Assigned to Nellcor Incorporated, a Delaware corporation
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Publication number: 20110071375Abstract: A method and apparatus for reducing the effects of noise on a system for measuring physiological parameters, such as, for example, a pulse oximeter. The method and apparatus of the invention take into account the physical limitations on various physiological parameters being monitored when weighting and averaging a series of measurements. Varying weights are assigned different measurements, measurements are rejected, and the averaging period is adjusted according to the reliability of the measurements. Similarly, calculated values derived from analyzing the measurements are also assigned varying weights and averaged over adjustable periods. More specifically, a general class of filters such as, for example, Kalman filters, is employed in processing the measurements and calculated values. The filters use mathematical models which describe how the physiological parameters change in time, and how these parameters relate to measurement in a noisy environment.Type: ApplicationFiled: November 23, 2010Publication date: March 24, 2011Applicant: Nellcor Incorporated, a Delaware corporationInventors: Clark R. Baker, JR., Thomas J. Yorkey
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Publication number: 20050143634Abstract: A method and apparatus for reducing the effects of noise on a system for measuring physiological parameters, such as, for example, a pulse oximeter. The method and apparatus of the invention take into account the physical limitations on various physiological parameters being monitored when weighting and averaging a series of measurements. Varying weights are assigned different measurements, measurements are rejected, and the averaging period is adjusted according to the reliability of the measurements. Similarly, calculated values derived from analyzing the measurements are also assigned varying weights and averaged over adjustable periods. More specifically, a general class of filters such as, for example, Kalman filters, is employed in processing the measurements and calculated values. The filters use mathematical models which describe how the physiological parameters change in time, and how these parameters relate to measurement in a noisy environment.Type: ApplicationFiled: March 1, 2005Publication date: June 30, 2005Applicant: Nellcor Incorporated, a Delaware corporationInventors: Clark Baker, Thomas Yorkey
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Publication number: 20050085735Abstract: In a physiological monitor, a method and an apparatus for determining a patient's pulse rate using data corresponding to a plurality of wavelengths of electromagnetic energy transmitted through the tissue of the patient. The method includes tracking the pulse rate in the data using an adaptive comb filter, the data having signal portions corresponding to the pulse rate and signal portions corresponding to noise, periodically calculating a frequency power spectrum of one of the wavelengths, and using the frequency power spectrum in a pulse rate calculator to determine the pulse rate or to verify the pulse rate calculated by the pulse rate calculator.Type: ApplicationFiled: October 12, 2004Publication date: April 21, 2005Applicant: Nellcor Incorporated, a Delaware corporationInventors: Clark Baker, Thomas Yorkey
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Publication number: 20040158135Abstract: A method and apparatus for reducing the effects of noise on a system for measuring physiological parameters, such as, for example, a pulse oximeter. The method and apparatus of the invention take into account the physical limitations on various physiological parameters being monitored when weighting and averaging a series of measurements. Varying weights are assigned different measurements, measurements are rejected, and the averaging period is adjusted according to the reliability of the measurements. Similarly, calculated values derived from analyzing the measurements are also assigned varying weights and averaged over adjustable periods. More specifically, a general class of filters such as, for example, Kalman filters, is employed in processing the measurements and calculated values. The filters use mathematical models which describe how the physiological parameters change in time, and how these parameters relate to measurement in a noisy environment.Type: ApplicationFiled: February 9, 2004Publication date: August 12, 2004Applicant: Nellcor Incorporated, a Delaware corporationInventors: Clark R. Baker, Thomas J. Yorkey
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Publication number: 20020137994Abstract: A method and apparatus for reducing the effects of noise on a system for measuring physiological parameters, such as, for example, a pulse oximeter. The method and apparatus of the invention take into account the physical limitations on various physiological parameters being monitored when weighting and averaging a series of measurements. Varying weights are assigned different measurements, measurements are rejected, and the averaging period is adjusted according to the reliability of the measurements. Similarly, calculated values derived from analyzing the measurements are also assigned varying weights and averaged over adjustable periods. More specifically, a general class of filters such as, for example, Kalman filters, is employed in processing the measurements and calculated values. The filters use mathematical models which describe how the physiological parameters change in time, and how these parameters relate to measurement in a noisy environment.Type: ApplicationFiled: February 5, 2002Publication date: September 26, 2002Applicant: Nellcor Incorporated, a Delaware corporationInventors: Clark R. Baker, Thomas J. Yorkey