Patents by Inventor Bradford B Chew
Bradford B Chew has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8874181Abstract: A pulse oximeter method and apparatus which provides (1) a notch filter at a distance between a modulation frequency and a common multiple of commonly used power line frequencies (50, 60, 100 and 120) and also (2) a demodulation frequency greater than a highest pulse rate of a person and lower than any harmonic of 50, 60, 100 or 120 Hz, to filter ambient light interference, while choosing an optimum demodulation frequency that avoids interference from the notch filter or from harmonics of the line interference. Also, ambient light for any low frequency interference, such as power line interference, is measured both before and after each of the light emitter wavelengths and the average of the ambient light is then subtracted from the detected signal.Type: GrantFiled: October 29, 2012Date of Patent: October 28, 2014Assignee: Covidien LPInventors: Ethan Petersen, William Shea, Bradford B. Chew
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Patent number: 8515512Abstract: A medical sensor may be adapted to prevent unwanted light and electrical interference from corrupting physiological measurements. Sensors are provided with features that reduce the amount of outside light or shunted light that impinge the detecting elements of the sensor. The sensor is adapted to reduce crosstalk between electrical signals, increasing the accuracy of measurements. The sensor is also adapted to reduce the effect of outside light or shunted light on pulse oximetry measurements.Type: GrantFiled: November 23, 2010Date of Patent: August 20, 2013Assignee: Covidien LPInventors: Albert L. Ollerdessen, Bradford B. Chew, Phillip S. Palmer
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Patent number: 8315684Abstract: A pulse oximeter method and apparatus which provides (1) a notch filter at a distance between a modulation frequency and a common multiple of commonly used power line frequencies (50, 60, 100 and 120) and also (2) a demodulation frequency greater than a highest pulse rate of a person and lower than any harmonic of 50, 60, 100 or 120 Hz, to filter ambient light interference, while choosing an optimum demodulation frequency that avoids interference from the notch filter or from harmonics of the line interference. Also, ambient light for any low frequency interference, such as power line interference, is measured both before and after each of the light emitter wavelengths and the average of the ambient light is then subtracted from the detected signal.Type: GrantFiled: July 14, 2008Date of Patent: November 20, 2012Assignee: Covidien LPInventors: Ethan Petersen, William Shea, Bradford B. Chew
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Patent number: 8195262Abstract: A light emitter drive circuit for an oximeter which utilizes a single inductor for driving multiple light emitters. The inductor is connected to a switching circuit to multiple energy storage circuits, such as capacitors. These are alternately charged up, using the same inductor. Subsequently, the capacitors are alternatively discharged for their corresponding light emitters through the same inductor. Also, the magnetic susceptibility of the LED drive circuit is reduced by using magnetic flux canceling in the inductor. In one embodiment, a toroidal inductor is used with geometric symmetry and its magnetic flux. In other embodiment, a dual core closed bobbin shielded inductor is used.Type: GrantFiled: July 26, 2006Date of Patent: June 5, 2012Assignee: Nellcor Puritan Bennett LLCInventors: Bradford B. Chew, Ethan Petersen, William Shea
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Publication number: 20110066016Abstract: A medical sensor may be adapted to prevent unwanted light and electrical interference from corrupting physiological measurements. Sensors are provided with features that reduce the amount of outside light or shunted light that impinge the detecting elements of the sensor. The sensor is adapted to reduce crosstalk between electrical signals, increasing the accuracy of measurements. The sensor is also adapted to reduce the effect of outside light or shunted light on pulse oximetry measurements.Type: ApplicationFiled: November 23, 2010Publication date: March 17, 2011Applicant: Nellcor Puritan Bennett LLCInventors: Albert L. Ollerdessen, Bradford B. Chew, Phillip S. Palmer
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Patent number: 7869849Abstract: A medical sensor may be adapted to prevent unwanted light and electrical interference from corrupting physiological measurements. Sensors are provided with features that reduce the amount of outside light or shunted light that impinge the detecting elements of the sensor. The sensor is adapted to reduce crosstalk between electrical signals, increasing the accuracy of measurements. The sensor is also adapted to reduce the effect of outside light or shunted light on pulse oximetry measurements.Type: GrantFiled: September 26, 2006Date of Patent: January 11, 2011Assignee: Nellcor Puritan Bennett LLCInventors: Albert L. Ollerdessen, Bradford B. Chew, Phillip S. Palmer
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Patent number: 7794266Abstract: A device and method for reducing crosstalk between wires is provided. The method includes spatially separating first and second sets of wires. A device is disposed relative to the first and second sets of wires to maintain the spatial separation. The method also comprises coupling pins to the first and second sets of wires. Additionally, the method includes covering the device with a connector housing.Type: GrantFiled: September 13, 2007Date of Patent: September 14, 2010Assignee: Nellcor Puritan Bennett LLCInventors: Ken Sawatari, Paul D. Mannheimer, Bradford B Chew
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Patent number: 7658652Abstract: A device and method for reducing crosstalk between wires is provided. The method includes spatially separating first and second sets of wires. A device is disposed relative to the first and second sets of wires to maintain the spatial separation. The method also comprises coupling pins to the first and second sets of wires. Additionally, the method includes covering the device with a connector housing.Type: GrantFiled: January 28, 2009Date of Patent: February 9, 2010Assignee: Nellcor Puritan Bennett LLCInventors: Ken Sawatari, Paul D. Mannheimer, Bradford B. Chew
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Publication number: 20090163083Abstract: A device and method for reducing crosstalk between wires is provided. The method includes spatially separating first and second sets of wires. A device is disposed relative to the first and second sets of wires to maintain the spatial separation. The method also comprises coupling pins to the first and second sets of wires. Additionally, the method includes covering the device with a connector housing.Type: ApplicationFiled: January 28, 2009Publication date: June 25, 2009Applicant: Nellcor Puritan Bennett LLCInventors: Ken Sawatari, Paul D. Mannheimer, Bradford B. Chew
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Patent number: 7476131Abstract: A device and method for reducing crosstalk between wires is provided. The method includes spatially separating first and second sets of wires. A device is disposed relative to the first and second sets of wires to maintain the spatial separation. The method also comprises coupling pins to the first and second sets of wires. Additionally, the method includes covering the device with a connector housing.Type: GrantFiled: September 29, 2006Date of Patent: January 13, 2009Assignee: Nellcor Puritan Bennett LLCInventors: Ken Sawatari, Paul D. Mannheimer, Bradford B. Chew
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Publication number: 20090005662Abstract: A pulse oximeter method and apparatus which provides (1) a notch filter at a distance between a modulation frequency and a common multiple of commonly used power line frequencies (50, 60, 100 and 120) and also (2) a demodulation frequency greater than a highest pulse rate of a person and lower than any harmonic of 50, 60, 100 or 120 Hz, to filter ambient light interference, while choosing an optimum demodulation frequency that avoids interference from the notch filter or from harmonics of the line interference. Also, ambient light for any low frequency interference, such as power line interference, is measured both before and after each of the light emitter wavelengths and the average of the ambient light is then subtracted from the detected signal.Type: ApplicationFiled: July 14, 2008Publication date: January 1, 2009Applicant: Nellcor Puritan Bennett IncInventors: Ethan Petersen, William Shea, Bradford B. Chew
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Patent number: 7400919Abstract: A pulse oximeter method and apparatus which provides (1) a notch filter at a distance between a modulation frequency and a common multiple of commonly used power line frequencies (50, 60, 100 and 120) and also (2) a demodulation frequency greater than a highest pulse rate of a person and lower than any harmonic of 50, 60, 100 or 120 Hz, to filter ambient light interference, while choosing an optimum demodulation frequency that avoids interference from the notch filter or from harmonics of the line interference. Also, ambient light for any low frequency interference, such as power line interference, is measured both before and after each of the light emitter wavelengths and the average of the ambient light is then subtracted from the detected signal.Type: GrantFiled: July 28, 2006Date of Patent: July 15, 2008Assignee: Nellcor Puritan Bennett LLCInventors: Ethan Petersen, William Shea, Bradford B. Chew
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Patent number: 7373192Abstract: A pulse oximeter with drive lines for driving red and IR LEDs, and a drive circuit for driving those drive lines. A processor controls the drive circuit using a red zero output line and an IR zero output line directly connected between the processor and the drive circuit. This allows a control signal to directly control the turning off of either the red or IR drive transistors to prevent forward current flow through the red and IR LEDs by overriding the ongoing programmable logic state machine control of the drive transistors. The effects of crosstalk and capacitive coupling are reduced as a result.Type: GrantFiled: February 25, 2004Date of Patent: May 13, 2008Assignee: Nellcor Puritan Bennett Inc.Inventors: Bradford B. Chew, Ethan Petersen, William Shea
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Patent number: 7355539Abstract: There is provided a pulse oximeter circuit including a feedback circuit configured to receive a digital output signal of a multi-bit sigma-delta modulator and generate a pulse width modulated signal (PWM). The PWM signal is directed to a first switching circuit and a D flip-flop. The first switching circuit provides a first or second reference voltage as a feedback signal to the multi-bit sigma-delta modulator. The D flip-flop generates a sample and hold signal. The sample and hold signal controls a second switching circuit coupled to the input of the multi-bit sigma-delta modulator.Type: GrantFiled: November 27, 2006Date of Patent: April 8, 2008Assignee: Nellcor Puritan Bennett Inc.Inventors: Ethan Petersen, William Shea, Bradford B. Chew
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Publication number: 20080081492Abstract: A device and method for reducing crosstalk between wires is provided. The method includes spatially separating first and second sets of wires. A device is disposed relative to the first and second sets of wires to maintain the spatial separation. The method also comprises coupling pins to the first and second sets of wires. Additionally, the method includes covering the device with a connector housing.Type: ApplicationFiled: September 13, 2007Publication date: April 3, 2008Inventors: Ken Sawatari, Paul D. Mannheimer, Bradford B. Chew
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Publication number: 20080081508Abstract: A device and method for reducing crosstalk between wires is provided. The method includes spatially separating first and second sets of wires. A device is disposed relative to the first and second sets of wires to maintain the spatial separation. The method also comprises coupling pins to the first and second sets of wires. Additionally, the method includes covering the device with a connector housing.Type: ApplicationFiled: September 29, 2006Publication date: April 3, 2008Inventors: Ken Sawatari, Paul D. Mannheimer, Bradford B. Chew
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Publication number: 20080076982Abstract: A medical sensor may be adapted to prevent unwanted light and electrical interference from corrupting physiological measurements. Sensors are provided with features that reduce the amount of outside light or shunted light that impinge the detecting elements of the sensor. The sensor is adapted to reduce crosstalk between electrical signals, increasing the accuracy of measurements. The sensor is also adapted to reduce the effect of outside light or shunted light on pulse oximetry measurements.Type: ApplicationFiled: September 26, 2006Publication date: March 27, 2008Inventors: Albert L. Ollerdessen, Bradford B. Chew, Phillip S. Palmer
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Patent number: 7215985Abstract: A method and apparatus for reducing cross-talk in an oximeter. The oximeter includes a band pass filter. The amount of cross-talk through the band pass filter is estimated. Based on this estimate, the corner frequencies of the band pass filter are adjusted when it is designed to minimize the cross-talk. In one embodiment, a calibration mode is performed when a sensor is attached to the oximeter. In the calibration mode, the signals are measured with first only the red LED on and then with only the IR LED on. Any signal measured in the off channel is assumed to be a result of cross-talk from the other channel. The magnitude of the cross-talk is determined as a percentage, and subsequently the percentage is multiplied by the actual signal and subtracted from the other LED signal as cross-talk compensation.Type: GrantFiled: February 25, 2004Date of Patent: May 8, 2007Assignee: Nellcor Puritain Bennett Inc.Inventors: Ethan Petersen, Bradford B. Chew, William Shea
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Patent number: 7212847Abstract: A method and apparatus for providing a substantially real-time representation of an analog representation of a physiological signal is provided. The waveform signal from the sensor is converted into digital form. A delta-sigma modulator is used as a simple Digital-to-analog Converter (DAC). The output can then be provided through a simple hardware filter to give an analog output signal in nearly real-time, which can be used for other instruments, synchronization, display, etc.Type: GrantFiled: February 25, 2004Date of Patent: May 1, 2007Assignee: Nellcor Puritan Bennett LLCInventors: Ethan Petersen, William Shea, Bradford B. Chew
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Patent number: 7190985Abstract: A pulse oximeter method and apparatus which provides (1) a notch filter at a distance between a modulation frequency and a common multiple of commonly used power line frequencies (50, 60, 100 and 120) and also (2) a demodulation frequency greater than a highest pulse rate of a person and lower than any harmonic of 50, 60, 100 or 120 Hz, to filter ambient light interference, while choosing an optimum demodulation frequency that avoids interference from the notch filter or from harmonics of the line interference. Also, ambient light for any low frequency interference, such as power line interference, is measured both before and after each of the light emitter wavelengths and the average of the ambient light is then subtracted from the detected signal.Type: GrantFiled: February 25, 2004Date of Patent: March 13, 2007Assignee: Nellcor Puritan Bennett Inc.Inventors: Ethan Petersen, William Shea, Bradford B. Chew