Patents by Inventor Toai Doan
Toai Doan 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: 10687757Abstract: A method and system for determining psychological acute stress are disclosed. In a first aspect, the method comprises detecting a physiological signal using a wireless sensor device, determining a stress feature using a normalized heart rate and a plurality of heart rate variability (HRV) features, wherein the normalized heart rate and the plurality of heart rate variability features are calculated using the detected physiological signal, and determining a stress level using the stress feature to determine the psychological acute stress. In a second aspect, the system comprises a wireless sensor device that includes a processor and a memory device coupled to the processor, wherein the memory device stores an application which, when executed by the processor, causes the wireless sensor device to carry out the steps of the method.Type: GrantFiled: May 22, 2018Date of Patent: June 23, 2020Assignee: Vital Connect, Inc.Inventors: Alexander Chan, Ravi Narasimhan, Nandakumar Selvaraj, Toai Doan
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Patent number: 10595776Abstract: A method and system for determining energy expenditure (EE) are disclosed. The method comprises determining a plurality of sensor streams using a plurality of detected physiological signals and processing the plurality of sensor streams to determine the EE. The system includes at least one sensor to detect a plurality of physiological signals, a processor coupled to the at least one sensor, and a memory device coupled to the processor, wherein the memory device includes an application that, when executed by the processor, causes the processor to determine a plurality of sensor streams using a plurality of detected physiological signals and to process the plurality of sensor streams to determine the EE.Type: GrantFiled: September 9, 2014Date of Patent: March 24, 2020Assignee: Vital Connect, Inc.Inventors: Nandakumar Selvaraj, Toai Doan
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Patent number: 10373714Abstract: A method and system for automatically determining bed-time periods are disclosed. The method comprises detecting at least one physiological signal, determining a posture angle and an activity level using the at least one detected physiological signal, and determining a bed-time period using both the posture angle and the activity level. The system includes at least one sensor to detect a plurality of physiological signals, a processor coupled to the at least one sensor, and a memory device coupled to the processor, wherein the memory device includes an application that, when executed by the processor, causes the processor to detect a posture angle using at least one of the plurality of detected physiological signals and to determine a bed-time period using both the posture angle and the activity level.Type: GrantFiled: January 27, 2015Date of Patent: August 6, 2019Assignee: Vital Connect, Inc.Inventors: Nandakumar Selvaraj, Toai Doan
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Publication number: 20180310879Abstract: A method and system for determining psychological acute stress are disclosed. In a first aspect, the method comprises detecting a physiological signal using a wireless sensor device, determining a stress feature using a normalized heart rate and a plurality of heart rate variability (HRV) features, wherein the normalized heart rate and the plurality of heart rate variability features are calculated using the detected physiological signal, and determining a stress level using the stress feature to determine the psychological acute stress. In a second aspect, the system comprises a wireless sensor device that includes a processor and a memory device coupled to the processor, wherein the memory device stores an application which, when executed by the processor, causes the wireless sensor device to carry out the steps of the method.Type: ApplicationFiled: May 22, 2018Publication date: November 1, 2018Inventors: Alexander CHAN, Ravi NARASIMHAN, Nandakumar SELVARAJ, Toai DOAN
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Patent number: 9980678Abstract: A method and system for determining psychological acute stress are disclosed. In a first aspect, the method comprises detecting a physiological signal using a wireless sensor device, determining a stress feature using a normalized heart rate and a plurality of heart rate variability (HRV) features, wherein the normalized heart rate and the plurality of heart rate variability features are calculated using the detected physiological signal, and determining a stress level using the stress feature to determine the psychological acute stress. In a second aspect, the system comprises a wireless sensor device that includes a processor and a memory device coupled to the processor, wherein the memory device stores an application which, when executed by the processor, causes the wireless sensor device to carry out the steps of the method.Type: GrantFiled: April 11, 2016Date of Patent: May 29, 2018Assignee: VITAL CONNECT, INC.Inventors: Alexander Chan, Ravi Narasimhan, Nandakumar Selvaraj, Toai Doan
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Publication number: 20160338640Abstract: A method and system for determining psychological acute stress are disclosed. In a first aspect, the method comprises detecting a physiological signal using a wireless sensor device, determining a stress feature using a normalized heart rate and a plurality of heart rate variability (HRV) features, wherein the normalized heart rate and the plurality of heart rate variability features are calculated using the detected physiological signal, and determining a stress level using the stress feature to determine the psychological acute stress. In a second aspect, the system comprises a wireless sensor device that includes a processor and a memory device coupled to the processor, wherein the memory device stores an application which, when executed by the processor, causes the wireless sensor device to carry out the steps of the method.Type: ApplicationFiled: April 11, 2016Publication date: November 24, 2016Inventors: Alexander CHAN, Ravi NARASIMHAN, Nandakumar SELVARAJ, Toai DOAN
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Patent number: 8583991Abstract: Embodiments of the present invention provide high density, multi-level memory. Thus, various embodiments of the present invention provide a memory apparatus in accordance with various embodiments of the present invention includes a memory block comprising a plurality of cells, each cell adapted to operate with multi-level signal. Such a memory apparatus also includes a channel block adapted to code data values in accordance with a coding scheme that favorably effects a distribution of the multi-levels of the multi-level signals, and to output the corresponding multi-level signals of the coded data values to the memory block. Other embodiments may be described and claimed.Type: GrantFiled: July 5, 2012Date of Patent: November 12, 2013Assignee: Marvell International Ltd.Inventors: Pantas Sutardja, Zining Wu, Toai Doan, Aditya Ramamoorthy
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Patent number: 8441752Abstract: A receiving device may be configured to derive an oversampled dibit pulse response estimate using symbols sampled at substantially the read channel symbol rate of the receiving device. The receiving device may include a data acquisition circuit configured to digitize data derived from a memory medium, as well as a dibit pulse estimation circuit configured to estimate the oversampled dibit pulse response using symbols sampled at the read channel rate of the receiving device.Type: GrantFiled: August 23, 2007Date of Patent: May 14, 2013Assignee: Marvell International Ltd.Inventors: Hongwei Song, Zining Wu, Toai Doan
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Patent number: 8441751Abstract: A receiving device may be configured to derive an oversampled dibit pulse response estimate using symbols sampled at substantially the read channel symbol rate of the receiving device. The receiving device may include a data acquisition circuit configured to digitize data derived from a memory medium, a symbol timing loop and read circuit, as well as a dibit pulse estimation circuit configured to estimate the oversampled dibit pulse response using symbols sampled at the read channel rate of the receiving device without disturbing the symbol timing loop and read circuit.Type: GrantFiled: August 17, 2007Date of Patent: May 14, 2013Assignee: Marvell International Ltd.Inventors: Hongwei Song, Zining Wu, Jingfeng Liu, Toai Doan
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Patent number: 8359498Abstract: A method of communicating a bitstream having a characteristic Hamming weight to a destination via a channel comprises determining the characteristic Hamming weight of the bitstream, inverting each bit in the bitstream if the characteristic Hamming weight of the bitstream is below a threshold value and developing an indication of whether the bits in the bitstream are inverted, delivering the bitstream and the indication of whether the bits in the bitstream are inverted to the destination via the channel, and inverting each bit in the bitstream at the destination if the indication indicates that the bits are inverted.Type: GrantFiled: November 30, 2006Date of Patent: January 22, 2013Assignee: Marvell International Ltd.Inventors: Pantas Sutardja, Toai Doan
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Patent number: 8219886Abstract: Embodiments of the present invention provide high density, multi-level memory. Thus, various embodiments of the present invention provide a memory apparatus in accordance with various embodiments of the present invention includes a memory block comprising a plurality of cells, each cell adapted to operate with multi-level signal. Such a memory apparatus also includes a channel block adapted to code data values in accordance with a coding scheme that favorably effects a distribution of the multi-levels of the multi-level signals, and to output the corresponding multi-level signals of the coded data values to the memory block. Other embodiments may be described and claimed.Type: GrantFiled: December 21, 2006Date of Patent: July 10, 2012Assignee: Marvell International Ltd.Inventors: Pantas Sutardja, Zining Wu, Toai Doan, Aditya Ramamoorthy
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Patent number: 8077419Abstract: A read-channel module including a VGA module to amplify a signal based on a variable gain, an ADC module to generate a sample based on the amplified signal, and an AGC module to control the variable gain of the VGA module. A gain adjusting module generates (i) a first gain and (ii) a second gain when an amplitude of the sample is (i) less than or equal to a first predetermined threshold and (ii) greater than or equal to a second predetermined threshold, respectively. The AGC module (i) increases and (ii) decreases the variable gain of the VGA module based on (i) the first gain and (ii) the second gain, respectively. The gain adjusting module generates the first gain and the second gain by (i) multiplying a present gain of the AGC module by a predetermined multiplier or (ii) adding a predetermined offset to the present gain.Type: GrantFiled: October 18, 2010Date of Patent: December 13, 2011Assignee: Marvell InternationalInventors: Vasudev V. Pai, Toai Doan, Hongying Sheng
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Patent number: 7817366Abstract: A read-channel module includes a variable-gain amplifier (VGA) module, an analog-to-digital converter (ADC) module, an amplitude measuring module, a gain adjusting module, and a zero phase start (ZPS) module. The VGA module has a variable gain, amplifies input signals, and generates amplified signals. The ADC module converts the amplified signals from analog to digital format and generates samples. The amplitude measuring module receives N of the samples and measures amplitudes of the N samples, where N is an integer greater than 1. The gain adjusting module communicates with the amplitude measuring module and selectively adjusts the variable gain of the VGA module based on the amplitudes. The zero phase start (ZPS) module communicates with the amplitude measuring module, receives the samples, and selectively generates phase information from the samples based on the amplitudes.Type: GrantFiled: May 2, 2007Date of Patent: October 19, 2010Assignee: Marvell International Ltd.Inventors: Vasudev V. Pai, Toai Doan, Hongying Sheng
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Patent number: 7802151Abstract: A communication decoding method comprises receiving processed binary data including a binary code word and an indication of whether bits of the binary code word are inverted and inverting each bit of the binary code word if the indication indicates that the bits are inverted.Type: GrantFiled: November 30, 2006Date of Patent: September 21, 2010Assignee: Marvell International Ltd.Inventors: Pantas Sutardja, Toai Doan
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Patent number: 7783937Abstract: A method comprises obtaining a first sequence of binary digits that collectively have a characteristic Hamming weight, inverting each of the binary digits in the first sequence of binary digits if the Hamming weight of the first sequence of binary digits is below a predetermined threshold Hamming weight value, and providing an indication of whether the binary digits in the first sequence of binary digits have been inverted.Type: GrantFiled: November 30, 2006Date of Patent: August 24, 2010Assignee: Marvell International Ltd.Inventors: Pantas Sutardja, Toai Doan
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Patent number: 7715135Abstract: Methods, circuits, and systems for processing a preamble field in a read channel (e.g., in a magnetic storage device such as a hard disk drive). The methods generally include the steps of (a) reading the preamble field, wherein the preamble field comprises a repetitive bit pattern having a logical transition every x bit periods, where x is an integer of at least 3 when d is 0 or 1, or where x is an integer of at least d+2 when d is greater than 1, and (b) processing the repetitive bit pattern. The methods may further relate to processing the preamble for synchronization with the read channel and/or for measuring the fly height of a read/write head. The invention also relates to methods of enabling read channel synchronization and/or fly height measurement.Type: GrantFiled: June 13, 2006Date of Patent: May 11, 2010Assignee: Marvell International Ltd.Inventors: Pantas Sutardja, Toai Doan, Zining Wu, Michael Madden
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Patent number: 7535955Abstract: Methods, algorithms, software, architectures, systems and circuits for targeting certain dominant error types in an adaptive FIR filter and/or signal equalizer. The method and algorithm generally include processing a data sequence in accordance with the adaptive algorithm to produce a processed data sequence, filtering the data sequence to generate a filtered data term for the adaptive algorithm, generating a filtered error term for the adaptive algorithm from at least the processed data sequence, and updating the adaptive algorithm in response to the filtered data and error terms. The architectures generally include an equalizer configured to equalize and/or filter a data sequence and provide an equalized data output, a first filter configured to receive the data sequence and generate a filtered data term for the adaptive algorithm, and an error term circuit configured to receive the equalized data output and provide a filtered error term for the adaptive algorithm.Type: GrantFiled: July 17, 2003Date of Patent: May 19, 2009Assignee: Marvell International Ltd.Inventors: Pantas Sutardja, Toai Doan
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Patent number: 7518820Abstract: A fly height control system comprises a measurement circuit that receives M pulses that are based on a predetermined pattern stored on a storage medium and that determines a first amplitude and a second amplitude for each of the M pulses, where M is an integer greater than one. The first amplitude is determined at a first time and the second amplitude is determined at a second time that is different than the first time. A calculation circuit determines a distance between a head and a storage medium based on a function of the first amplitudes for the M pulses and the second amplitudes for the M pulses. A head controller controls the head based on the distance determined by the calculation circuit.Type: GrantFiled: April 11, 2008Date of Patent: April 14, 2009Assignee: Marvell International, Ltd.Inventors: Zining Wu, Toai Doan
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Patent number: 7359139Abstract: A fly height control system comprises a measurement circuit that measures a first amplitude of a pulse, which is based on a predetermined pattern recorded on a storage medium, at a first predetermined time and second amplitudes of the pulse at respective second predetermined times. A calculation circuit estimates a distance between a head and the storage medium based on a function of the first amplitude and the second amplitudes. A head controller that controls the distance between the head and the storage medium based on the estimate.Type: GrantFiled: January 22, 2007Date of Patent: April 15, 2008Assignee: Marvell International Ltd.Inventors: Zining Wu, Toai Doan
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Patent number: 7199961Abstract: One embodiment features a method, apparatus, and computer-readable media comprising receiving a pulse generated in response to a transition of a head over a predetermined pattern on a storage medium; measuring a first amplitude of the pulse at a first predetermined time and one or more second amplitudes of the pulse at respective second predetermined times; and calculating a distance between the head and the storage medium based on a function of the first and second amplitudes. Another embodiment features a method, apparatus, and computer-readable media comprising receiving a pulse generated in response to a transition of a head over a predetermined pattern on a storage medium; measuring a first amplitude of a power spectrum of the pulse at a first predetermined frequency and a second amplitude of the power spectrum of the pulse at respective second predetermined frequencies; and calculating a distance between the head and the storage medium based on a function of the first and second amplitudes.Type: GrantFiled: September 24, 2003Date of Patent: April 3, 2007Assignee: Marvell International Ltd.Inventors: Zining Wu, Toai Doan