Patents by Inventor Ravi Narasimhan

Ravi Narasimhan 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).

  • Patent number: 11096606
    Abstract: A method and wireless sensor device for determining body postures and activities. In one aspect, a method includes receiving sensor data. The method also includes detecting and classifying a body transition of a body based on the sensor data. The method also includes detecting if there is activity of the body based on the sensor data. If there is activity, the method also includes classifying the activity. If there is no activity, the method also includes classifying a rest position of the body based on the sensor data and based on a previous body transition.
    Type: Grant
    Filed: June 8, 2018
    Date of Patent: August 24, 2021
    Assignee: Vital Connect, Inc.
    Inventors: Alexander Chan, Nima Ferdosi, Ravi Narasimhan
  • Publication number: 20210236014
    Abstract: A finger-wearable blood pressure monitor device includes a cuff, a tactile sensor array, and control circuitry. The tactile sensor array is disposed on or adjacent to an inward facing surface of the cuff. The tactile sensor array includes a plurality of sensors. The control circuitry is coupled to the tactile sensor array and includes logic that when executed by the control circuitry causes the finger-wearable blood pressure monitoring device to perform operations. The operations include monitoring, over a first time period, a pressure applied to each of the plurality of sensors by a digital artery of a finger. The operations also include generating a plurality of tactile waveforms in response to monitoring the pressure. Each of the plurality of tactile waveforms corresponds to the pressure applied to a respective one of the plurality of sensors over the first time period. The operations further include estimating blood pressure based, at least in part, on the plurality of tactile waveforms.
    Type: Application
    Filed: April 19, 2021
    Publication date: August 5, 2021
    Inventor: Ravi Narasimhan
  • Patent number: 11076810
    Abstract: A method and system for assessing an electrocardiogram (ECG) signal quality are disclosed. In a first aspect, the method comprises determining a Kurtosis calculation of the ECG signal and determining whether the Kurtosis calculation satisfies a first threshold to continuously assess the ECG signal quality. In a second aspect, the system comprises a wireless sensor device coupled to a user via at least one electrode, wherein the wireless sensor device 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 processor to determine a Kurtosis calculation of the ECG signal and to determine whether the Kurtosis calculation satisfies a first threshold to continuously assess the ECG signal quality.
    Type: Grant
    Filed: September 5, 2012
    Date of Patent: August 3, 2021
    Assignee: VITAL CONNECT, INC.
    Inventors: Nima Ferdosi, Ravi Narasimhan
  • Patent number: 11051745
    Abstract: A method and system for filtering a detected ECG signal are disclosed. In a first aspect, the method comprises filtering the detected ECG signal using a plurality of digital filters. The method includes adaptively selecting one of the plurality of digital filters to maintain a minimum signal-to-noise ratio (SNR). In a second aspect, the system comprises a wireless sensor device coupled to a user via at least one electrode, wherein the wireless sensor device 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 processor to carry out the steps of the method.
    Type: Grant
    Filed: February 16, 2017
    Date of Patent: July 6, 2021
    Assignee: Vital Connect, Inc.
    Inventors: Ravi Narasimhan, Nersi Nazari, Nima Ferdosi
  • Patent number: 11026632
    Abstract: A method and system for determining a respiratory rate of a user are disclosed. The method comprises measuring a differential voltage across first and second electrodes of a sensor device coupled to the user. The method includes sampling the differential voltage using an analog-to-digital converter to produce an output signal. The method includes processing the output signal to detect a breath of the user based on a positive voltage transition through a midpoint, wherein the breath of the user is utilized to determine the respiratory rate of the user.
    Type: Grant
    Filed: April 20, 2012
    Date of Patent: June 8, 2021
    Assignee: Vital Connect, Inc.
    Inventors: Ravi Narasimhan, Nima Ferdosi
  • Patent number: 11013421
    Abstract: A finger-wearable blood pressure monitor device includes a cuff, a tactile sensor array, and control circuitry. The tactile sensor array is disposed on or adjacent to an inward facing surface of the cuff. The tactile sensor array includes a plurality of sensors. The control circuitry is coupled to the tactile sensor array and includes logic that when executed by the control circuitry causes the finger-wearable blood pressure monitoring device to perform operations. The operations include monitoring, over a first time period, a pressure applied to each of the plurality of sensors by a digital artery of a finger. The operations also include generating a plurality of tactile waveforms in response to monitoring the pressure. Each of the plurality of tactile waveforms corresponds to the pressure applied to a respective one of the plurality of sensors over the first time period. The operations further include estimating blood pressure based, at least in part, on the plurality of tactile waveforms.
    Type: Grant
    Filed: November 10, 2017
    Date of Patent: May 25, 2021
    Assignee: VERILY LIFE SCIENCES LLC
    Inventor: Ravi Narasimhan
  • Publication number: 20210133251
    Abstract: Example data processing systems and methods are described. In one implementation, a system accesses a corpus of data and analyzes the data contained in the corpus of data to identify multiple documents. The system generates vector indexes for the multiple documents such that the vector indexes allow a computing system to quickly access the plurality of documents and identify an answer to a question associated with the corpus of data.
    Type: Application
    Filed: November 6, 2019
    Publication date: May 6, 2021
    Inventors: Mitul Tiwari, Ravi Narasimhan Raj, Madhusudan Mathihalli, Kaushik Rangadurai, Srivatsava Daruru, Quaizar Vohra, Deepak Bobbarjung, Abhisaar Yadav
  • Publication number: 20210133264
    Abstract: Example data processing systems and methods are described. In one implementation, a system accesses a corpus of data and analyzes the data contained in the corpus of data to identify multiple documents. The system generates vector indexes for the multiple documents such that the vector indexes allow a computing system to quickly access the plurality of documents and identify an answer to a question associated with the corpus of data.
    Type: Application
    Filed: November 6, 2019
    Publication date: May 6, 2021
    Inventors: Mitul Tiwari, Ravi Narasimhan Raj, Madhusudan Mathihalli, Kaushik Rangadurai, Srivatsava Daruru, Quaizar Vohra, Deepak Bobbarjung, Abhisaar Yadav
  • Publication number: 20210133224
    Abstract: Example data processing systems and methods are described. In one implementation, a system accesses a corpus of data and analyzes the data contained in the corpus of data to identify multiple documents. The system generates vector indexes for the multiple documents such that the vector indexes allow a computing system to quickly access the plurality of documents and identify an answer to a question associated with the corpus of data.
    Type: Application
    Filed: November 6, 2019
    Publication date: May 6, 2021
    Inventors: Mitul Tiwari, Ravi Narasimhan Raj, Madhusudan Mathihalli, Kaushik Rangadurai, Srivatsava Daruru, Quaizar Vohra, Deepak Bobbarjung, Abhisaar Yadav
  • Patent number: 10874307
    Abstract: An example of a digital artery blood pressure monitor may include a tactile sensor array disposed on an inner surface of a cuff, the tactile sensor array including a plurality of capacitive sensors to detect pressure changes within a digital artery of a finger due to blood flow, where the pressure changes cause changes to capacitance values of one or more capacitive sensors of the tactile sensor array, and control circuitry coupled to the tactile sensor array to receive the capacitance values from the tactile sensor array, and determine a blood pressure based on the capacitance values.
    Type: Grant
    Filed: January 24, 2017
    Date of Patent: December 29, 2020
    Assignee: Verily Life Sciences LLC
    Inventors: Ravi Narasimhan, Tushar Parlikar, Todd Whitehurst
  • Publication number: 20200337571
    Abstract: An example of a digital artery blood pressure monitor may include a tactile sensor array disposed on an inner surface of a cuff, the tactile sensor array including a plurality of capacitive sensors to detect pressure changes within a digital artery of a finger due to blood flow, where the pressure changes cause changes to capacitance values of one or more capacitive sensors of the tactile sensor array, and control circuitry coupled to the tactile sensor array to receive the capacitance values from the tactile sensor array, and determine a blood pressure based on the capacitance values.
    Type: Application
    Filed: July 8, 2020
    Publication date: October 29, 2020
    Inventors: Ravi Narasimhan, Tushar Parlikar, Todd Whitehurst
  • Patent number: 10779738
    Abstract: Wrist-worn devices and related methods measure a pulse transit time non-invasively and calculate a blood pressure value using the pulse transit time. A wrist-worn device include a wrist-worn elongate band, at least four EKG or ICG electrodes coupled to the wrist-worn device for detecting a ventricular ejection of a heart, a photo-plethysmogram (PPG) sensor coupled to the wrist-worn device for detecting arrival of a blood pressure pulse at the user's wrist, and a controller configured to calculate a pulse transit time (PTT) for the blood pressure pulse. The controller calculates one or more blood pressure values for the user based on the PTT.
    Type: Grant
    Filed: August 18, 2017
    Date of Patent: September 22, 2020
    Inventors: Thomas J. Sullivan, Wren Nancy Dougherty, Richard C. Kimoto, Erno Klaassen, Ravi Narasimhan, Stephen J. Waydo, Todd K. Whitehurst, Derek Park-Shing Young, Santiago Quijano, Zijing Zeng
  • Patent number: 10772512
    Abstract: The present invention provides non-invasive devices, methods, and systems for determining a pressure of blood within a cardiovascular system of a user, the cardiovascular system including a heart and the user having a wrist covered by skin. More particularly, the present invention discloses a variety of wrist-worn devices having a variety of sensors configured to non-invasively engage the skin on the wrist of the user for sensing a variety of user signals from the cardiovascular system of the user. Generally, approaches disclosed herein may passively track blood pressure values without any interaction required on the part of the user or may allow for on demand or point measurements of blood pressure values by having a user actively interact with the sensors of the wrist-worn device.
    Type: Grant
    Filed: August 18, 2017
    Date of Patent: September 15, 2020
    Inventors: Erno H. Klaassen, Wren Nancy Dougherty, Richard C. Kimoto, Ravi Narasimhan, Thomas J. Sullivan, Stephen J. Waydo, Todd K. Whitehurst, Santiago Quijano, Derek Park-Shing Young, Zijing Zeng
  • Patent number: 10719574
    Abstract: A method and system for calibrating a wireless sensor device are disclosed. In a first aspect, the method comprises determining a vertical calibration vector and determining a rotation matrix using the vertical calibration vector to line up native axes of the wireless sensor device with body axes. In a second aspect, a wireless sensor device comprises a processor 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 vertical calibration vector and to determine a rotation matrix using the vertical calibration vector to line up native axes of the wireless sensor device with body axes.
    Type: Grant
    Filed: January 8, 2018
    Date of Patent: July 21, 2020
    Assignee: Vital Connect, Inc.
    Inventors: Alexander Chan, Nima Ferdosi, Ravi Narasimhan
  • Patent number: 10702171
    Abstract: The present invention generally relates to blood pressure monitoring. In some embodiments, methods and devices of measuring a mean arterial pressure are provided and/or monitoring blood pressure changes. A wrist-worn device may include a plurality of sensors backed by a plurality of actuators. Subsets of the plurality of sensors may be selectively actuateable against a wrist of a user using one or more of the plurality of actuators. A preferred sensor and location may be identified based on pressure signals received from each of the sensors. In some embodiments, devices may use a fluid bladder coupled with piezoelectric film sensors. A fluid bladder pressure sensor may be used to calibrate the piezoelectric film signal to provide a static and dynamic pressure reading. In yet another embodiment, a mean arterial pressure may be calculated by processing a swept pressure signal obtained as a sensor is swept through different heights.
    Type: Grant
    Filed: September 8, 2015
    Date of Patent: July 7, 2020
    Inventors: Ravi Narasimhan, Zijing Zeng, Richard C. Kimoto, Erno Klaassen, Thomas J. Sullivan, Derek Park-Shing Young, Todd K. Whitehurst
  • Patent number: 10687757
    Abstract: 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: Grant
    Filed: May 22, 2018
    Date of Patent: June 23, 2020
    Assignee: Vital Connect, Inc.
    Inventors: Alexander Chan, Ravi Narasimhan, Nandakumar Selvaraj, Toai Doan
  • Patent number: 10667713
    Abstract: A method and system for R-R interval measurement of a user are disclosed. In a first aspect, the method comprises detecting an electrocardiogram (ECG) signal of the user. The method includes performing QRS peak detection on the ECG signal to obtain a low resolution peak and searching near the low resolution peak for a high resolution peak. The method includes calculating the R-R interval measurement based upon the high resolution peak. In a second aspect, a wireless sensor device comprises a processor 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 carry out the steps of the method.
    Type: Grant
    Filed: November 8, 2017
    Date of Patent: June 2, 2020
    Assignee: Vital Connect, Inc.
    Inventors: Yun Yang, Ravi Narasimhan, Nima Ferdosi
  • Patent number: 10617325
    Abstract: A method and system for measuring respiratory rate are disclosed. In a first aspect, the method comprises measuring at least one respiration signal and filtering the respiration signal using a lowpass filter. The method includes peak-picking the respiration signal to determine the respiratory rate and determining a quality metric of the respiratory rate. In a second aspect, the system comprises a wireless sensor device coupled to a user via at least one electrode, wherein the wireless sensor device 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 processor to carry out the steps of the method.
    Type: Grant
    Filed: November 30, 2017
    Date of Patent: April 14, 2020
    Assignee: Vital Connect, Inc.
    Inventors: Alexander Chan, Ravi Narasimhan
  • Publication number: 20200046231
    Abstract: A method and system for contextual heart rate monitoring are disclosed. In a first aspect, the method comprises calculating a heart rate using a detected ECG signal and detecting an activity level. In a second aspect, the system comprises a wireless sensor device coupled to a user via at least one electrode, wherein the wireless sensor device 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 processor to calculate a heart rate using a detected ECG signal and to detect an activity level.
    Type: Application
    Filed: October 18, 2019
    Publication date: February 13, 2020
    Inventors: Nima FERDOSI, Ravi NARASIMHAN, ALEXANDER CHAN
  • Patent number: 10517489
    Abstract: Wrist-worn devices and related methods measure a pulse transit time non-invasively and calculate a blood pressure value using the pulse transit time. A wrist-worn device includes an accelerometer, a photo-lethysmogram (PPG) or a pulse pressure sensor, and a controller. The PPG or the pulse pressure sensor coupled to the wrist-worn device for detecting an arrival of a blood pressure pulse at the user's wrist. The controller is configured to process output signals from the accelerometer to detect when the blood pressure pulse is propagated from the left ventricle of the user's heart, process a signal from the PPG or the pulse pressure sensor to detect when the blood pressure pulse arrives at the wrist, calculate a pulse transit time (PTT) for propagation of the blood pressure pulse from the left ventricle to the wrist, and generate one or more blood pressure values for the user based on the PTT.
    Type: Grant
    Filed: September 8, 2015
    Date of Patent: December 31, 2019
    Inventors: Ravi Narasimhan, Richard C. Kimoto, Thomas J. Sullivan, Todd K. Whitehurst, Derek Park-shing Young, Zijing Zeng, Erno Klaassen