Patents by Inventor Thomas Heldt

Thomas Heldt 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: 8282564
    Abstract: The methods and systems for estimating cardiac output and total peripheral resistance include observing arterial blood pressure waveforms to determine intra-beat and inter-beat variability in arterial blood pressure and estimating from the variability a time constant for a lumped parameter beat-to-beat averaged Windkessel model of the arterial tree. Uncalibrated cardiac output and uncalibrated total peripheral resistance may then be calculated from the time constant. Calibrated cardiac output and calibrated total peripheral resistance may be computed using calibration data, assuming an arterial compliance that is either constant or dependent on mean arterial blood pressure. The parameters of the arterial compliance may be estimated in a least-squares manner.
    Type: Grant
    Filed: May 15, 2008
    Date of Patent: October 9, 2012
    Assignee: Massachusetts Institute of Technology
    Inventors: Tushar A. Parlikar, Gireeja V. Ranade, Thomas Heldt, George C. Verghese
  • Patent number: 8262579
    Abstract: Systems and methods for prediction and detection of circulatory shock using estimates or measurements of arterial blood pressure, heart rate, stroke volume, cardiac output, total peripheral resistance, cardiac ejection fraction, cardiac contractility and ventricular end-diastolic volume are provided. These estimates and measurements are used to determine a type of circulatory shock. In some embodiments, the type of circulatory shock is determined to be one of septic shock, hypovolemic shock, anaphylactic shock, hemorrhagic shock, and cardiogenic shock.
    Type: Grant
    Filed: May 16, 2008
    Date of Patent: September 11, 2012
    Assignee: Massachusetts Institute of Technology
    Inventors: Tushar A. Parlikar, Thomas Heldt, George C. Verghese, Roger G. Mark
  • Patent number: 8235910
    Abstract: The methods and systems for estimating cardiac ejection fraction, cardiac contractility, and ventricular end-diastolic volume on a beat-by-beat basis include observing arterial blood pressure waveforms to determine ventricular compliances for a pressure-volume loop in the ventricle. Uncalibrated or calibrated cardiac ejection fraction may be calculated from estimates of stroke volume and the ventricular compliances. Cardiac contractility may be calculated from estimates of a ventricular compliance. Uncalibrated or calibrated ventricular end-diastolic volume may also be calculated from estimates of stroke volume and the ventricular compliances. A set of calibration parameters for calibrating cardiac ejection fraction or ventricular end-diastolic volume may be estimated in a least-squares manner.
    Type: Grant
    Filed: May 16, 2008
    Date of Patent: August 7, 2012
    Inventors: Tushar A. Parlikar, George C. Verghese, Thomas Heldt, Ramakrisna Mukkamala
  • Publication number: 20100063405
    Abstract: The systems, devices, and methods described herein provide for the estimation and monitoring of cerebrovascular system properties and intracranial pressure (ICP) from one or more measurements or measured signals. These measured signals may include central or peripheral arterial blood pressure (ABP), and cerebral blood flow (CBF) or cerebral blood flow velocity (CBFV). The measured signals may be acquired noninvasively or minimally-invasively. The measured signals may be used to estimate parameters and variables of a computational model that is representative of the physiological relationships among the cerebral flows and pressures. The computational model may include at least one resistive element, at least one compliance element, and a representation of ICP.
    Type: Application
    Filed: September 8, 2009
    Publication date: March 11, 2010
    Applicant: Massachusetts Institute of Technology
    Inventors: Faisal Mahmood Kashif, Thomas Heldt, George Cheeran Verghese
  • Publication number: 20080294057
    Abstract: The methods and systems for estimating cardiac ejection fraction, cardiac contractility, and ventricular end-diastolic volume on a beat-by-beat basis include observing arterial blood pressure waveforms to determine ventricular compliances for a pressure-volume loop in the ventricle. Uncalibrated or calibrated cardiac ejection fraction may be calculated from estimates of stroke volume and the ventricular compliances. Cardiac contractility may be calculated from estimates of a ventricular compliance. Uncalibrated or calibrated ventricular end-diastolic volume may also be calculated from estimates of stroke volume and the ventricular compliances. A set of calibration parameters for calibrating cardiac ejection fraction or ventricular end-diastolic volume may be estimated in a least-squares manner.
    Type: Application
    Filed: May 16, 2008
    Publication date: November 27, 2008
    Inventors: Tushar A. Parlikar, George C. Verghese, Thomas Heldt, Ramakrisna Mukkamala
  • Publication number: 20080287812
    Abstract: The methods and systems for estimating cardiac output and total peripheral resistance include observing arterial blood pressure waveforms to determine intra-beat and inter-beat variability in arterial blood pressure and estimating from the variability a time constant for a lumped parameter beat-to-beat averaged Windkessel model of the arterial tree. Uncalibrated cardiac output and uncalibrated total peripheral resistance may then be calculated from the time constant. Calibrated cardiac output and calibrated total peripheral resistance may be computed using calibration data, assuming an arterial compliance that is either constant or dependent on mean arterial blood pressure. The parameters of the arterial compliance may be estimated in a least-squares manner.
    Type: Application
    Filed: May 15, 2008
    Publication date: November 20, 2008
    Inventors: Tushar A. Parlikar, Gireeja V. Ranade, Thomas Heldt, George C. Verghese
  • Publication number: 20080287753
    Abstract: Systems and methods for prediction and detection of circulatory shock using estimates or measurements of arterial blood pressure, heart rate, stroke volume, cardiac output, total peripheral resistance, cardiac ejection fraction, cardiac contractility and ventricular end-diastolic volume are provided. These estimates and measurements are used to determine a type of circulatory shock. In some embodiments, the type of circulatory shock is determined to be one of septic shock, hypovolemic shock, anaphylactic shock, hemorrhagic shock, and cardiogenic shock.
    Type: Application
    Filed: May 16, 2008
    Publication date: November 20, 2008
    Inventors: Tushar A. Parlikar, Thomas Heldt, George C. Verghese, Roger Greenwood Mark