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Minimally invasive method to determine the left ventricular pressure waveform

  • US 5,445,159 A
  • Filed: 11/21/1994
  • Issued: 08/29/1995
  • Est. Priority Date: 11/21/1994
  • Status: Expired due to Fees
First Claim
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1. A minimally invasive method of determining a patient'"'"'s left ventricular pressure waveform without placement of a catheter inside the left ventricle, said method comprising the steps of:

  • recording and digitizing a human subject'"'"'s EKG, peripheral arterial pressure waveform, pulmonary small arterial pressure waveform, pulmonary capillary wedge pressure waveform, and left ventricular pressure waveform;

    separating said left ventricular pressure waveform into an ejection phase waveform, an isovolumetric relaxation phase waveform, a filling phase waveform and an isovolumetric contraction phase waveform;

    separating said peripheral arterial pressure waveform to obtain an ejection phase waveform;

    a first factoring step utilizing said ejection phase waveform of said peripheral arterial pressure waveform and said ejection phase waveform of said left ventricular pressure waveform to form an ejection correlation curve;

    separating said pulmonary capillary wedge pressure waveform to obtain a filling phase waveform;

    a second factoring step utilizing said filling phase waveform of said pulmonary capillary wedge pressure waveform and said filling phase waveform of said left ventricular pressure waveform to form a filling correlation curve;

    storing, sorting and standardizing said ejection and filling correlation curves obtained from a predetermined number of human subjects to provide standardized ejection and filling correlation curves;

    recording and digitizing a patient'"'"'s EKG, peripheral arterial pressure waveform, pulmonary small arterial pressure waveform and pulmonary capillary wedge pressure waveform;

    separating said peripheral arterial pressure waveform of said patient to obtain an ejection phase waveform of said patient;

    a third factoring step utilizing said standardized ejection correlation curve and said ejection phase waveform of said patient to form an ejection phase waveform of a left ventricular pressure of said patient;

    separating said pulmonary capillary wedge pressure waveform of said patient to obtain a filling phase waveform of said patient;

    a fourth factoring step utilizing said standardized filling correlation curve and said filling phase waveform of said patient to form a filling phase waveform of the left ventricular pressure of said patient; and

    connecting said ejection and filling phase waveforms of the left ventricular pressure of the patient with two straight lines, one of said straight lines representing said patient'"'"'s isovolumetric relaxation phase waveform and the other of said straight lines representing the patient'"'"'s isovolumetric contraction phase waveform to complete a left ventricular pressure waveform of said patient.

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