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US 5,181,517 AGranted
Method and apparatus for the measurement of atrial pressure
AssigneeState University of New York
InventorDonald D. Hickey
Life of this patent
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AssigneeState University of New York
InventorDonald D. Hickey
Estimating the term…
Non-invasive apparatus and method for obtaining a quantitative determination of mean left atrial pressure or otherwise obtaining a quantitative determination of a left atrial pressure value. A balloon is inserted by means of a catheter into the esophagus and positioned adjacent the left atrium. The balloon is gradually inflated. A tracing of mean balloon pressure is obtained as the balloon is inflated. In addition, a tracing of balloon pressure on a steady baseline and with low frequency oscillations due to respiration filtered out is obtained whereby the tracing represents balloon pressure oscillations effected by left atrial pressure. In accordance with the oscillometric principle the mean balloon pressure is measured at the time when the amplitude of the balloon pressure oscillations effected by the left atrial pressure is at a peak. This mean balloon pressure is indicative of approximate mean left atrial pressure. Mean left atrial transmural pressure may be determined by subtracting therefrom the mean esophageal pressure as measured at a position in the esophagus where it is unaffected by the heart.
Apparatus comprising a catheter means which includes a balloon and is insertable into an esophagus for positioning said balloon adjacent the left atrium, means for inflating said balloon, and means for measuring the balloon pressure when the amplitude of balloon pressure oscillations effected by the left atrial pressure when said balloon is adjacent the left atrium is at a peak.
Apparatus for determining mean left atrial pressure comprising a catheter means which includes a balloon and is insertable into an esophagus for positioning said balloon adjacent the left atrium, means for gradually inflating said balloon whereby left atrial pressure and respiratory waves effect balloon pressure oscillations as said balloon is inflated while adjacent the left atrium, means for measuring mean balloon pressure, and means for filtering the balloon pressure to pass oscillations effected by the left atrial pressure whereby the mean left atrial pressure may be determined in accordance with the oscillometric principle by reference to the mean balloon pressure when the amplitude of the oscillations effected by the left atrial pressure is at a peak.
Apparatus for determining mean left atrial pressure comprising a catheter means which includes a balloon and is insertable into an esophagus for positioning said balloon adjacent the left atrium, means for sensing position of said balloon adjacent the left atrium, means for gradually inflating said balloon whereby left atrial pressure and respiratory pressure waves effect balloon pressure oscillations as the balloon is inflated while adjacent the left atrium, transducer means for converting the balloon pressure to an electrical signal, means for converting said electrical signal to an electrical signal of mean balloon pressure, a differential transducer means having a diaphragm for application of pressures on opposite sides thereof for converting the difference in the applied pressures to an electrical signal, means for applying balloon pressure to one side of said diaphragm, means for applying balloon pressure oscillations having a frequency less than about 0.8 Hertz to the other side of said diaphragm whereby balloon pressure oscillations having a frequency greater than about 0.8 Hertz effected by the left atrial pressure are converted to an electrical signal having a steady baseline by the differential transducer means and whereby the mean left atrial pressure may be determined in accordance with the oscillometric principle by reference to the mean balloon pressure when the amplitude of said balloon pressure oscillations effected by the left atrial pressure is at a peak.
Apparatus comprising a catheter means which includes a balloon and is insertable into an esophagus for positioning said balloon adjacent the left atrium, means for inflating said balloon whereby left atrial pressure and respiratory waves effect balloon pressure oscillations as said balloon is inflated while adjacent the left atrium, and means for filtering the balloon pressure to remove oscillations thereof effected by respiratory waves whereby oscillations effected by the left atrial pressure may be passed free of the effects of respiratory waves.
Apparatus comprising a catheter means which includes a balloon and is insertable into an esophagus for positioning said balloon adjacent the left atrium, means for inflating said balloon, means for filtering the balloon pressure to remove oscillations thereof having a frequency less than about 0.8 Hertz whereby a wave form of oscillations effected by left atrial pressure free of oscillations having a frequency less than about 0.8 Hertz may be obtained, and means for measuring the means balloon pressure when the amplitude of balloon pressure oscillations effected by the left atrial pressure is at a peak.
A method of determining means left atrial pressure comprising the steps of:
A method of determining means left atrial pressure comprising the steps of:
A method of determining mean left atrial transmural pressure comprising the steps of:
Dependencies are inferred from the claim text.