Method and apparatus utilizing heart sounds for determining pressures associated with the left atrium
First Claim
1. Apparatus for determining a mean pressure from a source within a body comprising a balloon positionable within the body adjacent the source, means for inflating said balloon, means for detecting and determining intensity of a sound wave from said source after the sound wave is transmitted through said balloon, and means for, determining the balloon pressure when the intensity of the sound wave is, after the sound wave is transmitted through said balloon, at a peak.
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Accused Products
Abstract
Non-invasive apparatus and method for obtaining a quantitative determination of mean left atrial transmural 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 when the intensity of a sound wave, after its transmission through the balloon, is at a peak. This mean balloon pressure, after adjustment for the effect, if any, of heart weight, is indicative of approximate mean left atrial pressure. Mean left atrial transmural pressure may be determined by adjusting for the effects of heart weight and intrapleural pressure on mean pressure at peak sound intensity by subtracting therefrom the balloon pressure at which balloon volume begins to increase greatly relative to the increase in balloon pressure.
138 Citations
30 Claims
- 1. Apparatus for determining a mean pressure from a source within a body comprising a balloon positionable within the body adjacent the source, means for inflating said balloon, means for detecting and determining intensity of a sound wave from said source after the sound wave is transmitted through said balloon, and means for, determining the balloon pressure when the intensity of the sound wave is, after the sound wave is transmitted through said balloon, at a peak.
- 8. Apparatus comprising a catheter 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 detecting and determining intensity of heart sounds from the left atrium after the heart sounds are transmitted through said balloon, and means for determining the balloon pressure when the intensity of the heart sounds, after they are transmitted through said balloon, is at a peak.
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17. A method of determining a mean pressure from a source within a body comprising the steps of:
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a. positioning a balloon within the body adjacent the source; (b) inflating the balloon; and (c) determining intensity of a sound wave from the source after the sound wave is transmitted through the balloon, and determining the balloon pressure when the intensity of the sound wave is, after the sound wave is transmitted through the balloon, at a peak. - View Dependent Claims (18, 19, 20, 21)
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22. A method of determining a mean pressure from a source within a body comprising the steps of:
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a. positioning a balloon within the body adjacent the source; b. inflating the balloon; and c. determining intensity of a sound wave from the source after the sound wave is transmitted through the balloon, and determining the mean balloon pressure when the intensity of the sound wave is, after the sound wave is transmitted through the balloon, at a peak.
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23. A method of determining mean left atrial pressure comprising the steps of:
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a. inserting a catheter including a balloon into an esophagus of a subject; b. positioning the balloon adjacent the left atrium; c. inflating the balloon; and d. determining intensity of heart sounds from the left atrium after the heart sounds are transmitted through the balloon, and determining the balloon pressure when the intensity of the heart sounds after they are transmitted through the balloon is at a peak. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
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Specification