HEART-SOUND DETECTING APPARATUS, SYSTEM FOR MEASURING PRE-EJECTION PERIOD BY USING HEART-SOUND DETECTING APPARATUS, AND SYSTEM FOR OBTAINING PULSE-WAVE-PROPAGATION-VELOCITY-RELATING INFORMATION BY USING HEART-SOUND DETECTING APPARATUS
First Claim
1. A heart-sound detecting apparatus, comprising:
- a heart-sound microphone which detects at least one heart sound produced by a heart of a living subject and outputs a heart-sound signal representing the detected heart sound;
a time-frequency analyzing means for analyzing, with respect to time and frequency, at least a portion of the heart-sound signal that includes a first heart sound I; and
an aortic-valve-opening-timing determining means for determining a timing when an aortic valve of the heart opens, based on a time when a magnitude of the analyzed signal at a frequency higher than a frequency range of a main component present in an initial portion of the first heart-sound I is greater than a prescribed threshold value.
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Accused Products
Abstract
A heart-sound detecting apparatus, including a heart-sound microphone which detects at least one heart sound produced by the heart of a living subject and outputs a heart-sound signal representing the detected heart sound, a time-frequency analyzing device for analyzing, with respect to time and frequency, at least a portion of the heart-sound signal that includes a first heart sound I, and an aortic-valve-opening-timing determining device for determining a timing when the aortic valve of the heart opens, based on a time when a magnitude of the analyzed signal at a frequency higher than a frequency range of a main component present in an initial portion of the first heart-sound I is greater than a prescribed threshold value.
11 Citations
12 Claims
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1. A heart-sound detecting apparatus, comprising:
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a heart-sound microphone which detects at least one heart sound produced by a heart of a living subject and outputs a heart-sound signal representing the detected heart sound;
a time-frequency analyzing means for analyzing, with respect to time and frequency, at least a portion of the heart-sound signal that includes a first heart sound I; and
an aortic-valve-opening-timing determining means for determining a timing when an aortic valve of the heart opens, based on a time when a magnitude of the analyzed signal at a frequency higher than a frequency range of a main component present in an initial portion of the first heart-sound I is greater than a prescribed threshold value. - View Dependent Claims (3, 5, 6, 7, 8)
an electrocardiograph for detecting an electrocardiogram from the subject;
a heart-sound detecting apparatus according to claim 1; and
a pre-ejection-period determining means for determining, as the pre-ejection period, a time difference between a timing when a portion of the electrocardiogram indicative of excitation of a ventricular muscle of the heart is detected by the electrocardiograph, and the timing of opening of the aortic valve determined by the aortic-valve-opening-timing determining means of the heart-sound detecting apparatus.
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5. A system for obtaining information relating to a propagation velocity at which a pulse wave propagates along an artery of a living subject,-the system comprising:
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a heart-sound detecting apparatus according to claim 1;
a pulse-wave detecting device which is adapted to be worn on the subject to detect the pulse wave which propagates along the artery of the subject; and
a pulse-wave-propagation-velocity-relating-information obtaining means for obtaining said information based on the timing of opening of the aortic valve determined by the aortic-valve-opening-timing determining means of the heart-sound detecting apparatus, and a timing when a rising point of the pulse wave is detected by the pulse-wave detecting device.
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6. A system according to claim 5, wherein the pulse-wave-propagation-velocity-relating-information obtaining means comprises a pulse-wave-propagation-time determining means for determining, based on the timing of opening of the aortic valve determined by the aortic-valve-opening-timing determining means, and the timing when the rising point of the pulse wave is detected by the pulse-wave detecting device, a propagation time needed for the pulse wave to propagate from the aorta to a position where the pulse-wave detecting device is worn on the subject.
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7. A system according to claim 5, wherein the pulse-wave-propagation-velocity-relating-information obtaining means comprises a pulse-wave-propagation-velocity determining means for determining the propagation velocity at which the pulse wave propagates, by dividing a distance from the aorta to a position where the pulse-wave detecting device is worn on the subject, by a time difference between the timing of opening of the aortic valve determined by the aortic-valve-opening-timing determining means and the timing when the rising point of the pulse wave is detected by the pulse-wave detecting device.
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8. A system according to claim 5, further comprising an output device which outputs the information obtained by the pulse-wave-propagation-velocity-relating-information obtaining means, so that an observer can observe said information.
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2. A heart-sound detecting apparatus, comprising:
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a heart-sound microphone which detects at least one heart sound produced by a heart of a living subject and outputs a heart-sound signal representing the detected heart sound;
a time-frequency analyzing means for analyzing, with respect to time and frequency, at least a portion of the heart-sound signal that includes a first heart sound I; and
an aortic-valve-opening-timing determining means for determining a timing when an aortic valve of the heart of the subject opens, based on a time when at least one magnitude of the analyzed signal at least one frequency in a frequency range of a main component present in an initial portion of the first heart-sound I is minimal. - View Dependent Claims (4, 9, 10, 11, 12)
an electrocardiograph for detecting an electrocardiogram from the subject;
a heart-sound detecting apparatus according to claim 2; and
a pre-ejection-period determining means for determining, as the pre-ejection period, a time difference between a timing when a portion of the electrocardiogram indicative of excitation of a ventricular muscle of the heart is detected by the electrocardiograph, and the timing of opening of the aortic valve determined by the aortic-valve-opening-timing determining means of the heart-sound detecting apparatus.
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9. A system for obtaining information relating to a propagation velocity at which a pulse wave propagates along an artery of a living subject, the system comprising:
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a heart-sound detecting apparatus according to claim 2;
a pulse-wave detecting device which is adapted to be worn on the subject to detect the pulse wave which propagates along the artery of the subject; and
a pulse-wave-propagation-velocity-relating-information obtaining means for obtaining said information based on the timing of opening of the aortic valve determined by the aortic-valve-opening-timing determining means of the heart-sound detecting apparatus, and a timing when a rising point of the pulse wave is detected by the pulse-wave detecting device.
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10. A system according to claim 9, wherein the pulse-wave-propagation-velocity-relating-information obtaining means comprises a pulse-wave-propagation-time determining means for determining, based on the timing of opening of the aortic valve determined by the aortic-valve-opening-timing determining means, and the timing when the rising point of the pulse wave is detected by the pulse-wave detecting device, a propagation time needed for the pulse wave to propagate from the aorta to a position where the pulse-wave detecting device is worn on the subject.
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11. A system according to claim 9, wherein the pulse-wave-propagation-velocity-relating-information obtaining means comprises a pulse-wave-propagation-velocity determining means for determining the propagation velocity at which the pulse wave propagates, by dividing a distance from the aorta to a position where the pulse-wave detecting device is worn on the subject, by a time difference between the timing of opening of the aortic valve determined by the aortic-valve-opening-timing determining means and the timing when the rising point of the pulse wave is detected by the pulse-wave detecting device.
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12. A system according to claim 9, further comprising an output device which outputs the information obtained by the pulse-wave-propagation-velocity-relating-information obtaining means, so that an observer can observe said information.
Specification