Electronic sphygmomanometer
First Claim
1. In an electronic sphygmomanometer, the combination comprising:
- means for providing, from a first source, detected korotkoff sounds as electrical signals;
means for providing, from a second source, associated pressure waveform korotkoff sound precursors as electrical signals, each of said korotkoff sound precursors relating solely to the indivdidual korotkoff sound signal with which that precursor is associated; and
analyzing means for analyzing the waveforms of all of said electrical signals to determine their conformity with predetermined waveform characteristics, whereby those electrical signals having waveforms representative of true korotkoff sounds are separated from those electrical signals which do not represent true korotkoff sounds.
6 Assignments
0 Petitions
Accused Products
Abstract
An electronic method and apparatus for automatically determining systolic and diastolic blood pressures and heart rate by accurately detecting, verifying and evaluating the full stream of korotkoff sounds produced as electrical signals from a microphone in a cuff occluding the brachial artery of a patient and the corresponding blood pressure pulse signals which accompany and are precursors to genuine korotkoff sound signals. Blood pressure is measured with the aid of a programmed data processor such as a microprocessor. Waveform analysis is first performed upon the incoming signal waveforms to initially separate true pressure pulses and korotkoff sound signals from a variety of artifact and noise signals and to provide digital pulse streams in memory correctly indicating proper pressure pulse and korotkoff sound occurrences in the time and blood pressure domains, with each pressure pulse proportional in amplitude to the amplitude of the corresponding detected precursor input pressure signal represented and each korotkoff pulse proportional to the negative slope amplitude of the corresponding detected korotkoff sound. The output pulse signal streams are then further analyzed by the digital processing subsystem and compared with each other to additionally remove any noise and artifact signals passed as otherwise misleading genuine signals, to modify and certify the resultant data as either reliable or suspect, to determine heart rate and the most probable values of systolic and diastolic blood pressure levels indicated by the pulse signal streams detected during the measurement cycle.
64 Citations
100 Claims
-
1. In an electronic sphygmomanometer, the combination comprising:
-
means for providing, from a first source, detected korotkoff sounds as electrical signals; means for providing, from a second source, associated pressure waveform korotkoff sound precursors as electrical signals, each of said korotkoff sound precursors relating solely to the indivdidual korotkoff sound signal with which that precursor is associated; and analyzing means for analyzing the waveforms of all of said electrical signals to determine their conformity with predetermined waveform characteristics, whereby those electrical signals having waveforms representative of true korotkoff sounds are separated from those electrical signals which do not represent true korotkoff sounds. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
-
18. In an electronic sphygmomanometer, the combination comprising:
-
first means for detecting korotkoff sounds; second means, independent of said first means, for detecting pressure waveform kortokoff sound precursor waveforms, each of said precursor waveforms relating solely to the individual korokoff sound with which that precursor is associated; means for providing said detected korotkoff sounds and said associated korotkoff sound precursor waveforms as two separate streams of electrical signals; and analysis means for separately analyzing the waveforms of all of said korotkoff sound electrical signals and said associated precursor waveform signals, to selectively determine the conformity of all of said signals with predetermined waveform characteristics and to correlate said korotkoff sound signals with said precursor waveforms, whereby those electrical signals having waveforms representative of true korotkoff sounds are not separated from those electrical signals which do not represent true korotkoff sounds and those electrical signals having waveforms representative of true korotkoff sound precursors are separated from those electrical signals which do not represent true korotkoff sound precursors. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
-
-
31. In an electronic sphygmomanometer for analyzing korotkoff sounds produced by an auscultation blood pressure measuring process and associated blood pressure korotkoff sound precursor waveforms, the combination comprising:
-
first means for providing said korotkoff sounds and said associated korotkoff sound precursor waveforms as separate input electrical signals from separate sources, each of said korotkoff sound precursor waveforms relating solely to and being correlated with the individual korotkoff sound signal with which that precursor is associated; second means for analyzing the waveforms of all of said input electrical signals representing said korotkoff sounds to selectively determine their conformity with predetermined waveform characteristics; third means for analyzing the waveforms of all of said input electrical signals relating to said associated korotkoff sound precursor waveforms to determine selectively their conformity with predetermined waveform characteristics; fourth means for analyzing and correlating the waveforms of all of said input electrical signals relating to said korotkoff sounds and said associated korotkoff sound precursors to selectively determine their conformity with each other; and fifth means responsive to said second means, said third means and said fourth means for selectively producing output electrical signals in correlaton only with those input electrical signals corresponding to true korotkoff sounds and true korotkoff sound precursors, whereby those input electrical signals representing true korotkoff sounds and true korotkoff sound precursors are separated from artifact and noise signals.
-
-
32. In an electronic sphygmomanometer, the combination comprising:
-
means for providing, from a first source, detected korotkoff sounds as electrical signals; means for providing, from a second source, associated pressure waveform korotkoff sound precursors as electrical signals, each of said korotkoff sound precursors relating solely to the individual korotkoff sound signal with which that precursor is associated; and means for analyzing the waveforms of all of said electrical signals to determine their conformity with predetermined waveform characteristics, so that those electrical signals having waveform representative of true korotkoff sounds and true korotkoff sound precursors are separated from those electrical signals which do not represent true korotkoff sounds and associated korotkoff sound precursors, whereby systolic and diastolic blood pressure may be determined. - View Dependent Claims (33)
-
-
34. An electronic sphygmomanometer, comprising:
-
input means for providing korotkoff sounds from a first source and associated pressure waveform korotkoff sound precursors from a second source as separate input electrical signals, each of said korotkoff sound precursors relating solely to the individual korotkoff sound signal with which the precursor is associated; waveform analysis means for receiving and analyzing the waveforms of all of said of input electrical signals relating to said korotkoff sounds and associated korotkoff sound precursors to determine selectively the conformity of each individual input electrical signal with predetermined waveform characteristics and to produce an electrical output indicative of the presence or absence of such conformity, as well as the presence and correlation of said input electrical signals relating to said korotkoff sounds with said electrical signals relating to said korotkoff sound precursors; and output means responsive to said electrical output from said waveform analysis means for producing output electrical signals indicative of only those input electrical signals which represent the occurrence of true korotkoff sounds. - View Dependent Claims (35, 36)
-
-
37. An electrical sphygmomanometer, comprising:
-
first means for providing electrical waveforms from a first source representing korotkoff sounds; second means for providing electrical waveforms from a second source representing associated pressure waveform korotkoff sound precursors, each of said korotkoff sound precursors relating solely to the individual korotkoff sound signal with which that precursor is associated; third means for analyzing the slope amplitude of portions of said waveforms representing korotkoff sounds and producing an output representative of the slope magnitude and occurrence of those waveforms; fourth means for determining the slope and amplitude of said waveforms representing associated korotkoff sound precursors; fifth means for determining the phase of said waveforms representing korotkoff sounds relative to said waveforms representing said associated korotkoff sound precursors; sixth means for providing an electrical output representative of the occurrence of true korotkoff sounds, in response to the analysis by said third means, said fourth means and said fifth means; and seventh means for anlayzing the electrical output of said sixth means to determine blood pressure. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44)
-
-
45. In an electronic sphygmomanometer for analyzing korotkoff sounds produced by an auscultation blood pressure measuring process and associated korotkoff sound precursors, the combination comprising:
-
first means for providing korotkoff sounds from a first source and associated pressure waveform korotkoff sound precursors from a second source as separate input electrical signals, each of said korotkoff sound precursors relating solely to the individual korotkoff sound signal with which that precursor is associated; second means for pre-screening selectively said input electrical signals from said first means relating to said korotkoff sounds for the presence of said input electrical signals relating to associated korotkoff sound precursors, and producing output electrical signals representing those input electrical signals corresponding to the occurrence of true korotkoff events; and third means for analyzing the output electrical signals from said second means to determine blood pressure.
-
-
46. An electronic sphygmomanometer comprising:
-
first means for providing from a first source electrical waveforms representing korotkoff sounds and from a second source electrical waveforms representing blood pressure signals defining associated pressure waveform korotkoff sound precursors, each of said korotkoff sound precursors relating solely to the individual korotkoff sound signal with which that precursor is associated; second means for analyzing selectively portions of said waveforms representing said korotkoff sounds; third means for analyzing selectively portions of said waveforms representing associated korotkoff sound precursors; fourth means for determining selectively the presence of specified korotkoff sound precursors by the correlation of said electrical waveforms with prescribed waveform characteristics to produce an electrical output representing only true korotkoff events as distinguished from artifacts and noise signals.
-
-
47. In an electronic sphygmomanometer, the combination comprising:
-
means for converting detected korotkoff sounds and associated pressure waveform korotkoff precursors to electrical signals; and analysis means for analyzing the waveforms of all said electrical signals to determine their conformity with predetermined waveform characteristics and to locate each korotkoff sound on the rising slope portion of the associated korotkoff precursor, whereby those electrical signals having waveforms representative of true korotkoff sounds are separated from those electrical signals which do not represent true korotkoff sounds. - View Dependent Claims (48, 49, 50, 51)
-
-
52. In an electronic sphygmomanometer, the combination comprising:
-
first signal source means for detecting korotkoff sounds and differentiating said sounds to provide a stream of korotkoff sound signals; second signal source means, independent of said first means, for detecting cardiac cycle blood pressure pulses as korotkoff sound precursor pressure waveforms, each of said precursor waveforms relating solely to the individual korotkoff sound signal with which that precursor is associated; means for providing said korotkoff sound signals and said associated korotkoff sound precursors as two separate streams of electrical signals; analyzer means for separately analyzing the waveforms of all of said korotkoff sound electrical signals and said associated precursor waveforms, to selectively determine the conformity of each individual korotkoff sound signal and each individual precursor waveform with predetermined waveform characteristics and to correlate each genuine korotkoff sound signal with its associated precursor waveform, whereby those electrical signals having waveforms representative of true korotkoff sounds are separated from those electrical signals which do not represent true korotkoff sounds and those electrical signals having waveforms representative of true korotkoff sound precursors are separated from those electrical signals which do not represent true korotkoff sound precursors; and means for determining blood pressure from said true korotkoff sounds. - View Dependent Claims (53, 54, 55, 56)
-
-
57. In an electronic sphygmomanometer, the combination comprising:
-
means for inflating a cuff; means for deflating said cuff; means for monitoring for the presence of noise signals during deflation of said cuff; and means for temporarily arresting said deflation in response to detection of excessive noise signals. - View Dependent Claims (58)
-
-
59. A method of blood pressure measurement, comprising the steps of:
-
converting detected korotkoff sounds and associated blood pressure pulse precursors from separate sources to separate waveform signals; and analyzing the individual waveforms of all of said waveform signals to determine their conformity with predetermined waveform characteristics including correlation of said korotkoff waveform signals with said pressure pulse waveform signals, whereby those waveforms representative of true korotkoff sounds are separated from those waveforms which do not represent true korotkoff sounds. - View Dependent Claims (60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76)
-
-
77. In a method of blood pressure measurement, the steps comprising:
-
inflating a cuff on the arm of a patient; deflating said cuff; monitoring for the presence of noise signals during said deflation; and arresting said deflation temporarily in response to detection of excessive noise signals. - View Dependent Claims (78, 79)
-
-
80. In a method of blood pressure measurement, the combination comprising:
-
generating a pulse stream representing blood pressure waveforms which are precursors to korotkoff sound signals; generating a pulse stream representing said korotkoff sound signals; generating a noise threshold for said korotkoff signals only during selected time periods between successive precursors when said korotkoff signals are not likely to occur.
-
-
81. In a method wherein a korotkoff pulse stream is to be analyzed in the determination of blood pressure, the steps comprising:
-
generating a pulse stream representing korokoff sound signals; generating a corresponding pulse stream representing associated pressure waveform korotkoff sound precursors; locating the first pair of adjacent korotkoff signals above a maximum amplitude threshold adjacent either extreme end of the blood pressure spectrum; and establishing as a blood pressure limit the first korotkoff sound signal below said threshold encountered in proceeding away from said pair of korotkoff signals in the direction of the selected extreme end of said pressure spectrum.
-
-
82. In a method wherein a korotkoff pulse stream is to be analyzed in the determination of blood pressure, the steps comprising:
-
generating a pulse stream representing korotkoff sound signals in the blood pressure domain; generating a corresponding pulse stream representing associated blood pressure waveform korotkoff sound precursors in the blood pressure domain; locating the first pair of adjacent korotkoff signals above a minimum amplitude threshold adjacent either extreme end of the blood pressure spectrum; extrapolating the amplitudes of said pair of korotkoff signals to determine an extreme value of blood pressure in the direction of the selected extreme end of said pressure spectrum; and establishing said extreme value as a blood pressure limit if said value is spaced from said pair of korotkoff signals by no more than the average pressure change per pulse period between successive precursors.
-
-
83. In a method wherein a korotkoff pulse stream is to analyzed in the determination of blood pressure, the steps comprising:
-
generating a pulse stream representing korotkoff sound signals in the blood pressure domain; generating a corresponding pulse stream representing associated blood pressure waveform korotkoff sound precursors in the blood pressure domain; locating the first pair of adjacent korotkoff signals above a minimum amplitude threshold adjacent either extreme end of the blood pressure spectrum; extrapolating the amplitudes of said pair of korotkoff signals to determine an extreme value of blood pressure in the direction of the selected extreme end of said pressure spectrum; and establishing as a blood pressure limit beyond said pair of korotkoff signals toward said selected extreme end of said pressure spectrum an additional pressure equal to the average pressure change per pulse period between successive precursors, if said extreme value yields a pressure value spaced from said pair of korotkoff signals by more than said average pressure change.
-
-
84. In a method of blood pressure measurement, the steps comprising:
-
providing as electrical input, from a first source, signals representing korotoff sound waveforms; providing as electrical input, from a second source, separate from said first source, signals representing associated korotkoff sound precursor pressure waveforms, each of said korotkoff sound precursor waveforms relating solely to the individual korotkoff sound signal waveform with which that precursor is associated; analyzing the waveforms of said signals representing korotkoff sounds; analyzing the waveforms of said signals relating to associated korotkoff sound precursors; analyzing the waveforms of all of said signals to determine selectively the presence of specified korotkoff sound precursors and the conformity of such precursors with said korotkoff sounds, whereby those waveforms representative of true korotkoff sounds are separated from those waveforms which do not represent true korotkoff sounds. - View Dependent Claims (85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100)
-
Specification