System and method of determining whether to recalibrate a blood pressure monitor
First Claim
1. A noninvasive blood pressure monitor, comprising:
- an input calibration signal from a calibration device configured to provide an accurate representation of the blood pressure of a patient;
an input noninvasive sensor signal from a sensor configured to detect one or more attributes of a perturbation of an artery of the patient; and
a processor which determines when to employ the input calibration signal to recalibrate one or more of a plurality of parameters, wherein the processor uses the plurality of parameters and the input noninvasive sensor signal to continuously calculate the blood pressure of the patient, wherein the one or more parameters comprise a combination of values of a pressure-volume relationship and a trigger parameter.
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Accused Products
Abstract
A monitor for determining a patient'"'"'s physiological parameter includes a calibration device configured to provide a calibration signal representative of the patient'"'"'s physiological parameter. An exciter is positioned over a blood vessel of the patient for inducing a transmitted exciter waveform into the patient. A noninvasive sensor is positioned over the blood vessel, where the noninvasive sensor is configured to sense a hemoparameter and to generate a noninvasive sensor signal representative of the hemoparameter containing a component of a received exciter waveform. In this context, a hemoparameter is defined as any physiological parameter related to vessel blood such as pressure, flow, volume, velocity, blood vessel wall motion, blood vessel wall position and other related parameters. A processor is configured to determine a relationship between a property of the received exciter waveform and a property of the physiological parameter. The processor is connected to receive the calibration signal and the noninvasive sensor signal, and the processor is configured to process the calibration signal and the noninvasive sensor signal to determine the physiological parameter. In the preferred embodiment, the physiological parameter measured is blood pressure, however, the present invention can also be used to analyze and track other physiological parameters such as vascular wall compliance, strength of ventricular contractions, vascular resistance, fluid volume, cardiac output, myocardial contractility and other related parameters.
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Citations
9 Claims
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1. A noninvasive blood pressure monitor, comprising:
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an input calibration signal from a calibration device configured to provide an accurate representation of the blood pressure of a patient;
an input noninvasive sensor signal from a sensor configured to detect one or more attributes of a perturbation of an artery of the patient; and
a processor which determines when to employ the input calibration signal to recalibrate one or more of a plurality of parameters, wherein the processor uses the plurality of parameters and the input noninvasive sensor signal to continuously calculate the blood pressure of the patient, wherein the one or more parameters comprise a combination of values of a pressure-volume relationship and a trigger parameter. - View Dependent Claims (2, 3)
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4. A monitor for determining a physiological parameter of a patient comprising:
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a calibration device configured to provide a calibration signal representative of one of a patient'"'"'s physiological parameters;
an exciter adapted to be positioned over a blood vessel of the patient and configured to induce a transmitted exciter waveform into the patient;
a noninvasive sensor adapted to be positioned over said blood vessel and configured to sense a hemoparameter and to generate a noninvasive sensor signal representative of said hemoparameter containing a component of a received exciter waveform;
a processor configured to determine a relationship between a property of said received exciter waveform and a property of said physiological parameter;
wherein said processor includes a filter configured to separate a signal exciter waveform component of said received exciter waveform from at least one other component of said received exciter waveform;
wherein said processor is connected to receive said calibration signal and said noninvasive sensor signal and is configured to determine said physiological parameter based at least in part on said calibration signal, said signal exciter waveform component, and said relationship;
wherein said processor is configured to determine the validity of said calibration signal and to initiate a calibration when said calibration signal is not valid;
wherein said processor employs an Internal Consistency Analysis (ICA) technique to determine when said calibration signal is not valid; and
wherein said ICA technique includes determining a plurality of parameters and comparing the parameters over time to a predetermined threshold to determine when said calibration signal is not valid.
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5. A monitor for determining a physiological parameter of a patient comprising:
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a calibration device configured to provide a calibration signal representative of one of a patient'"'"'s physiological parameters;
an exciter adapted to be positioned over a blood vessel of the patient and configured to induce a vibrational transmitted exciter waveform into the patient;
a noninvasive sensor adapted to be positioned over said blood vessel and configured to sense a hemoparameter and to generate a noninvasive sensor signal representative of said hemoparameter containing a component of a received exciter waveform;
a processor configured to determine a relationship between a property of said received exciter waveform and a property of said physiological parameter;
wherein said processor includes a filter configured to separate a component of said noninvasive sensor signal having a phase that varies with blood pressure from at least one other component of said noninvasive sensor signal having a phase that does not so vary;
wherein said processor is connected to receive said calibration signal and said noninvasive sensor signal and is configured to determine said physiological parameter based at least in part on said calibration signal, said component having a phase that varies with blood pressure, and said relationship;
wherein said processor is configured to determine the validity of said calibration signal and to initiate a calibration when said calibration signal is not valid;
wherein said processor employs an Internal Consistency Analysis (ICA) technique to determine when said calibration signal is not valid; and
wherein said ICA technique includes determining a plurality of parameters and comparing the parameters over time to a predetermined threshold to determine when said calibration signal is not valid.
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6. A monitor for determining a physiological parameter of a patient, comprising:
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a calibration device configured to provide a calibration signal representative of one of a patient'"'"'s physiological parameters;
at least one exciter adapted to be positioned over a blood vessel of the patient and configured to induce a plurality of different frequency transmitted exciter waveforms into the patient;
a noninvasive sensor adapted to be positioned over said blood vessel and configured to sense a hemoparameter and to generate a noninvasive sensor signal representative of said hemoparameter containing components of a plurality of different frequency received exciter waveforms;
a processor configured to determine a relationship between a property of one of said received exciter waveforms and a property of said physiological parameter;
wherein said processor is connected to receive said calibration signal and said noninvasive sensor signal and is configured to determine said physiological parameter based at least in part on said calibration signal, said noninvasive sensor signal and said relationship;
wherein said processor is configured to determine the validity of said calibration signal and to initiate a calibration when said calibration signal is not valid;
wherein said processor employs an Internal Consistency Analysis (ICA) technique to determine when said calibration signal is not valid; and
wherein said ICA technique includes determining a plurality of parameters and comparing the parameters over time to a predetermined threshold to determine when said calibration signal is not valid.
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7. A method for determining a physiological parameter of a patient comprising:
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providing a calibration signal representative of one of a patient'"'"'s physiological parameters and storing the calibration signal;
inducing a transmitted exciter waveform into the patient;
noninvasively sensing a hemoparameter and generating a noninvasive sensor signal representative of said hemoparameter containing a component of a received exciter waveform; and
processing said noninvasive sensor signal including the steps of;
(a) determining a relationship between a property of said received exciter waveform and a property of said physiological parameter;
(b) separating a signal exciter waveform component of said received exciter waveform, from at least one other component of said received exciter waveform;
(c) determining said physiological parameter based at least in part on said calibration signal, said signal exciter waveform component, and said relationship;
wherein processing said noninvasive sensor signal also includes the step of determining the validity of said calibration signal and initiating said step of providing a calibration signal when said calibration signal is not valid;
wherein said processing includes employing an Internal Consistency Analysis (ICA) technique to determine when said calibration signal is not valid; and
wherein said ICA technique includes determining a plurality of parameters and comparing the parameters over time to a predetermined threshold to determine when said calibration signal is not valid.
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8. A method for determining a physiological parameter of a patient comprising:
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providing a calibration signal representative of one of a patient'"'"'s physiological parameters and storing the calibration signal;
inducing a vibrational transmitted exciter waveform into the patient;
noninvasively sensing a hemoparameter and generating a noninvasive sensor signal representative of said hemoparameter containing a component of a received exciter waveform; and
processing said noninvasive sensor signal including the steps of;
(a) determining a relationship between a property of said received exciter waveform and a property of said physiological parameter;
(b) separating a signal exciter waveform component of said noninvasive sensor signal having a phase that varies with blood pressure, from at least one other component of said noninvasive sensor signal having a phase that does not so vary;
(c) determining said physiological parameter based at least in part on said calibration signal, said component having a phase that varies with blood pressure, and said relationship;
wherein processing said noninvasive sensor signal also includes the step of determining the validity of said calibration signal and initiating said step of providing a calibration signal when said calibration signal is not valid;
wherein said processing includes employing an Internal Consistency Analysis (ICA) technique to determine when said calibration signal is not valid; and
wherein said ICA technique includes determining a plurality of parameters and comparing the parameters over time to a predetermined threshold to determine when said calibration signal is not valid.
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9. A method of determining a physiological parameter of a patient, comprising the steps of:
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providing a calibration signal representative of one of a patient'"'"'s physiological parameters and storing the calibration signal;
inducing a plurality of different frequency transmitted exciter waveforms into the patient;
noninvasively sensing a hemoparameter and generating a noninvasive sensor signal representative of said hemoparameter containing components of a plurality of different frequency received exciter waveforms;
processing said noninvasive sensor signal including the steps of;
(a) determining a relationship between a property of one of said received exciter waveforms and a property of said physiological parameter;
(b) determining said physiological parameter based at least in part on said calibration signal, said noninvasive sensor signal and said relationship;
wherein processing said noninvasive sensor signal also includes the step of determining the validity of said calibration signal and initiating said step of providing a calibration signal when said calibration signal is not valid;
wherein said processing includes employing an Internal Consistency Analysis (ICA) technique to determine when said calibration signal is not valid; and
wherein said ICA technique includes determining a plurality of parameters and comparing the parameters over time to a predetermined threshold to determine when said calibration signal is not valid.
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Specification