US5590649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for measuring an induced perturbation to determine blood pressure
Assignee: Canon Inc
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Filing: 1994-04-15
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Granted: 1997-01-07
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Expires: 2014-04-15
Abstract
Abstract A monitor for continuously determining a patient's physiological parameter includes a means for obtaining a periodic calibration measurement of the patient's physiological parameter. An exciter, positioned over an artery of the patient induces an exciter waveform into the patient's arterial blood. A noninvasive sensor, positioned over the artery, senses a hemoparameter and provides a noninvasive sensor signal output representative of the hemoparameter. A processor receives the calibration measurement and noninvasive sensor signal output. The processor determines a DC offset based on the calibration measurement and processes the noninvasive sensor signal to continuously determine the patient's physiological parameter. A method includes steps for performing the present invention. 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.
Inventors
- 👤 Richard G. Caro
- 👤 Mark H. Sher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:45
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/021; A61B5/02108; A61B5/02133; A61B5/022
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
140 words
A monitor for determining a patient's physiological parameter, comprising: a calibration device configured to provide a calibration signal representative of the patient's physiological parameter; an exciter, positioned over a blood vessel of the patient, for inducing a transmitted exciter waveform into the patient; a noninvasive sensor, positioned over said blood vessel, said noninvasive sensor 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 the physiological parameter; and wherein said processor is connected to receive said calibration signal and said noninvasive sensor signal, said processor configured to determine said physiological parameter based at least in part on said calibration signal, said noninvasive sensor signal, and said relationship.
Claim 2
Dependent Claim
140 words
A monitor for determining a patient's physiological parameter, comprising: a calibration device configured to provide a calibration signal representative of the patient's physiological parameter; an exciter, positioned over a blood vessel of the patient, for inducing a transmitted exciter waveform into the patient; a noninvasive sensor, positioned over said blood vessel, said noninvasive sensor 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 the physiological parameter; and wherein said processor is connected to receive said calibration signal and said noninvasive sensor signal, said processor configured to determine said physiological parameter based at least in part on said calibration signal, said noninvasive sensor signal, and said relationship.
Claim 3
Dependent Claim
43 words
The monitor of claim 1, wherein: said processor includes a filter configured to separate from said noninvasive sensor signal a component of one of the group consisting of said physiological parameter waveform, said received exciter waveform, signal exciter waveform and a noise waveform.
Claim 4
Dependent Claim
25 words
The monitor of claim 1, wherein: said processor includes a filter configured to separate from said noninvasive sensor signal a component having a time-varying phase.
Claim 5
Dependent Claim
103 words
The monitor of claim 1, wherein: said processor includes a filter configured to determine an arc representing time varying positions of said received exciter waveform, to determine a center point of said arc and to determine a noise vector from an origin to said center point; and said processor is configured to determine an arc vector from said center point to said time varying positions, where said arc vector has an arc vector angle that moves from a first angle to a second angle over time; and wherein said processor is configured to process said arc vector angle to determine the physiological parameter.
Claim 6
Dependent Claim
69 words
The monitor of claim 1, wherein: said exciter is further configured to induce a second transmitted exciter waveform into the patient; and said processor includes a filter configured to separate from said noninvasive sensor signal a component of one of the group consisting of said physiological parameter waveform, said received exciter waveform, a second received exciter waveform, a signal exciter waveform, second signal exciter waveform and a noise waveform.
Claim 7
Dependent Claim
39 words
The monitor of one of claims 1, 2, 3 or 4, wherein: said processor is further configured to determine a relationship between a component of said received exciter waveform and an amplitude and DC offset of the physiological parameter.
Claim 8
Dependent Claim
44 words
The monitor of one of claims 1, 2, 3 or 4, wherein: said processor is further configured to determine a relationship between an amplitude and phase of a component of said received exciter waveform and an amplitude and DC offset of the physiological parameter.
Claim 9
Dependent Claim
45 words
The monitor of one of claims 1, 2, 3, 4 or 5, wherein: said processor is responsive to said noninvasive sensor signal, and further configured to determine the validity of said calibration signal and to initiate a calibration when said calibration signal is not valid.
Claim 10
Dependent Claim
52 words
The monitor of one of claims 1, 2, 3, 4 or 5, wherein: said processor is further configured to scale said physiological parameter waveform based on the relationship between a property of said received exciter waveform and a property of the physiological parameter and to generate a scaled physiological parameter waveform signal.
Claim 11
Dependent Claim
162 words
A processor for determining a patient's physiological parameter with an apparatus having a calibration device configured to provide a calibration signal representative of the patient's physiological parameter, an exciter positioned over a blood vessel of the patient for inducing a transmitted exciter waveform into the patient, and a noninvasive sensor positioned over said blood vessel, said noninvasive sensor configured to sense a hemoparameter and to generate a noninvasive sensor signal representative of said hemoparameter, said processor comprising: a first input configured to receive said calibration signal; a second input configured to receive said noninvasive sensor signal; a filter configured to separate from said noninvasive sensor signal a component representing a received exciter waveform; a relationship routine configured to determine a relationship between a property of said received exciter waveform and a property of said physiological parameter; and a determination routine configured to determine said physiological parameter based at least in part on said calibration signal, said noninvasive sensor signal, and said relationship.
Claim 12
Dependent Claim
162 words
A processor for determining a patient's physiological parameter with an apparatus having a calibration device configured to provide a calibration signal representative of the patient's physiological parameter, an exciter positioned over a blood vessel of the patient for inducing a transmitted exciter waveform into the patient, and a noninvasive sensor positioned over said blood vessel, said noninvasive sensor configured to sense a hemoparameter and to generate a noninvasive sensor signal representative of said hemoparameter, said processor comprising: a first input configured to receive said calibration signal; a second input configured to receive said noninvasive sensor signal; a filter configured to separate from said noninvasive sensor signal a component representing a received exciter waveform; a relationship routine configured to determine a relationship between a property of said received exciter waveform and a property of said physiological parameter; and a determination routine configured to determine said physiological parameter based at least in part on said calibration signal, said noninvasive sensor signal, and said relationship.
Claim 13
Dependent Claim
23 words
The processor of claim 10, wherein: said filter is configured to separate from said noninvasive sensor signal a component having a time-varying phase.
Claim 14
Dependent Claim
102 words
The processor of claim 10, wherein: said filter is configured to determine an arc representing time varying positions of said received exciter waveform, to determine a center point of said arc and to determine a noise vector from an origin to said center point; and said filter is configured to determine an arc vector from said center point to said time varying positions, where said arc vector has an arc vector angle that moves from a first angle to a second angle over time; and wherein said determination routine is configured to process said arc vector angle to determine the physiological parameter.
Claim 15
Dependent Claim
40 words
The processor of one of claims 10, 11 or 12, wherein: said determination routine is further configured to compare a phase relationship between said transmitted exciter waveform and a component of said noninvasive sensor signal to determine the physiological parameter.
Claim 16
Dependent Claim
31 words
The processor of one of claims 10, 11 or 12, wherein: said filter is further configured to separate from said noninvasive sensor signal a component representing a second received exciter waveform.
Claim 17
Dependent Claim
60 words
The processor of one of claims 10, 11 or 12, wherein: said determination routine is further configured to compare a phase relationship between said transmitted exciter waveform and a component of said noninvasive sensor signal, and to compare a phase relationship between a second transmitted exciter waveform and a component of said noninvasive sensor signal to determine the physiological parameter.
Claim 18
Independent Claim
97 words
A method of determining a patient's physiological parameter, comprising the steps of: providing a calibration signal representative of the patient's physiological parameter 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 and containing a component of a received exciter waveform; determining a relationship between a property of said received exciter waveform and a property of the physiological parameter; and determining said physiological parameter based at least in part on said calibration signal, said non-invasive sensor signal, and said relationship.
Claim 19
Independent Claim
97 words
A method of determining a patient's physiological parameter, comprising the steps of: providing a calibration signal representative of the patient's physiological parameter 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 and containing a component of a received exciter waveform; determining a relationship between a property of said received exciter waveform and a property of the physiological parameter; and determining said physiological parameter based at least in part on said calibration signal, said non-invasive sensor signal, and said relationship.
Claim 20
Dependent Claim
44 words
The method of claim 16, wherein: said processing step includes a filtering step of separating from said noninvasive sensor signal a component of one of the group consisting of said physiological parameter waveform, said received exciter waveform, signal exciter waveform and a noise waveform.
Claim 21
Dependent Claim
26 words
The method of claim 16, wherein: said processing step includes a filtering step of separating from said noninvasive sensor signal a component having a time-varying phase.
Claim 22
Dependent Claim
88 words
The method of claim 16, wherein: said processing step includes a filtering step of determining an arc representing time varying positions of said received exciter waveform, determining a center point of said arc and determining a noise vector from an origin to said center point; and said processing step includes a filtering step of determining an arc vector from said center point to said time varying positions, where said arc vector has an arc vector angle that moves from a first angle to a second angle over time.
Claim 23
Dependent Claim
66 words
The method of claim 16, further comprising: inducing a second transmitted exciter waveform into the patient; and wherein said processing step includes a filtering step of separating from said noninvasive sensor signal a component of one of the group consisting of said physiological parameter waveform, said received exciter waveform, a second received exciter waveform, a signal exciter waveform, second signal exciter waveform and a noise waveform.
Claim 24
Independent Claim
37 words
The method of one of claims 16, 17, 18 or 19, wherein: said processing step includes determining a relationship between a component of said received exciter waveform and an amplitude and DC offset of the physiological parameter.
Claim 25
Independent Claim
42 words
The method of one of claims 16, 17, 18 or 19, wherein: said processing step includes determining a relationship between an amplitude and phase of a component of said received exciter waveform and an amplitude and DC offset of the physiological parameter.
Claim 26
Independent Claim
40 words
The method of one of claims 16, 17, 18, 19 or 20, wherein: said processing step includes determining the validity of said calibration signal and initiating said step of providing a calibration signal when said calibration signal is not valid.
Claim 27
Independent Claim
49 words
The method of one of claims 16, 17, 18, 19 or 20, wherein: said processing step includes scaling said physiological parameter waveform based on the relationship between a property of said received exciter waveform and a property of the physiological parameter and generating a scaled physiological parameter waveform signal.
Claim 28
Dependent Claim
180 words
A monitor for determining a patient's blood pressure, comprising: an inflatable cuff positioned on an extremity of the patient and configured to provide a calibration signal representative of the patient's physiological parameter; an exciter positioned over a blood vessel of the patient and configured to induce a transmitted exciter waveform into the patient; a noninvasive sensor, positioned over said blood vessel and at a distance from said exciter, said noninvasive sensor 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 is connected to receive said calibration signal and said noninvasive sensor signal; wherein said processor includes a filter configured to separate from said noninvasive sensor signal a component representing said received exciter waveform; and wherein said processor is configured to determine said physiological parameter based at least in part on said calibration signal, said noninvasive sensor signal, and said relationship.
Claim 29
Dependent Claim
180 words
A monitor for determining a patient's blood pressure, comprising: an inflatable cuff positioned on an extremity of the patient and configured to provide a calibration signal representative of the patient's physiological parameter; an exciter positioned over a blood vessel of the patient and configured to induce a transmitted exciter waveform into the patient; a noninvasive sensor, positioned over said blood vessel and at a distance from said exciter, said noninvasive sensor 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 is connected to receive said calibration signal and said noninvasive sensor signal; wherein said processor includes a filter configured to separate from said noninvasive sensor signal a component representing said received exciter waveform; and wherein said processor is configured to determine said physiological parameter based at least in part on said calibration signal, said noninvasive sensor signal, and said relationship.
Claim 30
Dependent Claim
62 words
The monitor of claim 25, further comprising: an exciter sensor, positioned near said exciter and configured to sense said transmitted exciter waveform and generating an exciter sensor signal representative of said transmitted exciter waveform, and wherein said processor is further configured to compare the phase relationship of said transmitted exciter sensor signal and said received exciter waveform to determine said blood pressure.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-01-07 | 2000-07-08 | 2001-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-07 | 2004-07-08 | 2005-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-07 | 2008-07-08 | 2009-01-07 | $7700.00 | Window Closed / Lapsed |