US3893452A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blood pressure monitoring system
Assignee: Medtronic Inc
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Filing: 1974-07-09
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Granted: 1975-07-08
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Expires: 1994-07-09
Abstract
Abstract A blood pressure monitoring system is disclosed as comprising a pressure transducer coupled as by a catheter inserted into the blood vessels of a patient whose blood pressure is to be measured, for providing an output signal indicative of the patient''s blood pressure, a filter for removing undesired highfrequency components imposed upon the transducer output, a maximum peak detector, a minimum peak detector and a mean detector for providing outputs indicative respectively of the systolic blood pressure, the diastolic blood pressure and the mean blood pressure of the patient. Depending upon the desired indication, the output of one of the aforementioned detectors is coupled by a switch to an oscillator the frequency of whose output is dependent upon the level of the input signal. The output of the oscillator is gated for a fixed period of sufficient length to provide an accurate measurement of the highest blood pressure of interest; in particular, a free-running clock circuit provides a gating signal of such a period enabling a gate to pass the oscillator output to a counter. The counter receives and counts the number of gated pulse to provide an indication of the blood pressure to be measured, which indication is displayed as upon a digital display. The free-running clock circuit further provides clock or latch signals to transfer the count indication from the counter to the display and to reset the maximum and minimum peak detectors; the period of such latch signals is sufficient to permit at least one pulse of lowest pulse rate of interest to be sampled by the peak detectors.
Inventors
- 👤 Michael R Birnbaum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 17:41
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/021; A61B5/0215
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
336 words
A system for monitoring the blood pressure of a patient, said system comprising: a. transducer means adapted to be coupled to the arterial system of the patient for providing an output indicative of the patient''s blood pressure; b. detector means for sampling the output of said transducer means to detect and to store the maximum and minimum magnitudes of the transducer means output within a predetermined period and to provide first and second outputs indicative thereof, said detector means responsive to a reset signal to remove the stored magnitudes in preparation for sampling the next portion of said transducer means output; c. oscillatoR means responsive to one of the first and second outputs of said detector means for providing a train of pulses whose frequency is dependent upon the magnitude of the one output of said detector means; d. gate means for selectively gating the train of pulses derived from said oscillator means therethrough in response to a gating pulse signal; e. counter means responsive to the gated train of pulses for providing an output indicative of the number of the train of pulses applied thereto; f. display means for receiving the output of said counter to provide a display thereof; and g. free-running clock means for providing and applying a latch signal of the predetermined period to said counter means to transfer the output of said counter means to said display means, the predetermined period being set in accordance with the lowest pulse beat of the patient to be monitored by said system, and for providing and applying the gating pulse signal of the predetermined period to said gate means to gate the passage of the oscillator means output to said counter means, the pulsewidth of the gating pulse signal being sufficient to permit said oscillator means to generate a number of pulses corresponding to the highest blood pressure of interest, the periodic latch signal also being applied to said detector means whereby the stored minimum and maximum magntidues are removed from said detector means.
Claim 2
Independent Claim
336 words
A system for monitoring the blood pressure of a patient, said system comprising: a. transducer means adapted to be coupled to the arterial system of the patient for providing an output indicative of the patient''s blood pressure; b. detector means for sampling the output of said transducer means to detect and to store the maximum and minimum magnitudes of the transducer means output within a predetermined period and to provide first and second outputs indicative thereof, said detector means responsive to a reset signal to remove the stored magnitudes in preparation for sampling the next portion of said transducer means output; c. oscillatoR means responsive to one of the first and second outputs of said detector means for providing a train of pulses whose frequency is dependent upon the magnitude of the one output of said detector means; d. gate means for selectively gating the train of pulses derived from said oscillator means therethrough in response to a gating pulse signal; e. counter means responsive to the gated train of pulses for providing an output indicative of the number of the train of pulses applied thereto; f. display means for receiving the output of said counter to provide a display thereof; and g. free-running clock means for providing and applying a latch signal of the predetermined period to said counter means to transfer the output of said counter means to said display means, the predetermined period being set in accordance with the lowest pulse beat of the patient to be monitored by said system, and for providing and applying the gating pulse signal of the predetermined period to said gate means to gate the passage of the oscillator means output to said counter means, the pulsewidth of the gating pulse signal being sufficient to permit said oscillator means to generate a number of pulses corresponding to the highest blood pressure of interest, the periodic latch signal also being applied to said detector means whereby the stored minimum and maximum magntidues are removed from said detector means.
Claim 3
Dependent Claim
28 words
A system as claimed in claim 1, wherein there is further included filter means for removing the undesired high frequency components from the output of said transducer means.
Claim 4
Dependent Claim
40 words
The system as claimed in claim 2, wherein said filter means effects the filtering of the high frequency components corresponding to those frequency components above a selected harmonic of the highest pulse beat rate to be monitored by said system.
Claim 5
Dependent Claim
63 words
The system as claimed in claim 1, wherein there is further included mean detector means responsive to the output of said transducer means to provide an indication of the mean blood pressure of the patient, and switch means disposable to one of three positions for selectively applying one of the first and second outputs and said mean detector output to said oscillator means.
Claim 6
Dependent Claim
47 words
The system as claimed in claim 1, wherein said clock means provides and applies a periodic latch signal to said counter means to transfer the information stored on said counter means to said display means after the application of the gating pulse signal to said gate means.
Claim 7
Dependent Claim
42 words
The system as claimed in claim 1, wherein there is included alarm means responsive to the first and second outputs of said detector means for providing alarms when the blood pressure of the patient exceeds and is less than pre-selected levels, respectively.
Claim 8
Dependent Claim
40 words
The system as claimed in claim 6, wherein said alarm means includes differentiating means for differentiating the first and second outputs whereby said alarm means provides alarms when the first and second outputs change at rates greater than pre-selected rates.
Claim 9
Independent Claim
264 words
A system for monitoring the blood pressure of a patient, said system comprising: a. transducer means adapted to be coupled to the arterial system of the patient for providing an output indicative of the patient''s blood pressure; b. detector means responsive to the output of said transducer for providing first and second outputs indicative respectively of the maximum and minimum magnitudes of said transducer means output, said detector means comprising means for detecting the occurrences of the minimum and maximum values of said transducer means output; c. first memory means responsive to the occurrences of the maximum values for sampling and storing the corresponding value of the patient''s systolic blood pressure; d. second memory means responsive to the occurrences of the minimum values of the blood pressure for sampling and storing signals indicative of the patient''s diastolic blood pressure; e. oscillator means responsive to one of the stored values within said first and second memory means for providing a train of pulses whose frequency is dependent upon the magnitude of the one stored value; f. gate means for selectively gating the train of pulses derived from said oscillator means therethrough in response to a gating signal; g. counter means responsive to the gated train of pulses for providing an output indicative of the number of the train of pulses applied thereto; h. display means for receiving the output of said counter to provide a display thereof; and i. clock means for providing and applying a periodic latch signal to said counter means to transfer the output of said counter means to said display means.
Claim 10
Independent Claim
264 words
A system for monitoring the blood pressure of a patient, said system comprising: a. transducer means adapted to be coupled to the arterial system of the patient for providing an output indicative of the patient''s blood pressure; b. detector means responsive to the output of said transducer for providing first and second outputs indicative respectively of the maximum and minimum magnitudes of said transducer means output, said detector means comprising means for detecting the occurrences of the minimum and maximum values of said transducer means output; c. first memory means responsive to the occurrences of the maximum values for sampling and storing the corresponding value of the patient''s systolic blood pressure; d. second memory means responsive to the occurrences of the minimum values of the blood pressure for sampling and storing signals indicative of the patient''s diastolic blood pressure; e. oscillator means responsive to one of the stored values within said first and second memory means for providing a train of pulses whose frequency is dependent upon the magnitude of the one stored value; f. gate means for selectively gating the train of pulses derived from said oscillator means therethrough in response to a gating signal; g. counter means responsive to the gated train of pulses for providing an output indicative of the number of the train of pulses applied thereto; h. display means for receiving the output of said counter to provide a display thereof; and i. clock means for providing and applying a periodic latch signal to said counter means to transfer the output of said counter means to said display means.
Claim 11
Dependent Claim
38 words
The system as claimed in claim 8, wherein said clock means is responsive to the occurrence of a maximum or minimum value of the blood pressure for providing and applying the gate pulse signal to said gate means.
Claim 12
Dependent Claim
54 words
The system as claimed in claim 9, wherein said clock means further includes a free-running clock circuit for providing the periodic latch signal, and a first gate circuit responsive to the occurrences of a maximum or minimum value of the blood pressure for inhibiting the passage of the latch signals to said counter means.
Claim 13
Dependent Claim
22 words
The system as claimed in claim 1, wherein said display means displays the output of said counter means in a digital fashion.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |