US4011860A
Expired / Lapsed
US
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Calibrated blood pressure measuring system and method
Assignee: FILAC CORP
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Filing: 1975-10-20
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Granted: 1977-03-15
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Expires: 1995-10-20
Abstract
Abstract Blood pressure measuring system and method in which the pressure transducer connected to an occluding cuff is isolated from the pressure source provided for inflating the cuff and a reference pressure is maintained in the transducer during a calibration cycle at the outset of a blood pressure measurement. During the calibration cycle, the level of the output signal provided by the transducer is adjusted until a reference level is reached, and thereafter the transducer is reconnected to the pressure source for the blood pressure measurement.
Inventors
- 👤 John J. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:50
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/021; A61B5/022
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
170 words
In a blood pressure measuring system of the type having an inflatable cuff for occluding the flow of blood in a portion of the circulatory system of a patient, a pressure source connected to the cuff for delivering air to the cuff to inflate the same, and transducer means connected to the cuff for delivering an output signal corresponding to the pressure in the cuff, the improvement comprising: valve means connected between the cuff and the transducer means for controlling communication between the cuff and the transducer means, means for conditioning the valve means to disconnect the transducer means from the cuff at the outset of a blood pressure measurement, a reference signal source, means for changing the level of the output signal to calibrate the system at the outset of the measurement, and means for comparing the output signal with the reference signal and conditioning the valve means to reconnect the transducer means to the cuff when the output signal reaches a predetermined level relative to the reference signal.
Claim 2
Dependent Claim
170 words
In a blood pressure measuring system of the type having an inflatable cuff for occluding the flow of blood in a portion of the circulatory system of a patient, a pressure source connected to the cuff for delivering air to the cuff to inflate the same, and transducer means connected to the cuff for delivering an output signal corresponding to the pressure in the cuff, the improvement comprising: valve means connected between the cuff and the transducer means for controlling communication between the cuff and the transducer means, means for conditioning the valve means to disconnect the transducer means from the cuff at the outset of a blood pressure measurement, a reference signal source, means for changing the level of the output signal to calibrate the system at the outset of the measurement, and means for comparing the output signal with the reference signal and conditioning the valve means to reconnect the transducer means to the cuff when the output signal reaches a predetermined level relative to the reference signal.
Claim 3
Dependent Claim
41 words
The blood pressure measuring system of claim 1 wherein the valve means comprises a solenoid operated valve having a first port connected to the cuff, a second port vented to the atmosphere, and a third port connected to the transducer means.
Claim 4
Dependent Claim
35 words
The blood pressure measuring system of claim 1 wherein the means for changing the level of the output signal comprises a calibration signal source and means for adding the calibration signal to the output signal.
Claim 5
Dependent Claim
82 words
The blood pressure measuring system of claim 3 wherein the calibration signal source comprises a source of clock pulses, digital-to-analog converter means responsive to the clock pulses for providing an analog calibration signal corresponding to the number of pulses applied thereto, and gate means for passing pulses from the clock source to the converter means until the output signal reaches the predetermined level and thereafter inhibiting the passage of pulses whereby the calibration signal remains at a constant level during the measurement.
Claim 6
Dependent Claim
40 words
The blood pressure measuring apparatus of claim 1 further including means for applying a control signal to the means for conditioning the valve means and to the means for changing the level of the output signal to initiate the measurement.
Claim 7
Dependent Claim
38 words
The blood pressure measuring system of claim 5 further including means for delivering a reset signal and timing means responsive to the reset signal for delivering the control signal a predetermined time after delivery of the reset signal.
Claim 8
Dependent Claim
138 words
In a method for calibrating a blood pressure measuring system comprising an inflatable cuff for occluding the flow of blood in a portion of the circulatory system of a patient, a pressure source connected to the cuff for delivering air to the cuff to inflate the same, and a transducer connected to the cuff for delivering an output signal corresponding to the air pressure in the cuff, the steps of: disconnecting the transducer from the cuff and establishing a reference pressure in the transducer at the outset of a blood pressure measurement, comparing the output signal with a reference signal, adjusting the level of the output signal in discrete increments until the output signal reaches a predetermined level relative to the reference signal, and reconnecting the transducer to the cuff when the output signal reaches the predetermined level.
Claim 9
Dependent Claim
138 words
In a method for calibrating a blood pressure measuring system comprising an inflatable cuff for occluding the flow of blood in a portion of the circulatory system of a patient, a pressure source connected to the cuff for delivering air to the cuff to inflate the same, and a transducer connected to the cuff for delivering an output signal corresponding to the air pressure in the cuff, the steps of: disconnecting the transducer from the cuff and establishing a reference pressure in the transducer at the outset of a blood pressure measurement, comparing the output signal with a reference signal, adjusting the level of the output signal in discrete increments until the output signal reaches a predetermined level relative to the reference signal, and reconnecting the transducer to the cuff when the output signal reaches the predetermined level.
Claim 10
Dependent Claim
58 words
The method of claim 7 wherein the level of the output signal is adjusted by providing clock pulses at a predetermined rate, applying the clock pulses to a digital-to-analog converter, adding the output of the converter to the output signal, and inhibiting passage of further clock pulses to the converter when the output signal reaches the predetermined level.
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) | 1980-03-14 | 1980-09-13 | 1981-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-14 | 1984-09-13 | 1985-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-14 | 1988-09-13 | 1989-03-15 | $7700.00 | Window Closed / Lapsed |