US3905354A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blood pressure measuring system
Assignee: Medical Monitors Inc
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Filing: 1974-02-19
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Granted: 1975-09-16
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Expires: 1994-02-19
Abstract
Abstract The blood pressure measuring system includes the generation of output signals by correlation of pressure pulses detected in a fluid system used to close off the blood flow, with acoustic pulses detected downstream near the blood flow close-off point in a patient''s arm or other portion of his body. Correlating the pressure pulses with the acoustic pulses and generating output signals only when there is a coincidence between the pressure and acoustic pulses minimizes the effect of spurious signals and artifacts to the end that a more accurate systolic and diastolic blood pressure reading may be provided. In this respect, the systolic pressure is indicated at the point in time that the output signals start and the diastolic pressure is indicated at the point in time that the output signals terminate.
Inventors
- 👤 Abraham Lichowsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:44
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/021; A61B5/022; A61B5/02208; A61B5/02141; A61B7/00; A61B7/02; A61B7/04; A61B7/045; A61B5/72; A61B5/7235; A61B5/7239
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
158 words
A method of automatically measuring a patient''s systolic and diastolic blood pressure comprising the steps of: a. applying pressure to close off blood flow to a portion of the patient; b. detecting pressure pulses corresponding to the patient''s heartbeat; c. decreasing the applied pressure gradually; d. generating quantized pressure signals in response to said pressure pulses to provide individually defined pressure signals of uniform amplitude; e. detecting acoustic pulses in said portion of the patient as the applied pressure is being decreased; f. generating quantized signals in response to saiD acoustic pulses to provide individually defined acoustic signals of uniform amplitude; g. correlating said pressure signals and acoustic signals to provide an output signal only when a pressure signal occurs simultaneously with an acoustic signal; and, h. utilizing said output signals to provide indications of pressure being applied at the start and termination of the output signals, whereby the patient''s systolic and diastolic blood pressures are respectively measured.
Claim 2
Independent Claim
158 words
A method of automatically measuring a patient''s systolic and diastolic blood pressure comprising the steps of: a. applying pressure to close off blood flow to a portion of the patient; b. detecting pressure pulses corresponding to the patient''s heartbeat; c. decreasing the applied pressure gradually; d. generating quantized pressure signals in response to said pressure pulses to provide individually defined pressure signals of uniform amplitude; e. detecting acoustic pulses in said portion of the patient as the applied pressure is being decreased; f. generating quantized signals in response to saiD acoustic pulses to provide individually defined acoustic signals of uniform amplitude; g. correlating said pressure signals and acoustic signals to provide an output signal only when a pressure signal occurs simultaneously with an acoustic signal; and, h. utilizing said output signals to provide indications of pressure being applied at the start and termination of the output signals, whereby the patient''s systolic and diastolic blood pressures are respectively measured.
Claim 3
Dependent Claim
80 words
The method of claim 1, in which said pressure is applied at a given rate over a given range and thence held for a given time interval and thence again applied at said given rate over a second given range and held for said given time interval, the application and holding being repeated until there is an absence of said output signals detected during any two successive time intervals, said step of decreasing the applied pressure gradually then being initiated.
Claim 4
Independent Claim
214 words
A system for automatically measuring the systolic and diastolic blood pressures of a patient, comprising, in combination: a. means for applying pressure to close off blood flow to a portion of the patient''s circulatory system; b. means responsive to the patient''s heartbeat to detect pressure pulses in substantial synchronism with said heatbeat; c. means connected to said means for applying pressure for gradually decreasing the applied pressure; d. pressure transducer means connected to said means for gradually decreasing the applied pressure to provide an analog pressure signal of the pressure; e. means responsive to pulses in the downstream side of the close-off pressure point in the patient''s circulatory system to detect acoustic pulses; f. filtering and threshold detecting means for respectively filtering and detecting said pressure and acoustic pulses and respectively providing quantized individually defined electrical pressure and acoustic signals; g. coincidence circuit means receiving said pressure and acoustic signals and providing an output signal only upon coincidence of a pressure signal and an acoustic signal; and h. measuring means connected to receive the output signals and responsive to said analog pressure signal to provide indications of the pressure detected by said pressure transducer means at the start and termination of said output signals, whereby the systolic and diastolic blood pressures are automatically measured.
Claim 5
Independent Claim
214 words
A system for automatically measuring the systolic and diastolic blood pressures of a patient, comprising, in combination: a. means for applying pressure to close off blood flow to a portion of the patient''s circulatory system; b. means responsive to the patient''s heartbeat to detect pressure pulses in substantial synchronism with said heatbeat; c. means connected to said means for applying pressure for gradually decreasing the applied pressure; d. pressure transducer means connected to said means for gradually decreasing the applied pressure to provide an analog pressure signal of the pressure; e. means responsive to pulses in the downstream side of the close-off pressure point in the patient''s circulatory system to detect acoustic pulses; f. filtering and threshold detecting means for respectively filtering and detecting said pressure and acoustic pulses and respectively providing quantized individually defined electrical pressure and acoustic signals; g. coincidence circuit means receiving said pressure and acoustic signals and providing an output signal only upon coincidence of a pressure signal and an acoustic signal; and h. measuring means connected to receive the output signals and responsive to said analog pressure signal to provide indications of the pressure detected by said pressure transducer means at the start and termination of said output signals, whereby the systolic and diastolic blood pressures are automatically measured.
Claim 6
Dependent Claim
184 words
A system according to claim 3, in which said means for applying pressure includes a flexible fluid chamber arranged to surround said portion of the patient and having an inlet fluid line and associated inlet control valve, said means for gradually decreasing the applied pressure including an outlet fluid line from said chamber and associated outlet control valve, said means responsive to the patient''s heartbeat to detect pressure pulses including a differentiating circuit receiving said analog pressure signal and providing said pressure pulses in response to pressure fluctuations in said analog pressure signal; an analog-to-digital converter responsive to said analog pressure signal to generate digital coded signals indicative of the pressure, said coded signals being applied to and stored in said measuring means; and a logic control circuit connected to said inlet and outlet control valves and connected to receive said coded signals and said output signals whereby automatic proportional opening and closing of the valves is controlled by the coded and output signals in accord with a programmed application of pressure and gradual decreasing of pressure to be provided in said fluid chamber.
Claim 7
Dependent Claim
73 words
A system according to claim 4, in which said means responsive to pulses downstream of the close-off pressure point includes an acoustical conduit with one end in physical contact with said portion of the patient and its other end terminating in a microphone for receiving sound in said conduit and converting the sound into said acoustic pulses, tHere being provided insulation material around said microphone to shield it from ambient noise and vibration.
Claim 8
Dependent Claim
25 words
A system according to claim 4, in which said measuring means includes means providing a visual digital display of the systolic and diastolic blood pressures.
Claim 9
Dependent Claim
22 words
A system according to claim 4, in which said measuring means includes means for automatically recording said systolic and diastolic blood pressures.
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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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |