SPHYGMOMANOMETRIC METHOD AND APPARATUS

• US 3,552,381 A
• Filed: 05/23/1967
• Issued: 01/05/1971
• Est. Priority Date: 05/23/1967
• Status: Expired due to Term

• Current Assignee: Gordon K. Burns, Jeofry S. Courtney-Pratt
• Original Assignee: Gordon K. Burns, Jeofry S. Courtney-Pratt
• Inventors: Burns, Gordon K., Courtney-pratt, Jeofry S.
• Application Number:
  US04/640,628
• Time in Patent Office: 1,323 Days
• US Class Current: 600/496
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/02208 using the Korotkoff method
• CPC Class Codes: A61B 5/0225 the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence

Abstract

Diastolic blood pressure measurement by arterial auscultation is afforded by arresting flow as with a pressure cuff and then applying increasingly negative pressure probes to the cuff generally coincident with each phono- or electrocardiographically ascertained minimum of the heart'"'"''"'"'s pressure cycle, maintaining the negative wave amplitude always in excess of the pulse pressure. Cuff pressure at the onset of Korotkow sound signifies diastolic pressure level. Apparatus is described for unattended, automatic and continuous blood pressure monitoring using this method for diastolic readings. Cuff pressure in one embodiment is held constant as increasingly large negative pressure excursions are applied; in another embodiment cuff pressure is decreased while the negative pressure excursions are held constant in amplitude.

Claims

1. A method for determining diastolic blood pressure comprising the steps of:

arresting arterial flow with applied pressure;

coincident with the occurrences of pulse pressure minima, momentarily relieving the applied pressure by increasing amounts until the relieved applied pressure and the pulse pressure minima overlap sufficiently to permit spurts of arterial flow; and

concurrently with the onset of such spurts, measuring the relieved applied pressure as representing the desired diastolic pressure.

2. A method for determining diastolic blood pressure comprising the steps of:

arresting flow in a selected artery;

upon the occurrence of arterial pulse wave minima points only, progressively reducing the extent of arrest until the recommencement of arterial flow; and

reading the arterial pressure concurrently with the onset of said flow.

3. A method for determining diastolic blood pressure comprising the steps of:

subjecting a selected arterial point to an applied initial pressure above systolic;

subjecting said arterial point further to an increasingly negative-going pressure pulse applied only at minima of the arterial pulse wave, said negative pulse having an amplitude in excess of the arterial pulse amplitude; and

registering the onset of arterial flow following conjunction of an arterial pulse pressure minimum with the peak of a negative-going pressure pulse.

4. A method for the measurement of blood pressure comprising the steps of:

applying an initial pressure in excess of systolic to a selected artery through an inflatable cuff;

applying to said artery through said cuff a series of narrow negative-going pressure pulses each centered in time at one of a plurality of successive minimum points of the arterial pulse wave;

causing the peaks of said negative-going pulses to approach and then intercept successive minimum points by varying the applied cuFf pressure;

detecting the onset of arterial spurts following said interception; and

, concurrently, reading the instantaneous cuff pressure as representing a measure of diastolic pressure.

5. A method in accordance with claim 4 wherein said negative-going pressure pulses are substantially constant in amplitude, and wherein the cuff pressure is varied by bleeding the cuff.

6. A method in accordance with claim 4 wherein said cuff pressure variation is effected by progressively increasing the amplitude of said negative-going pressure pulses while otherwise maintaining said cuff pressure in excess of systolic.

7. Apparatus for measuring blood pressure comprising:

a pressure member for the application of controlled constricting force to an artery;

a pressure monitor for registering the pressure applied by said member to said artery;

means for registering the occurrence of successive minima points of the arterial pulse pressure wave;

means for applying to said member an initial pressure in excess of systolic to fully constrict said artery;

means for further applying to said member a succession of narrow, increasingly negative-going pressure pulses, each centered in time at successive ones of said arterial pulse wave minimum points, in response to said registration thereof;

means for detecting the onset of arterial flow following the abrupt momentary penetration of one of said negative-going pulses through a minimum point of said arterial pulse wave; and

means responsive to said arterial flow onset detection for recording the instantaneous pressure registered by said pressure monitor, said recording being a measure of the diastolic pressure.

8. Apparatus for determining diastolic blood pressure comprising:

first means for applying pressure to a selected artery sufficient to arrest flow;

second means for registering the occurence of minimum points of the arterial pulse pressure wave;

third means responsive to each successive said registration for reducing the pressure applied by said first means, said reduction being in increasingly greater amounts causing said arresting pressure to approach, and finally to equal, the value of said diastolic pressure as indicated by the onset of arterial spurts; and

fourth means for indicating the arterial pressure concurrently with the onset of said spurts.

9. Apparatus in accordance with claim 8 wherein said second means comprises:

means for monitoring the cardiac cycle events and for deriving therefrom a recurrent timing pulse in rhythm with the arterial pulse;

means for synchronizing the occurrence of said timing pulses with successive minima of the arterial pulse; and

means for transmitting said timing pulses to said third means.

10. Apparatus in accordance with claim 9 wherein said first means comprises an inflatable arm cuff and wherein said fourth means comprises a pressure-indicating device connected thereto.