Method for performing non-invasive blood pressure and pulse rate measurements
First Claim
1. A method for determining when a sufficiently high occluding pressure exists in the cuff of a blood pressure measuring instrument;
- said instrument including means for pumping up the cuff pressure in discrete steps, means for allowing air in said cuff to bleed out, and means for periodically sampling the instantaneous cuff pressure;
comprising the steps of;
(a) maintaining a relative peak pressure value and continuously up-dating it to equal a newly taken sample if the latter is larger,(b) maintaining a relative minimum pressure value and continuously up-dating it to equal a newly taken sample if the latter is smaller than the smallest sample previously taken subsequent to the last up-dating of said relative peak pressure value,(c) starting a time measure whenever said relative peak pressure value is up-dated,(d) determining the pressure rises which occur during said time measure, and(e) after said time measure has reached a predetermined length, determining that a sufficiently high occluding pressure exists if all of the pressure rises were less than a pre-set threshold value during said time measure.
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Accused Products
Abstract
There is disclosed a blood pressure measuring instrument which utilizes a standard cuff, a bulb for manually pumping up the cuff pressure, and a bleed hole which allows the cuff pressure to decrease at the rate of a few mm Hg per second. A single pressure transducer is in communication with the cuff interior and its output is sampled at a rate much higher than that of the blood pressure pulses. The sampled data, representing the occluding pressure which is being pumped up or bleeding down, with blood pressure pulses superimposed on it, are used to monitor the pump-up procedure and to determine when the artery is completely occluded, to analyze each blood pressure pulse for validating it and for measuring its amplitude, to determine systolic pressure only if the pulse amplitude sequence is a valid sequence, to determine diastolic pressure by comparing decreasing average pulse amplitudes with a threshold level dependent upon maximum pulse amplitude data, and to determine pulse rate in accordance with the number of pulses detected during a fixed time interval. A display circuit guides the operator as to the steps he must take in accordance with the present system state, and it displays both error messages and measurement values. The high reliability of the system is a consequence of the particular methodology employed during each processing step; the high sampling rate allows the system to follow instantaneous pressure changes, and the various analytical routines take full advantage of this capability.
9 Citations
20 Claims
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1. A method for determining when a sufficiently high occluding pressure exists in the cuff of a blood pressure measuring instrument;
- said instrument including means for pumping up the cuff pressure in discrete steps, means for allowing air in said cuff to bleed out, and means for periodically sampling the instantaneous cuff pressure;
comprising the steps of;(a) maintaining a relative peak pressure value and continuously up-dating it to equal a newly taken sample if the latter is larger, (b) maintaining a relative minimum pressure value and continuously up-dating it to equal a newly taken sample if the latter is smaller than the smallest sample previously taken subsequent to the last up-dating of said relative peak pressure value, (c) starting a time measure whenever said relative peak pressure value is up-dated, (d) determining the pressure rises which occur during said time measure, and (e) after said time measure has reached a predetermined length, determining that a sufficiently high occluding pressure exists if all of the pressure rises were less than a pre-set threshold value during said time measure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- said instrument including means for pumping up the cuff pressure in discrete steps, means for allowing air in said cuff to bleed out, and means for periodically sampling the instantaneous cuff pressure;
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13. A method for determining when a sufficiently high occluding pressure exists in the cuff of a blood pressure measuring instrument;
- said instrument including means for pumping up the cuff pressure, means for allowing air in said cuff to bleed out, and means for periodically sampling the instantaneous cuff pressure;
comprising the steps of;(a) maintaining a relative peak pressure value and continuously up-dating it in accordance with the value of a newly taken sample, (b) maintaining a relative minimum pressure value and continuously up-dating it in accordance with the value of a newly taken sample, (c) starting a time measure whenever said relative peak pressure value is up-dated, (d) determining the pressure rises which occur during said time measure, and (e) when said time measure reaches a predetermined length, determining that a sufficiently high occluding pressure exists if the maximum pressure rise during said time measure was less than a pre-set threshold value. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
- said instrument including means for pumping up the cuff pressure, means for allowing air in said cuff to bleed out, and means for periodically sampling the instantaneous cuff pressure;
Specification
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- Resources
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Current AssigneeQMI Medical, Inc. (Atrion Corporation)
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Original AssigneeMedtek Corporation
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InventorsCroslin, Michael E.
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Primary Examiner(s)Kamm, William E.
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Application NumberUS06/212,120Time in Patent Office588 DaysField of Search128/677, 128/680, 128/681, 128/682, 128/683US Class Current600/490CPC Class CodesA61B 2560/0223 of calibration, e.g. protoc...A61B 5/02225 using the oscillometric methodA61B 5/0235 Valves specially adapted th...
