Surgery – Diagnostic testing – Cardiovascular
Reexamination Certificate
1999-02-26
2001-01-09
O'Connor, Cary (Department: 3736)
Surgery
Diagnostic testing
Cardiovascular
C600S485000, C600S493000
Reexamination Certificate
active
06171254
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the real time monitoring of a patient's blood pressure and in particular to the taking of continuous automatic blood pressure readings.
2. Description of the Related Art
In working with a large number of different automatic blood pressure reading systems, it has been recognized that the deployment of the blood pressure cuff must be carefully considered in order to achieve accuracy in the blood pressure readings taken. It has been observed, for example, that the width of the blood pressure cuff (taken in the direction along the length of the patient's arm) must be maintained within certain ranges in order to prevent erroneous blood pressure readings.
Most of the blood pressure cuffs in use today take the form of a double-ended, elongated strip which is wrapped about as patient's limb with ends of the blood pressure cuff partly overlapping. As a minimal requirement, the amount of overlap must be sufficient to allow proper self-attachment of the strip ends so as to free an operator to perform other tasks, such as operating monitoring equipment. Recently, attention has been paid to the amount of overlap of the blood pressure cuff ends, with the appreciation that errors in overwrap, either too large or too small, even if satisfactory to allow blood pressure readings to be taken, result in an unwanted shift of those readings.
In addition to variations encountered in applying a blood pressure cuff to a patient's limb, a variation of blood pressure readings also arises from the fact that, as a practical matter, there are a relatively large number of different size cuffs by manufacturers of blood pressure reading equipment. For example, systems having nine or more differently sized blood pressure cuffs are not uncommon. Cuff sizes typically include a smallest size blood pressure cuff for neonatal patients and a largest blood pressure cuff size for adult thigh readings. Some blood pressure reading equipment requires the user to specify the cuff size by a special purpose input, such as a special, identifying switch or some other pre-defined selection means. Other systems require that special pneumatic fittings be employed to provide a self-identification of the size of the blood pressure cuff with which the fitting is associated. Accordingly, some type of keying system between the blood pressure cuff and the associated pneumatic circuitry is employed. The complexities in taking blood pressure readings is growing at a time when increasing demands are being made on care givers and other personnel charged with the responsibility of taking blood pressure readings. The need for an improved, automatic blood pressure reading system still exists.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a system and method for the automatic, continuous reading of blood pressure.
Another object of the present invention is to provide a system and method of the above-described type which are suitable for use with a plurality of differently sized blood pressure cuffs and which automatically adapt for the accurate use of such cuffs.
A further object of the present invention is to provide a system and method for the automatic reading of blood pressure in which blood pressure cuff size is automatically determined at the initial phase of a blood pressure reading, before the actual blood pressure reading commences, allowing for the calculation of several parameters important to the rapid, comfortable and safe reading of a patient's blood pressure.
These and other objects of the present invention are provided in an automatic, non-invasive blood pressure measuring device of the type which detects blood pressure pulses in a patient's appendage, comprising:
a cuff for constricting blood flow in the patient's appendage;
a pump connected to the cuff for inflation thereof in response to a pump control signal;
valve means connected to the cuff for deflation thereof in response to a valve control signal;
a pressure sensing means connected to the cuff to sense pressure in the cuff and to send a pressure signal in response thereto;
microprocessor means connected to said pump, said valve means and said pressure sensing means, including means to observe the initial pressure-time characteristics of said cuff during an observed inflation period in which the pressure of the cuff is increased to a level less than a target pressure needed to take a blood pressure reading; and
said microprocessor means including means for determining the cuff size by comparing the initial pressure-time characteristic of said cuff with stored pressure-time characteristics of cuffs of known sizes, and means for determining, in response to said cuff size determination, a cuff inflation rate, a cuff deflation rate and at least one deflation pressure drop step size, said microprocessor means sending control signals to said pump to inflate said cuff to said target pressure according to said cuff inflation rate, and to deflate said cuff at said deflation rate, using said at least one deflation pressure drop step.
REFERENCES:
patent: 3585987 (1971-06-01), Svensson
patent: 3699945 (1972-10-01), Hanafin
patent: 3744490 (1973-07-01), Fernandez
patent: 4109646 (1978-08-01), Keller
patent: 4116230 (1978-09-01), Gorelick
patent: 4501280 (1985-02-01), Hood, Jr.
patent: 4572205 (1986-02-01), Sjönell
patent: 4768518 (1988-09-01), Peltonen
patent: 4924873 (1990-05-01), Sorensen
patent: 4969466 (1990-11-01), Brooks
patent: 5003981 (1991-04-01), Kankkunen et al.
patent: 5022403 (1991-06-01), LaViola
patent: 5060654 (1991-10-01), Malkam{umlaut over (a)}ki et al.
patent: 5069219 (1991-12-01), Knoblich
patent: 5172697 (1992-12-01), Koven et al.
patent: 5240008 (1993-08-01), Newell
patent: 5243991 (1993-09-01), Marks
patent: 5301676 (1994-04-01), Rantala et al.
patent: 5447160 (1995-09-01), Kankkunen et al.
patent: 5746213 (1998-05-01), Marks
Carter Ryan
Fitch Even Tabin & Flannery
Medical Research Laboratories, Inc.
O'Connor Cary
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