Blood pressure monitor

Abstract

The present invention relates to an apparatus and method for facilitating blood pressure measurement. An additional fluid reservoir is arranged to be connected in fluid communication with the blood pressure cuff. The fluid reservoir provides an additional, compliant volume to the fluid volume of the cuff, facilitating blood pressure measurement, particularly for small volume cuffs.

Description

FIELD OF THE INVENTION[0001]The present invention relates to the measurement of pressure and, more particularly, but not exclusively, to a method, system and apparatus for measuring systemic arterial blood pressure.BACKGROUND OF THE INVENTION[0002]Blood pressure is an important measurement in both veterinary and human medicine. For example, a frequent determination of blood pressure is routine during anaesthesia. It is also routine to measure blood pressure to obtain an indication of the general health of a patient.[0003]Non-invasive measurement of arterial blood pressure is almost always carried out utilising a distensible cuff or a distensible bladder enclosed in an unyielding cuff. The cuff is placed around a limb or extremity of a patient, and is then inflated until blood flow through an underlying blood vessel (usually an artery) is occluded.[0004]The cuff is then deflated in a controlled manner and measurements taken to detect occurrence of blood flow through the vessel. The m...

AI Technical Summary

Benefits of technology

[0009]In accordance with a first aspect, the present invention provides an apparatus for facilitating blood pressure measurement, including a fluid reservoir arranged to be connected in fluid communication with a blood pressure cuff, the fluid reservoir being arranged to provide an additional fluid volume to the fluid volume of the cuff during measurement of blood pressure of a patient.

[0011]In an embodiment, the use of the fluid reservoir advantageously results in the blood pressure measurement being less prone to error than without use of the fluid reservoir. It is particularly advantageous when blood pressure of a small human or animal patient is being measured. In an embodiment, by utilising the fluid reservoir, the effective volume of a small cuff may be significantly increased, thereby resulting in a slower drop in pressure once the bleed valve is opened, allowing for more accurate point readings for systolic or diastolic pressure to be taken and repeatedly detected.

[0012]In an embodiment the fluid reservoir has a compliance, and in an embodiment the compliance is sufficient such that oscillations of pressure from the blood pressure cuff are not significantly damped by the fluid reservoir.

[0018]In an embodiment, a further advantage of the provision of the fluid reservoir is improvement of accuracy by reducing motion artefacts in the detected pressure. With smaller cuffs, in particular, a sensitive pressure transducer is required for blood pressure measurement—motion artefacts may easily be mistaken for systole. By adding the additional fluid volume, motion artefacts are dampened plus the need for sensitive pressure measurement devices may be avoided.

[0024]In an embodiment, the additional fluid volume has a compliance. In an embodiment, the compliance is sufficient such that oscillations of pressure from the blood pressure cuff are not significantly damped.

[0027]Embodiments of the present invention may be utilised for other applications than systemic arterial blood pressure measurement. Embodiments of the invention are particularly useful for measuring pressure where small pressure changes are involved in small volume situations. This is because embodiments of the present invention operate to increase the relative volume of the system, and therefore increase accuracy of the pressure measurement.

Problems solved by technology

As the size of the limb or extremity becomes smaller, however, and as a smaller cuff must be used in these cases, accuracy of measurement is more difficult to achieve and variations between the size of patients for a particularly small cuff size have much more of a pronounced effect on measurement accuracy.

For infants and small animals, for example, measurement errors can be so significant as to render any blood pressure reading so inaccurate as to be useless.

Further, use of a smaller volume cuff will lead to more errors, regardless of variations between limb size.

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