Cuffs errors in blood pressure may lose 30 % of high blood pressure

High blood pressure, or high blood pressure, is the highest factor of early death, associated with heart disease, strokes and heart attacks. However, the inaccuracy in the most common form of measuring blood pressure means that up to 30 % of high blood pressure can be missed.

The researchers, from the University of Cambridge, built a clearer experimental model behind this inaccuracy and provided a better understanding of the cuff -based blood pressure mechanics.

The researchers say that some direct changes, which do not necessarily include replacement of the standard stand -based standard, can lead to more accurate readings of blood pressure and better results for patients. Its results were reported in the magazine PNAS Nexus.

Anyone who might have blood pressure will be aware of the cuff -based way. This type of measurement, also known as the tropical method, depends on inflating a slap around the upper arm to the point where the blood flow is cut into the lower arm, then the doctor listens to take advantage of the sounds in the arm through the doctor’s headset while the cuff is slowly cleaned.

Blood pressure is deduced from readings taken from a pressure scale connected to the collapsed. Blood pressure is given as two separate numbers: the maximum (systolic) and minimal pressure (diastolic). Reading blood pressure from 120/80 is “perfect”.

“The expansion method is the golden standard, but it exaggerates the estimation of diastolic pressure, while the systolic pressure has been reduced,” said Kate Bassil, the author participating from the Cambridge Ministry of Engineering. “We have a good understanding of the reason for the exaggeration in the estimation of diastolic pressure, but why the systolic pressure is reduced to some mystery.”

“Every doctor knows largely that blood pressure readings are sometimes wrong, but no one can explain the reason for underestimating it-there is a real gap in understanding,” said Professor Anurag Agarawal, the co-author, from the Cambridge Ministry of Engineering.

Previous non -clinical studies were used in inaccuracy of the measurement of rubber tubes that did not completely repeat how the arteries collapsed under the pressure of the cuff, causing the effect of the reduction.

The researchers built a simplified physical model for the insulation and study of the effects of blood pressure – blood pressure in the arm part at the bottom of the cuff. When the cuff and blood flow are amplified to the lower arm, it creates very low pressure. By cloning this condition on the experimental platform, they decided that this pressure difference causes the artery to remain closed for a longer period during the deviation of the cuff, which delays its reopening and leads to reducing blood pressure.

This physical mechanism – delayed reopening due to low power pressure – is the potential cause of the revolution, and it is an unspecified factor. “We are not currently modifying this error when diagnosing or describing treatments, which they can lead to up to 30 % of systolic high blood pressure cases that are missed,” Basil said.

Instead of the rubber tubes used in the previous physical models of the arteries, Cambridge researchers used flat tubes when they are completely deviated and closed when the pressure of the cuff is amplified, which is the main state of the low power pressure that was observed in the body.

The researchers say that there is a set of possible solutions to this reduction, which includes raising the arm before the measurement, and may produce a predictable pressure in the direction of the estuary, and thus reduce the meaning. This change does not require new devices, but rather a modified protocol.

“You may not even need new devices, just changing how to make the measurement can make them more accurate,” said Aguardo.

However, if new blood pressure monitoring devices are developed, additional inputs may be related to the estuary pressure, to adjust what “perfect” readings may be for each individual. These may include age properties, body mass index, or tissues.

The researchers hope to secure funding for clinical trials to test the results they reached in patients, and are looking for industrial partners or research to help improve their calibration models and verify the validity of the influence in the diverse population. Cooperation with doctors will also be necessary to implement changes in clinical practice.

The research has been supported by the EPSRC, a part of the United Kingdom’s research and innovation (UKRI).