Monitor offers more accurate blood-pressure readings

Scientists have unveiled a new, more accurate blood-pressure monitor that calculates the flow close to the heart.

The wrist-mounted device, developed at Leicester University, uses computer modelling to convert readings taken at the arm to a measurement of blood pressure in the aorta, the body’s main artery.

Doctors hope the technology will better identify patients with high central aortic systolic pressure (CASP) because readings at the wrist can be significantly different from those at the heart, especially for young people.

Being able to measure blood pressure in the aorta is also important because it is closer to the heart and brain where hypertension can cause damage.

‘It is difficult to argue against the proposition that the pressure near to your heart and brain is likely to be more relevant to your risk of stroke and heart disease than the pressure in your arm,’ said research team leader Prof Bryan Williams.

‘It is not going to replace what we do overnight, but it is a big advance. Further work will define whether such measurements are preferred for everybody or whether there is a more defined role in selective cases to better decide who needs treatment.’

The blood pressure in large vessels close to the heart is lower than in the arm because of the amplification of the pressure wave as it moves away from the heart.

This amplification can change with ageing, blood-vessel disease and medication, meaning that routine measurements of blood pressure at the arm are not a good predictor of the pressure near the heart.

The amplification is also greater in younger people with healthy arteries, meaning some people can appear to have high blood pressure based on readings at the arm, when their aortic pressure is normal.

The new device records a pulse wave and measures the blood pressure at the wrist at the same time and then uses mathematical modelling to filter out the amplified portion of the pulse wave to reveal the CASP.

The Leicester team collaborated with Singapore-based medical technology company HealthSTATS International, which developed a simple wrist-strap device that uses a skin contact sensor to record the pulse wave.

Combined with a traditional blood-pressure monitoring cuff, the device then calculates the CASP within a few minutes.

Dr Choon Meng Ting, chairman and chief executive officer of HealthSTATS, said: ’It will empower doctors and their patients to monitor their central aortic systolic pressure easily, even in their homes, and modify the course of treatment for blood-pressure-related ailments.

‘Pharmaceutical companies can also use CASP devices for clinical trials and drug therapy. All these will ultimately bring about more cost savings for patients, reduce the incidences of stroke and heart attacks and save more lives.’

The government’s National Institute for Health Research (NIHR) invested £3.4m in the project, while the Department of Health provided £2.2m capital funding to establish a Biomedical Research Unit at Glenfield Hospital in Leicester.