A new stage in cuffless blood pressure monitoring has begun

A new study by scientists at Boston University (Massachusetts, USA) has opened up the prospect of revolutionary changes in approaches to the diagnosis and monitoring of blood pressure. For the first time, it has been proven that speckle contrast optical spectroscopy (SCOS) technology can be used for accurate, non-invasive, cuffless blood pressure measurement. This discovery could have great clinical significance, particularly for the early detection of high blood pressure, the monitoring of masked hypertension, and the management of patients with unstable hemodynamics.

SCOS is a method of analyzing scattered coherent light that passes through tissue and is reflected from blood cells, forming so-called speckle images. Changes in these images allow real-time assessment of blood flow characteristics. Previously, SCOS was used primarily to monitor cerebral blood flow or tissue perfusion, but new results indicate its potential in cardiology.

The study, published in Biomedical Optics Express, involved 30 volunteers who were simultaneously measured using a SCOS device attached to their wrist or finger and a control device for continuous blood pressure measurement. The participants were at rest and then performed physical exercise (leg press) to simulate changes in pressure. A machine learning model was developed to compare the obtained blood flow and blood filling parameters with actual blood pressure readings.

One of the most important clinical conclusions of the study was that the combination of blood flow and blood filling signals allowed systolic pressure to be predicted with high accuracy — the average error was only 2.26 mmHg, which significantly exceeds the results demonstrated by currently available photoplethysmographic (PPG) devices. In addition, it was found that the combined model improves measurement accuracy by 31% compared to PPG monitoring, which is particularly important for outpatient monitoring.

SCOS opens up new horizons in continuous, daily blood pressure monitoring, a key factor in the prevention of cardiovascular events. Today, the standard approach is based on one-time measurements in the clinic, which do not always reflect the real picture, especially in the case of hidden hypertension. Instead, the SCOS device potentially allows hundreds of measurements per day without discomfort for the patient.

Developers are already working on miniaturizing the device to transform it into a form that is comfortable for continuous wear. The next stages of research include testing during active movement, developing an internal data processing system, and verifying the stability of measurements during prolonged wear.