Ultrasound said to offer better technique for measuring blood pressure
By Ben Coxworth
June 14, 2011
Not only is the old inflatable-cuff-around-the-arm an uncomfortable way of having one's blood pressure measured, but it turns out that it doesn't always provide enough information, either. If a physician wishes to check for vascular diseases such as atherosclerosis, thrombosis or aneurysms, for instance, they're going to want to know how the blood is flowing in areas besides the patient's arm. Because the cuff works by temporarily stopping the blood flow, however, it's not going to work too well on a patient's neck or torso. Fortunately, scientists from The Netherlands' Eindhoven University of Technology (TU/e) have discovered that ultrasound can be used instead, and that it provides more details.
Working with Italian medical imaging company Esaote, the TU/e researchers started their experiments using plastic tubes, worked their way up to carotid arteries from pigs, and are now performing trials on human subjects.
Using the new technique, blood pressure can be non-invasively measured at any point in the body. The skin in the area is first covered in gel, to maintain a good contact, and then the ultrasound scanner is applied. Utilizing sophisticated signal processing techniques, the system is able to visualize the blood flow and the blood vessel wall motion. By plugging that data into a mathematical model, the blood pressure at that exact location can be derived.
The technology also allows users to observe variations in blood pressure and flow, in time with the beating of the heart, which will provide information on what's going on "downstream" from that location.
Traditionally, if physicians which to measure the blood pressure in a specific part of the body, they have to insert a catheter equipped with a pressure sensor.
Although the initial trials of the ultrasound system have been promising, the researchers state that it will likely be several years before it is available for general use.
The research was recently published in the journal Ultrasound in Medicine and Biology.