A wearable ultrasound patch could soon be saving lives, by monitoring the blood flow in hospital patients' brains. The device is only about the size of a postage stamp plus it works continuously, unlike traditional methods.
Currently, in order to check the cerebral blood flow of patients such as those recovering from strokes, a technician holds an ultrasound probe against the side of the person's head. According to scientists from the University of California San Diego, there are two drawbacks to this approach.
For one thing, the accuracy of readings obtained in this manner varies according to the skill of each technician. For another, the readings are typically taken at spaced intervals throughout the day. This means that any variations in blood flow which take place between those times aren't detected. That's where the UC San Diego patch is designed to come in.
The stretchy, flexible, silicone-bodied device stays adhered to one of the patient's temples throughout their stay at the hospital. During that time, it continuously monitors and records the blood flow in their brain.
The patch incorporates multiple layers of stretchable electronics, including layers of copper electrodes and piezoelectric transducers. When stimulated by an electrical current, the transducers produce 2-megahertz ultrasound waves that travel into the brain and get reflected back by the major arteries.
Utilizing an ultrafast ultrasound imaging system, a hard-wired computer analyzes the ultrasound echoes to produce a real-time 3D digital model of the arteries, showing their current volume, angle and position. In lab tests performed on 36 healthy volunteers, the technology was able to measure peak systolic, mean flow and end diastolic blood flow velocities as accurately as a traditional handheld ultrasound probe.
Clinical trials on actual patients with neurological conditions are now being planned, along with a self-contained wireless version of the patch. The technology is being commercialized via spinoff company Softsonics.
A paper on the research, which was led by Prof. Sheng Xu, was recently published in the journal Nature.
Source: UC San Diego
