Pain-free ultrasonic device measures brain pressure

Scientists in Lithuania say they have developed a way to accurately and safely measure brain pressure without risky invasive surgery.

Professor Arminas Ragauskas of Kaulas University of Technology led the team developing the Vittamed device, which measures the difference between the pressure inside and outside the skull using ultrasound scanners.

"The device consists of just three parts: first of all it is ultrasonic Doppler blood flow meter, which measures blood flow in ophthalmic artery and of course computer and some mechanical parts to fix ultrasonic transducer on to the face of the patient. It works like a pair of scales: we are comparing intracranial pressure with externally applied pressure to the tissue surrounding the eyeball and ultrasonic Doppler device is used as indicator of the pressure balance," he told Reuters.

A small amount of pressure is put on the eye to match the blood pressure in the central retinal artery located just behind the eye, which leads to the brain. The device compares the external pressure with the pressure in the artery, known as the autonomous intracranial pressure.

Raised intracranial pressure is associated with traumatic brain injuries and central nervous system tumours.

In a healthy adult, the figure is usually in the range of 0 to 10 millimetres of mercury (mmHg). An abnormal reading is greater than 20 mmHg, while intracranial pressure greater than 40 mmHg is almost always associated with neurological dysfunction. Readings above 60 mmHg tend to be fatal.

Ragauskas said the principle behind the device is similar to that of the inflated arm band used to measure blood pressure, and the technology takes its cue from Doppler ultrasound devices already available.

"This ultrasonic Doppler device is a very usual medical device, a little bit advanced, because we need better sensitivity, better precision, better accuracy, than devices in the market and we are using this device for the indication of the balance," he said.

Even relatively small changes in intracranial pressure can have serious and sometimes fatal effects on patients. The Vittamed device is safer than the invasive, costly surgical procedures that require patients to be anaesthetised, according to its developers.

It can be used beyond emergency neurological care, Ragauskas explained, as the device does not need to be calibrated for individual patients.

"Intracranial pressure is a very important biomarker in many fields: in neurology, in transplantology, in infective deceases, also even in ophthalmology," he said

Being able to monitor intracranial pressure quickly and accurately means quicker treatment of traumatic brain injuries, one of the leading causes of death worldwide.

"We believe and we had clinical evidences, that non-invasive intracranial pressure measurement and non-invasive intracranial pressure monitoring is very widely needed in very wide fields of medicine, where invasive intracranial pressure measurement and monitoring is not applicable."

According to the CENTER-TBI 2.5 million people in Europe suffer a traumatic brain injury each year, and 75,000 die from their injuries.

The device is already being used across borders.

"Our device has been used in many European countries, including Switzerland for clinical studies, for scientific studies. Also our device was used in Houston in the United States for very special problem, which NASA wants to solve, this is visual impairment and intracranial pressure problem in microgravity. Astronauts, they have brain swelling, they have optic nerve swelling, they have visual impairment, and this syndrome needs to be understood and managed. Our devices are used for these purposes, too,"

Ragauskas was named a finalist in the European Inventor Awards for his Vittamed device in May. — Reuters