Dr. Fabián García Nocetti, specialist at the Research Institute in Applied Mathematics and Systems (IIMAS) of the National Autonomous University of Mexico (UNAM), developed a device that accurately measures the blood flow in patients after the removal of an aneurysm.

A cerebral aneurysm is a bulge in the wall of a blood vessel that causes dilation of blood flow in the artery; the consequences of these can be infarcts or strokes.

The device – called a bidirectional Doppler system for measuring blood flow – operates using ultrasonic waves directed to the blood flow in the brain after performing surgery to remove a cerebral aneurysm.

The design of the device is similar to a cabinet with a monitor on its top; from there a cable extends with the terminal that performs the measurement. Its creator said it is portable, which makes it more practical.

According to a research article from the National Medical Center La Raza of the Mexican Institute of Social Security (IMSS), the causes of this condition include degenerative or acquired disorders and are typical lesions of adults.

The device works using a system that sends the data – in real time – of blood flow from the brain to a monitor and allows the neurosurgeons to determine if the irrigation in the patient’s brain is adequate and confirm a successful surgical procedure.

This is possible because the device analyzes the frequency change from a fixed receiver in regards of a source of ultrasound moving emission towards the blood particles. This allows knowing the speed of the blood flow after the operation.

Aneurysms can occur in different ways. The most common form in which they occur is the sacciform aneurysm; in these cases, a kind of sac is formed, so the blood flow is altered,” explained García Nocetti.

This problem can cause strokes when blood begins to leak after the artery breaks and, in many cases, causes death due to the amount of blood that is lost.

The endovascular repair of the aneurysm and the clipping of the aneurysm are the surgical treatments that exist to address the problem; however, the doctors after performing the procedure cannot know if the blood flow is normal.

For doctors it is necessary to wait for the patient’s response and make sure that the operation was successful. The new device allows surgeons verifying that the flow is correct before completing the procedure.

According to information from the Foundation for the Coverage of Cerebral Aneurysm (Fucac), 10 to 15 percent of patients who have suffered a ruptured cerebral aneurysm are at risk of immediate death before reaching the emergency room; and more than 50 percent could die within the first 30 days after the stroke occurred.

Doppler effect in the operating room

The device for neurosurgery developed at the UNAM acts under the Doppler effect, so the measurement is based on the fact that the instantaneous mean frequency of the Doppler signal is directly proportional to the instantaneous mean blood flow velocity.


Source: Agencia Informativa CONACYT