Aug. 8 (UPI) -- German researchers have developed a new method to monitor intracranial pressure in a noninvasive way that may replace the current invasive method.
Researchers from Klinikum Stuttgart and the University of Erlangen, Germany, developed a noninvasive monitoring device that uses advanced signal analysis algorithms to evaluate properties of acoustic signals that pass through the brain to determine ICP levels.
Normal ICP is 20 mm Hg or lower, however, a traumatic head injury, brain disease, or hydrocephalus, cerebral spinal fluid, or CSF, can accumulate putting pressure on the brain that can lead to brain damage or death if the ICP is high enough.
It is necessary to continuously monitor the ICP in critical-care patients to determine whether the ICP level is too high and surgery is needed to relieve the ICP.
Current methods of ICP monitoring include invasive intraventricular and intraparenchymal monitoring requiring surgery. The invasive procedure involves a hole being drilled into the patient's skull and a catheter inserted into the brain tissue or a ventricle, the space in the brain that contains the CSF. Sensors in the catheter continuously measure ICP, and it can be used to reduce the pressure if it is too high.
The study, published today in the Journal of Neurosurgery, suggests the HS-1000 device -- which emits 6-second-long bursts of sound near one ear to pass acoustic signals throughout the cranium, detecting them with receiving sensors located in the opposite ear -- may be an effective, but noninvasive, method of monitoring CSF.
ICP values are determined using advanced signal analysis algorithms that evaluate properties of the acoustic signals sent through a patient's cranium.
The monitoring method was tested on 14 patients treated for traumatic brain injury or subarachnoid hemorrhage in the intensive care unit. The patients were already undergoing invasive intraventricular or intraparenchymal monitoring, and researchers compared those ICP values with readings they got using the noninvasive HS-1000 device system.
Comparing 2,543 data points, researchers found similar results with invasive and noninvasive monitoring methods with differences in mean ICPs of +/- 3 mm Hg in 63 percent of readings and +/- 5 mm Hg in 85 percent of readings.
The results show a good correlation between ICP values using both the noninvasive and invasive methods of ICP monitoring.