A Non-invasive Intracranial Pressure (nICP) Monitoring System

Traumatic brain injury (TBI) is the most common cause of death and disability in the under 40 age group both in the United Kingdom and worldwide, and prevalence is increasing. The mainstay of severe TBI management is intracranial pressure (ICP) measurement. ICP is defined as the pressure within the skull and brain. TBI often causes a rise in ICP as the brain swells within the rigid skull and therapy is directed at keeping this pressure at an acceptable level with medications or surgery. Very high ICP may lead to further brain damage resulting in increased disability or death. Existing techniques to measure ICP involve placing an electrical sensor into the brain tissue through a small hole drilled in the skull. This procedure risks infection and bleeding into the brain and can only be performed by a neurosurgeon. Therefore, there is a vital demand to develop non-invasive technologies that will allow measuring the ICP without inserting a sensor in the brain. This technology will decrease the risks, permit monitoring outside the hospital (eg in an ambulance) and reduce the costs. It will also increase the indication for ICP monitoring to include other conditions (e.g. stroke or brain tumours) which are not currently monitored. The proposed non-invasive ICP (nICP) monitor works by shining a harmless light into the brain through the skull. The developed sensor was attached to the skin of the forehead and recorded optical signals (known as photoplethysmography (PPG)) from the brain, which are related to changes in the ICP. This pilot aims to build the first clinical database of nICP signals in intensive care patients. The acquisition of an extensive set of signals would allow the generation of advanced algorithms and Machine Learning (ML) models utilising optical signal feature extraction techniques. The resulting model will be implemented in translating the optical signals into absolute measurements of ICP.