Non-invasive intracranial pressure and TMD research projects
The use of tympanic membrane displacement (TMD) measurements to assess inner ear pressure has been the subject of research for more than 15 years. In most people, the inner ear fluids are connected through to the intracranial fluids, so that a change in intracranial pressure (ICP) is reflected by a corresponding change in inner ear pressure. Applications of the TMD technique (the MMS-11 CCFP analyser) include screening patients with audiovestibular disorders to investigate whether an abnormal ICP is the underlying cause.
Accurate ICP measurements are also vital for the successful treatment and monitoring of many seriously ill patients with neurological problems. The development of the MMS-11 cerebral and cochlear fluid pressure (CCFP) analyser by Marchbanks Measurement Systems has provided the opportunity for a number of diverse research projects where intracranial pressure needs to be assessed non-invasively.
Detecting brain injury faster
The importance of developing a non-invasive tool to accurately measure ICP, and the potential value of our TMD technique, has been recognised by Innovate UK and they have given us funding to
- further validate the efficacy of the measurement in patients
- develop the equipment and software so that it is smaller and easier to use
- establish a normal range of ICP values in a healthy population.
We now need the help of 360 healthy people to identify a normal range of pressures. If you’re interested in taking part, or if you’d like more information, please visit our website, call us on 023 8120 3370 or 023 8120 3713, or you can send an email to ICPstudy@uhs.nhs.uk.
NASA project into space adaptation syndrome (SAS)
We are working on a collaborative project with the NASA Johnson Space Center. Project E148 is to use our TMD technique aboard the NASA space shuttles to investigate changes in crew-members’ intracranial pressure and any relationships with space adaptation syndrome (SAS) as the astronauts adapt to zero gravity conditions and on return to Earth. The project aims to better understand the pathophysiology of space adaptation syndrome, to improve the treatment and performance of astronauts.
Non-invasive TMD intracranial pressure measurements are being combined with assessments of middle ear function, ECG and continuous blood pressure. The interdependencies will be investigated and considered in terms of cerebral fluid dynamics.
The project may also provide considerable Earth benefits, in terms of understanding the relationships between increased ICP and imbalance, headache, motion sickness, and cognitive performance. Furthermore, the equipment that has been designed for NASA allows continuous intracranial pressure measurements to be undertaken by the TMD method for the first time.
Cerebral malaria project, Kenya
Each year many thousands of children suffer cerebral malaria and many of these children will die. A concerted effort is underway throughout the African continent to more fully understand and clinically manage patients with this condition. Important objectives are the rapid differential diagnosis of cerebral malaria on patient admission and the identification of sudden increases in the intracranial pressure that inhibit blood flow to the brain and result in death.
The TMD technique is being used in a KEMRI (Kenya Medical Research Institute) cerebral malaria project based in Kilifi, Kenya, and will be used to measure intra-aural pressure waves in terms of TMD. It is expected that these pressure waves will change in a predictable manner if the mean ICP is raised, with changes in intracranial compliance and when sudden pressure increases occur. Ultimately, it is intended that continuous ICP monitoring will be used, facilitated by the new equipment designed for the NASA project.
Studying altitude sickness on Mount Everest
Meet the team
Dr Robert Marchbanks developed the MMS-11 CCFP TMD analyser and leads our research into its use in non-invasive inner ear and intracranial pressure measurement.
Medical physics department
Southampton General Hospital