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A light touch: Changing the way we treat traumatic brain injury

  • Traumatic brain injury is surprisingly common.
  • Successful treatment relies on accurate multi-modal monitoring of arterial blood pressure, intracranial pressure, cerebrovascular blood flow autoregulation status, and intracranial compliance. However, current technologies to do so can be cumbersome and invasive.
  • Professor Arminas Ragauskas at Kaunas University of Technology in Lithuania has helped design devices that are mobile and non-invasive.
  • The technology opens new neuroprotection pathways for the human brain.

Contrary to popular perception, traumatic brain injury (TBI) is not the reserve of car accidents and punishing contact sports; it’s surprisingly common. Up to 50 million new cases of traumatic brain injury are registered each year worldwide. Notably, 80% of TBI occurs in low- to middle-income countries, and it is also the leading cause of death and disability in young adults. Overall, the global economic burden of TBI is estimated at 400 billion USD.

Minimising the devastating effects of TBI doesn’t rely solely on reducing the risk of an injury; it’s also essential to improve treatment after one has happened. For that, physiological real-time monitoring of vital signals is critical. One inventor has made it his mission to create devices that can do this accurately, easily, anywhere, and what’s more, they are also non-invasive.

Professor Arminas Ragauskas is a founder and director of the Health Telematics Science Institute at Kaunas University of Technology in Lithuania, which develops innovative industrial and physiological measurement and process monitoring technologies. He is particularly known for his work on non-invasive intracranial pressure and cerebral blood flow autoregulation measurement devices. He was also the national coordinator of the CENTER-TBI project, funded by the European Commission and the EU industry, with a budget of 40 million EUR, and focused European efforts to advance the care of patients with traumatic brain injury.

Among the devices Ragauskas and his team have designed within this field, are the Vittamed 505 cerebral autoregulation monitor and the Vittamed 205, which measures intracranial pressure (ICP). The devices are remarkable because they are non-invasive and simple to use.The Vittamed 205 can measure ICP value in minutes. The speed and simplicity of the device make it ideally suited for diverse applications where quick or ongoing assessment for possible brain injury or pathology is needed, such as emergency rooms, sports medicine, and aerospace.

Up to 50 million new cases of traumatic brain injury are registered each year worldwide.

Their latest inventions, Archimedes 01 and 02 – with US and European patents pending – focus on non-invasive monitoring of intracranial volume and pressure pulse waves, which are created by the rhythmic beating of the heart and the subsequent flow of blood through the brain. Analysing pulse wave morphology (shape and form) can provide valuable insights into brain health and function.

Genuine innovations in healthcare come about by cleverly overcoming or side-stepping perceived barriers; what Ragauskas and his team have created is a case in point.

Hi Arminas. Please could you tell us why it’s so important to measure ICP and blood flow in assessing possible TBI?

The critical treatment target of severe TBI patients in neurosurgical intensive care units (ICU) is keeping patient-specific optimal brain perfusion to prevent secondary brain insults. Cerebral perfusion pressure (CPP) is a crucial component to critical care medicine with respect to brain function. It refers to the net pressure difference that drives oxygen and nutrient-rich blood to the brain tissue and is calculated as the difference between the mean arterial pressure – the pressure exerted by circulating blood upon the walls of blood vessels, particularly arteries – and ICP. ICP describes the pressure inside the cranial vault (ie, the skull).

Monitoring both CPP and cerebral blood flow autoregulation – the brain’s ability to maintain a relatively constant blood flow despite changes in systemic blood pressure – in real-time is needed for treatment decision-making in severe TBI cases. Secondary brain insults can damage or destroy the neural pathways in minutes because of too low intracranial compliance – a reduced capacity of the skull to accommodate changes in intracranial volume within its fixed space – even when ICP is normal. Accurate and precise monitoring of intracranial compliance in ICUs has, until now, been a scientific and technical challenge.

Traditional methods for measuring ICP, though critical, can be invasive. Being non-invasive, how would your devices be used?

Invasive-only technologies are available for physiological monitoring of patients in coma after severe brain injury. There are medical situations outside ICUs that need non-invasive ICP, brain compliance, and cerebral autoregulation measurements and monitoring. These include cardiac surgery, organ transplantation, emergency, sports and aerospace medicine, and even glaucoma diagnosis and treatment, because normal tension glaucoma is caused by abnormally low ICP when intraocular pressure is normal.

The Vittamed 205 device works by applying a controlled amount of pressure to the outside of a person’s closed eyelid. This externally applied pressure is denoted as Pe. The key to the Vittamed 205’s measurement technique is identifying the point where Pe applied to the eye equals ICP within the skull. When these two pressures balance out, the device can accurately determine the ICP, measured in millimetres of mercury (mmHg), a standard unit for arterial and intracranial pressures. This reading gives doctors a clear indication of the pressure inside the skull. A balance Pe=ICP is identified automatically using ultrasonic two depth transcranial Doppler device for simultaneous blood flow velocities measurement in intracranial and intraorbital segments of an ophthalmic artery.

Monitoring intracranial pressure and cerebral perfusion pressure are crucial to treating traumatic brain injury.

Our latest inventions – the Archimedes 01 and 02 intraorbital and intracranial pulse wave non-invasive monitors – also work by mechanical contact between the closed eyelid and a hermetically sealed rigid chamber attached to the face of the patient. The chamber has a pressure sensor and is filled with a non-compressible liquid. The devices convert miniscule vibrations within the eyeball caused by intracranial volume/pressure waves into an electrical output signal via the pressure sensor.

What were the biggest challenges in the design of the devices and their eventual introduction to the market?

Introducing the Archimedes 01/02 devices to the market requires prospective clinical validation. We already started prospective clinical validation studies on patients in two hospitals in Kaunas and Vilnius in Lithuania.

What will your technology teach us about traumatic brain injury?

Because Archimedes 02 is mobile, wireless, and works through both eyes, it can be used in various settings outside the ICU, such as sports medicine facilities, temporary emergency facilities, and even orbiting space stations. This mobility will significantly increase the scope of the study of ICP. Furthermore, the wireless Archimedes 02 is a two-channel device that can independently monitor intracranial pulse wave morphology in two hemispheres of a human brain.

The Vittamed 205 non-invasive ICP absolute value meter.
Photo Credit: Vaizdu, CC BY-SA 3.0 DEED, via Wikimedia Commons

Such capacity is illuminating because it allows doctors to understand how different parts of the brain are responding and functioning – or not – simultaneously, which can be crucial in correctly treating brain injuries or diseases. This, in itself, is a radical innovation in brain compliance monitoring. Clinical studies will surely show the added value within different fields of medicine by the ability to monitor intracranial compliance changes non-invasively.

Your research suggests the eye is more than the window to the soul – it is a portal to understanding what’s happening in the brain. What stands out from what you’ve learned in this respect?

Our technology opens new neuroprotection pathways for the human brain. We’ve realised it has applications in multiple scientific fields. For example, as an instrument to better understand and control the mechanisms behind neural damage by fast secondary brain insults, to get a clearer picture of the mechanisms of glaucoma development, and within aerospace medicine to address the physiological effects of extended microgravity conditions on astronauts’ brain and vision.

Our technology opens new neuroprotection pathways for the human brain.

Measuring ICP is critical in preparations for human space flights to Mars because of the threat of neuro-ocular syndrome to astronauts. Please explain what this is and how your device could help.

Up to 70% of astronauts develop visual impairments during a space flight, including spaceflight-associated neuro-ocular syndrome (SANS). It is still not possible to predict which astronauts will develop visual impairment in space or treat those who do during space flight. We previously worked with NASA to apply our technology in SANS studies at DLR, the German Aerospace Centre in Cologne.

Our novel, non-invasive, real-time intracranial pulse wave monitoring technology can help solve the problem of SANS. The European Space Agency (ESA) has already expressed interest in utilising our novel Archimedes 01/02 devices during parabolic flights, prior to their application in microgravity conditions. I see our novel invention eventually being used in the international space station to help study the human brain and ocular reactions to microgravity conditions.

Up to 70% of astronauts develop visual impairments during a space flight.

Two studies are underway to road-test the device further. What do they intend to test?

We already started two prospective clinical studies in Lithuania to validate our novel technology. The first is for diagnosing brain compliance in glaucoma patients and comparing those with a control group of healthy volunteers. Our working hypothesis is that brain compliance is a novel and valuable biomarker for diagnosing normal tension glaucoma and glaucoma treatment monitoring.

The second study is for simultaneous invasive and non-invasive intracranial compliance monitoring of severe TBI patients to identify the diagnostic value of compliance monitoring and associating patient outcomes with patients’ treatment decision-making, including information about intracranial compliance changes.

What drives your particular interest in this field?

The brain and its extensions, such as the optic nerve, are so important to human life quality. We need to understand the dynamic processes that damage or destroy neural pathways to better treat the many pathological conditions of patients.

Our primary focus lies in neuroprotection, including the optic nerve, within the framework of personalised precise medicine. We are confident that our monitoring technologies will enhance real-time multimodal monitoring, addressing the challenge of tracking multiple vital signals simultaneously and enabling personalised treatment for each patient. Through the automatic application of advanced AI algorithms, our aim is to safeguard neurons, considering their vulnerability to degradation in just 4-5 minutes without sufficient oxygen and nutrients. Fast, automated treatment decisions are crucial for effective neuroprotection.

We’ve initially tested our neuroprotection hypothesis in cardiac surgery, intensive care, and among glaucoma patients, recognising glaucoma as a two-pressure (intraocular pressure is normal or too high and intracranial pressure is too low) disease. Presently, we’re conducting a multicentre, non-invasive intracranial compliance monitoring study to refine our multimodal monitoring system. This advancement will significantly enhance the speed and accuracy of automatic treatment decision-making for individual patients.

Related posts.

Further reading

Stoskuviene, A, et al, (2023) The relationship between intracranial pressure and visual field zones in normal-tension glaucoma patients. Diagnostics, 13, 174.

Deimantavicius, M, et al, (2022) Feasibility of the optimal cerebral perfusion pressure value identification without a delay that is too long. Sci Rep, 12, 17724.

Krakauskaite, S, et al, (2022) Non-invasive intracranial pressure dynamics during cardiac bypass surgery: prospective study. In Proceedings of the 12th International Conference on Biomedical Engineering and Technology (ICBET ‘22). Association for Computing Machinery, New York, NY, USA, 175–179.

Hamarat Y, et al, (2018) Graphical and statistical analyses of the oculocardiac reflex during a non-invasive intracranial pressure measurement. PLOS ONE, 13(4), e0196155.

Arminas Ragauskas

Professor DSc FBC FLSHD Arminas Ragauskas is a founder and director of the Health Telematics Science Institute at Kaunas University of Technology in Kaunas, Lithuania. During a career in measurement sciences spanning over 50 years, he has published over 100 peer-reviewed scientific papers and filed over 90 granted or pending patent families.

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Ragauskas, A, (2024) A light touch: Changing the way we treat traumatic brain injury, Research Features, 151.

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