By Omar Ford
A problem that some astronauts face is the development of serious visual impairment conditions that are associated symptoms suggestive of elevated pressure on the brain, or increased intracranial pressure. This has prompted the National Space Biomedical Research Institute (NSBRI), a non-profit organization that is funded by NASA to partner with Vittamed (Boston), a med-tech firm that has developed a device to non-invasively measure absolute intracranial pressure (ICP), to initiate a clinical research study.
The independent study, which will evaluate the Vittamed 205 device, will include the monitoring of neurological patients, as a prelude to possible future use with astronauts.
According to the company, the study was initiated in September of 2013 and is due to be completed in mid-2014. Vittamed is providing equipment, training, and expert technical advice. ICP measurements obtained using the Vittamed 205 device are being compared with simultaneous lumbar puncture readings, which are considered the "gold-standard" in patients undergoing evaluation for medical reasons. A total of 40 patients will participate in the study. The Houston team is also evaluating the device for its suitability in assessing the astronauts ICP in the space environment.
The technology was initially developed to target patients suffering from traumatic brain injuries, concussions, neurological diseases, hydrocephalus and other complications.
"Currently, the only reliable way to monitor the ICP is place a catheter into the brain or cerebrospinal fluid space. Therefore, there is an urgent need to develop non-invasive devices for measuring this important indicator of brain health," said Eric Bershad , a neuro-intensivist and vascular neurologist at Baylor College of Medicine and St. Luke's Medical Center (both in Houston).
According to the firm, the measurement technology solves the main limiting problem of all other technologies designed to measure ICP the individual patient calibration problem. The only solution is to eliminate need of calibration by direct comparison of aICP and externaly applied pressure same fundamental principle used to measure blood pressure with a sphygmomanometer.
A sphygmomanometer works using a balance principle; an air-filled pressure cuff wrapped around the arm compresses the brachial artery to a point where blood can no longer flow. The examiner slowly releases the air from the cuff and uses a stethoscope to listen for the return of blood flow. At the balance point, where pressure in the cuff equals systolic artery pressure, a 'whooshing' noise can be heard as blood flows through the artery again.
The company uses a Doppler ultrasound to translate this principle to the measurement of intracranial pressure. As with a sphygmomanometer, a pressure cuff is used - in this case to compress the tissues surrounding the eye and change the characteristics of blood flowing from inside the skull cavity into the eye socket. The eye artery (ophthalmic artery) is a unique vessel with intracranial and extracranial segments - natural scales for absolute ICP measurement.
In place of the stethoscope, a Doppler ultrasound beam measures the blood flow in intracranial and extracranial segments of the ophthalmic artery. The point where the pulsatility in the two sections is equal is the point at which the applied external pressure equals the intracranial pressure.
"The advantage of this technique is that there are very minimal risks," Dorit Donoviel, NSBRI's Deputy Chief Scientist and Industry Forum Lead, told Medical Device Daily. "Now you can monitor people a lot more frequently and repeatedly. You can do this measure over and over again. If you can get an accurate measure of brain pressure without having the risks of having to put a needle into the patient, you're going to start monitoring people that you really weren't monitoring before. It gives you, as a doctor, a really powerful tool to more closely monitor your patients to make sure they don't develop complications." Vittamed is still vying for approval of the device both in the U.S. and in Europe.
"Currently we are embarking on a regulatory pathway in Europe," Remis Bistras Vittamed, CEO told MDD. "We're seeking a CE mark and hope that we will get that sometime mid-2014. In the U.S. we will seek 510(k) clearance."
But to do this, the company will need to secure funding a goal which it feverishly working on at the moment.
"We're a small venture capital backed-company and we're raising a Series B," he said. "We're currently received around $8 million from different research grants. We have around more than $2.5 million invested in smaller funds and angel investors. We are looking to raise $5 million to finish regulatory approvals and commercialization in Europe."
Published December 19, 2013