|Acquisition Program: ||MRMC Deputy for Acqusition|| Objective: ||Prototype and test a handheld or man portable system utilizing either ultrasound or Ophthalmodynamometry technologies that can provide battlefield triage of traumatic brain injuries (TBI). The system shall be able to provide diagnostic data related to intracranial pressure (ICP), and preferably cerebral perfusion pressure, blood oxidation and intracranial hemorrhage.
|| Description: ||Recent developments in ultrasound technology suggest it as one potential method for noninvasively monitoring intracranial pressure and cerbrovascular flow, while also detecting the presence of intracranial hemorrhage and decreased cerebral perfusion pressure [1-5]. Ophthalmodynamometry and Ultrasound-obtained optic nerve sheath diameter measurements have also been shown to provide accurate assessment of increased intracranial pressure [6-8]. To make these or any competing technologies practical for combat casualty care, they must be integrated into a portable, low-power diagnostic unit. Such a system should also have a simple interface that makes the system easy to use by medics, physicians assistants and general trauma surgeons in a battlefield setting. It is believed that advances in both ultrasound and Ophthalmodynamometry technologies will now enable the creation of such a device. Performance Objectives: Ability to provide rapid assessment of intracranial pressure elevation is of primary importance; device should be hand held or easily man portable, emphasis on minimal size and weight; ability to detect cerebral vascular flow, cerebral perfusion pressure, blood oxidation and intracranial hemorrhage are desired but not mandatory. The system would need to be validated by comparison with the gold standard of invasive ICP monitoring; The system should be capable of producing multiple measurements over time which are consistent and reproducible; Patient position should not impact measurement. The device should be capable of performing measurements without repeated calibration, providing consistent measurements from patient to patient. The device should be capable of being used on both conscious and unconscious patients.
Background: From previous wars, it has been estimated that approximately 20% of all military casualties have sustained a brain injury , and in a recent study of 155 injured soldiers returning from Iraq, 62% were found to have a brain injury . This dramatic increase has been attributed to improved body armor—leading to a higher survival rate in blast injuries—and improved diagnosis of mild and moderate traumatic brain injury once a soldier has been evacuated. Improved diagnosis of TBI during the early posttraumatic period will significantly reduce the risk of secondary ischemic injuries and reduce mortality and morbidity of TBI.
|| ||PHASE I: Analyze the problem of field-based ICP monitoring and determine technical feasibility of an ultrasound or Ophthalmodynamometry-based system capable of monitoring intracranial pressure according to the performance objectives noted in the topic description. Develop engineering specifications and if feasible develop a prototype system. Deliver a report of the technical feasibility and engineering specifications to include a description of plans for performance objectives and validation for phase II execution. This includes the preparation of plans and protocols for any required animal or human testing as well as seeking local and Army regulatory approvals for potential phase II work.
|| ||PHASE II: Build a prototype man-portable or handheld battlefield TBI diagnostic and monitoring system, refine any additional performance objectives met in phase I and conduct system tests on appropriate animal and phantom models. Validate the system by demonstrating equivalence to invasive monitoring. If capable, conduct human clinical trials and obtain FDA approval for use.
|| ||PHASE III: Transition the capability to dual use in civilian and military emergency departments/Forward Surgical Teams/Combat Support Hospitals, and with military and civilian medical first responders. For example, the device could be used by paramedics at the site of injury to allow for immediate neuroprotective care to be provided. Data could be forwarded verbally or via wireless communications from the device itself to neurosurgical experts for real time consultation in the field.
|| References: ||1) T. Ueno, B. R. Macias, W. T. Yost and A .R. Hargens. “Noninvasive assessment of intracranial pressure waveforms by using pulsed phase lock loop technology. Technical note. J. Neurosurg, 2005, Aug;103(2):361-7.
2) T. Ueno, B. R. Macias, W. T. Yost and A. R. Hargens. “Pulsed phase locked loop device for monitoring intracranial pressure during space flight.” Journal of Gravitational Physiology, 2003; 10(1), 117-118.
3) S. G. Voulgaris, et al. “Early cerebral monitoring using transcranial Doppler pulsatility index in patients with severe brain trauma.” Med. Sci Monit 2005; 11(2): CR49-52.
4) Fountas K. N., et al. “Is non-invasive monitoring of intracranial pressure waveform analysis possible? Preliminary results of a comparative study of non-invasive vs. invasive intracranial slow-wave waveform analysis monitoring in patients with traumatic brain injury.” Med. Sci. Monit. 2005; 11(2): CR58-63.
5) H. van Santbrink, et al. “Serial transcranial Doppler measurements in traumatic brain injury with special focus on the early posttraumatic period.” Acta Neurochir (Wien). 2002 Nov;144(11):1141-9.
6) Firsching, R, et al. “Venous opthalmodynamometry: a noninvasive method for assessment of intracranial pressure.” J Neurosurg. 2000 Jul;93(1):33-6.
7) Blaivas, M, et al. “Elevated intracranial pressure detected by bedside emergency ultrasonography of the optic nerve sheath.” Acad Emerg Med. 2003 Apr;10(4):376-81.
8) Romagnuolo, L, et al. “Optic nerve sheath diameter does not change with patient position.”
Am J Emerg Med. 2005 Sep;23(5):686-8.
9) ARNEWS (Army News Service), Spc Chuck Wagnerm Nov. 24, 2003, “Brain Injuries High Among Iraq Casualties.” Accessed at: http://www4.army.mil/ocpa/read.php?story_id_key=5445
10) Defense and Veterans Brain Injury Center website on blast injury, http://www.dvbic.org/blastinjury.html
|Keywords: ||ultrasound, ophthalmodynamometry, traumatic brain injury, intracranial pressure, monitor|