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Forward Deployable Full Spectrum Oculomotor Assessment (OMA) and TBI Diagnostic Device

Description:

TECHNOLOGY AREA(S): Bio Medical 

OBJECTIVE: Current oculomotor assessment practices in clinical bed-side and field environments utilize non-instrumented measures that rely on subjective (Kontos 2018) or observational measures to identify deficits. While these solutions have some limited clinical utility, they lack the capability to appreciate sub-clinical but pathological oculomotor signatures or to localize neuropathology necessary for appropriate diagnosis, management, and disposition of an injured Warfighter. An operationally feasible oculomotor measurement solution which measures physiologic eye movement characteristics would minimize or obviate reliance on subjective measures to diagnose and characterize concussion related oculomotor dysfunction. 

DESCRIPTION: The development of sensitive TBI assessment practices are particularly important in cases where subtle deficits may go underappreciated potentially resulting in premature or inappropriate return to duty decisions which could impact the well-being of the SM, the unit, and potentially adversely impact overall mission success. The use of an instrumented assessment tool capable of characterizing performance in specific oculomotor sub-systems could provide better diagnosis, injury localization, and injury characterization data to guide management, rehabilitation, and disposition decisions in operational environments. Comprehensive oculomotor assessment requires measurement across a broad spectrum of physiologic sub-systems with distinct and integrated neuroanatomy to drive the full range of functional eye movements including rapid re-fixation, smooth pursuit, and gaze stability during head movements (Cheever et al 2018). The assessment of saccades- rapid re-foviating eye movements which direct gaze to specific targets of interest or provide compensatory refoviation to augment gaze stability; smooth pursuit eye movements which allow smooth following of a moving visual target; optokinetic (OKN) eye movements facilitating rapid visual motion processing; and the ability to stabilize gaze during rapid head motion (vestibulo-ocular reflex (VOR): are typically impaired following TBI. At present, comprehensive vestibular and oculomotor testing is limited by the fact that the gold standard video-oculography (VOG) systems are not only unsuitable for field use, they do not control the position of a visual target in space, a feature which is critical to ensure diagnostic accuracy in the measurement of saccadic and smooth pursuit eye movements. 

PHASE I: Develop and provide a prototype of a portable oculomotor assessment (OMA) system consisting of a lightweight goggle head module (< 200 grams) that incorporates binocular tracking cameras, a minimum 9 degree-of-freedom Inertial Measurement Unit, and a laser projection and position control unit. The head module should communicate via wired connection to a lightweight (< 1500 grams) laptop computer or comparable data processing, storage, and display unit (DPU) housed in an impact resistant case suitable for transport in a small rucksack or utility bag. The system’s DPU should support > 3 hours continuous use, data storage, processing, and clinical data display. The laptop/ clinician interface should be loaded with a user-intuitive software interface supporting the execution of proof of concept oculomotor assessment algorithms with demonstrated adherence to the aforementioned technical and output specifications. Required Phase I deliverables include: 1) a research design for engineering a portable oculomotor assessment (OMA) device; 2) A preliminary partially ruggedized prototype system with proof of concept testing and data sufficient to demonstrate the ability to capture, transmit, process, store, analyze, and report functional scores for saccadic (i.e. stationary head and stationary target that instantaneously jumps to a new position and vestibular catch up/ compensatory eye movements), smooth pursuit (i.e. stationary head and moving target), OKN (i.e. stationary head and moving vertical target lines), combined eye/head coordination (moving head and moving target) and VOR (moving head and stationary target) function; 3) demonstrate capability to deliver aforementioned clinical output from the oculomotor assessment system in a clinically useful format to inform clinical decision making relative to normative human performance data.  

PHASE II: Validate the prototype of a compact, modular, ruggedized OMA system that can be used in an operational (field) setting to collect and analyze eye, head and target position motion data and display clinically relevant results of assessment on the laptop unit. The Phase II system should consist of the head module sensors that communicate via wire to the laptop serving as the data storage, processing and display unit. Required Phase II deliverables will include: 1. Validated ruggedization standards should include system’s ability to perform in rainy conditions, vibration tolerant to support transport without damage on military aircraft and vehicles, and impact resistance sufficient to withstand a drop of up to 5 feet. 2. Battery life should be sufficient to support at least 3 hours of continuous use. 3. Mass of head unit and laptop should not exceed 200 grams and 1500 grams, respectively. 4. Recharging should be compatible with existing military power source availability and require no longer than 60 minutes to achieve 80% of full charge. 5. Sampling rate and resolution should be sufficient to reliably characterize the bandwidth of oculomotor, OKN and VOR physiological systems. 6. Algorithms supporting computation of clinical outcome measures should allow for periodic updates by the manufacturer as the state of the science advances to allow integration of emerging assessment conditions using specific measurements. 7. Algorithms to process oculomotor, OKN and VOR data should compute stable, repeatable performance data (saccade size and timing, smooth pursuit gain, OKN gain and time constant, VOR gain during sinusoidal and transient head rotations). 8. Relevant clinical outputs from OMA should include evidence based characterization of oculomotor, OKN and VOR function. A functional score for each physiological system ranging from 0 (complete loss) to 1 (completely normal) will be generated and a single TBI likelihood score will be generated with suggestions to likely cortical region of injury. 9. Outputs should be exportable to a stand-alone monitor, a printable output chart, and in a format that may be saved within a patient’s electronic medical record. 10. Propose Sensitivity and Specificity values using an index score of oculomotor findings that predict presence or absence of central nervous system pathology associated with mild or moderate traumatic brain injury. 11. Deliver a plan for the FDA clearance process and deliver a manufacturing plan.  

PHASE III: Develop and deliver a user’s manual and provisional instructions for use which can support reasonable clinical adoption and sustainment within 10 hours of instruction. Conduct preliminary validation testing to characterize human performance under field conditions in a sample of Active Duty Service Members or a like age, gender and ability matched cohort. Validation of the prototype system should additionally include ability to discriminate healthy control personnel from a cohort with known TBI associated deficits. Based on results of system validation studies, system output should provide an aggregate estimate of duty readiness in the form of a “Green”, “Yellow” or “Red” signal on the clinician interface to indicate how closely patient performance approximates that of the patient’s baseline function and healthy control and duty ready personnel in each oculomotor sub-system. Plans on the commercialization/technology transition and regulatory pathway should lead to eventual FDA clearance/approval. The small business should also consider a strategy to secure additional funding from non-SBIR government sources and /or the private sector to support these efforts. In addition to the stated DoD purpose of assessing injured Service Members with suspected TBI in the training or operational environments, potential civilian customers for this technology may include clinicians or organizations who assess persons with suspected concussion, oculomotor, OKN or vestibular deficits in rural, remote, and underserved regions. Additionally, clinicians assessing pre- and post-injury performance in athletes at risk for acquired head injury in pediatric, collegiate, or professional populations also likely constitute a significant commercial target population.  

REFERENCES: 

1. Kontos AP, Collins MW, Holland CL, Reeves VL, Edelman K, Benso S, Schneider W, Okonkwo D. Preliminary Evidence for Improvement in Symptoms, Cognitive, Vestibular, and Oculomotor Outcomes Following Targeted Intervention with Chronic mTBI Patients. Mil Med. 2018 Mar 1;183(suppl_1):333-338. PMID: 29635578. ; 2. Cheever KM, McDevitt J, Tierney R, Wright WG. Concussion Recovery Phase Affects Vestibular and Oculomotor Symptom Provocation. Int J Sports Med. 2018 Feb;39(2):141-147. PMID: 29190849.

KEYWORDS: Oculomotor Measurement, Concussion Assessment, Vestibular Assessment, Saccadic Assessment 

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