Passive Eye Response as a Surrogate for Brain Response to Head Acceleration

 描述（由申请人提供）：轻度创伤性脑损伤（mTBI）是一种高患病率损伤，由头部/身体撞击期间颅骨中的大脑移位和变形引起。各级接触性体育运动员都是高危人群。为了防止进一步的伤害和长期的神经损伤，识别运动员在球场上接受潜在的震荡打击是非常重要的。为此目的，大量研究致力于头部加速度（HACC）的现场监测，遵循高HACC与脑震荡的较高风险相关联的假设。到目前为止，HACC和mTBI临床结果之间的联系似乎是“难以捉摸的”，因为尚不清楚现场记录的HACC如何转化为大脑移位和变形。目前还没有一种方法可以直接评估从事高风险活动的活人对身体/头部撞击的大脑反应。人们认识到，头部的其他器官在撞击过程中可能会经历与大脑类似的位移和变形，因此可以作为推断大脑反应的替代物。其中一个器官就是眼睛。已经证明，在HACC之后的短时间窗内，眼睛和周围组织（眼块）立即在眼窝中经历被动（非神经控制的）机械位移和变形。因此，假设对HACC的被动眼反应（PER）的直接评估可以用于更好地推断对身体/头部撞击的大脑反应，并且因此可以提供比HACC本身更好的预测mTBI的机会。为了检验上述假设，将追求三个具体目标。(1)开发一种由封装在硅水凝胶晶片中的应变计阵列制成的拴系眼传感器，该传感器可以插入人眼的下穹窿。眼睛传感器测量多个位置处的动态应变，从而提供眼睛质量对冲击的响应的真实的时间评估。将使用解剖头部模型对其进行测试和改进。(2)记录由已知会产生轻度、非震荡性HACC的日常活动引起的PER。20名年轻的正常人类参与者将被要求执行任务，例如坐在椅子上，站起来，走路，在跑步机上跑步，跳跃和移动眼睛，同时用眼睛传感器监测PER。(3)在监测HACC和PER的同时，将使用标记MRI对5名年轻正常人参与者中由轻度、非震荡性线性和角度HACC引起的脑移位和变形进行成像。这些实验将量化HACC，PER和大脑反应之间的联系，并将为进一步开发无线眼传感器奠定基础，供运动员在比赛期间佩戴，并识别那些可能受到震荡打击的人。

 DESCRIPTION (provided by applicant): Mild Traumatic Brain Injury (mTBI) is a high prevalence injury, caused by the displacement and deformation of the brain in the skull during head/body impacts. Athletes in contact sports at all levels are a high-risk population. It is vitaly important to identify athletes receiving potentially concussive blows on the field in order to prevent further injury and long-term neurological damage. For this purpose, a lot of research has been devoted to on- field monitoring of head accelerations (HACC) following the hypothesis that a high HACC is associated with a higher risk of concussion. So far, it appears that the link between HACC and clinical outcome of mTBI is "elusive", because it is not clear how HACC recorded on-field translates to brain displacement and deformation. There is no method that can directly assess brain responses to body/head impacts in live human beings engaged in high-risk activities at this moment. It is recognized that other organs in the head may undergo similar displacement and deformation as the brain during impacts and thus may serve as a surrogate for inferring brain responses. One of these organs is the eye. It has been demonstrated that the eye and the surrounding tissue (the eye mass) undergo a passive (not neurally controlled) mechanical displacement and deformation in the eye socket in a short time window immediately after a HACC. It is thus hypothesized that a direct assessment of the passive eye response (PER) to HACC can be used to better infer brain response to body/head impact, and consequently, can offer a better chance to predict mTBI than HACC itself. Three specific aims will be pursued to test the hypothesis above. (1) Develop a tethered eye sensor that is made of an array of strain gauges packed in a silicone hydrogel wafer and that can be inserted in the inferior cul-de-sac of a human eye. The eye sensor measures dynamic strains at several locations and thus provides real time assessment of eye mass response to impact. It will be tested and refined using an anatomic head model. (2) Record PER induced by daily activities that are known to produce mild, non-concussive HACC. Twenty young, normal human participants will be asked to perform tasks such as sitting into a chair, standing up, walking, running on a treadmill, jumping and moving the eyes while the PER is monitored with the eye sensor. (3) Brain displacement and deformation caused by mild, non-concussive linear and angular HACC will be imaged using tagged MRI in 5 young normal human participants while the HACC and PER are monitored. These experiments will quantify the link between HACC, PER and brain responses, and will lay the foundation for further development of a wireless eye sensor for athletes to wear during games and to identify those who may have received concussive blows.