Fusion of Micro-Array Flow Sensor Data for Smart Cerebral Spinal Fluid Drainage Shunts

脑脊液分流术是脑积水的一种长期治疗选择，脑积水是一种与脑脊液在脑内积聚相关的先天性疾病。如果不及时治疗，脑积水会导致发育障碍和死亡。自20世纪50年代以来，一直在使用植入式脑脊液分流术；然而，大约39%的分流器在一年内失败，53%在头两年内失败，大约80%在植入后的某个时间点失败。该研究项目的目标是开发一种“智能”脑脊液流量传感器，能够报告植入后脑脊液流出的量。提出的解决方案是基于超灵敏磁电阻传感器、射频识别技术和超顺磁微结构制造技术的结合使用。这项研究有望显著提高脑积水患者的生活质量，因为可以及早发现即将发生的分流管衰竭，以便在不良健康或认知影响发生之前进行纠正。研究小组还计划将这项研究整合到本科生和研究生的教育活动中，并基于开发低成本医疗传感器的共同目标，开发一个将商业实践整合到设计过程中的本科生设计程序，以提高设计系统成功应用的可能性。这项提议的科学目标是证明使用巨磁电阻传感器检测非常缓慢流动的液体（如脑脊液）的可行性。最新一代的传感器被称为磁隧结装置，将用于检测脑室-腹膜分流管腔内纤毛状结构的血流引起的运动。实现这种非接触式测量需要新的传感器架构免受低频噪声（传感器漂移），抑制环境磁干扰，以及开发允许无线操作的超低功耗传感器询问方案。目前的工作将研究MTJ传感器中的低频噪声源，传感器重新校准的间接方法，并将开发一种能够以1mL/hr分辨率分辨CSF流量的电感式流量传感器。所获得的知识不仅适用于脑积水分流，而且更普遍地适用于低流量系统的测量。此外，预计在磁隧结器件本身的知识方面将有重大进展。

Cerebral spinal fluid (CSF) shunting is a long-term treatment option for hydrocephalus, a congenital condition associated with accumulation of cerebral-spinal fluid in the brain. If left untreated, hydrocephalus leads to developmental disabilities and death. Implanted cerebrospinal fluid shunts have been in use since the 1950's; however approximately 39% of shunts fail within the first year, 53% fail within the first two years, and about 80% fail at some point after implantation. The goal of this research project is to develop a "smart" CSF flow sensor, capable of reporting the amount of CSF drained from the brain after implantation. The proposed solution is based on the combined use of ultra-sensitive magnetoresistance sensors, radio-frequency identification technology, and advances in the manufacturing of super paramagnetic micro-structures. This research is expected to significantly improve the quality of life of individuals with hydrocephalus, as pending shunt failure can be detected early to allow correction before adverse health or cognitive effects occur. The research team also plans to integrate this research into undergraduate and graduate educational activities and, based on a common goal of developing low cost medical sensors, develop an undergraduate design program that integrates business practices into the design process to improve the likelihood of successful application of the designed systems.The scientific objective of this proposal is to demonstrate the feasibility of using giant magneto-resistance sensors in the detection of very slow-moving fluids, such as cerebral spinal fluid. The latest generation of these sensors, known as magneto tunneling junction devices, will be used to detect flow-induced motion of a cilia-like structure inside the lumen of a ventriculoperitoneal shunt. Realization of such non-contact measurements requires new sensor architectures immune to low-frequency noise (sensor drift), rejection of ambient magnetic interference, and development of an ultra-low power sensor interrogation scheme allowing for wireless operation. The present effort will investigate the low-frequency noise sources in MTJ sensors, indirect methods for re-calibration of the sensor, and will develop an inductively powered flow sensor capable of resolving CSF flow with 1mL/hr resolution. The knowledge gained will be applicable not only to hydrocephalus shunts, but to measurement of low-flow volume systems more generally. In addition, it is expected that there will be a significant advancement in knowledge regarding magneto tunneling junction devices themselves.