Microfabricated Implantable Flowmeter for CSF Shunts Phase II

用于脑脊液分流的微型植入式流量计第二阶段

• 批准号: 8331457
• 负责人: JAMES Hunter GOLDIE
• 金额: $ 98.36万
• 依托单位: INFOSCITEX CORPORATION
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-30 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8331457
• 关键词: Achievement; Animal Model; Animal Testing; Appearance; Calibration; Cerebrospinal fluid shunts procedure; Characteristics; Child; Chronic; Clinical; Clinical Trials; Coupling; Creation of ventriculo-peritoneal shunt; Data; Deposition; Detection; Development; Devices; Early Diagnosis; Electromagnetics; Emergency Situation; Ensure; Environment; Failure; Flowmeters; Frequencies; Hydrocephalus; Implant; In Situ; Indium; Laboratories; Liquid substance; Magnetic Resonance Imaging; Maps; Measurable; Measurement; Measures; Methods; Microfabrication; Modeling; Monitor; Obstruction; Office Visits; Output; Patients; Performance; Peritoneal; Phase; Physiological; Preparation; Probability; Process; Property; Protocols documentation; Pump; Reading; Relative (related person); Reporting; Risk; Risk Management; Safety; Sensitivity and Specificity; Sheep; Shunt Device; Specific qualifier value; Sterilization; Structure; Symptoms; System; Testing; Time; Tissues; Variant; Visit; Wireless Technology; base; biomaterial compatibility; cerebrospinal fluid flow; design; electrical property; feeding; fluid flow; hazard; implantation; implanted sensor; in vitro testing; meetings; meter; mortality; operation; phantom model; prototype; research study; seal; sensor; tissue phantom

DESCRIPTION (provided by applicant): An implantable wireless flow sensor system has been under development that would enable measurement of the flow of cerebrospinal fluid (CSF) through the ventriculoperitoneal (VP) shunt, currently used to treat hydrocephalus patients. CSF flow is a key indicator of shunt function, and there is currently no way to measure it in situ, resulting in the absence of clinical methods to directly assess shunt function or to predict its failure. Using MEMS microfabrication methods, the proposed flow sensor will be manufactured at a size small enough to be integrable with implanted VP shunts. The key elements in the flow meter are capacitive structures that change properties with change in CSF flow. Electromagnetic coupling between the internal passive circuitry and an external handheld circuit allows implantation of the flow sensor without the need for implanted batteries or transcutaneous wires. The proposed Phase II project will build on the encouraging results of Phase I, which demonstrated the wireless interrogation of proof-of-concept MEMS sensors and the presence of a readily measurable relationship of flow to the resonance of the sensor. In Phase II, fully-function flow-sensing MEMS chips will be manufactured, as well as a revised handheld unit that will display and output flow, based on the known relationship between flow rate and resonance. In vitro testing will establish calibration for the sensor implants, and will demonstrate measurement accuracy over the full physiological range of CSF flow, over long periods of time, and with appropriate phantom models. In parallel, a chronic sheep hydrocephalus model will be in preparation, along with implementation of appropriate packaging, biocompatibility, and sterilizability into the sensor implant prototypes, as well as consideration of MR compatibility. Performance of an animal test protocol shall evaluate the sensor in regard to (1) sensitivity and specificity with regard to detection of flow obstruction, (2) CSF flow measurement accuracy, and (3) effect on shunt patency.

描述（由申请人提供）： 一个可植入的无线流动传感器系统正在开发中，该系统将能够通过脑室流体（CSF）通过脑室脑层析（VP）分流器进行测量，目前用于治疗脑积水患者。 CSF流量是分流函数的关键指标，目前无法原位测量它，导致缺乏直接评估分流功能或预测其失效的临床方法。使用MEMS微生物方法，所提出的流动传感器将以足够小的尺寸制造，以与植入的VP分流器集成。流量计中的关键元素是电容结构，随着CSF流量的变化而改变属性。内部被动电路和外部手持电路之间的电磁耦合可以植入流动传感器，而无需植入电池或经皮线。拟议的II期项目将基于I期的令人鼓舞的结果，该项目证明了概念验证MEMS传感器的无线询问，以及在流动与传感器共振的易于测量关系的存在。在II阶段，将根据流速和共振之间的已知关系，将制造全功能流动性MEMS芯片以及将显示和输出流的修订单元。体外测试将为传感器植入物建立校准，并将在长期和适当的幻影模型中证明在CSF流量的完整生理范围内的测量精度。同时，将制备慢性绵羊脑积水模型，以及在传感器植入物原型中实施适当的包装，生物相容性和无菌性，并考虑MR兼容性。动物测试方案的性能应评估（1）关于（2）CSF流量测量精度的灵敏度和特异性，以及（3）对分流通路的影响。