Microfabricated Implantable Flowmeter for CSF Shunts

用于脑脊液分流器的微型植入式流量计

• 批准号: 7539699
• 负责人: JAMES Hunter GOLDIE
• 金额: $ 32.49万
• 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 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7539699
• 关键词: Altitude; Animals; Appearance; Biocompatible; Brain Injuries; Calibration; Catheters; Cerebrospinal Fluid; Cerebrospinal Fluid Pressure; Cerebrospinal fluid shunts procedure; Child; Clinical; Condition; Coupling; Creation of ventriculo-peritoneal shunt; Data; Detection; Devices; Disease; Early Diagnosis; Effectiveness; Electronics; Emergency Situation; Evaluation; Failure; Figs - dietary; Floor; Flowmeters; Frequencies; Government; Grant; Hour; Hydrocephalus; Implant; In Situ; Indium; Injury; Intake; Intracranial Pressure; Knowledge; Measurement; Measures; Mechanics; Methods; Microfabrication; Monitor; Neurosurgeon; Noise; Numbers; Office Visits; Operative Surgical Procedures; Patients; Persons; Phase; Physicians; Physiological; Procedures; Property; Proteins; Protocols documentation; Public Health; Published Comment; Purpose; Radioactive; Range; Rate; Reading; Relative (related person); Reporting; Research; Saline; Shunt Device; Side; Simulate; Skin; Structure; Symptoms; System; Technology; Temperature; Testing; Time; Trephine hole; Ventricular; Walking; Wireless Technology; Work; base; cerebrospinal fluid flow; cranium; day; design; implantable device; implantation; improved; instrument; member; meter; mortality; pressure; prevent; prototype; response; sensor; size

DESCRIPTION (provided by applicant): An implantable wireless flow meter is proposed 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 meter will be manufactured at a size small enough to be integratable with implanted VP shunts. The key elements in the flow meter are capacitive structures that change properties with change in CSF flow. Radioactive coupling between the internal passive circuitry and an external detection circuit allows implantation of the flow meter without the need for implanted batteries or transcutaneous wires. The proposed Phase I project will design and fabricate a set of MEMS flow sensor prototypes, which will then be inspected and bench tested to confirm key parameters. In parallel, the electronic circuitry required to wirelessly interrogate the sensor will be designed, assembled and tested. In order to perform a protocol that calls for testing of the sensor under realistic conditions, a test stand will be constructed that allows precise control of flow. Tests will be undertaken with the flow meter to confirm that it can meet a number of evaluation criteria: measurement range, accuracy, and measurement insensitivity to orientation and ambient conditions. In addition, testing which simulates a working shunt will evaluate the effectiveness of biocompatible coatings in preventing formation of occlusions in the sensor. Upon completion of Phase I, we will have proved feasibility of the proposed device. Upon completion of Phase II we intend to have developed a wireless flow sensor that could be included as part of an instrumented VP shunt for the treatment of hydrocephalus. PUBLIC HEALTH RELEVANCE: Every year there are approximately 23,000 shunt revisions performed in the U.S., in order to correct the relatively common failure of ventriculoperitoneal (VP) shunts used to treat hydrocephalus patients. However, children are still dying from shunt failure, and studies indicate that earlier detection would save a large fraction of these children. An implantable, wireless CSF flow meter would enable the clinician to monitor shunt function during routine office visits (rather than waiting for the re-appearance of hydrocephalus symptoms), allowing detection of impending shunt failure, avoidance of lifesaving treatment on an emergency basis, and reduction of mortality associated with VP shunt failure.

描述（由申请人提供）：申报了一种植入式无线流量计，可测量通过脑室腹膜（VP）分流管的脑脊液（CSF）流量，目前用于治疗脑积水患者。CSF流量是分流功能的关键指标，目前无法原位测量，导致缺乏直接评估分流功能或预测其失败的临床方法。使用MEMS微制造方法，所提出的流量计将以足够小的尺寸制造，以便与植入的VP分流器集成。流量计中的关键元件是电容结构，其随着CSF流量的变化而改变属性。内部无源电路和外部检测电路之间的放射性耦合允许在不需要植入电池或经皮导线的情况下植入流量计。拟议的第一阶段项目将设计和制造一套MEMS流量传感器原型，然后对其进行检查和台架测试，以确认关键参数。同时，将设计、组装和测试无线询问传感器所需的电子电路。为了执行要求在实际条件下测试传感器的协议，将构建一个测试台，以精确控制流量。将对流量计进行测试，以确认其能够满足多项评估标准：测量范围、准确度以及测量对方向和环境条件的不敏感性。此外，模拟工作分流管的试验将评价生物相容性涂层在防止传感器中形成闭塞方面的有效性。待第一阶段完成后，我们便可证明拟议装置的可行性。在第II阶段完成后，我们计划开发一种无线流量传感器，该传感器可作为用于治疗脑积水的仪表化VP分流器的一部分。公共卫生相关性：美国每年约有23，000例分流翻修术，以纠正用于治疗脑积水患者的脑室腹膜（VP）分流的相对常见的失败。然而，儿童仍然死于分流失败，研究表明，早期发现将挽救这些儿童中的很大一部分。植入式无线CSF流量计将使临床医生能够在常规门诊访视期间监测分流功能（而不是等待脑积水症状的再次出现），从而检测即将发生的分流失败，避免紧急救生治疗，并降低VP分流失败相关的死亡率。

项目成果

Demonstration that a new flow sensor can operate in the clinical range for cerebrospinal fluid flow.

证明新型流量传感器可以在脑脊液流量的临床范围内运行。

• DOI: 10.1016/j.sna.2015.08.023
• 发表时间: 2015
• 期刊: Sensors and actuators. A, Physical
• 作者: Raj,Rahul;Lakshmanan,Shanmugamurthy;Apigo,David;Kanwal,Alokik;Liu,Sheng;Russell,Thomas;Madsen,JosephR;Thomas,GordonA;Farrow,ReginaldC
• 通讯作者: Farrow,ReginaldC