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）：提出了一种植入式无线流量计，可以测量通过脑室腹膜（VP）分流器的脑脊液（CSF）流量，目前用于治疗脑积水患者。脑脊液流量是分流功能的关键指标，目前尚无方法对其进行原位测量，导致临床上缺乏直接评估分流功能或预测其失败的方法。使用 MEMS 微加工方法，所提出的流量计的制造尺寸将足够小，以便可与植入的 VP 分流器集成。流量计的关键元件是电容结构，其特性会随着 CSF 流量的变化而改变。内部无源电路和外部检测电路之间的放射性耦合允许植入流量计，而不需要植入电池或经皮电线。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，还将设计、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，将构建一个允许精确控制流量的测试台。将对流量计进行测试，以确认其能够满足许多评估标准：测量范围、精度以及测量对方向和环境条件的不敏感性。此外，模拟工作分流器的测试将评估生物相容性涂层在防止传感器中形成闭塞的有效性。第一阶段完成后，我们将证明所提议设备的可行性。第二阶段完成后，我们打算开发一种无线流量传感器，该传感器可以作为用于治疗脑积水的仪器化 VP 分流器的一部分。公众健康相关性：美国每年进行大约 23,000 例分流修复手术，以纠正用于治疗脑积水患者的脑室腹膜 (VP) 分流术相对常见的失败。然而，仍有儿童因分流失败而死亡，研究表明，及早发现可以挽救大部分儿童的生命。植入式无线脑脊液流量计将使临床医生能够在例行就诊期间监测分流功能（而不是等待脑积水症状再次出现），从而检测即将发生的分流失败，避免紧急情况下的救生治疗，以及降低与 VP 分流失败相关的死亡率。

项目成果

An Angstrom-sensitive, differential MEMS capacitor for monitoring the milliliter dynamics of fluids.

埃级敏感差分 MEMS 电容器，用于监测流体的毫升动力学。

• 发表时间: 2016-11-01
• 作者: Apigo, David J;Bartholomew, Philip L;Russell, Thomas;Kanwal, Alokik;Farrow, Reginald C;Thomas, Gordon A
• 通讯作者: Thomas, Gordon A

Evidence of an application of a variable MEMS capacitive sensor for detecting shunt occlusions.

应用可变 MEMS 电容传感器检测分流闭塞的证据。

• 发表时间: 2017-04-05
• 影响因子: 4.6
• 作者: Apigo, David J;Bartholomew, Philip L;Russell, Thomas;Kanwal, Alokik;Farrow, Reginald C;Thomas, Gordon A
• 通讯作者: Thomas, Gordon A

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。

• 发表时间: 2015-10-01
• 作者: Raj, Rahul;Lakshmanan, Shanmugamurthy;Apigo, David;Kanwal, Alokik;Liu, Sheng;Russell, Thomas;Madsen, Joseph R;Thomas, Gordon A;Farrow, Reginald C
• 通讯作者: Farrow, Reginald C