Micro-machined Joule-Thomson Cryosurgical Instrument

微机械 Joule-Thomson 冷冻手术器械

• 批准号: 6953984
• 负责人: YOGESH B GIANCHANDANI
• 金额: $ 30.13万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6953984
• 关键词: bioengineering /biomedical engineering; biomedical equipment development; cryosurgery; magnetic resonance imaging; silicon; temperature; thermodynamics

The objective of the proposed work is the development of a micro-machined cryosurgical instrument that utilizes a mixed-gas Joule-Thomson thermodynamic cycle to produce cryogenic tip temperatures. The device incorporates a micro-scale active valve and a composite recuperative heat exchanger in order to overcome limitations that currently limit cryosurgical instruments. The ultimate goal of this research is to provide surgeons with a cryosurgical probe that has significant advantages in terms of thermal performance, size, flexibility, and cost relative to the current state-of-the-art. The technical developments proposed here will enable MEMS technology, with all of its inherent advantages, to be brought to bear on the problem of cryosurgery. The cryoprobe wilJbe fabricated using conventional micro-fabrication techniques resulting in a low cost device that can be batch fabricated. Instrumentation and heaters to monitor and control the temperature field may be monolithically installed on the probe. The probe structure will be primarily silicon and glass and will therefore be compatible with magnetic resonance imaging, enabling real-time monitoring of cryosurgical procedures. During the R21 Phase of the project we will design and separately fabricate the active valve and recuperative heat exchanger. These components will be tested to demonstrate that they satisfy the requirements of the cryosurgical system. The R21 phase will culminate in a system level test that demonstrates the viability of the thermodynamic cycle and the reliability of the components. The goal of the R33 Phase is to utilize this technology base in order to design, fabricate, and demonstrate an integrated micro-fabricated cryosurgical probe. The demonstration probe will be packaged in a manner that is consistent with clinical usage. The ability of the probe to withstand pressure, thermal, and bending loads that are greater than those anticipated during usage will be demonstrated. The performance of the cryoprobe will be precisely measured in a thermal vacuum environment. Subsequent, in-vivo testing will occur in a gelatin solution and later in excised animal tissue in order to quantify the time and length scales associated with the freeze zone. Control algorithms that will enable automatic implementation of surgical protocols, defined in terms of freeze zone characteristics, will be developed and demonstrated.

拟议工作的目标是开发一种微加工冷冻外科仪器，该仪器利用混合气体焦耳-汤姆森热力学循环来产生低温尖端温度。该装置采用了一个微型主动阀和复合回热式热交换器，以克服目前限制冷冻手术器械的局限性。本研究的最终目标是为外科医生提供一种冷冻手术探针，该探针相对于当前最先进的技术在热性能、尺寸、灵活性和成本方面具有显著优势。这里提出的技术发展将使MEMS技术及其所有固有优势能够用于解决以下问题： 冷冻手术冷冻探针将使用常规的微制造技术制造，从而产生可以批量制造的低成本装置。监测和控制温度场的仪器和加热器可以整体地安装在探头上。探针结构将主要是硅和玻璃，因此将与磁共振成像兼容，从而能够实时监测冷冻外科手术。在项目的R21阶段，我们将分别设计和制造主动阀和回热式换热器。将对这些组件进行测试，以证明它们满足 冷冻手术系统的要求。R21阶段将在系统级测试中达到高潮， 证明了热力循环的可行性和组件的可靠性。R33阶段的目标是利用这一技术基础，以设计，制造和展示一个集成的微型冷冻外科探针。演示穿刺针将以与临床使用一致的方式包装。将证明穿刺针承受压力、热和弯曲载荷的能力，这些载荷大于使用过程中的预期载荷。冷冻探针的性能将在热真空环境中精确测量。随后，将在明胶溶液中进行体内试验，随后在切除的动物组织中进行体内试验，以量化与冷冻区相关的时间和长度尺度。控制算法，将使自动执行的手术方案，定义在冻结区的特点，将被开发和证明。