Flexible Ribbon Guide - In-Vivo & Hand-Held THz Imaging

柔性色带指南 - In-Vivo

• 批准号: 7115924
• 负责人: PETER H SIEGEL
• 金额: $ 19.72万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7115924
• 关键词: bioengineering /biomedical engineering; bioimaging /biomedical imaging; biomedical equipment development; electromagnetic radiation; endoscopy; fiber optics; physical property; portable biomedical equipment; radiowave radiation

DESCRIPTION (provided by applicant): Flexible Ribbon Guide for In-Vivo and Hand-Held THz Imaging: Recent interest in terahertz frequency imaging for medical applications (wavelength range from 1 mm to 100 microns) has stimulated a flurry of new instrument proposals using both time domain and high resolution frequency domain spectral techniques. However, the field is very new, and definitive contrast mechanisms other than strong liquid absorption, have not yet been established. Terahertz studies on basal cell carcinoma, both in-vivo and ex-vivo, are very promising but the instrumentation employed is limited to fixed-position skin surface scans only. The problem lies with the fact that there exists no methodology for flexibly transporting terahertz signals from place-to-place with low loss, other than rigid-path free-space quasi-optical beam propagation. This means no terahertz instrument can be used in a hand-scanning mode or an in-vivo endoscopic application, with its greatly enhanced range of surveyable tissue and contrast. This research will change the modality and capability of all terahertz imaging instruments providing contrast that cannot be obtained today. In order to take advantage of techniques common at optical wavelengths, including in-vivo and portable hand-held sensor/receiver systems, the equivalent of signal-confining optical fiber links must be developed for the terahertz bands. Commonly employed transparent materials in the visible are all extremely lousy at longer wavelengths due to strong vibrational mode absorption. Dielectric substances with low absorption coefficient and high index do exist at terahertz frequencies, but they tend to be crystalline and therefore have poor mechanical properties when it comes to forming flexible guiding structures. Metallic waveguide (hollow or coaxial), although somewhat flexible, has untenable high resistive wall loss. A few plastics have very low dispersion and absorption but have a low refractive index that makes it difficult to confine single mode terahertz energy as it propagates around bends or through joints. Work by our collaborators has shown that high index materials formed into ultra-thin ribbons can form very low loss guiding media at millimeter-wave frequencies (30-300 GHz). Extrapolating this concept into the terahertz bands, and taking advantage of modern thin film fabrication techniques, we believe it is possible to use a combination of electro-deposited high-dielectric-constant crystalline materials in conjunction with low-loss, low index plastics to produce the equivalent of flexible terahertz optical fiber, i.e., "terahertz ribbon guide." The work to be performed will offer a solution to a major stumbling block in terahertz imaging and will significantly enhance the range of applications for all terahertz imagers, making it possible to scan fixed samples directly, or transport terahertz signals into the body where additional modalities, such as localized thermography, may be explored.

描述（由申请人提供）： 用于体内和手持式THZ成像的柔性色带指南：对医疗应用的Terahertz频率成像的最新兴趣（从1 mm到100微米）刺激了使用时域和高分辨率频率域光谱的一系列新仪器提案。但是，该领域是非常新的，并且尚未确定强烈的液体吸收以外的明确对比机制。 Terahertz对基底细胞癌的研究非常有前途，但使用的仪器仅限于固定位置皮肤表面扫描。问题在于，没有方法可以灵活地将Terahertz信号从损失较低的位置转移，除了刚性路径自由空间准光束传播。这意味着没有Terahertz仪器可以在手工扫描模式或体内内窥镜外应用中使用，其可测量的组织和对比度大大增强。这项研究将改变所有Terahertz成像工具的方式和能力，提供今天无法获得的对比度。为了利用光波长在包括体内和便携式手持传感器/接收器系统在内的通用技术，必须为Terahertz频段开发相当于信号填充光纤链接的技术。由于强烈的振动模式吸收，在可见光中通常使用的透明材料在更长的波长下都非常糟糕。在Terahertz频率上确实存在具有低吸收系数和高指数的介电物质，但是它们倾向于结晶，因此在形成柔性指导结构时具有较差的机械性能。金属波导（空心或同轴）虽然有些灵活，但具有站不可分的高电阻壁损失。一些塑料具有非常低的分散体和吸收，但折射率低，这使得在弯曲周围或通过关节传播时很难将单模式的terahertz能量限制。我们的合作者的工作表明，在超薄丝带中形成的高指数材料可以在毫米波频率（30-300 GHz）上形成非常低的损失引导介质。将这个概念推断到Terahertz乐队中，并利用现代的薄膜制造技术，我们相信可以将电沉积的高含量高稳态晶体材料结合在一起，结合低损耗，低索引形状来产生柔韧性Terahertz光纤纤维的等效性。要执行的工作将为Terahertz成像中的一个主要绊脚石提供解决方案，并将大大提高所有Terahertz成像仪的应用范围，从而可以直接扫描固定样品，或将Terahertz信号传输到人体中，在该物体中，可以探索其他模态，例如局部热量表，例如可以探索。