A Low-Cost Cryosusceptometer

描述(由申请人提供)：临床上已确定需要一种安全、准确、成本效益高且容易获得的体内铁储存的非侵入性测量方法。一种基于低温超导(LTS)的准确的、经过临床验证的磁感应计已经问世20多年了，但其复杂性、成本(约100万美元)以及对液体氦的需求限制了它在少数研究中心的使用。考虑到对液氦的要求，以及自问世以来成本没有显著降低的事实，人们普遍认为超导感应法不太可能进入一般临床实践。高温超导的发现和使用超导体的柔性材料的出现极大地改变了技术图景。在第一阶段，我们将这些新材料与其他一些最新进展结合起来，克服了所指出的广泛实施的技术障碍。具体地说，我们开发了一种使用传统磁传感器和非常创新的磁通集中器的原理证明仪器。最近出现了低振动和小质量的制冷机，这使得该仪器只需依靠壁面功率就可以操作，而且低温过程也不复杂。新提议的仪器的材料部件成本往往比ITS系统低一倍，而且操作和维护要简单得多。一种新的测量方法已经开发出来，它消除了成本较高和不可靠的元素，同时保证了同等或更高的灵敏度。我们的第二阶段目标是在第一阶段取得强劲进展的基础上，建造一种准确、廉价、可由未受过专门技术培训的人员操作的冷冻仪原型。一台简单、低成本的冷冻仪将满足对多种铁库(0.2毫克/克湿重到10毫克/克以上)进行准确临床铁评估的迫切需要。它还有望打开超导灵敏度测量在医学和工业中的其他一些应用。为了实现这一点，我们提出了一个循序渐进的发展计划，包括20名铁超载(地中海贫血和镰状细胞)患者和5名正常对照受试者的初步临床评估。

DESCRIPTION (provided by applicant): There is an established clinical need for a non-invasive measure of body iron stores that is safe, accurate, cost effective and readily available. An accurate, clinically validated susceptometer based on low-temperature superconductivity (LTS) has been available for more than two decades, but its complexity, cost (~$1,000,000), and need for liquid helium have restricted its use to a handful of research centers. Given the liquid helium requirement, and the fact that no significant cost reduction has occurred since its inception, it has been widely felt that superconducting susceptometry is unlikely to enter general clinical practice. The discovery of high-Tc superconductivity and the recent emergence of flexible materials based employing superconductors have dramatically altered the technical picture. In Phase I, we combined these novel materials with a number of other recent advances and overcame the technical barriers to widespread implementation noted. Specifically, we developed an proof-of-principle instrument using conventional magnetic sensors and a very innovative flux concentrator. The recent availability of low vibration and small mass cryocoolers has made the instrument depend only on wall power for operation and uncomplicated cryogenics. The new proposed instrument will have a material parts cost often times less than the ITS system and be much simpler to operate and maintain. A new measurement methodology has been developed that eliminates the costlier and unreliable elements while promising equivalent or superior sensitivities. Our Phase II goal is to build on our strong progress in Phase I and construct a prototype cryosusceptometer that is accurate, inexpensive and can be operated by personnel who have no specialized technical training. A simple low-cost cryosusceptometer will satisfy the pressing need for accurate clinical iron assessment over a wide range of iron stores (0.2 mg/g-wet weight to above 10 mg/g). It also promises to open up a number of other applications for superconducting susceptometry, in both medicine and industry. To achieve this, we propose a step-by-step development program that concludes with a preliminary clinical evaluation involving twenty iron overloaded (thalassemic and sickle-cell) patients and five normal control subjects.