Ultra-High Resolution Magnetometers Based on APF SQUIDs

基于 APF SQUID 的超高分辨率磁力计

• 批准号: 6642616
• 负责人: MASOUD RADPARVAR
• 金额: $ 9.44万
• 依托单位: HYPRES, INC.
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6642616
• 关键词: bioengineering /biomedical engineering; biomagnetism measurement; biomedical equipment development; biosensor device; electrical conductance; imaging /visualization /scanning; magnetism; superconductivity

DESCRIPTION (provided by applicant): The objective of the proposed research is to develop Ultra-High Resolution, thin film low-temperature superconductivity (LTS) SQUID Magnetometers (UHRSM) with integrated pickup-loops and Additional Positive Feedback (APF). The UHRSM will be optimized for imaging of the magnetic fields produced by action currents, injury and developmental currents, remanent magnetization, and magnetic susceptibility in isolated living tissue and small experimental animal preparations. As a collaborative effort between HYPRES and several research institutions, including Living State Physics of Vanderbilt University, we are building analog SQUID magnetometers for imaging action currents in isolated living tissue. In order to utilize SQUIDs for these applications, their voltages are amplified by a step-up transformer so it could be instrumented with room temperature electronics. In addition, SQUID's transfer characteristics should be linearized. The use of a step-up transformer requires extensive peripheral electronics for linearization, thus limiting the number of SQUID magnetometer channels in a practical system. We are proposing to develop a novel SQUID with Additional Positive Feedback (APF) that eliminates the need for the transformer, and as a result simplifies the peripheral electronics significantly. The proposed APF SQUID integrates an on-chip feedback coil with the SQUID. This can increase the gain of the device substantially, and as a result no step-up transformer is required for read out. The APF SQUID system is compact and cost effective, and requires minimal support electronics. The proposed research involves the staged development and implementation of a SQUID design to enhance the spatial resolution and maximize the field sensitivity for specific applications. The existing expertise will be exploited further to develop and improve SQUID sensors for general and custom biomagnetic applications which require higher-sensitivity SQUID magnetometers and gradiometers but lower spatial resolution. An aggressive program of biophysical measurements at Vanderbilt coupled with the technical expertise at HYPRES will lead to both a commercially attractive UHRSM instrument and a valuable national capability for fabrication of new designs for SQUID sensors.

描述（由申请人提供）： 该研究的目的是开发超高分辨率，薄膜低温超导（LTS）SQUID磁强计（UHRSM）与集成的拾波回路和附加的正反馈（APF）。UHRSM将针对动作电流、损伤和发育电流、恢复磁化和离体活组织和小型实验动物制备物中的磁化率产生的磁场成像进行优化。作为HYPRES和几个研究机构，包括范德比尔特大学的生活状态物理学之间的合作努力，我们正在建立模拟SQUID磁强计成像动作电流在孤立的活组织。为了将SQUID用于这些应用，它们的电压通过升压Transformer放大，因此可以使用室温电子设备进行仪表化。此外，SQUID的传输特性应线性化。升压Transformer的使用需要大量的外围电子设备用于线性化，从而限制了实际系统中SQUID磁强计通道的数量。我们建议开发一种新型的SQUID与附加的正反馈（APF），消除了对Transformer的需要，并因此简化了外围电子显着。所提出的APF SQUID集成了一个片上反馈线圈的SQUID。这可以显著地增加器件的增益，并且因此不需要升压Transformer来进行读出。APF SQUID系统结构紧凑，成本效益高，需要最少的支持电子设备。拟议的研究涉及SQUID设计的分阶段开发和实施，以提高空间分辨率，并最大限度地提高特定应用的场灵敏度。将进一步利用现有的专业知识开发和改进SQUID传感器，用于一般和定制的生物磁应用，这些应用需要更高灵敏度的SQUID磁力计和梯度计，但空间分辨率较低。范德比尔特的一项积极的生物物理测量计划，加上HYPRES的技术专长，将导致一个商业上有吸引力的UHRSM仪器和一个宝贵的国家能力，为SQUID传感器的新设计的制造。