Enabling Millimeter Scale Deeply Implanted Glucose Sensors through Ultrasonic Power Transfer and a Novel Glucose Sensing Mechanism

通过超声波功率传输和新型葡萄糖传感机制实现毫米级深度植入葡萄糖传感器

• 批准号: 1408265
• 负责人: Shad Roundy
• 金额: $ 37.51万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1408265&HistoricalAwards=false
• 关键词: Enabling; Millimeter; Scale; Deeply; Implanted

Proposal Title:Enabling Millimeter Scale Deeply Implanted Glucose Sensors through Ultrasonic Power Transfer and a Novel Glucose Sensing Mechanism Proposal Goal:The goal of the proposed project is to enable a new mode for power transfer to and communication with a deeply implanted intraluminal glucose monitor. The current state of the art in integrated circuit and MEMS sensing technologies enables cubic mm size implementations of complex systems for implanted sensors. However, such implementations are never actually realized because the necessary power and communications systems are too large. At very small sizes and large implantdepths acoustic energy transfer through human tissue is fundamentally more efficient than either near field electromagnetic (EM) or far field (RF). The long term goal of this research is to create an ultrasonic power and communications platform that will enable unobtrusive long term monitoring of health status through implanted sensing and therapeutic devices.Nontechnical Abstract: The past few decades have seen a dramatic increase in the prevalence of diabetes mellitus and obesity. The chief complications of these chronic diseases are cardiac disease, kidney failure leading to dialysis, retinopathy leading to blindness, and neuropathy and vascular insufficiency leading to amputations. These exert a huge toll, both in financial terms and in human suffering. Our research directly addresses this problem by developing new technologies that will enable long term implantable glucose monitors without the need for transcutaneous wires. This project addresses two fundamental problems with the current state of the art in implantable glucose sensors: lack of a suitable power supply or power transmission mechanism, and the short lifetime and frequent need for re-calibration of glucose oxidase based sensors. As part of this project, the PIs will create an ultrasonic power transmission platform that will allow the glucose sensor (or any highly miniaturized implantable bio-sensor) to be directly powered by ultrasonic energy. At very small sizes and large implant depths acoustic energy transfer through human tissue is fundamentally more efficient than either near field electromagnetic (EM) or far field (RF), the two most common methods of powering implanted sensors. This project will investigate micro-scale acoustic transducer designs and architectures that enable higher power density transmission than either EM or RF transmission through human tissue. To address the second fundamental problem with the state of the art, the PIs will explore a new glucose sensing method using hydrogels with embedded magnetic particles. This method overcomes several limitations that plague current enzymatic continuous glucose sensors and also allows the electronics to be robustly encapsulated as the electronic sensing element does not have to be in direct contact with the hydrogel. Together these advancements promise to enable a vastly improved method of sensing blood glucose and delivering power to any highly miniaturized implantable bio-sensor.Technical Abstract: This research addresses two major challenges that limit the potential of implanted biosensors in general, and glucose monitors in particular. The first is transferring energy at sufficient densities to enable extreme miniaturization. While still more efficient than RF or EM energy transfer, at very small scales, standard ultrasonic transducers rapidly start to lose efficiency due to the interplay between the optimal device thickness, acoustic wavelength, and the frequency dependence of acoustic absorption in tissue. Our guiding hypothesis is that alternative piezoelectric structures will be more efficient at these small sizes. Our work will couple acoustic transmission models, transducer design, and experimental work to empirically determine key interaction effects probing the limits of acoustic power generation at very small scales.Secondly, the research will address a significant issue with glucose sensors, namely that their lifetime is severely limited and they must be frequently re-calibrated because of their reliance on the availability glucose oxidase and oxygen to perform accurate measurements. The PIs will explore a new method using hydrogels with embedded aligned magnetic particles to sense glucose rather than the traditional electrochemical process. These functionalized hydrogels swell in the presence of glucose. The swelling is sensed through the change in inductance value of a miniature coil placed next to the hydrogel. This method not only overcomes several limitations that plague current enzymatic continuous glucose sensors but also allows the electronics to be robustly encapsulated as the sensing coil does not have to be in direct contact with the hydrogel. The sensing coil will be multi-purposed to send data back from the implant in a mm scale system demonstration. Taken together, the three different aspects of this work could provide a basis for fundamentally smaller, longer life implanted sensors.

提案题目：通过超声功率传输和一种新的葡萄糖传感机制实现毫米级深度植入葡萄糖传感器提案目标：拟议项目的目标是实现一种新的模式，用于深度植入的腔内血糖监测仪的功率传输和通信。集成电路和MEMS传感技术的当前状态使植入传感器的复杂系统能够实现立方毫米大小。然而，这种实现从来没有真正实现过，因为必要的电源和通信系统太大了。在非常小的尺寸和大的植入深度下，通过人体组织的声能传输基本上比近场电磁（EM）或远场电磁（RF）更有效。这项研究的长期目标是创造一个超声波电源和通信平台，通过植入的传感和治疗设备，实现对健康状况的长期监测。摘要：在过去的几十年里，糖尿病和肥胖症的患病率急剧上升。这些慢性疾病的主要并发症是心脏病、导致透析的肾衰竭、导致失明的视网膜病变以及导致截肢的神经病变和血管功能不全。无论是在经济方面还是在人类苦难方面，这些都造成了巨大的损失。我们的研究通过开发新技术直接解决了这个问题，该技术将使长期植入式血糖监测仪无需经皮导线。该项目解决了目前植入式葡萄糖传感器存在的两个基本问题：缺乏合适的电源或动力传输机制，葡萄糖氧化酶传感器寿命短且经常需要重新校准。作为该项目的一部分，pi将创建一个超声波能量传输平台，该平台将允许葡萄糖传感器（或任何高度小型化的植入式生物传感器）直接由超声波能量供电。在非常小的尺寸和大的植入物深度下，通过人体组织的声能传输基本上比近场电磁（EM）或远场电磁（RF）两种最常用的植入传感器供电方法更有效。该项目将研究微尺度声换能器的设计和架构，使其能够通过人体组织进行比电磁或射频传输更高的功率密度传输。为了解决现有技术的第二个基本问题，pi将探索一种新的葡萄糖传感方法，使用嵌入磁性颗粒的水凝胶。该方法克服了困扰当前酶促连续葡萄糖传感器的几个限制，并且由于电子传感元件不必与水凝胶直接接触，也允许电子元件被坚固地封装。总之，这些进步有望极大地改善血糖检测方法，并为任何高度小型化的植入式生物传感器提供能量。技术摘要：本研究解决了限制植入式生物传感器潜力的两个主要挑战，特别是葡萄糖监测仪。第一个是以足够的密度传输能量，以实现极端小型化。虽然仍然比射频或电磁能量传递更有效，但在非常小的尺度下，由于最佳器件厚度、声波波长和组织中声吸收的频率依赖性之间的相互作用，标准超声换能器迅速开始失去效率。我们的指导假设是，替代压电结构将在这些小尺寸下更有效。我们的工作将结合声传输模型，换能器设计和实验工作，以经验确定关键的相互作用效应，探测极小尺度下声发电的极限。其次，该研究将解决葡萄糖传感器的一个重要问题，即它们的使用寿命受到严重限制，并且必须经常重新校准，因为它们依赖于可用的葡萄糖氧化酶和氧气来进行准确的测量。pi将探索一种新的方法，使用嵌入排列磁颗粒的水凝胶来感知葡萄糖，而不是传统的电化学过程。这些功能化的水凝胶在葡萄糖的存在下膨胀。膨胀是通过放置在水凝胶旁边的微型线圈电感值的变化来检测的。这种方法不仅克服了困扰当前酶促连续葡萄糖传感器的几个限制，而且由于传感线圈不必与水凝胶直接接触，也允许电子元件被坚固地封装。传感线圈将是多用途的，在毫米级系统演示中从植入物发回数据。总的来说，这项工作的三个不同方面可以为更小、更长寿的植入传感器提供基础。

项目成果

A MEMS-Scale Ultrasonic Power Receiver for Biomedical Implants

• DOI: 10.1109/lsens.2019.2904194
• 发表时间: 2019-04-01
• 期刊: IEEE SENSORS LETTERS
• 影响因子: 2.8
• 作者: Basaeri, Hamid;Yu, Yuechuan;Roundy, Shad
• 通讯作者: Roundy, Shad

An In-Vitro Study of Wireless Inductive Sensing and Robust Packaging for Future Implantable Hydrogel-Based Glucose Monitoring Applications

针对未来植入式水凝胶血糖监测应用的无线感应传感和坚固封装的体外研究

• DOI: 10.1109/jsen.2019.2949056
• 发表时间: 2020
• 期刊: IEEE Sensors Journal
• 影响因子: 4.3
• 作者: Yu, Yuechuan;Nguyen, Tram;Tathireddy, Prashant;Roundy, Shad;Young, Darrin J.
• 通讯作者: Young, Darrin J.

Acoustic power transfer for biomedical implants using piezoelectric receivers: effects of misalignment and misorientation

• DOI: 10.1088/1361-6439/ab257f
• 发表时间: 2019-08-01
• 期刊: JOURNAL OF MICROMECHANICS AND MICROENGINEERING
• 影响因子: 2.3
• 作者: Basaeri, Hamid;Yu, Yuechuan;Roundy, Shad
• 通讯作者: Roundy, Shad

Architectures for wrist-worn energy harvesting

• DOI: 10.1088/1361-665x/aa94d6
• 发表时间: 2018-04-01
• 期刊: SMART MATERIALS AND STRUCTURES
• 影响因子: 4.1
• 作者: Rantz, R.;Halim, M. A.;Roundy, S.
• 通讯作者: Roundy, S.