A NOVEL ANALOGUE BIO-IMPEDANCE SYSTEM-ON-A-CHIP FOR MONITORING OF NEONATE LUNG FUNCTION

本研究提出开发一种迫切需要的基于电阻抗断层成像（EIT）的生物成像系统，用于重症监护病房（ITUs）新生儿肺功能的体内监测。肺生长、成熟和呼吸控制障碍是新生儿医生面临的最重要的问题。早产发生在所有妊娠的5-10%，并且经常伴有由于肺不成熟引起的并发症。NHS每年的费用估计在数亿美元左右。国际电联监测新生儿肺功能的主要困难之一是，该系统必须以被动的方式测量受试者，不像成年人可以被要求执行特定的呼吸任务。EIT是解决这个问题的唯一办法。此外，EIT在许多临床应用中被证明是成功的，其中一个例子是用于检测乳腺癌的新的商业TSCAN系统。该系统将提供肺成熟和发育、氧气需求和肺功能的非侵入性测量，适用于未镇静的小婴儿。该工具将常规用于确定持续性肺部疾病的性质和严重程度，并确定发展为慢性肺部问题的危险因素。EIT的主要局限性是固有的共模误差，导致重建图像的质量下降。这些误差在多频EIT的情况下更为明显。我们发明了一种方法，通过使用一种新的宽带模拟共模增强技术来解决这个问题，这种技术可以最大限度地提高总体共模抑制比（CMRR）和信噪比（SNR）。为了充分利用我们的宽带CMRR反馈方法的能力，我们将使用完全定制的电路设计技术来创建一种新型的多频EIT硅片系统。我们还开发了先进的重建方法，涉及新的网格翘曲技术，利用边界信息来调节正演模型，同时考虑到问题域的解剖细节。这项研究的最终结果将是一种可穿戴设备形式的新技术，它将在监测新生儿时最大限度地减少干扰。这将涉及定制硅芯片的设计，集成可穿戴电极系统，新的3D图像重建算法和先进的后期图像处理方法。这项研究将在伦敦大奥蒙德街世界领先的儿童医院Portex麻醉、强化治疗和呼吸内科的全面临床支持下进行。

This research proposes the development of an urgently needed Electrical Impedance Tomography (EIT)-based bio-imaging system for in-vivo monitoring of neonate lung function in Intensive care Units (ITUs). Disorders of lung growth, maturation and breathing control are among the most important problems faced by the neonatologist. Premature birth occurs in 5-10% of all pregnancies, and is frequently accompanied by complications due to lung immaturity. The annual cost to the NHS is estimated in the order of hundreds of millions. One of the key difficulties of neonate ITU monitoring for lung function is that the system must measure the subject in a passive manner, unlike adults who can be asked to perform specific respiratory tasks. EIT is the only solution to this problem. Moreover, EIT is proving to be successful in many clinical applications, an example is the new commercial TSCAN system for detection of breast cancer.The proposed system will provide a non-invasive measure of lung maturity and development, oxygen requirements and lung function, suitable for use in small, unsedated infants. This tool will be routinely used to define the nature and severity of persisting lung disease, and to identify risk factors for developing chronic lung problems. Major limitations of EIT are the inherent common mode errors which result in reduction of the quality of the reconstructed images. These errors are more pronounced in the case of multi-frequency EIT. We have invented a method to address the problem by the use of a novel wideband analogue common-mode enhancement technique which can maximise the overall common-mode rejection ratio (CMRR) and signal-to-noise ratio (SNR). To take full advantage of the capabilities of our wideband CMRR feedback approach, we will use full custom circuit design techniques to create a novel multi-frequency EIT system-on-a-silicon-chip. We have also developed advanced reconstruction methods involving new mesh warping techniques that utilise the boundary information to condition the forward model, taking into account the anatomical details of the problem domain. The end result of this research will be new technology in the form of a wearable device which will minimise disruption when monitoring neonates. This will involve the design of custom made silicon chips, an integrated wearable electrode system, new 3D image reconstruction algorithms and advanced post image processing methodologies. This research will be carried out with the full clinical support of the Portex Anaesthesia, Intensive Therapy and Respiratory Medicine Unit at the world leading children's Hospital, Great Ormond Street, London.