High-Speed, Depth-Resolved Images of Cardiac physiology

心脏生理学的高速、深度分辨图像

• 批准号: 6938578
• 负责人: Guy Salama
• 金额: $ 43.83万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6938578
• 关键词: action potentials; arrhythmia; bioengineering /biomedical engineering; bioimaging /biomedical imaging; biomedical equipment development; calcium flux; computer program /software; computer system design /evaluation; confocal scanning microscopy; fluorescent dye /probe; guinea pigs; heart cell; heart electrical activity; heart function; heart imaging /visualization /scanning; image processing; laboratory rabbit; myocardium; optics; reagent /indicator

DESCRIPTION (provided by applicant): The long-term goal of this Bioengineering Research Partnership (BRP) is to develop a High-Speed, Depth-Resolved Imager (HSDRI) to map electrical activity or intracellular free Ca 2+ transients inside the myocardium of perfused hearts. The partnership consists of 3 groups. Dr. Guy Salama (PI at the University of Pittsburgh) will administer the BRP, develop the instrument and apply the new technology to problems in cardiac electrophysiology, that remain unresolved due to a lack of 3-D information. Drs. Alan Waggoner (at Carnegie-Mellon University, Director of the Center for Light Microscope Imaging and Biotechnology (CLMIB)) and Lauren Ernst will develop optical probes (voltage-sensitive and Ca2+ indicator dyes) with long excitation and emission wavelengths to improve tissue penetration and reduce light scattering from the myocardium. Dr. Fred Lanni (at CLMIB) will provide the theoretical and engineering expertise to develop and refine the HSDRI. The 3 groups will work in parallel. Aim 1 (Salama and Lanni, years 1-5): Two approaches will be developed and tested to obtain the best possible HSDRI system. (a) A system based on a Ronchi line grating to focus dark and bright bands in a focal plane 2-5 mm deep in ventricular tissue. Fluorescence images from the tissue will be taken (at 3k frames/s) during shifts of bright and dark bands of light excitation by 1/3 period. Images will be processed on-line to eliminate light emanating above and below the plane of focus to obtain depth-resolved images, at 1k frames/s. (b) A standard Nipkow spinning disk confocal imager will be modified for large fields-of-view (3x3 mm 2)and high frame rates. Aim 2 (years 1-5): Drs. Waggoner and Ernst will synthesize new longer wavelength fluorescent dyes to monitor action potentials (APs) or cytosolic free Ca2+(Cai) and Dr. Salama will test, analyze the spectral characteristics and response characteristics of the new probes in heart muscle. Aim 3 (Salama, Choi and Lanni years 1-5): Software will be developed to drive the HSDRI, analyze APs and Ca-i transients and map electrical activity in 3-D. Depth-resolved maps of activation, repolarization and AP durations will be used to investigate 2 topics in cardiac electrophysiology, where measurements in 3-D are essential to elucidate fundamental concepts. A) We will investigate the factors that modify electrical coupling (time-delay or block) between Purkinje fibers (P), Transitional (T) and Ventricular (V) cells to elucidate the role of PV junctions in the initiation and maintenance of arrhythmias. APs will be mapped in 3-D to resolve PV delays during antegrade and retrograde conduction, normoxic and ischemic in paced and during arrhythmias. B) Impulse propagation across the atrio-ventricular node (AVN) has been difficult to trace because of the complex 3-D structure of the node and the small region of compact cells. Activation maps of the AVN in 3-D will help us answer basic questions regarding the precise inputs to the node (fast and slow pathways), mechanisms of AVN reentry, Wenckebach periodicity and Wolf-Parkinson syndrome. Fast, depth-resolved images of voltage and Ca 2+are a powerful new tool that will have a wide range of applications in cardiac electrophysiology and can be extended to neuronal networks and other organ systems. We focus here on the heart because therein lie salient problems that are ready to be addressed by this new technology. However, the wide range of possible applications may lead to the commercialization of this new technology.

描述（由申请人提供）：这种生物工程研究伙伴关系（BRP）的长期目标是开发高速，深度分辨的成像仪（HSDRI），以绘制电动活动或细胞内无CA 2+瞬变的瞬变。灌注的心。该伙伴关系由3组组成。 Guy Salama博士（匹兹堡大学的PI）将管理BRP，开发乐器并将新技术应用于心脏电生理学的问题，由于缺乏3D信息，这些问题尚未解决。博士。艾伦·瓦格纳（Alan Wagoner）（卡内基 - 梅隆大学（Carnegie-Mellon University），光显微镜成像与生物技术中心主任（CLMIB））和劳伦·恩斯特（Lauren Ernst减少心肌的光散射。 Fred Lanni博士（在CLMIB）将提供理论和工程专业知识，以开发和完善HSDRI。这三个小组将并行工作。 AIM 1（Salama和Lanni，1 - 5年）：​​将开发和测试两种方法，以获得最佳的HSDRI系统。 （a）基于Ronchi线光栅的系统，该系统在心室组织深2-5毫米的焦平面上聚焦黑暗和明亮的带。在光激发的明亮和黑暗带换档1/3时，将拍摄组织中的荧光图像（以3K帧/s为单位）。图像将在线处理以消除焦点平面上方和下方发出的光，以获得1K帧/s的深度分辨图像。 （b）将为大型视野（3x3 mm 2）和高帧速率修改标准的Nipkow旋转磁盘共聚焦成像仪。目标2（1-5年）：Drs。 Wagoner和Ernst将合成新的更长的波长荧光染料来监测动作电位（AP）或胞质游离CA2+（CAI），Salama博士将测试，分析心肌新探针的光谱特征和响应特征。 AIM 3（Salama，Choi和Lanni 1-5年）：将开发软件以驱动HSDRI，分析APS和CA-I瞬变，并在3-D中绘制电活动。深度分辨的激活，复极化和AP持续时间将用于研究心脏生理学的两个主题，其中3-D中的测量对于阐明基本概念至关重要。 a）我们将调查在浦肯野纤维（P），过渡（T）和心室（V）细胞之间修改电耦合（时间延迟或块）的因素，以阐明PV连接在心律失常的启动和维持中的作用。 AP将在3D中映射，以解决在依依赖氏菌和逆行传导过程中的PV延迟，节奏和心律不齐期间的常氧和缺血性。 b）由于节点的复杂3-D结构和紧凑型细胞的小区域，跨心室淋巴结（AVN）的冲动繁殖很难追踪。 3-D中AVN的激活图将帮助我们回答有关节点的确切输入（快速和缓慢的路径），AVN重新进入的机制，Wenckebach周期性和Wolf-Parkinson综合征的基本问题。电压和Ca 2+的快速，深度分辨图像是一种强大的新工具，它将在心脏电生理学中具有广泛的应用，并且可以扩展到神经元网络和其他器官系统。我们将重点放在心脏上，因为这是该新技术准备解决的重要问题。但是，广泛的可能应用可能导致这项新技术的商业化。