A System for 3D Optical Action Potential Measurements

描述（由申请人提供）： 在电生理现象的研究中的一个重要限制是无法测量可兴奋组织中三维的跨膜动作电位。 已经使用传统的伏安电极进行了3D测量，但是关于细胞膜的电复极化的信息丢失或受损。 动作电位的形状可以通过使用光学方法和电压敏感染料来理解，但通常这种技术仅限于二维。 在本申请的R21阶段，拟证明使用基于光纤的原型设备（光极）进行3D心脏组织中动作电位的可靠、可重复和有效测量的可行性。 在可行性阶段要解决的问题包括信噪比、询问的组织体积的大小和形状、记录的保真度、可实现的空间分辨率和组织破坏。 一个小型的，多光极系统，很容易扩展到一个完整的256光纤配置将被开发，证明制造和使用的可行性。 在R33阶段，将组装一个完整的系统，以允许在生理调查期间进行数据采集，分析和显示。 软件开发将使用开放的行业标准编程环境，以便于向科学界传播。 这项工作的成功完成具有广泛的影响。 通过使用具有相同基本系统的各种染料，可以使用光学方法来测量pH值，钙瞬变和3D结构中的其他变量，对所研究的组织的影响最小。 这些新功能将为心脏电生理学家和其他研究电兴奋组织中3D现象的人提供新的研究途径。

DESCRIPTION (provided by applicant): A significant limitation in the investigation of electrophysiological phenomena has been the inability to measure transmembrane action potentials in three dimensions in excitable tissue. 3D measurements have been made using traditional voltametric electrodes, but information about electrical repolarization of cell membranes is lost or compromised. The shape of the action potential can be appreciated through the use of optical methods and voltage sensitive dyes, but in general this technique is limited to two dimensions. In the R21 phase of this application, it is proposed to demonstrate the feasibility of using a prototype optical fiber-based device (optrode) for making reliable, repeatable and effective measurements of action potentials in 3D cardiac tissue. Issues to be addressed in the feasibility phase include signal to noise ratio, size and shape of tissue volume interrogated, fidelity of recordings, achievable spatial resolution, and tissue disruption. A small, multioptrode system that is easily expandable to a full 256 fiber configuration will be developed, demonstrating the feasibility of fabrication and use. During the R33 phase of the grant, a complete system will be assembled to allow data acquisition, analysis, and display during physiological investigations. The software development will use open, industry standard programming environments to allow easy dissemination to the scientific community. The successful completion of this work has broad ramifications. By using a variety of dyes with the same basic system, it will be possible to use optical methods to measure pH, calcium transients, and other variables in 3D structures with minimal effect on the studied tissue. These new capabilities will provide new avenues of research for cardiac electrophysiologists and others studying 3D phenomena in electrically excitable tissue.