Optical Mapping of Electromechanics of the Stomach

胃是一个电子机械器官，它的收缩由电波协调。 它被称为慢波。这种活动传统上是在低空间分辨率下通过从稀疏记录来研究的 接触器官或体表的电极。最近，一些组织绘制了缓慢的地图 通过在支架上放置数十个电极阵列，以更高的空间分辨率传播波- ACH的表面。这些研究揭示了正常慢波传播和节律失常的细节 在疾病状态下出现的模式。然而，关于正常和异常减速的信息很少 波与肌肉收缩的详细空间模式有关。需要更好的理解来改进 诊断不足和研究不足的衰弱性胃动力障碍的诊断和治疗。 为此，这项生物工程研究拨款将开发新的研究仪器，以模拟- 从胃记录：(1)电激活和恢复的时空模式和(2)电刺激和恢复的时空模式 肌肉收缩的时间模式。这些方法将被用作动物实验的研究工具。 目的1.建立一种胃平滑肌细胞膜电位成像系统 浮出水面。在活体猪模型中，胃部将暴露并用荧光染料染色，其重新- Spanse受Vm的调节。小的基准标记将附着在浆膜表面。荧光发射光谱仪- Sion将用摄像机拍摄图像。通过跟踪基准标记的运动并交替 每一帧摄像机发射的激发光的波长，胃收缩引起的运动伪影 将被压制。这些数据将使我们能够追踪慢波在胃中传播的情况。 目标2：开发一种光学系统，以成像慢波引起的机械收缩- 诉讼。以双目方式安装的额外摄像机(S)将用于跟踪摄像机的运动- 三个维度的社会标记。由此，胃表面的变形将被量化为 有限应变项。这些数据将与VM数据在时间上同步。这些数据将使 对胃电和机械功能之间相互作用的尾随研究。 目的3：在正常制剂中进行联合机电标测研究 哪些异常的慢波传播模式(心律失常)是由药物引起的。胃空- 液体试餐的ING将与正常和节律失常时的机电标测数据进行比较 慢波传播。 该项目是PI之间的合作，PI是开发和应用新型光学技术的专家 心脏标测方法，以及奥克兰的研究人员，他们是胃肠道物理-IOL方面的专家- 书名和地图。我们希望该项目的成功将导致未来的合作应用新的 技术对生理学和医学问题的影响。

The stomach is an electromechanical organ whose contractions are coordinated by an electrical wave called the slow wave. This activity is traditionally studied at low spatial resolution by recording from sparse electrodes either in contact with the organ or on the body surface. Recently, a few groups have mapped slow wave propagation with much higher spatial resolution by placing arrays of dozens of electrodes on the stom- ach’s surface. These studies are revealing the details of normal slow wave propagation as well as dysrhythmic patterns that occur in disease states. However, there is little information on how normal and abnormal slow waves relate to detailed spatial patterns of muscle contraction. Improved understanding is needed to improve diagnosis and treatment of debilitating gastric motility disorders that are underdiagnosed and understudied. To this end, this Bioengineering Research Grant will develop novel research instrumentation to simultane- ously record from the stomach: (1) spatiotemporal patterns of electrical activation and recovery and (2) spatio- temporal patterns of muscle contraction. The methods will be used as research tools in animal experiments. Aim 1. Develop a system to image the membrane potential (Vm) of smooth muscle cells on the stomach’s surface. In an in vivo swine model, the stomach will be exposed and stained with a fluorescent dye whose re- sponse is modulated by Vm. Small fiducial markers will be attached to the serosal surface. Fluorescence emis- sion will be imaged with a video camera. By tracking the motion of the fiducial markers and alternating the wavelength of excitation light delivered with each camera frame, motion artifact caused by stomach contraction will be suppressed. These data will enable us to track slow waves as they propagate across the stomach. Aim 2: Develop an optical system to image the mechanical contraction that results from slow wave propa- gation. Additional video camera(s) mounted in a binocular fashion will be used to track the motion of the fidu- cial markers in three dimensions. From this, the deformation of the stomach’s surface will be quantified in terms of finite strain. These data will be temporally synchronized with the Vm data. These data will enable de- tailed study of the interactions between electrical and mechanical function in the stomach. Aim 3: Perform combined electromechanical mapping studies in normal preparations and preparations in which abnormal slow wave propagation patterns (dysrhythmias) are induced pharmacologically. Gastric empty- ing of liquid test meals will be compared with electromechanical mapping data during normal and dysrhythmic slow wave propagation. The project is a collaboration between the PI, who is an expert in developing and applying novel optical mapping methods for the heart, and Auckland-based investigators, who are experts in gastrointestinal physiol- ogy and mapping. We expect that success of this project will lead to future collaborations applying the new technology to problems in physiology and medicine.