High spatial-temporal resolution optical mapping of cardiac membrane action potentials using high intensity light emitting diodes and high spee3 digital video cameras

我们利用高强度发光二极管和高速数码摄像机，研制了一套高时空分辨率的心肌细胞膜动作电位光学标测系统。用电压敏感染料DI-4-ANEPPS对兔心脏进行了兰氏染色，其发射的荧光中心波长随膜动作电位的变化而变化。因此，通过光学长通滤光片监测灌流心脏发出的荧光，我们可以获得膜动作电位信息，即组织上每个点的荧光强度的变化。采用高强度蓝绿发光二极管作为激发光源。因为它是固态光源，所以很容易操作。其强度可以通过电子方式稳定下来。作为一种测量设备，我们使用了每0.25毫秒就能捕捉到图像的高速数码摄像机。我们以1125帧每秒或750帧每秒的帧速率使用它。作为r…结果越多，信噪比越高。其空间分辨率约为0.2 mm。其时间分辨率为1毫秒。与传统的心脏动作电位光学标测系统相比，该系统在保持较高的信噪比(平均2.35)的同时，还能提供较高的空间分辨率和时间分辨率。我们还开发了一个软件来处理Larga数量的图像数据，以获得心脏组织上任何观察点的动作电位信息。为了扩大系统的观测范围，系统同时使用了两台高速数码摄像机。与单摄像系统相比，双摄像系统能够跟踪螺旋波的曲折、激子阵面的破裂等复杂的激发传播模式。综上所述，研制的高时空分辨率光学标测系统能有效分析心律失常时复杂的电刺激模式。较少

We have developed a High spatial-temporal resolution optical mapping system of cardiac membrane action potentials using high intensity light emitting diodes and high-speed digital video cameras. A rabbit heart perfused in a Langendorff apparatus was stained with voltage sensitive dye : di-4-ANEPPS.Central wavelength of emitted fluorescence changes depending on membrane action potential. Thus by monitoring the emitted fluorescence from the perfused heart through optical long-pass filter, we can obtain membrane action potential information as change in fluorescence intensity at each point on the tissue. High intensity bluish green light emitting diodes were used as an excitation light source. Since it is a solid-state light source, it is easy to handle. Its intensity can be stabilized electronically. As a measurement device, We used high-speed digital video cameras that can capture images every 0.25 msec. We used it at frame rate of 1125 frames per second or 750 frames per second. As a r … More esults, high signal to noise ratio was obtained. Its spatial resolution was approximately O.2 mm. And its temporal resolution was 1 msec. Developed system can provide high resolution of measurement both for spatial resolution and temporal resolution while keeping relatively high signal to noise ratio (2.35 as an average) compared with conventional optical mapping system of cardiac action potentials. We also developed a software to process larga amount image data to obtain action potential information at any observation point on the heart tissue. In order to enlarge the observable area by the system, two high speed digital video cameras were used simultaneously. Compared with a single camera system, the double camera system could track the complicated excitation propagation pattern such as meandering of spiral wave and break up of the excitaion front. In conclusion, the developed high spatial-temporal resolution optical mapping system was effective in analyzing complicated electrical excitation pattern during arrhythmia. Less