A novel apparatus for measuring the velocity of platelet aggregation, with TV image processing.

我们制作了一种定量测量血小板聚集和粘附的装置（带软件）。 1．操作原理如下。 (1)反应室由旋转锥体(变速)和板(如聚甲基丙烯酸甲酯)组成，将血小板(与ADP或肾上腺素混合)倒入锥体和板之间的间隙中，以给出一定的剪切速率。 (2)利用电视图像处理器将显微电视图像分成两幅图像：一幅是(连续8张电视图像的)平均图像，其中粘附的血小板的静止点被强化；另一种是流动血小板运动斑点的图像，它是从下一个电视图像中减去平均图像而得到的。 (3) 这些图像在一定的灰度级下被数字化（1 位），然后使用电视图像分析仪编码为一帧（实际尺寸为 190 x 150 <micro> m）中斑点的数量和总面积。 (4)以5秒的间隔重复上述过程(2和3)，最后显示时间进程：例如，粘附点的总面积随时间变化、流动点的总面积/点随时间变化等。 (5)用另一个程序获得观察点的大小直方图。2.建立了富含人血小板血浆的适当实验条件：即 1 - 3 /s 的剪切速率，80 - 200 x 1000 / <micro> l 血小板，0.2 - 0.5 <micro> M ADP 或 1 - 5 <micro> M 肾上腺素，25°C.3。通过基于简单动力学模型的计算，成功地模拟了观察到的血小板粘附的时间过程，具有三个速率常数：证明粘附点的生长速率比自由表面上新粘附的生长速率更快。

We have made an apparatus (with software) for the quantitative measurement of platelet aggregation and adhesion.1. The principles of operation are as follows. (1) The reaction chamber is composed of a rotating cone (variable speed) and a plate (e.g., polymethylmethacrylate), and the platelets (mixed with ADP or adrenaline) are poured into the gap between the cone and the plate, in order to give a certain shear rate. (2) The microscopic TV images are separated into two images using a TV image processor: one is the averaged image (of consecutive 8 TV pictures) in which the stationary spots of the adhered platelets are intensified; the other is the image of the moving spots of the flowing platelets which is obtained by subtracting the averaged image from the next TV picture. (3) These images are digtized (1 bit) at a certain grey level, then encoded to the number and the total area of the spots in a frame(real dimension of 190 x 150 <micro> m) using a TV image analyzer. (4) Above processes (2 and 3) are repeated at an interval of 5 sec, and finally the time courses are displayed: e.g., total area of the adhered spots vs. time, total area/spot of the flowing spots vs. time, etc. (5) The size histograms of the observed spots are obtained with another program.2. The appropriate experimental conditions for human platelet rich plasma are established: i.e., 1 - 3 /s of shear rate, 80 - 200 x 1000 / <micro> l of platelets, 0.2 - 0.5 <micro> M ADP or 1 - 5 <micro> M adrenaline, at 25゜C.3. The observed time courses of platelet adhesion are successfully simulated by the calculation based on a simple kinetic model, with three rate constants: it is proved that the growth rate of adhered spots is faster than that of de nove adhesion onto the free surface.