["Spatial shift alignment (SSA)"--a new method for determining blood flow velocity in video capillary microscopy].
A new technique (spatial shift alignment [SSA]) for measuring capillary blood velocity in human capillaries in the skin is described. A capillaroscopic image is digitized by means of a frame grabber. Within the lumen of a suitable capillary limb a region of interest known as a slot is placed. At a frame frequency of 25 per second, this slot is copied in a free part of the frame grabber store along a horizontal axis. A static space-time image with light diagonal bands representing the plasma gaps in their passage through the capillary limb is obtained. By determining the gradient of the diagonal bands, a measure of the capillary blood velocity is obtained. The SSA system was validated by means of a simulated model using known fixed velocities between 0 and 1.0 mm/sec (r = 0.979, n = 24). The procedure can be employed with any image processing systems, and enables continuous monitoring of the velocity measurements. Since it is time-saving and just as accurate as the frame-to-frame method, SSA could be widely applied to the measurement of blood cell velocity in capillaroscopy.
Lentner
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A
Abteilung Dermatologische Phlebologie, Hautklinik der Medizinischen, Fakultät der RWTH, Aachen.
Berger
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F
Wienert
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V
D001783:Blood Flow Velocity / Q000502:physiology*; D002196:Capillaries; D016287:Computer Peripherals; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D008838:Microcomputers; D018715:Microscopy, Video / Q000295:instrumentation*; D012867:Skin / Q000098:blood supply*; D012984:Software
Das "Spatial Shift Alignment (SSA)"--eine neue Methode zur Bestimmung der Blutflussgeschwindigkeit in der Video-Kapillarmikroskopie.