Serpell M G, Gray W M
Department of Anaesthesia, Western Infirmary, Glasgow, UK.
Anaesthesia. 1997 Mar;52(3):229-36. doi: 10.1111/j.1365-2044.1997.066-az0064.x.
We examined the flow pattern produced when liquid dye was actively injected into a fluid medium at various flows through five different commonly used spinal needles. At all flows, the Whitacre-type needles produced a directional stream exiting at an angle from the longitudinal axis. At intermediate rates the stream developed tracks which disappeared at faster rates. The Quincke needle always produced an undeviated stream of dye and did not form tracks at any flow rate. When a perspex plate (representing the spinal cord) was interposed in front of the needle, the dispersion of dye was always unidirectional from the Whitacre needle and bidirectional from the Quincke needle. The dye adhered to the surface of the plate as a concentrated film at slow rates and at faster rates it dispersed turbulently for both types of needle.
我们研究了在不同流速下，通过五根不同的常用脊髓穿刺针向流体介质中主动注入液体染料时所产生的流动模式。在所有流速下，惠特克型针产生一股从纵轴以一定角度射出的定向流。在中等流速时，该流会形成轨迹，而在较快流速时轨迹消失。奎克针总是产生一股无偏差的染料流，并且在任何流速下都不会形成轨迹。当在针前方插入一块有机玻璃板（代表脊髓）时，染料的扩散从惠特克针总是单向的，而从奎克针是双向的。在较慢流速下，染料以浓缩膜的形式附着在板表面，在较快流速下，两种类型的针的染料都会湍流扩散。
