| 摘要 |
<p>A method and apparatus are provided for determining the count per unit volume, that is, the density of particles such as platelets in diluted whole blood. The invention involves use of known information, namely, the count per unit volume of other (reference) particles, such as red blood cells, also suspended in the same sample of liquid. The other particles are generally distinguishable from the particles of unknown count per unit volume by a difference in some measurable characteristic of the particles, such as size. One embodiment of the invention is characterized by generating electrical pulses which represent detected particles in a sample of liquid of undetermined volume; discriminating between pulses which have different characteristics; separately counting such pulses until the count of particles of known density reaches a corresponding preset number or until a predetermined period of time has elapsed, or until the entire sample of liquid under test has been tested; and displaying the total count of particles of previously unknown density. This total count either corresponds directly to the density of such particles or is an easily converted indication of such particle density.</p> |
