METHOD OF AND APPARATUS FOR DETERMINING A PROPERTY OF A SAMPLE

摘要

The invention provides an apparatus and method for determining a property of a sample, derived from a response obtained from the sample after an electrical pulse has been applied to it. In a preferred embodiment blood cells (224) are subjected to an electrical pulse (figure 3c), a response (figure 3d) is obtained using data retrieval means and a Fourier Transform is applied to the response. As the pulse (202) applied is of very short duration (ideally a Dirac pulse) the Fourier Transform yields information across a very broad bandwidth, typically several MHz, and accordingly a wide range of frequency response data is obtained. Certain cellular defects can be deduced from the transformed data. In a preferred embodiment detection means (204, 206) is provided to precisely detect the presence of a cell (224) as it passes through a particular region of an orifice (220). This is then used to trigger the pulse at a precisely controlled instant. This reduces the effect of random dispersion and can be adapted to ignore noise peaks which inevitably occur. The invention may be operated continuously and provides information across a bandwidth which is wider than was previously possible.