| 摘要 |
The instrument of the present invention is designed to electrically alter membranes of vesicles in a suspension in order to perform vesicular alteration and electrostructuring of the membranes. The instrument includes a supply for delivering voltage to a pulse forming network. The output of the pulse forming network is selectively switched to deliver one or a plurality of output pulses across a chamber holding the suspension. Disposed in the chamber are a pair of electrodes which define a geometry for applying either a non-uniform field across the suspension or defining a uniform field across the suspension. The present invention is not limited to the type of field uniformity. Connected in parallel across the electrodes is a device for matching the impedance of the chamber containing the suspension of vesicles. This device is in parallel combination with the chamber and when properly adjusted, matches the impedance of the chamber to the pulse forming network. The device for matching the impedance can be manually or automatically controlled, such as through a computer, to selectively switch in a one or a plurality of parallel resistances until the impedance of the chamber matches the impedance of the pulse forming network. To properly determine the impedance of the chamber, a separate circuit delivers one or a plurality of low voltage pulses across the chamber, measures the resulting current flow and based upon that measurement selectively interconnects the parallel resistances until the chamber, in parallel combination with the resistances, equals the impedance of the pulse forming network. In this fashion, the treatment pulses being applied to the chamber containing the suspensions, despite possible wide variations of impedances for the chamber and the suspensions, insures precise reproducibility of the treatment pulses.
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