The Automatic Calibration Of The Head-Stage In The Automatic Patch-Clamp Amplifier

The patch-clamp technique is used to study various ion channels and its regulation mechanism based on measuring the micro-current of the membrane. The core of the patch-clamp amplifier is a sensitive current-voltage converter, converting the micro-current of the membrane into voltage signal which can be observed and sampled by analog to digital converter easily. The experiment parameters of traditional patch-clamp system were adjusted by hand, and it was complicated and inefficient. Therefore, automatization is the developing trend of patch-clamp amplifier.The head-stage of the patch-clamp amplifier is a resistor-feedback current- voltage converter. The primary work in this thesis is to research and improve the algorithm and software of the automatic calibration of the head-stage. With automatic calibration, the parameter values of the high frequency compensation and transient compensation can be determined automatically. The transient errors induced by the stray and distributed parameters can be minimized.This thesis consists of four sections. The first part concerned the main frame of the computer-controlled patch-clamp amplifier and the improvement of the amplifier for computer-control. Then the dynamic character of the head-stage and the scheme of its calibration were analyzed. In the last two parts, the principle and software algorithm of the high frequency compensation and transient compensation were described in detail.The experimental result demonstrated that the head-stage was able to meet the electrophysiological experiments as its bandwidth and stability had been greatly improved. The automatic compensation of the head-stage provided a good foundation for fulfilling the computer-controlled patch-clamp amplifier.