The Method for Increasing the Detail of Voltammetric Measurements of Small Changes in Concentrations

The paper considers a proposal to modify the existing circuit of the device for conducting voltammetric measurements of the concentration of neurotransmitters in the brain of an experimental animal (rat). Existing devices carry out measurements using a single ADC channel, which, due to the characteristics of the measured signal, leads to digitization of the information necessary to assess the concentration of information at an insufficient number of quantization levels. Increasing the bit depth of the ADC leads to an increase in its cost, which in this case is not an acceptable solution. The paper proposes a variant of using a multichannel ADC (structurally a single-channel ADC with a multiplexer at the input), in the channels of which there would be both the measured signal itself and the necessary fragments amplified by amplitude containing basic information about the concentration of neurotransmitters. Also, the amplified fragments and the main signal can be shifted along the vertical axis programmatically, which makes the system adaptive to various shapes of the measured signal and to various requirements of a specialist working directly with this device. Based on the proposed concepts, a structural and schematic diagram was developed for a new signal generation and processing module, and then a prototype of the device was designed and manufactured, which, due to its dimensions, is suitable for installation on an experimental animal (rat). The conducted experiments have shown the effectiveness of the proposed solution to the problem of increasing the detail of the measured data.