Stimulus-Resistant Bioelectric Amplifier

DESCRIPTION (provided by applicant): The capability to use the same microelectrode for electrical stimulation of neurons, as well as for neural signal recording from neurons in the vicinity of the electrode, has historically been a goal of neuroscientists. The need stems from the desire to study the response of neurons to artificial electrical stimulation in order to model and characterize biological neuronal networks within the central nervous system. For all commercially available neural recording systems, such a measurement is either impractical, or not feasible due to the presence of a large stimulus artifact resulting from the electrical stimulation. The stimulus artifact effectively disables the recording system until the residual effects of the artifact have dissipated. There is a compelling need for combined neural stimulation and recording technology that will allow the reliable and consistent recording of neuronal responses immediately following their artificial electrical stimulation. In order to accomplish this, the research and design of a dedicated system must be undertaken. The only practical way to achieve success is to fully integrate the constant-current bi-directional stimulation circuitry with a specialized bioelectric recording amplifier on the same electronic chip. This is because in order to implement the stimulus-resistant amplifier behavior, the low-noise amplifier circuitry must be intimately tied to the stimulus circuitry, and such functional integration can only be obtained by implementing the combined circuitry as a very-large-scale-integrated (VLSI) design. An essential and crucial first step in the development of a large, multichannel, stimulus-resistant neural signal recording system is the demonstration of the feasibility of this fundamental building block: A stimulus-resistant VLSI bioelectric stimulator/amplifier chip.