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Article in Chinese | WPRIM | ID: wpr-693100


Objective To design and implement a universal multi-channel software for neural electrophysiological stimulation experimental platforms. Method The layered design of software and hardware was adopted for the logical architecture to avoid excessive reliance on specific hardware. On the premise of ensuring compatibility with existing devices, an extensible control algorithm based on the .NET Frameworks platform was developed to realize multi-channel, feedback-controlled program-controlled stimulus output. The proposed software was designed with a user-friendly interface and stimulating/recording switch function, and could dynamically change stimulation programs and switch electrodes during the experiment process. Results The results showed that the software could control the stimulators steadily and generate random stimulation protocols and synchronization control signals according to the user-supplied dynamical parameters, including electrodes, amplitudes, and intervals. In the stimulation sequence, the switching delay between two electrodes was around 600 ms level. Conclusion The software has good compatibility with existing equipment systems. It can achieve multi-channel, real-time, feedback-controlled program-controlled stimulation according to the characteristics and needs of multi-lead neural electrophysiological stimulation researches. It has the functions of dynamically changing the stimulation program and switching electrodes during operation. This software provides tools for the study of the mechanism of network-level neural network feedback loops.

Article in English | WPRIM | ID: wpr-728528


A retinal prosthesis is being developed for the restoration of vision in patients with retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Determining optimal electrical stimulation parameters for the prosthesis is one of the most important elements for the development of a viable retinal prosthesis. Here, we investigated the effects of different charge-balanced biphasic pulses with regard to their effectiveness in evoking retinal ganglion cell (RGC) responses. Retinal degeneration (rd1) mice were used (n=17). From the ex-vivo retinal preparation, retinal patches were placed ganglion cell layer down onto an 8x8 multielectrode array (MEA) and RGC responses were recorded while applying electrical stimuli. For asymmetric pulses, 1st phase of the pulse is the same with symmetric pulse but the amplitude of 2nd phase of the pulse is less than 10 microA and charge balanced condition is satisfied by lengthening the duration of the pulse. For intensities (or duration) modulation, duration (or amplitude) of the pulse was fixed to 500 micros (30 microA), changing the intensities (or duration) from 2 to 60 microA (60 to 1000 micros). RGCs were classified as response-positive when PSTH showed multiple (3~4) peaks within 400 ms post stimulus and the number of spikes was at least 30% more than that for the immediate pre-stimulus 400 ms period. RGC responses were well modulated both with anodic and cathodic phase-1st biphasic pulses. Cathodic phase-1st pulses produced significantly better modulation of RGC activity than anodic phase-1st pulses regardless of symmetry of the pulse.

Animals , Humans , Mice , Electric Stimulation , Ganglion Cysts , Macular Degeneration , Prostheses and Implants , Retinal Degeneration , Retinal Ganglion Cells , Retinaldehyde , Retinitis Pigmentosa , Visual Prosthesis