An arbitrary waveform neurostimulator for preclinical studies: design and verification.

Area of Science:

• Biomedical Engineering
• Neuroscience
• Medical Devices

Background:

• Neural electrostimulation offers therapeutic solutions for various health conditions, including hearing loss and Parkinson's disease.
• Precise neuronal activation is crucial for developing advanced neural prosthetics, such as retinal implants.
• Arbitrary current waveform electrostimulation allows for selective activation of different neuron types.

Purpose of the Study:

• To design and implement a two-channel arbitrary waveform neurostimulator tailored for visual prosthetics research.
• To enable preferential activation of targeted neurons by generating custom current waveforms.
• To provide a scalable and adaptable platform for neurostimulation applications.

Main Methods:

• Utilized a Field Programmable Gate Array (FPGA) for digital-to-analog conversion and voltage waveform generation.
• Employed a modified Howland amplifier for electrical isolation and conversion to current waveforms.
• Integrated multiplexers for electrode shorting and tested the system using silver electrodes in saline.

Main Results:

• Achieved a system bandwidth of 30 kHz with voltage compliance of ±15 V.
• Verified FPGA gateware with 91.4% line coverage using a transaction-level modeled testbench.
• Demonstrated successful testing with silver electrodes of varying diameters (200-1000 µm).

Conclusions:

• The developed two-channel neurostimulator effectively generates arbitrary current waveforms for precise neural activation.
• The system's design is scalable and adaptable, offering potential for broader applications in neuroprosthetics and research.
• This technology advances the development of visual prosthetics and other neural stimulation therapies.