A voltage-controlled capacitive discharge method for electrical activation of peripheral nerves

Area of Science:

• Biomedical Engineering
• Neuroscience
• Medical Devices

Background:

• Peripheral nerve stimulation (PNS) therapies commonly use rectangular stimulus pulses.
• Investigating alternative stimulation methods is crucial for improving PNS efficacy and enabling new applications like wireless systems.

Purpose of the Study:

• To evaluate a voltage-controlled capacitive discharge (VCCD) method as a more charge-efficient alternative to traditional rectangular pulses for peripheral nerve stimulation.
• To compare the charge thresholds for evoking compound nerve action potentials (CNAPs) using VCCD versus constant current (CC) stimulation.

Main Methods:

• The study involved two anesthetized Gottingen mini pigs.
• Compound nerve action potentials (CNAPs) were evoked by stimulating the tibial and posterior cutaneous femoralis nerves using standard and modified Medtronic 3778 Octad devices.
• The charge threshold for CNAP evoked by constant current (CC) and VCCD methods was compared.

Main Results:

• VCCD stimulation, particularly with a modified Octad device, resulted in a significant decrease (-73 ± 7.4%) in the stimulation threshold for evoking CNAPs compared to CC stimulation.
• This charge reduction was observed consistently across different myelinated fiber types and stimulation locations.

Conclusions:

• The VCCD method offers a highly charge-efficient approach for activating myelinated nerve fibers.
• This charge efficiency makes VCCD a promising technology for developing advanced wireless peripheral nerve stimulator systems.