Detecting and managing partial shorts in Cochlear implants: A validation of scalp surface potential testing.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Otolaryngology

Background:

• Cochlear implants are crucial for hearing restoration.
• Partial short circuits in cochlear implant electrodes can degrade performance.
• Accurate identification of electrode malfunctions is essential for patient management.

Purpose of the Study:

• To evaluate the utility of scalp surface potentials in detecting partial short circuits to ground in cochlear implant electrodes.
• To correlate scalp surface potential findings with device performance and impedance measurements.

Main Methods:

• Retrospective review of patients with suspected partial short circuits.
• Measurement of individual electrode electrical output using scalp surface potentials.
• Comparison of electrical output with functional performance and impedance data.
• Validation of scalp surface potential results through explantation and artificial cochlea testing.

Main Results:

• All patients (n=49) with suspected partial shorts exhibited reduced electrical output, decreased impedance, and hearing decline.
• Reduced electrical output was exclusively observed in devices with atypical electrical field measurements (EFI).
• Scalp surface potential findings were reproducible in an artificial cochlea post-explantation.
• Explantation reports (n=42) confirmed partial short circuits in all cases, with additional device failures.

Conclusions:

• Scalp surface potential measurements accurately detect partial shorts in cochlear implants.
• There was a 100% correlation between surface potential measurements and atypical EFI, indicative of partial shorts.
• This technique can assess the extent of electrode array involvement, especially when behavioral testing is not feasible.