Methods for measuring pre-, intra-, and postoperative skin thickness for cochlear implants

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Medical Imaging

Background:

• Cochlear implantation (CI) requires precise external magnet force for optimal performance.
• Accurate measurement of retroauricular skin thickness is crucial for selecting the appropriate magnet strength.

Purpose of the Study:

• To evaluate reliable methods for measuring retroauricular skin thickness in cochlear implant patients.
• To correlate skin thickness measurements with the required external magnet force.

Main Methods:

• Retroauricular skin thickness was measured in 83 CI patients using three methods: pre- and postoperative CT scans, and intraoperative measurements.
• Magnet category selection was recorded, and correlation analyses were performed between skin thickness and magnet strength.

Main Results:

• All three measurement methods showed significant correlations with each other (Pearson's r = 0.457-0.585).
• Skin thickness, particularly flap thickness, was significantly correlated with the required magnet strength.
• The intraoperative needle method showed the lowest correlation with magnet strength.

Conclusions:

• Pre- and postoperative CT measurements are valuable for assessing and adjusting external magnet strength in cochlear implant recipients.
• These CT-based assessments facilitate timely postoperative device activation and management during follow-up.