A Bioimpedance Analysis Platform for Amputee Residual Limb Assessment

Area of Science:

• Biomedical Engineering
• Prosthetics and Orthotics
• Physiology

Background:

• Fluid volume changes in residual limbs can affect prosthetic fit and comfort.
• Monitoring these changes is crucial for optimizing prosthetic use and patient outcomes.
• Current methods for fluid volume assessment in residual limbs are limited.

Purpose of the Study:

• To develop and optimize a bioimpedance platform for monitoring fluid volume in residual limbs of trans-tibial amputees.
• To establish optimal electrode placement and stimulus profiles for accurate measurements.
• To validate the system's performance through bench and participant testing.

Main Methods:

• A multifrequency bioimpedance system with custom electrodes was designed.
• Electrodes were placed on the thigh and distal residual limb.
• Cole and segmental limb geometry models were used to calculate fluid volumes.
• System parameters and electrode configurations were optimized using bench and amputee testing.

Main Results:

• Optimal electrode spacing (≥25 cm) and hydrogel coupling were identified.
• Specific stimulus profiles (e.g., burst duration, sampling delays) were determined for effective measurement.
• A sampling rate of 19.7 Hz was achieved.
• The platform was optimized for measuring amputee limb fluid volume.

Conclusions:

• The developed bioimpedance platform is suitable for monitoring residual limb fluid volume in trans-tibial amputees.
• The system allows for optimization of prosthetic design and identification of factors influencing fluid volume.
• This technology has the potential to improve prosthetic fitting and patient care.