A self-made, low-cost infrared system for evaluating the sciatic functional index in mice

Area of Science:

• Biomedical Engineering
• Neuroscience
• Animal Models

Background:

• The sciatic functional index (SFI) is crucial for peripheral nerve injury assessment.
• Traditional ink-and-paper methods for SFI lack precision and dynamic data.
• Existing digital systems are prohibitively expensive.

Purpose of the Study:

• To develop and evaluate a low-cost, self-made infrared system for precise SFI measurement in mice.
• To compare the efficacy of the infrared SFI (I-SFI) system against conventional SFI (C-SFI) and the ladder beam walking test (LBWT).

Main Methods:

• Mice underwent unilateral sciatic nerve crush injury or sham surgery.
• Footprints were captured using a novel infrared system and traditional ink-and-paper methods.
• Data was collected pre-injury and at multiple time points post-injury up to 23 days.
• Ladder beam walking test was used as a reference.

Main Results:

• The infrared SFI (I-SFI) system significantly reduced measurement variability (standard deviation decreased by 33%).
• Variance around the baseline was reduced by 21% with the I-SFI system.
• The self-made infrared system cost only €321 to build, a fraction of commercial systems.

Conclusions:

• Digitization using a self-made, low-cost infrared system enhances the precision of SFI evaluation.
• This approach reduces the need for animal numbers and measurement repetitions, lowering research costs.
• The developed infrared system presents a viable, cost-effective alternative for peripheral nerve function assessment.