Geometry-Based Model for U-Shaped Strain Gauges on Medical Needles

Area of Science:

• Medical instrumentation
• Biomedical engineering
• Radiology

Background:

• Accurate needle tracking is crucial for interventional radiology procedure success.
• Needle deformation during insertion necessitates methods for monitoring its shape.
• Instrumented needles with U-shaped strain gauges are used for shape reconstruction.

Purpose of the Study:

• To develop a more complete model for U-shaped strain gauges used in instrumented needles.
• To improve the accuracy of strain estimation by accounting for gauge geometry.
• To assess the impact of incorporating gauge width into the strain model.

Main Methods:

• Development of an enhanced U-shaped strain gauge model that includes gauge width.
• Comparison of strain estimates from the new model versus existing models.
• Validation using real-world characteristics of instrumented needle devices.

Main Results:

• The enhanced model, considering gauge width, provides more accurate strain estimations.
• Differences in strain estimates between the new and current models are approximately a few percent.
• Accounting for both width and length of the gauge minimizes the necessity for gauge miniaturization.

Conclusions:

• The proposed U-shaped strain gauge model significantly improves strain estimation accuracy.
• Considering gauge geometry (width and length) enhances the reliability of needle shape reconstruction.
• This approach reduces the need for highly miniaturized gauges, simplifying device development.