Stresses from flexure in composite helical implantable leads

Area of Science:

• Biomedical Engineering
• Materials Science
• Mechanical Engineering

Background:

• Implantable leads are crucial for medical devices.
• Understanding stress in helical coils is vital for lead longevity.
• Existing models may not fully capture complex material and geometric effects.

Purpose of the Study:

• To develop a theoretical model for predicting stress in helical implantable leads under bending.
• To account for factors like coil pitch and material composition.
• To provide a tool for improved engineering design and fatigue analysis.

Main Methods:

• Development of a theoretical model based on coil flexural rigidity.
• Inclusion of parameters such as coil pitch and multi-material composition.
• Verification using finite element analysis (FEA) on specific coil designs.

Main Results:

• The model accurately predicts stress in large filarity coils made from clad wire.
• The model incorporates the effects of coil geometry and material properties.
• FEA results validated the theoretical predictions for MP35N and MP35N clad silver wire coils.

Conclusions:

• The developed theoretical model offers accurate stress prediction for helical implantable leads.
• This model is a valuable tool for the fatigue analysis and engineering design of such leads.
• The findings support the development of more robust and reliable implantable devices.