Flexible Needle Bending Model for Spinal Injection Procedures

An in situ needle manipulation technique used by physicians when performing spinal injections is modeled to study its effect on needle shape and needle tip position. A mechanics-based model is proposed and solved using finite element method. A test setup is presented to mimic the needle manipulation motion. Tissue phantoms made from plastisol as well as porcine skeletal muscle samples are used to evaluate the model accuracy against medical images. The effect of different compression models as well as model parameters on model accuracy is studied, and the effect of needle-tissue interaction on the needle remote center of motion is examined. With the correct combination of compression model and model parameters, the model simulation is able to predict needle tip position within submillimeter accuracy.

Automated summary

In this study, an in situ needle manipulation technique used for spinal injections is modeled and its effect on needle shape and position is studied. A mechanics-based model is proposed and solved using finite element method. A test setup is presented to mimic the needle manipulation motion. Tissue phantoms made from plastisol and porcine skeletal muscle samples are used to evaluate the model accuracy. The effect of different compression models and model parameters on accuracy is studied, and the impact of needle-tissue interaction on the needle remote center of motion is examined. With the correct combination of compression model and parameters, the model simulation can predict needle tip position with submillimeter accuracy.