Design, manufacture and experimental validation of an electromagnetic device for the vibratory insertion of needles

Robot-assisted needle insertion is increasingly developed for minimally invasive percutaneous treatments due to its high precision and repeatability. Nevertheless, needle–tissue interaction can still cause damage, thereby compromising targeting accuracy. Friction generated during this interaction is the main factor influencing tissue damage. In this context, the addition of axial vibration to the needle has proven effective in reducing friction. The greatest reduction occurs when a vibratory device operates at its natural frequency, as this condition maximizes the amplitude of vibration. Accordingly, this study aimed to develop a methodology for tuning the natural frequency of a designed vibratory device to match a predefined optimal vibration condition. Finite element analysis (FEA) was employed to evaluate the influence of the diaphragm—the core component of the device—on its natural frequency. Subsequently, the electromagnetic device was manufactured and experimentally tested. The experimental measurements validated the FEA model, confirming the natural frequencies predicted by the simulations. These findings demonstrate that the proposed methodology enables flexible tuning of the natural frequency of the device, offering a pathway to optimize vibratory needle insertion across different tissue types.