Several modalities for minimally invasive treatment have been developed, especially for tumor ablation. Modern tumor ablations such as cryoablation, microwave ablation, and radiofrequency ablation are popular for treating larger tumor since the affected area can be easily controlled. However, there is a chance where nearby healthy regions are also damaged. In addition, the dissipation of heat or know as heat sink effect can occur in the larger vascular due to the local blood flow which induces incomplete ablation.
Recently, a non-thermal ablation technique, Irreversible Electroporation (IRE), shown promising results for treating tumors. IRE utilizes an electrical field in the tumor cell membrane, resulting in cell death via apoptosis. Comparing with the previous methods, IRE has several advantages, including a shorter ablation time, avoidance of heat/cold sink effect, and preservation of vital structure from thermal injury.
One of the main procedures in IRE is related to needle placement process. Needles should be placed parallel and the same depth to allow the electrical field to distribute effectively across the cell to destroy tumors. In a small tumor case, two needles are enough to perform tumor ablation. However, for tumor with a diameter more than 3 cm, more needles are required for the treatment where normally a maximum of six probes can be used at the same time. Accurate needle placement is essential in this procedure, since the tumor may remain due to misplacement of the needles.
In this project, we aim to redesign the needle holder of existing robot prototype in order to support multiple needle placement procedure for irreversible electroporation treatment.