A Novel Bipolar Cautery Tool for Minimally-Invasive Neuroendoscopic Procedures

Electrosurgery is used in the operating room on a daily basis as a means to cut tissue and maintain hemostasis. The principle of this technology lies in the transfer of electricity from an electrosurgical unit to the operating site on a patient's body and modifying the waveform of that electricity to achieve the desired surgical effect. Bipolar cautery uses two electrodes, an active and a return, both at the surgical site to perform electrosurgery. Bipolar cautery can be very useful in helping surgeons to operate; however, current designs are not well suited to a 2.1 mm working channel in endoscopic procedures due to their rigid structure, limited range of motion, and bulky design. This paper describes a novel approach to designing a minimally- invasive bipolar cautery tool suitable for flexible neuroendoscopy. The system features 1.9 mm diameter bipolar tips which resemble grasping forceps, making it easier for surgeons to hold tissue while performing electrosurgery. The electrode wires also function as the actuating cables used to open and close the tips, which require 2.10 mm to open the tips to 30.9 °. The results show that the tool can safely cauterize a porcine brain specimen at various settings on the electrosurgical unit, and increasing the setting increases the area of tissue affected by the electricity. Repeatability was demonstrated and exhaustion was reached after the tool was opened and closed 73 times. Future work will involve improving the current design to increase the number of cycles the tool can survive before losing function.