Desenvolvimento de protótipo de equipamento de estimulação elétrica muscular para cirurgia de malformação anorretal de uso pediátrico

Abstract

Anorectal Malformations (ARMs) encompass a spectrum of medical conditions ranging from simpler to more complex defects that affect individuals of both sexes, compromising the distal anus and rectum. The standard technique, posterior anorectosigmoidoplasty, has been adopted for the correction of ARMs, leading to superior surgical outcomes, especially when accompanied by the use of electrical muscle stimulators. However, a deficiency is observed in the development of low-cost, digital devices specifically designed for muscular electrical stimulation in ARM surgery, particularly in Brazil, where there is a lack of devices approved by ANVISA (National Health Surveillance Agency). Given this landscape, this study focused on the development of a low-cost digital muscle electrical stimulator prototype with the additional feature of frequency modulation.The K-Takaoka 92 nerve stimulator and Alberto Peña's PS2 device served as references, capturing waves through an oscilloscope and digital multimeter. Using low-cost and recognized electronic materials, a fully digitized device was developed, similar to K-Takaoka and Alberto Peña's PS2, allowing adjustment of the frequency according to the surgeon's needs. The equipment prototype was housed in a polypropylene box containing an LCD screen and two perforated single-faced electronic boards. These interconnected circuits include: Power supply, Esp32-DevKitC Board, Voltage Regulator Module, ESP IDF Software, LCD Screen, Digital Potentiometers, Transformer. Simulated tests were conducted on the oscilloscope and digital multimeter to verify changes in both frequency and voltage and current amplitude for anal sphincter contraction. The device operates with a current ranging from 0 to 210 mA and voltage ranging from 0 to 27 volts. It also has the potential for connection to applications via Bluetooth or Wi-Fi, thanks to the Esp32-DevKitC board. Notably, there is a significant cost-benefit when comparing the cost with existing muscular electrical stimulation equipment (Peña's PS2 and DS7AP).