RESUMEN
A new type of disposable external defibrillation electrode has been developed to reduce the skin irritation commonly associated with defibrillation and synchronised cardioversion. This design employs an impedance gradient to reduce the proportion of current delivered to the electrode periphery. The temperature distribution under the new electrode was compared with that of four other types of commercially available electrodes after repeated high-energy biphasic defibrillation discharges to domestic swine. Skin temperature distributions were acquired using non-invasive thermography. Measurements of the maximum temperature rise at each electrode site, taken 3.6s after the fifth defibrillation discharge, demonstrated that the new impedance-gradient electrode produced 50-60% less skin heating than two of the three uniform-impedance electrode designs. Histological examination of erythematous sites excised 24 h after defibrillation quantified the associated skin damage using a scoring protocol developed for this study. In contrast to previous studies, histological examinations demonstrated second-degree skin burns following defibrillation. The new electrode design, however, induced 44-46% less skin damage than two of the traditional uniform-impedance electrodes.
Asunto(s)
Quemaduras por Electricidad/prevención & control , Cardioversión Eléctrica/efectos adversos , Animales , Quemaduras por Electricidad/etiología , Cardioversión Eléctrica/instrumentación , Impedancia Eléctrica , Electrodos , Diseño de Equipo , Temperatura Cutánea , PorcinosRESUMEN
ECG electrodes can provide an alternate path for the return of radio-frequency current to an electrosurgical generator. In the process, significant heat rise can take place at the electrode/skin interface. The contribution from the electrode to this heart rise was examined using face-to-face pairs as well as human subject testing. A comparison of various electrode designs revealed a wide range in their RF heating characteristics which affects the probability of burns.
Asunto(s)
Electrocardiografía/instrumentación , Electrodos , Calor , Ondas de Radio , Conductividad Eléctrica , Electrónica Médica/instrumentación , Electrocirugia/instrumentación , Geles , Humanos , Fenómenos Fisiológicos de la Piel , Temperatura Cutánea , TermografíaRESUMEN
The barrier layer in the intact epidermis of pig skin effectively limits the penetration of ferric ions even under conditions of iontophoresis. This was microscopically demonstrated using a ferric ion salt in conjunction with a soluble ferrocyanide to produce a Prussian blue ferric ferrocyanide precipitate. The effectiveness of various skin preparation techniques in breaking through the epidermal barrier layer was examined, utilizing this chemical reaction to stain the skin.