Clinical evaluation of safety and human tolerance of electrical sensation induced by electric fields with non-invasive electrodes

This paper reports the first clinical safety study of human tolerance of electrical sensation using non-invasive, flexible surface-type electrodes and exponentially decaying electric pulses. The study evaluated the effect of electric fields in the absence of a drug and an anesthetic, and was performed in light of potential applications in the field of erectile dysfunction (ED). Twenty impotent patients who had previously received injection or intraurethral therapies were enrolled in the study. Voltage escalations from 50 to 80 V (in 10-V increments) with a single pulse of 3-ms duration were performed with meander-type electrodes placed on the shaft and part of the glans of the penis. The electric fields-induced sensation was assessed via a pain scale from 0 to 10. All 20 patients, who were free to withdraw from the study at any point, completed the voltage escalation study. No clinical safety concerns were apparent and no skin irritation was observed after electric treatment. Our initial study indicates that the pulses in the tested voltage range were well tolerated by most patients. In previous animal experiments under analogous experimental conditions, the application of 50 V has been found effective for transdermal drug delivery into the penis.