Electrode coupling media for transcutaneous electrical nerve stimulation

In transcutaneous nerve stimulation current is supplied to the patient using surface electrodes which make electrical contact via wetted sponges or a conductive gel. This paper reports measurements of the electrical characteristics of ten commercially available gels. Five are recommended by the manufacturers as being suitable for electrode coupling only, three are recommended for ultrasound coupling only and two are designated 'dual purpose'. Marked differences in electrical conductivity are found. Both the dual purpose and ultrasound gels are found to be electrically inferior to 'electrode only' gels. The results are discussed in relation to different electrode types and in comparison with saline moistened sponges.