Comparison of Single-Use and Multiple-Use Electrodes for Sensory, Motor Threshold Amplitudes and Force Production

Author

Lucia Maloy, Brigham Young University - ProvoFollow

Abstract

Context: Electrodes play an important role in interfacing tissue with electrical stimulation devices. Manufacturers recommend that adhesive metallic mesh cloth electrodes be used no more than 10 times before they are discarded, however, clinically the electrodes are often used up to 30 times. Another concern is sanitation. When electrodes are used on different patients, there is a chance for cross-contamination and bacterial growth on the electrode. Objective: To compare amplitudes of perceived sensation, motor twitch and force produced at specific amplitudes using single-use electrodes that run no risk of cross-contamination, and multiple-use electrodes. Design: Mixed model ANOVA with the subject blocked. Setting: Therapeutic modalities research laboratory. Patients or Other Participants: 20 subjects comprised of 7 males (age 24.7 yrs ± 2.3 yrs, skin fold thickness 5.9 mm ± 2.4 mm) and 13 females (age 21.5 yrs ± 2.3 yrs, skin fold thickness 10.7 mm ± 4.1 mm) recruited by volunteer sample mainly from athletic and athletic training populations. They drew random numbers to determine which group they were assigned to. Interventions: Each subject had electrodes placed on their wrist extensors muscles. Measures were recorded of what intensity it took to achieve perceived sensation, motor twitch, and force produced at a specific intensity. To determine decay, multiple use electrodes were tested initially and on the 10th use. After the multiple use electrodes were tested initially, they were leached out. After eight uses, pretest procedures were repeated (10th use electrode) as the final trial on the subjects. Single use electrodes were tested one time. Main Outcome Measures: The dependent variables were sensation, motor twitch and force production. The experiment was a repeated measures study, using mixed models ANOVA with subjects blocked. Alpha was set at p<0.05. Data was analyzed using a SAS proc mixed 9.1. Results: There was no statistical difference between the measures taken during the initial trial and final trial of the multiple use electrodes for muscle twitch (FMUI MUF muscle twitch= 107.3, p= 0.09) and force production (FMUI MUF force production=28.7, p= 0.11). There was a significant difference between the single use and the multiple use electrodes for the initial and final trial. Average values in mA for perceived sensory were: single use 9.73, multiple use initial 16.70 , multiple use final 21.03; observed muscle twitch: single use 15.87, multiple use initial 29.16, multiple use final 31.78; and force produced: single use 22.8 Newtons, multiple use initial 10.0 Newtons, multiple use final 5.0 Newtons. Conclusion: Single-use electrodes produce more conductive power with fewer milliamps compared to multiple-use electrodes. Single use electrodes are just as, or more efficient as the multiple use electrodes and have the added advantage of eliminating the possibility of cross-contamination of bacteria from patient to patient.