Measurement of residual in vivo Ag ions from transcutaneous electrical stimulation for neuromodulation

• Published in: Technology and health care Vol. 28; no. 4; pp. 453 - 459
• Main Author: Wang, Heng Li
• Format: Journal Article
• Language: English
• Published: Netherlands IOS Press BV 01.01.2020
• Subjects: Drug resistance; Electrical stimuli; Electrodes; Health services; Heavy metals; Human tissues; Ion concentration; Ions; Medical treatment; Neuromodulation; Pain; Saline solutions; Silver; Silver chloride; Skin; Stimulation; Tissues; neuromodulation; Transcutaneous electrical stimulation; Ag ion dissolution concentration; pigskin experiment; saline experiment
• ISSN: 0928-7329; 1878-7401
• DOI: 10.3233/THC-202192

The use of transcutaneous electrical stimulation for neuromodulation is an important treatment strategy for functional nerve diseases. It can not only reduce patient pain and prevent the development of drug-resistant disease, but is also more effective than alternative treatment methods. Ag/AgCl electrodes are commonly used for transcutaneous stimulation. However, the silver ions can dissolve in tissue during electrical stimulation, which can lead to heavy metal poisoning and other issues. This study analyzed the amount of residual silver ions found in tissue after electrical stimulation. Saline solution and animal skin were chosen as experimental analogs for human tissue and the amount of residual silver ions were analyzed via ultraviolet spectrophotometer. After a volume-to-quantity conversion, we found that after using a pair of electrodes for three hours, the concentrations of silver ions dissolved in the saline solution and the skin were less than 0.1 ppb and 0.5 ppb, respectively, due to its low solubility. By analyzing the ion dissolution concentration, we found that the residual silver ion concentration in vivo was less than 0.1 ppb, which is within the safe range for humans. Therefore, we believe it is safe to use Ag/AgCl electrodes for transcutaneous electrical stimulation.