- Exterior sources of electromagnetic interference may perhaps trigger the device to malfunction and have an impact on stimulation. Cellular phones. While we don't anticipate any interference with cell phones, the complete effects of conversation with mobile phones are not known at the moment. Moveable RF communications products (as an example https://www.theorthopaedicandpainpractice.com/chronic-neck-and-shoulder-pain-relief-strategies-to-reduce-discomfort/