Medical devices may lead to patient trauma and time consuming clinical processes. The reason can be a lack of usability and / or untrained personal. We wanted to know which topic is more important to improve patient safety and efficiency. Therefore we performed a usability test with a radio frequency device and evaluated the “teaching” method of the company compared to “no teaching” and “teaching and training”. The results showed that the medical device has some minor design deficiencies, but there is no standardized teaching and training concept which could avoid problems caused by the design.