Usability test reports can be one of the most valuable sources of information to help design decisions for user interface in medical devices. The purpose of the paper is to share the learning from a usability testing observation of a medical device to the manufacturers, researchers and practitioners to maximize the safe use and minimize use-related errors in medical devices. We discuss about inferences made from a usability test of a medical device product with a touchscreen interface. A thematic analysis was done on a 200+ page report made based on observation during the usability test with 3 different user groups performing various touchscreen related tasks on a medical device with touchscreen interface. We come up with a set of inferences for touchscreen interface design derived from further interviews with users and lessons learned during the study. We see a clear need to consider factors outside the touchscreen itself influencing Graphic User Interface design for medical devices.