If you have an internal or external medical device, such as a pacemaker or metal implant, it's crucial to inform the TSA officer before screening begins. This step is for your safety and to ensure that you are treated with the utmost respect and understanding. You may request a pat-down instead of going through the metal detector or advanced imaging technology. The officers are trained to handle these situations with care, ensuring your medical devices are not affected, and you receive a respectful and thorough screening.