An exoskeleton device is capable of being applied to an outer surface of an elongated medical instrument, such as a catheter or a balloon (e.g., an angioplasty balloon, etc.). The exoskeleton device includes a sleeve or another element that is configured to be placed over a distal portion of the elongated medical instrument, one or more features on the sleeve or other element for performing a procedure within the body of a subject, and one or more elements that communicate with the sleeve or other element and/or the features carried thereby to enable performance of the procedure within the body of the subject. Methods of applying exoskeleton devices to elongated medical instruments and methods of using exoskeleton devices are also disclosed.