Medical devices with modular components and assemblies

A medical device, comprising:

• a shaft, wherein the shaft includes one or more lumens extending longitudinally from a proximal end of the shaft to a distal end of the shaft;
• a printed circuit board, wherein the printed circuit board is flexible and is positioned around an outer surface of the shaft, wherein the printed circuit board includes a plurality of electrical connections at a proximal end of the printed circuit board, wherein the printed circuit board includes another plurality of electrical connections at a distal end of the printed circuit board, wherein the printed circuit board includes a plurality of communication conduits connecting electrical connections at the proximal end of the printed circuit board with respective electrical connections at the distal end of the printed circuit board;
• and
• an end cap, wherein the end cap includes one or more cap lumens and a plurality of end cap electrical connections,
• wherein, when the end cap is coupled to the shaft, (1) the one or more cap lumens are in communication with the one or more lumens in the shaft, and (2) the plurality of end cap electrical connections are electrically connected to the electrical connections at the distal end of the printed circuit board.