A sense head comprises a plurality of coils and a needle window. The sense
head is operable to receive RF signals communicated from a needle target
such as an injection port located within a patient. A user interface is
configured to visually display an indication to a user relating to the
positioning and orientation of the sense head relative to the needle
target. The positioning and orientation may be determined based on RF
signals received by the coils in the sense head. With the sense head
positioned based on information provided through the visual display, the
user may insert a needle through the needle window to reach the needle
target. The sense head may also receive communications relating to the
pressure of fluid in an implanted device. The user interface may further
display information relating to the fluid pressure in the implanted
device.