Medical devices for diagnosis or treatment of tissue in a body. Representative devices include an elongate shaft having a proximal portion and a distal portion configured for movement relative to the proximal portion. A flexible member having a predetermined stiffness is disposed between the proximal and distal portions. One or more coils and an electrically passive element are disposed within the shaft with either the coils or element configured for movement with the distal portion. The element comprises a material effecting an electrical characteristic of the coils. Movement of the distal portion in response to its contact with the tissue and relative movement of the coils and element causes a change in the electrical characteristic in at least one of the coils indicative of at least a contact force magnitude between the distal portion and the tissue. Several embodiments allow determination of both force magnitude and force vector direction.
