A medical device for diagnosis or treatment of tissue in a body is provided. The device includes an elongate, tubular shaft configured to be received within the body. The shaft has 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. A plurality of coils are disposed within the shaft with one or more of the coils configured for movement with the distal portion. Electromagnetic fields generated from within or outside of the medical device induce currents in the coils from which movement of the distal portion in response to contact of the distal portion with the tissue may be determined. In one embodiment, several of the coils are connected in series to reduce the space required in the device for conductors.
