A pinned layer structure composed of cobalt iron vanadium is provided in a spin valve sensor for reducing sense current shunting and decreasing a sense current field exerted on a free layer structure. The foldable tool assembly includes a main body having a passage on top face and several tools one end of which is pivotally connected with one end of the main body, The tools can be folded and collectively arranged under the main body. In order to reduce the complexity of the algorithm, a constraint is removed resulting in an unconstrained frequency-domain recursive least mean squares method and apparatus. In one exemplary embodiment, the indication of elasticity is correlated with an image of the internal tissue area and an output of this image including elasticity indications is displayed for a user.