Methods and apparatus consistent with the invention provide improved organization of documents responsive to a search query. The invention is an electronic pen with a speaker located near the top of the device. During or after contrast agent injection, the ablation lesion and surrounding tissue is imaged using an imager that is responsive to the injected contrast agent. The second stage signals may then go through further computation to obtain a plurality of third stage signals that are 45 degrees out of phase. In other embodiments, the device may be at least partially integrated with a user device. The coupling layer regulates the ferromagnetic exchange coupling between the magnetic recording layer and the exchange-spring layer.