Abstract: A tissue-modifying catheter adapted for use with an MRI machine includes an elongated hollow sheath configured for intraluminal introduction with proximal and distal open ends. A coil of electrically conductive, non-magnetic wire, disposed at the proximal open end of the sheath is in electrical communication with an electrical waveform generator through a set of electrical conductors entering into the open proximal end of the sheath. A non-magnetic end effector is physically or mechanically coupled to the coil of wire, such that when a voltage is imposed upon the coil of wire through the waveform generator, the coil experiences a directional torque due to the presence of the MRI-oriented magnetic field, causing the end effector to interact with surrounding tissue. The waveform generator preferably delivers a time-varying waveform such as sinusoid that may be synchronized with the MRI-oriented magnetic field. The catheter may include a plurality of different end effectors for different application.

Abstract: A piezo-driven, vibrating beam is applicable to surgical procedures. A rod of piezoelectric material defines a length with proximal and distal ends. A pattern of electrodes, disposed adjacent to and along the length of the rod of piezoelectric material, is adapted for connection to a generator operative to stimulate the piezoelectric material, causing the rod to assume one or more vibratory states. In preferred embodiments, the proximal end of the rod of piezoelectric material is adapted for coupling to a blocking mass causing the vibratory states to be concentrated at the distal end of the rod of piezoelectric material. The pattern of electrodes may comprise interdigitated fingers, and the system may further include a material encapsulating the rod and the pattern of electrodes. Preferred embodiments may further include a plurality of coextensive, parallel rods forming a basic unit, each rod having a separate pattern of electrodes adjacent thereto.