摘要:
Embodiments of the present invention provide a continuum manipulator that can be used, for example, as a steerable catheter tip. The manipulator of the embodiments comprises a plurality of segments arranged in a stack, which is then able to bend in a range of directions away from the long axis of the stack. In one embodiment the segments include a helical portion which winds in the direction of the long axis of the stack, and can thus bend away from the long axis in any direction. In another embodiment the segments include a backbone portion with cantilevered rings extending from the backbone portion, separated by bending gaps which allow the segment to bend in a range of directions away from the backbone portion so that the bending gap between the rings closes. In some embodiments a carbon fibre rod is included as a backbone for the stack, to minimise hysteresis and improve repeatability of bending. In addition, in embodiments of the invention tendon control channels are provided formed within the segments, through which tendon control wires extend to apply compression and/or bending forces to the stack Having the control channels formed internally to the stack strengthens the stack and makes the stacked structure conform to the channel(s). In particular unwanted twisting of the tip of the stack can be prevented and torquability can be improved.
摘要:
Embodiments of the present invention provide a continuum manipulator that can be used, for example, as a steerable catheter tip. The manipulator of the embodiments comprises a plurality of segments arranged in a stack, which is then able to bend in a range of directions away from the long axis of the stack. In one embodiment the segments include a helical portion which winds in the direction of the long axis of the stack, and can thus bend away from the long axis in any direction. In some embodiments a carbon fiber rod is included as a backbone for the stack, to minimize hysteresis and improve repeatability of bending. In addition, in embodiments of the invention tendon control channels are provided formed within the segments, through which tendon control wires extend to apply compression and/or bending forces to the stack.
摘要:
A magnetic resonance system comprises a magnetic resonance scanner (10) including a main magnet (12) generating a static magnetic field biasing nuclear spins toward aligning along a direction of the static magnetic field, magnetic field gradient coils (14), a radio frequency coil (16), and a controller (20, 22) configured to: (a) drive the radio frequency coil to selectively tip spins predominantly of short T2* out of the direction of the static magnetic field; (b) drive at least one of the magnetic field gradient coils and the radio frequency coil to dephase said spins predominantly of short T2* tipped out of the direction of the static magnetic field; and (c) drive the magnetic field gradient coils and the radio frequency coil to acquire magnetic resonance data that is predominantly T2* weighted due to preceding operations (a) and (b).
摘要:
A method for generating an image comprises: acquiring a magnetic resonance image (DI); generating a magnetic susceptibility gradient vector map (DΔχ) from the magnetic resonance image; and filtering the magnetic susceptibility gradient vector map to generate a magnetic susceptibility gradient image (96, 110) depicting magnetic susceptibility gradient information including at least some magnetic susceptibility gradient directional information.
摘要:
The invention relates to a device for magnetic resonance imaging of a body (7), wherein the device (1) is arranged to a) generate a series of MR echo signals (20) by subjecting at least a portion of the body (7) to an MR imaging sequence comprising RF pulses and switched magnetic field gradients, b) acquire the MR echo signals for reconstructing an MR image (21) therefrom, c) calculate a susceptibility gradient map (22) from the MR echo signals or from the MR image (21), the susceptibility gradient map (22) indicating local susceptibility induced magnetic field gradients, d) determine the position of an interventional instrument (16) having paramagnetic or ferromagnetic properties from the susceptibility gradient map (22).
摘要:
Objects of this invention include provision of magnetic resonance (MR) imaging methods, MR apparatus, and radio-frequency (RF) receiving coil devices permitting interactive MR examination of a patient. In particular, this invention includes means for generating MR images by a moveable RF coil which can be moved across a patient during an MR examination. The MR apparatus includes a position detection system which detects the current position and orientation of the moveable RF coil. The coil can be hand held for manual movement or can be attached to mechanical manipulators for controlled movement. The imaging methods determine and generate magnetic gradient and RF pulse sequences to excite nuclear magnetization in a 3D region determined with respect to the current 3D position and 3D orientation of the moveable RF coil. The invention also includes moveable RF coils for receiving and transmitting which are configured and sized for convenient manipulation by an operator. A preferable moveable RF coil assembly includes markers necessary to interact with a particular position detection system, display means for displaying reconstructed images in real-time, and control means for operator entry of signals controlling the MR apparatus. This invention also includes a carrier medium with recorded program instructions for controlling a programmable MR apparatus to perform the disclosed methods.
摘要:
A magnetic resonance system comprises a magnetic resonance scanner (10) including a main magnet (12) generating a static magnetic field biasing nuclear spins toward aligning along a direction of the static magnetic field, magnetic field gradient coils (14), a radio frequency coil (16), and a controller (20, 22) configured to: (a) drive the radio frequency coil to selectively tip spins predominantly of short T2* out of the direction of the static magnetic field; (b) drive at least one of the magnetic field gradient coils and the radio frequency coil to dephase said spins predominantly of short T2* tipped out of the direction of the static magnetic field; and (c) drive the magnetic field gradient coils and the radio frequency coil to acquire magnetic resonance data that is predominantly T2* weighted due to preceding operations (a) and (b).