By using a multiple receiving coil composed of receiving coils, an imaging portion of a subject is subjected to a first pulse sequence to create n sensitivity images (701 to 703) fewer than the examination images. When these sensitivity images are created, an NMR signal is measured for only the low-frequency region of the k space. A second pulse sequence from which a phase encode step is removed is conducted to create m (m>n) examination images (704, 705) of the subject by using the receiving coils. When sensitivity distributions (707, 708) of the receiving coils are determined for the sensitivity images (701 to 703), and if there are no sensitivity distributions corresponding to the slice positions of the examination images (704, 705), they are determined by slice interpolation using the sensitivity distributions (701 to 703), and the aliasing artifacts of the examination images (704, 705) are removed by matrix operation by using the sensitivity distributions (707, 708).

Magnetic resonance imaging device

A surgical instrument including a switching mechanism which allows a surgeon to selectively advance or retract a staple driver and/or cutting member within a staple cartridge. In various embodiments, the surgical instrument can include a handle, a trigger operatively coupled to the handle, a firing drive, and an end effector. The firing drive can include a first ratchet assembly configured to advance a cutting member in the end effector and a second ratchet assembly configured to retract the cutting member. The trigger can include first and second pawls pivotably mounted thereon which are configured to be selectively engaged with the first and second ratchet assemblies, respectively. In at least one embodiment, the trigger can be configured to slide between a first position in which the first pawl is engaged with the first ratchet assembly and a second position in which the second pawl is engaged with the second ratchet assembly.

Surgical instrument having a directional switching mechanism

Magnetic resonance imaging apparatus

PURPOSE: To develop a superconducting magnetic resonance (MR) imager that provides direct access to the patient and permits interactive MR-guided interventional procedures. MATERIALS AND METHODS: A 0.5-T superconducting magnet that allows a region of vertical access to the patient was designed and constructed. This magnet was integrated with newly designed shielded gradient coils, flexible surface coils, and nonmagnetic displays and with position-monitoring probes and device-tracking instrumentation. RESULTS: The magnet homogeneity was 12.3 ppm, and the gradient field was linear to within 1% over an imaging region 30 cm in diameter. The signal-to-noise ratio was 10% higher than in a comparable 0.5-T superconducting imager. Images were obtained in several anatomic regions with use of routine pulse sequences. Interactive image plane selection and near real-time imaging, with use of fast gradient-recalled echo sequences, were demonstrated at a rate of one image every 1.5 seconds. CONCLUSION: MR-guided interv...

Superconducting open-configuration MR imaging system for image-guided therapy.

Magnetic resonance information acquired by a movable magnetic resonance instrument is used to monitor hyperthermia treatments such as tissue ablation. The instrument may include both the magnetic resonance equipment and an energy applicator such as a high intensity focused ultrasound unit. The treatment can be conducted under automatic control after the operator marks a treatment volume on an image of the subject, such as a magnetic resonance image acquired using the movable magnetic resonance instrument. The automatic treatment can be based on interpolation of tissue response curves at plural test points near the treatment volume. The system can also provide automatic supervisory control during manual operation, to prevent application of heat to sensitive anatomical structures.

MRI-guided therapeutic unit and methods

The invention relates to a superconducting magnet system and a quench protection method of a high temperature superconductor lead thereof. The superconducting magnet system comprises a superconducting coil, the high temperature superconductor lead, a heater, a heater trigger and a high temperature superconductor lead sensing unit. The high temperature superconductor lead sensing unit is used for detecting a working state of the high temperature superconductor lead, and outputting a control signal to the heater trigger when a detection signal from the high temperature superconductor lead is greater than a preset value so as to trigger the heater to quench the superconducting coil. The preset value corresponds to a quench point or a quench critical point of the high temperature superconductor lead.

Superconducting magnet system and quench protection method of high temperature superconductor lead thereof

A rotating machine comprising a superconductive coil (12) and a temperature sensor (38) operable to provide a signal representative of superconductive coil temperature. The rotating machine may comprise a control system (20) communicatively coupled (18) to the temperature sensor. The control system may be operable to reduce electric current in the superconductive coil when a signal representative of a defined superconducting coil temperature is received from the temperature sensor.

Superconductor quench monitoring and control system and method of operating the same

A system 100 for generating power includes a homopolar electrical generator having, a superconducting field coil 211 operative to create a magnetic field, and a homopolar rotor assembly 201 operative to rotate in the magnetic field such that a rotating magnetic field couples with a stationary winding by an interaction of a rotating permeance wave produced by the homopolar rotor assembly and the magnetic field created by the superconducting field coil, and a wind turbine mechanically linked to the homopolar electrical generator operative to rotate the homopolar rotor assembly 201.

Superconducting homopolar alternator for wind power applications

Magnet assembly and manufacturing method thereof

A superconductive magnet includes a superconductive coil assembly having a cryogenic vessel, a thermal shield enclosing the cryogenic vessel, and a vacuum enclosure enclosing the thermal shield. The cryogenic vessel, thermal shield and vacuum vessel have annular shells radially spaced apart from one another with reference to a common longitudinal axis and coaxially aligned with the common longitudinal axis. The magnet also includes a tube suspension assembly having a plurality of tubes located between respective ones of the cryogenic vessel, thermal shield and vacuum enclosure. The tubes are axially overlapped and are interconnected with one another and with the cryogenic vessel, thermal shield and vacuum enclosure. One tube has an end forming a sliding joint with the cryogenic vessel that allows both radial and axial movement of the cryogenic vessel relative to the thermal shield and vacuum enclosure during cooldown of the cryogenic vessel from ambient to cryogenic temperatures.

Evangelos Trifon Laskaris

Papers

Superconducting magnet system and quench protection method of high temperature superconductor lead thereof

Superconductor quench monitoring and control system and method of operating the same

Superconducting homopolar alternator for wind power applications

Magnet assembly and manufacturing method thereof

Tube suspension assembly for superconductive magnets