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

A cooling fluid system is disclosed for providing cryogenic cooling fluid to a high temperature super-conducting machine, wherein said system includes a main cooling system ( 52, 88 ) and a second cooling system, said second cooling system comprising a storage device having a first cryogenic fluid; at least one cooling coupling in fluid communication with the first cryogenic fluid from the storage device and a second cryogenic fluid flowing through the main cooling system.

Cryongenic cooling refrigeration system and method having open-loop short term cooling for a superconducting machine

General Electric proposes to apply transformational technology in the form of low-temperature superconductivity to the design of direct-drive wind turbine generators of the 10-MW power level and greater. Generally, optimal steady state 4 K cryogenic cooling of a large thermal mass (> 10 000 kg) and its dimensions (> 4 m diameter and 2.5 m length) with minimum levelized cost of energy is difficult to achieve. A cooling strategy has been found that turns this size disadvantage to ones favor, and furthermore enables the design scalability of the field winding cooling assembly towards 15 to 20 MW. In this design study, we show that size and efficiency are not mutually exclusive and that it is indeed possible to minimize cryogenic complexity and reduce cost. The cryogenic push-button closed loop circulating system is invisible within the nacelle of a wind turbine and requires no handling of cryogenic liquids. Besides the occasional cryocooler service requirement, the proposed solution is maintenance-free in all operating states and allows the system health to be monitored remotely. The design solutions proposed could potentially make large superconducting generators a reality for off-shore wind turbine deployment.

Large Scale Superconducting Wind Turbine Cooling

Cryogenic liquid coolant is transferred from a stationary liquefier through a bayonet to a conduit rotating with the rotor of a superconducting generator, using a cryogenic fluid transfer joint attached to the collector end of the rotor. A relative-motion gap about the bayonet has its inner and outer diameters reduced in size near the outlet end of the bayonet. The gap thus stepped downward in size extends into a core of boil-off coolant within the rotating conduit, preventing liquid coolant centrifugally forced against the inside of the conduit from entering the gap, and allowing only boil-off coolant to enter.

Cryogenic fluid transfer joint employing a stepped bayonet relative-motion gap

A superconductive magnet having a superconductive coil located within a thermal shield located within a vacuum enclosure. A cryocooler coldhead's first stage is in solid-conductive thermal contact with the thermal shield, and its second stage is in solid-conductive thermal contact with the superconductive coil. A magnet re-entrant support assembly includes an outer support cylinder located between the vacuum enclosure and the thermal shield and includes an inner support cylinder located between the thermal shield and the superconductive coil. The outer support cylinder's first end is rigidly connected to the vacuum enclosure, and its second end is rigidly connected to the thermal shield. The inner support cylinder's first terminus is rigidly connected to the thermal shield near the outer support cylinder's second end, and its second terminus is located longitudinally between the outer support cylinder's first and second ends and is rigidly connected to the superconductive coil.

Superconducting magnet having a shock-resistant support structure

A method and structure for restricting relative sliding motion at the interfaces between a superconducting winding and a supporting structure for the winding. An interface lining material having a low shear modulus of elasticity so as to accommodate large shear displacements with low shear stresses is used as opposed to the use of sliding frictional contact between the contacting surfaces of the electrical winding and the supporting structure. The invention is completed by subjecting the lined interfaced surfaces to large compressional pressure forces so that frictional forces between the interface material and the opposing superconducting winding and supporting structure surfaces, even at low coefficients of friction, are considerably higher than the internal shear forces of the interfacing lining material. The superconducting winding is comprised of a plurality of conductors of superconducting material bunched together in close thermal contact with each other and secured in a solid winding bundle by epoxy resin. The interface lining material preferably is wrapped completely around and surrounds the superconducting winding.

Evangelos Trifon Laskaris

Papers

Cryongenic cooling refrigeration system and method having open-loop short term cooling for a superconducting machine

Large Scale Superconducting Wind Turbine Cooling

Cryogenic fluid transfer joint employing a stepped bayonet relative-motion gap

Superconducting magnet having a shock-resistant support structure

Support method and structure for epoxy impregnated saddle-shaped superconducting windings