摘要:
Active resistive shim coil assemblies may be used in magnetic resonance imaging (MRI) systems to reduce in-homogeneity of the magnetic field in the imaging volume. Disclosed embodiments may be used with continuous systems, gapped cylindrical systems, or vertically gapped systems. Disclosed embodiments may also be used with an open MRI system and can be used with an instrument placed in the gap of the MRI system. An exemplary embodiment of the active resistive shim coil assembly of the present disclosure includes active resistive shim coils each operable to be energized by separate currents through a plurality of power channels. In some embodiments, the disclosed active resistive shim coil assemblies allow for various degrees of freedom to shim out field in-homogeneity.
摘要:
A Mini-PCI (MPCI) interface, and associated circuits and methods are provided for connecting a Peripheral Component Interconnect (PCI) device to one or more external devices. The MPCI interface, circuits and methods provide for a substantial if not full implementation of a PCI Local Bus without requiring the standard number of pins, traces, or signals. The MPCI interface includes a PCI/MPCI bridge connected between a PCI bus and to up to eight external devices in the form of MPCI devices and linear memory devices. The PCI/MPCI bridge is capable of receiving an incoming PCI transaction and multiplexing some of its signals together to create a corresponding incoming MPCI transaction. This incoming MPCI transaction may then be passed over an MPCI bus, having fewer lines and optimally operating at a higher frequency, the external devices. The process is reversed for outgoing transactions, i.e., the MPCI transactions are de-multiplexed to create PCI transactions. Additionally, the MPCI interface may also be configured to provide for direct access to linearly addressed memory devices without adding a PCI interface to the external interface. The invention may be implemented through integrated circuitry and/or computer implemented instructions, and may be included within a personal computer.
摘要:
A showerhead has at least a first set of nozzles and a second set of nozzles for discharging water. The showerhead discharges water according to one of multiple water delivery functions, where a first water delivery function corresponds to water being discharged through only the first set of nozzles, a second water delivery function corresponds to water being discharged through only the second set of nozzles and a third water delivery function corresponds to water being discharged through the first and second sets of nozzles simultaneously. The spacing between the first set of nozzles and the second set of nozzles is carefully selected so that the third water delivery function corresponds to the integrated nozzles of the first and second sets of nozzles. As a result, the third water delivery function provides a coherent and balanced water flow resulting in a more pleasant feel.
摘要:
A method of determining a treatment plan for intensity modulated radiation treatment (IMRT) divides a three-dimensional volume of a patient into a grid of dose voxels. At least a portion of the dose voxels are designated to belong to at least one target or to at least one critical structure. An ionizing radiation dose as delivered by a plurality of beamlets each having a beamlet intensity is modeled. A non-linear convex voxel-based penalty function model is provided for optimizing a fluence map. The fluence map defines the beamlet intensities for each of the plurality of beamlets. The model is then solved based on defined clinical criteria for the target and the critical structure using an interior point algorithm with dense column handling to obtain a globally optimal fluence map.
摘要:
Method for introducing harmonics into an audio stream for improving three dimensional audio positioning. The method adds high frequency harmonics into sampled sound signals to replace high frequency sound components eliminated before sampling. By adding high frequency harmonics into the sampled sound signals, a “richer sound” will be produced. The resulting sampled sound signals will have a frequency spectrum containing a larger number of frequencies. Thus, the ear will have more cues to better position the sampled sound signals.
摘要:
A method and a system for the nonlinear storage of data points of a texture map matrix within a linear memory device has two embodiments. A first embodiment involves the implementation of subdividing the texture map matrix into storage matrixes, and storing each storage matrix into distinct memory locations within the linear memory device. Each storage matrix includes at least one pair of adjacent data points from two adjacent row of data points. As a result, data points of the texture map matrix are in a nonlinear storage arrangement within the linear memory device. A second embodiment involves the implementation of subdividing the rows of the texture map matrix into multi-data point groups, and placing adjacent multi-data point groups into a linear string. The linear string is subsequently written to the linear memory device. As a result, data points of the texture map matrix are in a nonlinear storage arrangement within the linear memory device.
摘要:
Active resistive shim coil assemblies may be used in magnetic resonance imaging (MRI) systems to reduce in-homogeneity of the magnetic field in the imaging volume. Disclosed embodiments may be used with continuous systems, gapped cylindrical systems, or vertically gapped systems. Disclosed embodiments may also be used with an open MRI system and can be used with an instrument placed in the gap of the MRI system. An exemplary embodiment of the active resistive shim coil assembly of the present disclosure includes active resistive shim coils each operable to be energized by separate currents through a plurality of power channels. In some embodiments, the disclosed active resistive shim coil assemblies allow for various degrees of freedom to shim out field in-homogeneity.
摘要:
A device and a process for performing high temporal- and spatial-resolution MR imaging of the anatomy of a patient during intensity modulated radiation therapy (IMRT) to directly measure and control the highly conformal ionizing radiation dose delivered to the patient for the treatment of diseases caused by proliferative tissue disorders. This invention combines the technologies of open MRI, multileaf-collimator or compensating filter-based IMRT delivery, and cobalt teletherapy into a single co-registered and gantry mounted system.