Abstract: Methods and systems are provided for indirectly measuring a current of a radiation source. In one embodiment, a method comprises generating a scan dataset by transmitting a radiation from a radiation source directly to a detector; calculating a signal to noise ratio of the scan dataset; and determining a current that was used to generate the scan dataset based on the calculated signal to noise ratio. In this way, current of the radiation source may be evaluated without connecting extra equipment to the radiation source.

Abstract: Methods and systems are provided for measuring vibrations in an imaging system. In one embodiment, a method for a computed tomography (CT) system includes measuring a vibration level of a rotatable gantry of the CT system with a balance sensor coupled to a stationary housing of the CT system and outputting a notification indicating potential image artifacts based on the vibration level exceeding a vibration threshold.

Abstract: Methods and systems are provided for measuring vibrations in an imaging system. In one embodiment, a method for a computed tomography (CT) system includes measuring a vibration level of a rotatable gantry of the CT system with a balance sensor coupled to a stationary housing of the CT system and outputting a notification indicating potential image artifacts based on the vibration level exceeding a vibration threshold.

Abstract: Methods and systems are provided for indirectly measuring a current of a radiation source. In one embodiment, a method comprises generating a scan dataset by transmitting a radiation from a radiation source directly to a detector; calculating a signal to noise ratio of the scan dataset; and determining a current that was used to generate the scan dataset based on the calculated signal to noise ratio. In this way, current of the radiation source may be evaluated without connecting extra equipment to the radiation source.

Abstract: Method and apparatus are provided for aligning a cradle supported by a table in an imaging system with a gantry scan plane in a bore of the gantry. More particularly, various embodiments provide a laser alignment structure having at least two alignment apertures arranged along an axis of the bore, and an adjustment device configured to adjust a position of the laser so that the laser beam is aligned with the alignment apertures. Highly accurate alignment of the cradle to the gantry scan plane is achieved by utilizing this apparatus in tandem with an imaging-based alignment analysis method.

Abstract: Method and apparatus are provided for aligning a cradle supported by a table in an imaging system with a gantry scan plane in a bore of the gantry. More particularly, various embodiments provide a laser alignment structure having at least two alignment apertures arranged along an axis of the bore, and an adjustment device configured to adjust a position of the laser so that the laser beam is aligned with the alignment apertures. Highly accurate alignment of the cradle to the gantry scan plane is achieved by utilizing this apparatus in tandem with an imaging-based alignment analysis method.

Abstract: Methods and systems are generally described for measuring a voltage used by an imaging system to generate radiation used in imaging. In embodiments, different datasets are acquired using different degrees of attenuation of the radiation. The differently attenuated datasets are processed to derive a ratio of the differential attenuation. The attenuation ratio is processed to derive a measure of the voltage used by the imaging system to generate the radiation used to acquire the different datasets.

Abstract: Methods and systems are generally described for measuring a voltage used by an imaging system to generate radiation used in imaging. In embodiments, different datasets are acquired using different degrees of attenuation of the radiation. The differently attenuated datasets are processed to derive a ratio of the differential attenuation. The attenuation ratio is processed to derive a measure of the voltage used by the imaging system to generate the radiation used to acquire the different datasets.

Abstract: A system and method for controlling thermal output of a medical device is disclosed. A thermal controller receives operational parameters for an impending use of a medical device and predicts a thermal output of the medical device from the operational parameters. The thermal controller compares the predicted thermal output to a desired limit on thermal output and, if the predicted thermal output exceeds the desired limit on thermal output, dynamically controls power consumption by the medical device to maintain an actual thermal output substantially at or below the desired limit on thermal output during use of the medical device.

Abstract: A thermal control system having an initial bore condition and a thermal boundary condition for an MRI includes a thermal controller adapted to set at least one dynamic limit on power input into an MRI gradient coil. The dynamic limit is determined for a first commanded prescription as a function of the initial bore condition and the thermal boundary condition.

Abstract: A method for measuring table sag of a table may include utilizing images of an unloaded table and a loaded table, plotting pixel values for a range of pixels for each image within a particular column, identifying a pixel within each plot that has a highest pixel value, calculating a difference between the identified pixel row numbers, and converting the difference into a measurement of table sag. A storage medium encoded with machine-readable computer program code for measuring table sag of a table may include instructions for causing a computer to implement the method. A computer for use in an imaging system may utilize digital images for the measurement of table sag and an imaging system may include such a computer.

Abstract: A method for measuring table sag of a table may include utilizing images of an unloaded table and a loaded table, plotting pixel values for a range of pixels for each image within a particular column, identifying a pixel within each plot that has a highest pixel value, calculating a difference between the identified pixel row numbers, and converting the difference into a measurement of table sag. A storage medium encoded with machine-readable computer program code for measuring table sag of a table may include instructions for causing a computer to implement the method. A computer for use in an imaging system may utilize digital images for the measurement of table sag and an imaging system may include such a computer.

Abstract: A system and method for controlling thermal output of a medical device is disclosed. A thermal controller receives operational parameters for an impending use of a medical device and predicts a thermal output of the medical device from the operational parameters. The thermal controller compares the predicted thermal output to a desired limit on thermal output and, if the predicted thermal output exceeds the desired limit on thermal output, dynamically controls power consumption by the medical device to maintain an actual thermal output substantially at or below the desired limit on thermal output during use of the medical device.

Abstract: A thermal control system having an initial bore condition and a thermal boundary condition for an MRI includes a thermal controller adapted to set at least one dynamic limit on power input into an MRI gradient coil. The dynamic limit is determined for a first commanded prescription as a function of the initial bore condition and the thermal boundary condition.

Abstract: A shoot-through protection system for an electric power generating system including a synchronous generator, a bridge rectifier coupled to an output of the generator for converting alternating current (AC) from the generator to direct current (DC) at a rectifier output, and at least one inverter coupled to the rectifier output for converting the DC output to a controlled frequency AC output for application to a load. The generator has a separately excited field winding in which the magnitude of field excitation controls the voltage output of the generator. A microprocessor-based controller regulates generator field excitation in a manner to control the DC output of the rectifier. The generator is protected from a shoot-through in the inverter by detecting a sustained voltage drop in the rectifier DC output and reversing generator field excitation in response to such a voltage drop to rapidly drive generator output voltage to substantially zero volts.

Abstract: A self-test system for a shorted diode protection circuit in an electric vehicle propulsion system includes a series of relays for selectively coupling a battery in circuit with a field winding of a generator, the shorted diode protection circuit being coupled in voltage sensing arrangement with the field winding. The relays are operated to induce current in forward and reverse directions through the winding in separate test stages. At each stage the winding is disconnected from the battery so that inductive reactance creates a voltage on the winding to actuate the protection circuit. A system controller records whether the protection circuit is responsive and therefore operable and alerts a vehicle operator.