Abstract: A method for making a rotating X-ray tube provides a rotating anode having an integral stem. Initially, a cathode which emits electrons is provided. Next, a preheated anode target which radiates x-ray in response to bombardment by the electrons is provided. The method further comprises the steps of providing an anode stem and inertia welding the preheated anode target to the anode stem to form a rotating anode with an integral stem.

Abstract: A brightness detector is used to control the x-ray exposure and the displayed image level in a diagnostic x-ray imaging system. Initially, a region of interest of an image is specified. The average pixel value within the specified region of interest of the image is then found, ignoring regions below a preselected low signal level threshold. Finally, the average pixel value is fed back to the x-ray generator to control the x-ray exposure. The average pixel value is also used to determine a scaling factor to be applied to the image in order to maintain an optimum brightness level when the desired x-ray exposure cannot be attained.

Abstract: A container of ultrasound coupling medium, used in conjunction with an ultrasound imaging system, is stored for operator convenience and patient comfort. Initially, at least one location on the ultrasound imaging system is identified, which has a predetermined thermal profile. The container of coupling medium is then stored at any of the identified locations to maintain the coupling medium at a desired temperature.

Abstract: A mobile x-ray unit operates from a rechargeable battery in a number of different modes which draw current from the battery. The present invention determines the number of patient exams remaining in the mobile x-ray unit, and has the capability of monitoring battery capacity usage as well as displaying information. The current drawn from the battery is measured as the system operates, which allows for the remaining capacity of the battery to be calculated. The remaining capacity of the battery can be adjusted based on usage of the system in each particular application. The system then calculates patient exams remaining based on the adjusted calculated remaining capacity of the battery, and displays the calculated patient exams remaining.

Abstract: A method for increasing dynamic range of ultrasound imaging signals uses a barrel shifter. The barrel shifter shifts large bit two's complement input data into a standard size bit two's complement output. The method, then, comprises the steps of reducing a large data bus to a smaller data bus, and dynamically changing the amount of reduction. The bus reduction is achieved using a barrel shifter. Since time gain compensation (TGC), used to compensate for diminishing echo strength, increases with the depth of the signal, the amount of shift is directly related to the TGC value.

Abstract: In a method for maximizing frame rate of an ultrasound imaging apparatus, ultrasound B and color mode vector density are reduced. Initially, an actual displayed image size is determined. A minimum vector density requirement is then determined for B which will provide a useful image based on the actual displayed image size. The number of vectors in the image is then adjusted to meet the minimum vector density requirement.

Abstract: A time gain compensation technique is applicable for use with ultrasound imaging systems, including systems having digital architecture. The time gain compensation apparatus of the present invention comprises a time gain compensation curve generator and the ability to drive the time gain compensation curve generator to provide digital generation of the time gain compensation curve. Digital generation of the time gain compensation curve is achieved by an initial gain and data represented by a series of slopes and associated time-dependent break-points.

Abstract: A dynamic firing sequence for ultrasound imaging apparatus can be achieved in accordance with the present invention. Initially, operator selected parameters are provided and predetermined system constants are stored. The operator selected parameters in B mode include imaging depth. The operator selected parameters in Doppler mode include velocity scale, doppler range gate position and Doppler range gate size. The operator selected parameters in color mode include velocity scale and region of interest depth. PRI and minimum vector time are calculated using the operator selected parameters and the predetermined system constants. These calculations are used to maximize interleaving, thereby maximizing frame rate.

Abstract: A dynamic apodization gain correction technique for use with ultrasound imaging systems comprises an apodization curve generator and the ability to drive the curve generator to provide digital generation of the apodization gain correction curve. The ability to drive the curve generator comprises an initial plurality of active elements and data represented by a series of slopes and associated time-dependent break-points.

Abstract: An acoustic power control technique computes relevant system transmit parameters in real-time by optimally combining a current system imaging configuration with an empirically derived measurement database. The database contains measurement information that is used by the acoustic power control technique to determine optimal transmit parameters for a given imaging situation. The optimal parameters are determined by adjusting the measured database parameters through the use of the current scanning parameters to maximize system performance. Utilizing system constraints, the acoustic power control technique computes the optimal transmit parameters to maximize system performance.

Abstract: A color adaptive frame averaging method for an ultrasound imaging system adds persistence to images. The color adaptive frame averaging is achieved by computing filter weighting coefficients and using the filter weighting coefficients to compensate for aliased color data. Frame rate compensation is achieved by adjusting the filter weighting coefficients. In accordance with the present invention, the color adaptive frame averaging method comprises a filter, such as an infinite impulse response filter.

Abstract: An automated qualitative image quality method is used for an ultrasound imaging system. Initially, an impulse response of the system is determined. The impulse response is used with a cystic filling determination to achieve automated qualitative image quality for the ultrasound imaging system. The impulse response of the system is determined using a wire-in-water test. That is, a wire target is put in a water tank. Next, a transducer is set to be perpendicular to the axis of the wire, to get a cross-section of the wire. Sound waves are transmitted and reflected echoes are received at different gain settings. Curve fitting techniques are then used to form a system beam profile. Finally, acoustic peak to noise and detail resolution qualitative image quality measurements are made using the system beam profile. The cystic filling of the system is determined by defining a first region of interest in a darkened region of an image and a second region of interest in a surrounding region of the image.

Abstract: A doppler dead zone avoidance method is used in an ultrasound imaging apparatus to avoid the situation where time of flight equals PRI, or the time between doppler firings. Initially, range gate size and transmit parameters are optimized. This optimization of range gate size and transmit parameters is used to minimally adjust an operator selected velocity scale, as needed. Higher velocity scales can be achieved, based on optimization and minimization.

Abstract: Offset signals are removed from an incoming x-ray image produced by a large area solid state x-ray detector. A sequence of incoming dark images from the detector, when the detector is not exposed to x-rays, is recursively filtered to generate a low-noise, continuously-updated offset image. This low-noise continuously-updated offset image is stored in an offset image memory. The image in memory is subtracted from the incoming x-ray image to create a corrected image when the detector is exposed to x-rays.

Abstract: In a method for obtaining temporal equity of multiple images for ultrasound imaging equipment, a vector set is determined for each of the multiple images, representative of vectors to be aligned. A plurality of independent weights is then calculated for each image based on the vector sets. The plurality of calculated independent weights is used to determine a firing sequence which provides temporal equity of the multiple images.

Abstract: The motor efficiency of a rotating X-ray tube having an anode assembly and a cathode assembly, can be greatly improved. The improved efficiency x-ray tube motor comprises a stator and rotor assembly having an air gap between the stator and rotor. The improved efficiency is achieved by reducing the air gap. The stator is operated at anode potential and electrically connected through an anode high voltage cable.