Abstract: Method for matching transmit voltages in imaging modes of a medical ultrasound imaging system having different transmit power requirements in which a common power supply voltage is directed from a power supply to transmitting elements and when switching between the imaging modes on a line-by-line basis, if the transmit power requirement for an imaging mode is less than that provided by the power supply voltage, the transmit waveform for that imaging mode is pulse width modulated, e.g., by directing pulse width modulation (PWM) signals to the transmitting elements. The power supply voltage is not changed between different imaging modes when imaging on a line-by-line basis. The PWM signals are generated by a timing generator based on the transmit power requirements of the imaging mode so that the total power in the waveform generated by the transmitting elements during that imaging mode does not exceed the transmit power thereof.

Abstract: An ultrasound imaging system is provided along with a method for spatially compounding a plurality of ultrasound images in an elevation dimension. The ultrasound imaging system and method reduce image speckle. The ultrasound imaging system may include a transducer in electrical communication with an ultrasound system controller configured to generate, transmit, and receive a series of ultrasound energy pulses. The ultrasound system controller is further configured to recover image information using beamforming techniques from steered or focused ultrasound imaging planes prior to spatial compounding of a plurality of image frames. The present invention may also be broadly viewed as providing a method for ultrasound imaging.

Abstract: Apparatus and methods for controlling electrostrictive transducer sensitivity in a pulse-echo medical ultrasound system. Certain characteristics of each transducer element are tested after manufacture and recorded on a storage medium. The stored data is then used, along with certain model relations, for monitoring certain operational parameters of the transducer during use, and feedback compensation applied for maintaining the transducer sensitivity substantially constant. The parameters to be monitored may include the temperature, acoustic pressure, input power, and a figure of merit determined from the dielectric constant and coupling coefficient.

Abstract: An ultrasound imaging system includes an array of ultrasound transducer elements, wherein the transducer array is divided into plural transducer elements arranged in the direction of a scan plane and each transducer element is divided into three or more segments in the direction of an elevation plane. Also included are a transmitter for transmitting ultrasound energy into a region of interest from the array, a receiver for receiving signals generated by the array in response to the ultrasound echoes, a signal processing section including a signal processing circuit, a beam former, and a controller. The signal processing section is operable for effecting system control and for effecting signal processing and image display, and in particular, for allocating the channels with respect to the segments to vary the arrangement of signal processing channels applied to selected segments wherein the allocation is performed according to beam focal length.

Abstract: Apparatus and methods for controlling electrostrictive transducer sensitivity in a pulse-echo medical ultrasound system. Certain characteristics of each transducer element are tested after manufacture and recorded on a storage medium. The stored data is then used, along with certain model relations, for monitoring certain operational parameters of the transducer during use, and feedback compensation applied for maintaining the transducer sensitivity substantially constant. The parameters to be monitored may include the temperature, acoustic pressure, input power, and a figure of merit determined from the dielectric constant and coupling coefficient.

Abstract: Apparatus and methods for controlling electrostrictive transducer sensitivity in a pulse-echo medical ultrasound system. Certain characteristics of each transducer element are tested after manufacture and recorded on a storage medium. The stored data is then used, along with certain model relations, for monitoring certain operational parameters of the transducer during use, and feedback compensation applied for maintaining the transducer sensitivity substantailly constant. The parameters to be monitored may include the temperature, acoustic pressure, input power, and a figure of merit determined from the dielectric constant and coupling coefficient.

Abstract: An improved ultrasonic mechanical sector scanning transducer assembly is disclosed. An ultrasonic transducer is disposed for movement within a generally tubular housing. A drive element extends longitudinally within the housing and is coupled for transmitting motion to the transducer. Power means produces oscillatory rotative movement of the drive element and transducer. A diaphragm seal, comprising a resilient tubular membrane, provides a liquid tight seal between longitudinally displaced interior sections of the housing. The tubular membrane has one relatively narrow end and flares along its length to a wider opposite end. The narrow end is bonded about the drive element. The wider end is affixed about the periphery of the housing. A coaxial cable is coupled to the transducer and extends to the exterior of the housing. The cable is wrapped within a spiral groove extending about the outer surface of a spool or reel mounted for movement in unison with the transducer.

Abstract: An improved ultrasonic mechanical sector scanning transducer assembly is disclosed. An ultrasonic transducer is disposed for movement within a generally tubular housing. A drive element extends longitudinally within the housing and is coupled for transmitting motion to the transducer. Power drive apparatus produces oscillatory rotative movement of the drive element and transducer. A diaphragm seal, comprising a resilient tubular membrane, provides a liquid tight seal between longitudinally displaced interior sections of the housing. The tubular membrane has one relatively narrow end and flares along its length to a wider opposite end. The narrow end is bonded about the drive element. The wider end is affixed about the periphery of the housing. A coaxial cable is coupled to the transducer and extends to the exterior of the housing. The cable is wrapped within a spiral groove extending about the outer surface of a spool or reel mounted for movement in unison with the transducer.

Abstract: An ultrasonic transducer probe assembly. The assembly includes a multiple segment transducer truncated along opposed edges to define an elongated transducer shape which is pivoted about a pivot axis coincident with the transducer. The resulting pivoting movement of the transducer allows a smaller dimension probe assembly housing with only limited diminution of control over ultrasonic depth of field and resolution. A multiconductor cable routes energizing and monitoring signals to and from the transducer array. The multiple conductors needed to carry these signals are arranged in a geometric configuration to enhance the signal carrying characteristics of the cable.

Abstract: An electronically step scanned real time ultrasonic imaging system and method is disclosed. The system includes a transducer assembly having an unequally spaced array of elements, each with an axis of transmission along which it transmits its main ultrasonic energy when electrically stimulated. The elements are disposed in a curvilinear array, wherein their axes of transmission are approximately co-planar, but divergent in the common plane. In the preferred embodiment, the axes of transmission diverge from one another by unequal angles, such that the tangent functions of each of the angles varies in equal increments along the array. Scan conversion techniques are used for displaying purposes, operating in the Y .theta. and Y tan .theta. formats.

Abstract: An electronically step scanned real time ultrasonic imaging system and method is disclosed. The system includes a transducer assembly having an array of elements, each with an axis of transmission along which it transmits its main ultrasonic energy when electrically stimulated. The elements are disposed in a curvilinear array, wherein their axes of transmission are approximately coplanar, but divergent in the common plane. This configuration provides a relatively large scanned area without need for either electronic or mechanical sector scanning techniques to steer the incident ultrasonic energy over a large angle.