Abstract: A data synchronizer (60) receives a data ready signal (40) at a selector (82). The selector (82) selects either the data ready signal (40) or a delayed version of the data ready signal (40) in response to a speed select signal (88) determined according to a clock speed of a receive core clock (52). The selector (82) provides a select signal (92) to a first latch unit (94) and a second latch unit (96). The first latch unit (94) generates a latched select signal (A) that is provided as a receive data valid signal (48) by a signal generator (108) in response to a slow clock rate for the receive core clock (52). The second latch unit (96) generates a delayed select signal (B) that is used by the signal generator (108) to remove an extra width inserted into the latched select signal (A) prior to providing the receive data valid signal (48) in response to a fast clock rate for the receive core clock (52).

Abstract: A system and method for controlling a medical device is provided such as a medical imaging device. The preferred embodiment of the present invention receives a verbal command for assigning a function of a medical imaging device from an operator. An additional verbal command from the operator assigns an input device to control the function of the selected medical imaging device. A system control and voice recognition processor then assigns the function specified by the verbal command to the input device selected by the additional verbal command. After the function of the medical device is assigned to the input device, the operator may control the selected function of the medical device with the selected input device. The system and method provides for the unobtrusive and hands-free control of discreet and continuous functions of a medical imaging device.

Abstract: A method and an apparatus for correcting refraction delay errors on curved probes for all ranges using cordic rotation. The angle &phgr; from the normal of an element to the focus is determined as a function of the angle of cordic rotation. Then a delay error correction is indexed using this angle &phgr;. The angular correction method is efficient in that it uses the inherent property of cordic rotation to calculate the only range-dependent variable required for the correction. Thus the additional hardware required to calculate the corrections is minimal, as the remaining correction variables are vector and range independent.

Abstract: A method and an apparatus for correcting refraction delay errors on curved probes for all ranges using cordic rotation. The angle &phgr; from the normal of an element to the focus is determined as a function of the angle of cordic rotation. Then a delay error correction is indexed using this angle &phgr;. The angular correction method is efficient in that it uses the inherent property of cordic rotation to calculate the only range-dependent variable required for the correction. Thus the additional hardware required to calculate the corrections is minimal, as the remaining correction variables are vector and range independent.

Abstract: An ultrasound system (1) acquires data using a gray scale mode of operation and a color flow mode of operation. A transducer (10) generates receive signals in response to echo ultrasound waves received from a subject (S) being studied. A gray scale receive channel (9G) generates gray scale data representing movement of portions of the subject, in particular that of blood flow or contrast agents in blood or tissue. A color flow receive channel (9C) generates color flow data (e.g., either power data or velocity data) also representing movement of portions of the subject. A processor (30) combines the gray scale flow data with the color flow data and displays the result on a display monitor (19) such that moving portions of the subject are displayed with a colored gray scale image.

Abstract: A bridge device (12) in a computer system interconnects with peripheral component interconnect (PCI) devices (14) over a PCI bus (16). The bridge device (12) includes a plurality of read response buffers (10) to provide data to the PCI devices (14). Each of the read response buffers (10) has a plurality of counters/registers (22) associated therewith. The counters/registers (22) measure various parameters associated with the request and retrieval of requested data and speculative data through the read response buffers (10). In response to the parameters measured by the counters/registers (22), the read response buffers (10) can be optimally allocated among the PCI devices (14).

Abstract: The present invention provides speech and audio user-computer interface mechanisms for accessing and editing information in electronic records. A mechanism is provided by which the user can direct inputs to any of a variety of fields without following a predetermined order of input. This allows the user to be proactive in making entries rather than simply reacting to requirements set by computer-generated prompts. Audio is provided as feedback to the user, not as a fixed path prompt for the user. This feedback can be in the form of non-verbal auditory signals or synthesized speech. The invention uses audio to inform the user of whether or not the system understood the spoken words or phrases as valid inputs to the electronic record, what the system recognized as the input, and to identify the contents of various fields in the electronic record.

Abstract: A switched router for transmitting packetized data concurrently between a plurality of devices coupled to the switched router. The devices are coupled to the I/O ports of the switched router. The switched router is then programmed to route packets of data from various source ports to several destination ports. Different packets may be transmitted concurrently through the switched router. The packets are comprised of a command word containing information corresponding to packet routing, data format, size, and transaction identification. Furthermore, the command word may include a destination identification number for routing the packet to a destination device, a source identification number used by a destination device to send back responses, a transaction number to tag requests that require a response, and a packet type value indicating a particular type of packet.

Abstract: Upon detection of systole by a detector (21), a master controller (20) adjusts a transmit level control (36) to cause a transducer array (2) to transmit ultrasound waves with a high acoustic output approaching the mechanical index FDA limit with sufficient dwell time between HAO frames to limit the temporal average below the FDA limit. The dwell time may be occupied by lower acoustic output frames (LAO) which are generated using the transmit level control (36).

Abstract: An architecture in which a plurality of delay calculators are distributed throughout the beamformer. Each delay calculator provides beamforming delays and apodization values for a plurality of channels/elements. The delay calculators are initialized with element position coordinates. Then, while imaging, focal coordinates and steering angles are broadcast to all delay calculators. The delay calculator uses a cordic rotator to perform the aperture projections and calculate the hypotenuse. The cordic rotator performs successive coordinate transformations, in two dimensions, using coefficients that are simple powers of two. The resulting apodization values and time delays are then provided by a channel control bus to a plurality of channels.

Abstract: A method and an apparatus for tracking scan plane motion in free-hand three-dimensional ultrasound scanning using adaptive speckle correlation. The method employs a correlation index which adapts to different display dynamic range and post-processing filters. The method may include the following steps: choosing a kernel within each frame image for correlation calculations; rejecting duplicate image frames; measuring the degree of correlation between successive image frames; rejecting correlation estimates which may be associated with hand jitter and other artifacts; and computing the average frame-to-frame (i.e., interslice) spacing based on the average correlation estimate. This image-based motion tracking technique enables three-dimensional reconstruction with good geometric fidelity, without use of any external position-sensing device.

Abstract: A method and an apparatus for adaptively enhancing the B-mode image during post-detection image processing in an ultrasound imaging system. A low pass filter which smooths out speckle and a high pass filter which enhances edges are placed in parallel signal paths connected to the output of an envelope detector in a B-mode processor. The signals in the high pass filter path are logarithmically compressed before high pass filtering. The signals in the low pass filter path are logarithmically compressed after low pass filtering. Respective weighting factors are applied to the low- and high-pass-filtered signals by an adaptive weighting device, which may take the form of a processor or a look-up table. The weighted low- and high-pass-filtered signals are then summed and optionally input to an anti-aliasing low pass filter before decimation and scan conversion.

Abstract: In a computer system, a mechanism for minimizing memory latencies. An improved, high-speed packet switched router is used to route packets quickly and efficiently between the microprocessor and the main memory. The computer system also supports PCI devices by implementing a bridge which acts as an interface between the PCI bus and the packet switched router. In order to minimize the memory latencies for PCI based memory accesses through the bridge, a plurality of read and write buffers are implemented. Write gathering is used to gather a plurality of write transactions on the PCI bus into the write buffers and sent by the bridge as one cache line sized transfer to the routing mechanism. For PCI based read operations, data is pre-fetched from the main memory and stored in the read buffers. Thereby, PCI devices can access the read buffers multiple times to retrieve the requested data.

Abstract: A phased array sector scanning ultrasonic system includes a separate receive channel for each respective element in an ultrasonic transducer array. Each receive channel imparts a delay to the echo signal produced by each respective element. The delayed echo signals are summed to form a steered, dynamically focused and dynamically windowed receive beam even when the transmit beam does not emanate from the center of the array. The receiver has a beamformer including a multiplicity of beamformer channels. The beamformer dynamically increases delays to each channel without introducing unwanted discontinuities, by combining and synchronizing a FIFO and an interpolator. The interpolator uses "Wallace tree" adders to accumulate bit-shifted versions of the inputs. The number of additions is less than the number of bits which would be needed to represent equivalent coefficients.

Abstract: A method using a progressive sampling rate technique to maintain the sampling rate at the Nyquist frequency of the I/Q data through a tunable equalization bandpass filter in the front end of the imager and then increasing the sampling rate via axial interpolation to prevent aliasing during the nonlinear detection process. If an envelope detector is used, the bandwidth of the detector output should be approximately double that of the I/Q data. In this case, the sampling rate is doubled (or more) by axial interpolation before envelope detection. A 2-point linear interpolator can be used. Depending on the application, this axial interpolator can be turned on or off automatically by the system. After detection, the signal can be low-pass filtered to restrict the speckle bandwidth prior to log compression.

Abstract: A phased array sector scanning ultrasonic system includes a separate beamformer channel for each respective element in an ultrasonic transducer array. Each beamformer channel has a three-stage complex FIR filter downstream of an analog-to-digital converter. Each filter circuit stage has a register pipeline, an in-phase FIR filter and a quadrature FIR filter. The first stage only has real samples, so there is a single pipeline. The other stages have complex inputs composed of in-phase (real) and quadrature (imaginary) samples, requiring a pipeline for each. Each register pipeline is made up of a multiplicity of registers connected in series. The number of registers in a given pipeline must equal the number of taps being used on the FIR filter immediately downstream of the register pipeline. The registers are clocked in synchronism and store successive echo data samples. Each register in the pipeline has an output connected to a respective tap of the corresponding FIR filter.

Abstract: The present invention discloses a novel arbitration procedure for selecting among devices in a computer system requesting access to a single resource such as, for example, a system bus or main memory. The arbitration procedure provides an efficient means for guaranteeing the available system bus bandwidth to devices having high bandwidth requirements. Each device can be allotted a certain amount of bandwidth that is guaranteed to be available for that device within a given time interval. Excess bandwidth not consumed by the guaranteed allotments can be used as remainder (e.g., available but not guaranteed) bandwidth by the devices. The arbitration procedure further provides a guaranteed maximum latency so that no device is prevented from completing data transfers in a timely manner. The arbitration procedure still further provides the ability to dynamically program the amount of the bandwidth that is guaranteed a particular device.

Abstract: An apparatus for generating the required beamforming delays for an ultrasound imaging system with minimal hardware and software. The apparatus performs an algorithm which allows the required computations to be separated into three groups. The first group includes transducer array geometry computations which are beam independent. The second group includes a small number of beam-dependent computations which are channel independent. The final group includes the channel- and beam-dependent calculations which combine the results of the first two groups to generate the required beamforming delays. This last computation is distributed to logic and simple real-time state machines per channel. This approach reduces the required computations and takes advantage of simple parallel processing to reduce the required hardware and computational time relative to conventional beamformer designs.