Ultrasound research interface

An ultrasound research interface (URI) is a software tool loaded onto a diagnostic clinical ultrasound device which provides functionality beyond typical clinical modes of operation.

A normal clinical ultrasound user only has access to the ultrasound data in its final processed form, typically a B-Mode image, in DICOM format. For reasons of device usability they also have limited access to the processing parameters that can be modified.

A URI allows a researcher to achieve different results by either acquiring the image at various intervals through the processing chain, or changing the processing parameters.

Typical B-mode receive processing chain
A typical digital ultrasound processing chain for B-Mode imaging may look as follows:
 * Multiple analog signals are acquired from the ultrasound transducer (the transmitter/receiver applied to the patient)
 * Analog signals may pass through one or more analog notch filters and a variable-gain amplifier (VCA)
 * Multiple analog-to-digital converters convert the analog radio frequency (RF) signal to a digital RF signal sampled at a predetermined rate (typical ranges are from 20MHz to 160MHz) and at a predetermined number of bits (typical ranges are from 10 bits to 16 bits)
 * Beamforming is applied to individual RF signals by applying time delays and summations as a function of time and transformed into a single RF signal
 * The RF signal is run through one or more digital FIR or IIR filters to extract the most interesting parts of the signal given the clinical operation
 * The filtered RF signal runs through an envelope detector and is log compressed into a grayscale format

Multiple signals processed in this way are lined up together and interpolated and rasterized into a readable image.

Data access
A URI may provide data access at many different stages of the processing chain, these include:
 * Pre-beamformed digital RF data from individual channels
 * Beamformed RF data
 * Envelope detected data
 * Interpolated image data

Where many diagnostic ultrasound devices have Doppler imaging modes for measuring blood flow, the URI may also provide access to Doppler related signal data, which can include:
 * Demodulated (I/Q) data
 * FFT spectral data
 * Autocorrelated velocity color Doppler data

Tools
A URI may include many different tools for enabling the researcher to make better use of the device and the data captured, some of these tools include:
 * Custom MATLAB programs for reading and processing signal and image data
 * Software Development Kits (SDKs) for communicating with the URI, signal processing and other specialized modes of operation available on the URI