Multi-Sensing Techniques with Ultrasound for Musculoskeletal Assessment: A Review.

The study of muscle contractions generated by the muscle-tendon unit (MTU) plays a critical role in medical diagnoses, monitoring, rehabilitation, and functional assessments, including the potential for movement prediction modeling used for prosthetic control. Over the last decade, the use of combined traditional techniques to quantify information about the muscle condition that is correlated to neuromuscular electrical activation and the generation of muscle force and vibration has grown. The purpose of this review is to guide the reader to relevant works in different applications of ultrasound imaging in combination with other techniques for the characterization of biological signals.

FPGA Implementation and Evaluation of an Approximate Hilbert Transform-Based Envelope Detector for Ultrasound Imaging Using the DSP Builder Development Tool.

In this paper, we present the FPGA implementation of an approximate Hilbert Transform-based envelope detector to compute the magnitude of the received ultrasound echo signals in real-time using a Model-based design flow. The proposed architecture exploits the negative odd-symmetry and interleaved zero-valued coefficients of a Hilbert Transform-based FIR filter to reduce hardware resource requirements and complexity. The hardware design is modeled using the DSP Builder development tool allowing the automatic generation of HDL algorithms directly from the Matlab/Simulink environment.

Image reconstruction utilizing median filtering applied to elastography.

Background: The resources of ultrafast technology can be used to add another analysis to ultrasound imaging: assessment of tissue viscoelasticity. Ultrafast image formation can be utilized to find transitory shear waves propagating in soft tissue, which permits quantification of the mechanical properties of the tissue via elastography. This technique permits simple and noninvasive diagnosis and monitoring of disease.

Generation and Analysis of Ultrasound Images Using Plane Wave and Sparse Arrays Techniques.

Ultrasonic imaging is one of the most important techniques to help medical diagnosis. However, obtaining high quality images requires the acquisition, processing, and storage of a large amount of data. In this work, we evaluated a new ultrasound imaging technique based on plane wave and sparse arrays to increase the scan rate and reduce the amount of data amount to be stored.

Eigenspace generalized sidelobe canceller combined with SNR dependent coherence factor for plane wave imaging.

Background: The eigenspace generalized sidelobe canceller (EGSC) beamformer combined with a signal-to-noise ratio (SNR) dependent coherence factor (CF) is suggested for coherent plane wave compounding (PW) imaging. Conventional CF based methods such as generalized CF and subarray CF can improve the image quality, however, they are not suitable for low SNR. On the other hand, the EGSC CF based approach can introduce improvements in image quality, however, in PW imaging is susceptible to suffer from degradation due to low SNR which leads to a poor image quality.

Initial experiments of a 128-channel FPGA and PC-based ultrasound imaging system for teaching and research activities.

Although widely employed in medical diagnostic applications, most of the available commercial ultrasound (US) scanners do not always fit the needs of research users. Access to raw US data, portability, flexibility and advanced user control are essential features to explore alternative biomedical signal and imaging processing algorithms. In this paper, we present the initial results of a reconfigurable, cost-effective and modular 128-channel FPGA and PC-based US system, specifically designed for teaching and medical imaging research.

A reconfigurable arbitrary waveform generator using PWM modulation for ultrasound research.

Background: In ultrasound imaging systems, the digital transmit beamformer is a critical module that generates accurate control over several transmission parameters. However, such transmit front-end module is not typically accessible to ultrasound researchers. To overcome this difficulty, we have been developing a compact and fully programmable digital transmit system using the pulse-width modulation (PWM) technique for generating simultaneous arbitrary waveforms, specifically designed for research purposes.

A programmable FPGA-based 8-channel arbitrary waveform generator for medical ultrasound research activities.

In modern ultrasound imaging systems, digital transmit beamformer module typically generates accurate control of the amplitude of individual elements in a multielement array probe, as well as of the time delays and phase between them, to enable the acoustic beam to be focused and/or steered electronically. However, these systems do not provide the ultrasound researchers access to transmit front-end module. This paper presents the development of a digital transmit beamformer system for generating simultaneous arbitrary waveforms, specifically designed for research purposes.