OSL and TL techniques combined in a beryllium oxide detector to evaluate simultaneously accumulated and single doses.

Optically stimulated luminescence (OSL) and thermoluminescence (TL) are similar techniques widely used in radiation dosimetry. The main difference between these techniques is the stimulus to induce luminescence emission: TL technique uses thermal stimulation, whereas OSL uses optical stimulation. One of the main intrinsic characteristics of the OSL technique is the possibility of reading several times the dosimetric materials with a negligible loss of signal.

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.

Correlation between mechanomyography features and passive movements in healthy and paraplegic subjects.

Mechanomyography (MMG) measures both muscular contraction and stretching activities and can be used as feedback in the control of neuroprostheses with Functional Electrical Stimulation (FES). In this study we evaluated the correlation between MMG features and passive knee angular movement of rectus femoris and vastus lateralis muscles acquired from healthy volunteers (HV) and spinal cord injured volunteers (SCIV). Twelve HV and thirteen SCIV were submitted to passive and FES elicited knee extensions and in each extension, eleven windows of analysis with 0.

Investigation of muscle behavior during different functional electrical stimulation profiles using Mechanomyography.

Mechanomyography (MMG) is a technique for measuring muscle oscillations and fatigue. Functional electrical stimulation (FES) has been applied to control movements mainly in people with spinal cord injury (SCI). The goal of this study is the application of the MMG signal as a tool to investigate muscle response during FES.

Mechanomyographic response during FES in healthy and paraplegic subjects.

Mechanomyography (MMG) registers lateral oscillations of contracting muscles. Functional electrical stimulation (FES) improves the rehabilitation of paraplegic subjects and can be used in neuroprosthesis control. During FES application, muscular contraction responses may vary, possibly due to fatigue or adaptation of nerve cells face to electrical stimuli.

Optimal FES parameters based on mechanomyographic efficiency index.

Functional electrical stimulation (FES) can artificially elicit movements in spinal cord injured (SCI) subjects. FES control strategies involve monitoring muscle features and setting FES profiles so as to postpone the installation of muscle fatigue or nerve cell adaptation. Mechanomyography (MMG) sensors register the lateral oscillations of contracting muscles.

Broadband ultrasound attenuation in the calcaneal region: a comparative study of single-position versus scanning systems.

This work describes a system developed to measure the broadband ultrasound attenuation (BUA) in the calcaneal region. The patient's calcanei were inspected using a microcomputer-controlled X-Y axis displacement unit with two 500-kHz, central-frequency, ultrasound transducers. The transducers facing each other are submerged in a small water tank with a support for the patient's foot between them.