Feasibility of Using Neuro-Fuzzy Subject-Specific Models for Functional Electrical Stimulation Induced Hand Movements

Functional Electrical Stimulation (FES) is a technique that artificially elicits muscle contractions and it is used to restore motor/sensory functions in both assistive and therapeutic applications. The use of multi-field surface electrodes is a novel popular approach in transcutaneous FES applications. Lately, hybrid systems that combine artificial neural networks and fuzzy logic have also been proposed for many applications in different areas. This paper presents the possibility of combining both approaches for obtaining subject-specific models of FES induced hand movements for grasping applications. Data of the hand and finger motion from two subjects affected by acquired brain injury were used to train two different approaches: coactive neuro-fuzzy inference system and recurrent fuzzy neural network. Preliminary results show that these approaches can be considered in modelling applications for their ability to learn and predict main characteristics of the system, as well as providing useful information from the original system that could be interpreted as subject-specific knowledge

Resonant pulse-shaping power supply for radar transmitters

The final radiofrequency power amplifier (PA) of a radar transmitter module is a large factor in system efficiency. Typical radar transmitter signals are frequency-modulated with constant-amplitude pulse envelopes in order to optimize efficiency, resulting in spectral broadening and power radiated outside of the radar frequency band. This paper demonstrates a PA with a dynamic power supply which enables high efficiency while reducing the spectral emissions. The resonant pulse-shaping power supply generates a raised-cosine pulse envelope waveform with efficiency greater than 90% and peak envelope power around 6 W. Measured results with a 2.14-GHz GaN power amplifier with an efficiency of 76% at peak power demonstrate over 67% transmitter efficiency.Peer ReviewedPostprint (published version

Resonant pulse-shaping power supply for radar transmitters

The final radiofrequency power amplifier (PA) of a radar transmitter module is a large factor in system efficiency. Typical radar transmitter signals are frequency-modulated with constant-amplitude pulse envelopes in order to optimize efficiency, resulting in spectral broadening and power radiated outside of the radar frequency band. This paper demonstrates a PA with a dynamic power supply which enables high efficiency while reducing the spectral emissions. The resonant pulse-shaping power supply generates a raised-cosine pulse envelope waveform with efficiency greater than 90% and peak envelope power around 6 W. Measured results with a 2.14-GHz GaN power amplifier with an efficiency of 76% at peak power demonstrate over 67% transmitter efficiency.Peer Reviewe