Post-operative cranial pressure monitoring system

System for monitoring of fluidic pressures in cranial cavity uses a miniaturized pressure sensing transducer, combined with suitable amplification means, a meter with scale calibrated in terms of pressures between minus 100 and plus 900 millimeters of water, and a miniaturized chart recorder covering similar range of pressures

Surface electromyographic control of a novel phonemic interface for speech synthesis

Many individuals with minimal movement capabilities use AAC to communicate. These individuals require both an interface with which to construct a message (e.g., a grid of letters) and an input modality with which to select targets. This study evaluated the interaction of two such systems: (a) an input modality using surface electromyography (sEMG) of spared facial musculature, and (b) an onscreen interface from which users select phonemic targets. These systems were evaluated in two experiments: (a) participants without motor impairments used the systems during a series of eight training sessions, and (b) one individual who uses AAC used the systems for two sessions. Both the phonemic interface and the electromyographic cursor show promise for future AAC applications.F31 DC014872 - NIDCD NIH HHS; R01 DC002852 - NIDCD NIH HHS; R01 DC007683 - NIDCD NIH HHS; T90 DA032484 - NIDA NIH HHShttps://www.ncbi.nlm.nih.gov/pubmed/?term=Surface+electromyographic+control+of+a+novel+phonemic+interface+for+speech+synthesishttps://www.ncbi.nlm.nih.gov/pubmed/?term=Surface+electromyographic+control+of+a+novel+phonemic+interface+for+speech+synthesisPublished versio

Modeling of Long Term Memory Effects in RF Power Amplifiers with Dynamic Parameters

This paper presents a new radio frequency power amplifier behavioral model that is capable of modeling long term memory effects. The proposed model is derived by assuming linear dependence of the parameters of a conventional model to a long term memory parameter, which enables the model to better track the signal-induced changes of the power amplifier electrical behavior. The model is experimentally tested and shows a 2-3 dB improvement compared to common behavioral models

On the Impact of Hardware Impairments on Massive MIMO

Massive multi-user (MU) multiple-input multiple-output (MIMO) systems are one possible key technology for next generation wireless communication systems. Claims have been made that massive MU-MIMO will increase both the radiated energy efficiency as well as the sum-rate capacity by orders of magnitude, because of the high transmit directivity. However, due to the very large number of transceivers needed at each base-station (BS), a successful implementation of massive MU-MIMO will be contingent on of the availability of very cheap, compact and power-efficient radio and digital-processing hardware. This may in turn impair the quality of the modulated radio frequency (RF) signal due to an increased amount of power-amplifier distortion, phase-noise, and quantization noise. In this paper, we examine the effects of hardware impairments on a massive MU-MIMO single-cell system by means of theory and simulation. The simulations are performed using simplified, well-established statistical hardware impairment models as well as more sophisticated and realistic models based upon measurements and electromagnetic antenna array simulations.Comment: 7 pages, 9 figures, Accepted for presentation at Globe-Com workshop on Massive MIM

Quality problems in materials kit preparation

Increasing customisation, together with a focus on assemblers’ value added time, inflates the number of component variants required in assembly, and drives implementation of kitting processes. Practice indicates that current kitting process designs exhibit quality problems, but research is scarce concerning which problems arise and why. Therefore, this paper provides a decomposition of quality in kitting processes by establishing a framework consisting of types, causes and determinants of quality problems in kitting processes. Through a multiple case study, several underlying mechanisms of quality problems and why they arise were revealed, thereby extending the current frame of knowledge