A portable device for intensive care brain function monitoring with event-related potentials

Monitoring level of consciousness or depth of sedation is essential in modern intensive care units and emergency rooms. Current methods are based on spontaneous EEG providing only indirect information on the reactivity of the brain. Measurement of auditory event-related potentials (ERPs) has been shown to have additional potential for evaluation of the level of consciousness. Unfortunately, compact and easy-to-use devices are not commercially available. In this study a portable battery-powered device for clinical auditory ERP measurements was designed, constructed and validated. The device consists of a five-channel data logger and a 16-bit stereo audio stimulator. The signals are digitized with a 22-bit sigma-delta analogue-to-digital converter and stored to a PC Card hard disk. Prior to the in vivo application, the device was validated with extensive technical tests. Importantly, the RMS noise amplitude of the EEG channels was found to be less than 1 mivroV and the delivered auditory stimulus intensity corresponded accurately the settings (mean difference 0.2+/-0.5 dB). In addition to technical tests the device was successfully validated in vivo. To summarize, a novel portable instrument for measurement of auditory event-related potentials in intensive care environment is introduced.     

Task effects on fatigue symptoms in overnight driving.

This study examined the effects of task and time-on-task on fatigue symptoms in overnight driving. Four participants drove an instrumented car 1200 km overnight and completed the same trip as passengers on another night. Subjective ratings of drowsiness, eye blink frequency and duration, microsleeps, and steering-wheel inputs were analysed as a function of time-on-task, and for separate samples when meeting oncoming heavy vehicles. Four video cameras were used to monitor the road view and the face of both the driver and passenger. In terms of eye closure duration, the reported microsleeps were shorter while driving (mean = 0.7 s, SD = 0.2 s) than as a passenger (mean = 2.6 s, SD = 2.0 s). Blink frequency increased with time-on-task as expected, indicating tiredness, and decreased when approaching an oncoming heavy vehicle, indicating attentive response to a potential critical situation. No consistent effect of time-on-task on high-frequency steering-wheel inputs when meeting oncoming heavy vehicles was found. The results raise the important question of what makes a driver wake from a microsleep earlier than a passenger and, given proper monitoring of long eyelid closures, what the proper intervention should be.     

The shared image guiding the treatment process. A precondition for integration of the treatment of schizophrenia

The aim of the study reported here was to develop psychotherapeutic in-patient treatment for acute schizophrenia, following the principles of a need-adapted approach. To improve the integration of experiences which hospital staff have with acutely psychotic patients and their families, systematic supervision sessions were organised. In these sessions, it was possible to achieve shared psychological images through while the whole staff could integrate patients' behaviour and symptoms, both symbolic and non-symbolic. Such an image was called 'the shared image guiding the treatment process' (SIGTP). The process of achieving the SIGTP was interpreted through Peircean semiotics, especially the concepts of indexical, iconic, and symbolical signs. An SIGTP was considered to have been achieved in the early phase of the supervision process in 32 of the 54 cases. For the patients, SIGTP and the need-adaptation connected with it meant achieving a more realistic and more functional ordering of their experiences.     

Role of red meat and arachidonic acid in protein kinase C activation in rat colonic mucosa

OBJECTIVES: To provide a review of the development and impact of palliative care; to discuss quality of lie as a framework for guiding clinical practice and research in palliative care; and to identify future trends that are likely to affect palliative care services. DATA SOURCES: Research studies, review articles, and book chapters. CONCLUSIONS: Palliative care is in the process of dynamic change. Advocates of palliative care are suggesting that cost-effective holistic care strategies should be available to patients and families throughout the illness trajectory, not just reserved for end of life care. IMPLICATIONS FOR NURSING PRACTICE: Incorporation of palliative care principles across the cancer illness trajectory requires an attitude shift by all members of the multidisciplinary team.     

Stabilisation of discrete-time systems via Schur stability region

In this paper, we consider the stabilisation problem of discrete-time systems by affine compensator. Using the known properties of the Schur stability region of monic polynomials, we give conditions under which stabilising controllers exist. A necessary and sufficient condition is obtained when the difference of the order of the system and the number of stabilising parameters is one. In the general case, two solution algorithms: division-elimination and least-square minimisation algorithms are suggested.     

An analysis of the angular momentum of a light field in terms of angular harmonics

Abstract

This paper proposes an optical interpretation for the Lie algebra's symmetry operators of the paraxial wave equation. In particular, the angular momentum operator is used to derive a relation for the expression of the angular momentum of an arbitrary light field in terms of angular harmonics. Furthermore, experimental results are presented demonstrating a filter that extracts angular harmonics from different Gauss-Laguerre modes.     

Diffractive shaping of excimer laser beams

Abstract

We address the problem of shaping the intensity distribution of a highly directional partially coherent field, such as an excimer laser beam, by means of diffractive optics. Our theoretical analysis is based on modelling the multi-transverse-mode laser beam as a Gaussian Schell-model beam. It is shown numerically that a periodic element, which is unsuitable for the shaping of a coherent laser beam, works well with an excimer laser beam because of its partial spatial coherence. The conversion of an approximately Gaussian excimer laser beam into a flat-top beam in the Fourier plane of a lens is demonstrated with a diffractive beam shaper fabricated as a multilevel profile in SiOl by electron-beam lithography and proportional reactive-ion etching.     

Dietary xylitol protects against weakening of bone biomechanical properties in ovariectomized rats

The effects of dietary xylitol (xyl) on bone biomechanical properties in ovariectomized rats (ovx) were studied. Forty-two 3-mo-old female Wistar rats were divided into three groups of 14. Rats in two groups were ovariectomized, while those in the control group underwent a sham operation. All rats received a basal diet, and half of the ovx were given an additional 10 g/100 g dietary xyl supplementation. Three months later the rats were killed and their tibias, femurs and humeri were prepared. The tibias were used for analyses of bone density and trabecular bone volume (BV/TV) and for the three-point bending test. The femurs were used for the torsion test and for the loading test of the femoral neck. The humeri were used for analyses of bone ash weight and bone concentrations of calcium and phosphorus. Dietary xyl gave a significant protection against ovariectomy-caused decline of tibial stress in the three-point bending test, of femoral shear stress in the torsion test, and of stress of the femoral neck, without affecting bone elasticity values. Xyl restricted the ovariectomy-caused reduction in bone density, in bone ash weight and in concentrations of bone calcium and phosphorus. Furthermore, trabecular bone loss in ovx was significantly suppressed by dietary xyl. These results indicate that a 10% dietary supplementation of xyl in ovx has a protective effect against the weakening of bone biomechanical properties. This is related to greater BV/TV and maintained bone mineral content.     

Ultrahigh-frequency surface acoustic wave transducers on ZnO/SiO₂/Si using nanoimprint lithography

Ultrahigh-frequency surface acoustic wave devices were fabricated on a ZnO/SiO?/Si substrate using step-and-flash nanoimprint lithography combined with hydrogen silsesquioxane (HSQ) planarization. Excellent critical dimension control was demonstrated for interdigital transducers with finger electrode widths from 125 down to 65 nm. Fundamental and higher-order Rayleigh modes up to 16.1 GHz were excited and detected, which is the highest frequency for ZnO-based transducers on silicon reported so far. Surface acoustic modes were confirmed with numerical simulations. Simulation results showed good agreement with the experimental data.