Layered RF Phantom Characterization for Wireless Medical Vital Sign Monitors

Wearable antenna performance measurements were used to characterize a synthetic variable layered phantom testbed, representative of human tissue for operation in the 868/915 MHz, and 2400 MHz industrial, scientific and medical frequency bands. Antenna radiation efficiency measurements on the phantom were compared with measurements on the thorax region of a human test subject. The results show that the phantom is representative of the human body for the application of wireless vital sign monitors, where conductive connections are made to the tissue.

Compact Low-Profile Antenna for Wireless Medical Vital Sign Monitors at 868 MHz

A low-profile wearable antenna suitable for integration into low-cost, disposable medical vital signs monitors is presented. Simulated and measured antenna performance was characterized on a layered human tissue phantom, representative of the thorax region of a range of human bodies. The wearable antenna has sufficient bandwidth for the 868 MHz Industrial, Scientific and Medical frequency band. Wearable radiation efficiency of up to 30 % is reported when mounted in close proximity to the novel human tissue phantom antenna test-bed at 868 MHz.

Beyond work-hour restrictions: a qualitative study of residents' subjective workload

INTRODUCTION: Following the introduction of work-hour restrictions, residents' workload has become an important theme in postgraduate training. The efficacy of restrictions on workload, however, remains controversial, as most research has only examined objective workload. The purpose of this study was to explore the less clearly understood component of subjective workload and, in particular, the factors that influenced residents' subjective workload.

METHOD: This study was conducted in Japan at three community teaching hospitals. We recruited a convenience sample of 31 junior residents in seven focus groups at the three sites. Audio-recorded and transcribed data were read iteratively and analyzed thematically, identifying, analyzing and reporting themes within the data and developing an interpretive synthesis of the topic.

RESULTS: Seven factors influenced residents' subjective workload: (1) interaction within the professional community, (2) feedback from patients, (3) being in control, (4) professional development, (5) private life, (6) interest and (7) protected free time.

DISCUSSION AND CONCLUSION: Our findings indicate that residents who have good interaction with colleagues and patients, are competent enough to control their work, experience personal development through working, have greater interest in their work, and have fulfilling private lives will have the least subjective workload.

Using microbiological tracers to assess the impact of winter land use restrictions on the quality of stream headwaters in a small catchment.

Diverse land use activities can elevate risk of microbiological contamination entering stream headwaters. Spatially distributed water quality monitoring carried out across a 17km(2) agricultural catchment aimed to characterize microbiological contamination reaching surface water and investigate whether winter agricultural land use restrictions proved effective in addressing water quality degradation. Combined flow and concentration data revealed no significant difference in fecal indicator organism (FIO) fluxes in base flow samples collected during the open and prohibited periods for spreading organic fertilizer, while relative concentrations of Escherichia coli, fecal streptococci and sulfite reducing bacteria indicated consistently fresh fecal pollution reached aquatic receptors during both periods. Microbial source tracking, employing Bacteroides 16S rRNA gene markers, demonstrated a dominance of bovine fecal waste in river water samples upstream of a wastewater treatment plant discharge during open periods. This contrasted with responses during prohibited periods where human-derived signatures dominated. Differences in microbiological signature, when viewed with hydrological data, suggested that increasing groundwater levels restricted vertical infiltration of effluent from on-site wastewater treatment systems and diverted it to drains and surface water. Study results reflect seasonality of contaminant inputs, while suggesting winter land use restrictions can be effective in limiting impacts of agricultural wastes to base flow water quality.