Patient safety in outpatient surgery: the viewpoint of the healthcare providers

The objective of this study is to understand the viewpoint of healthcare providers with regard to patient safety in outpatient surgery settings. Two methods were used to gather data from the healthcare providers: (1) questionnaire with open-ended questions about six predefined stages of the patient care process; (2) survey with closed questions. With the first method, the main quality and safety of care issues concerned communication to patients, coordination of reports and forms, patient and staff time pressures and standards of care. The first two stages of the outpatient surgery process, i.e. patient work-up prior to day of surgery and patient admission and preparation on the day of surgery, yielded many more comments than the other four stages. The results of the structured questionnaire show that, overall, the healthcare providers report high quality of care provided by themselves (98%) and their surgery centre (96%). With regard to patient safety (i.e. cancellations of surgeries, patient safety problems and serious mistakes), there was a clear difference in perceptions reported by the physicians vs. the nurses and other staff. Nurses and other staff were more likely to report patient safety problems than physicians. The combination of qualitative data from the initial questionnaire and the quantitative data from the structured questionnaire provides a rather complete view of the outpatient surgery staff perceptions of quality and safety of care. This research highlights the importance of getting input from the healthcare providers regarding the quality and safety of care rather than relying only on traditional measures about patient outcomes.     

A continuous-time delta-sigma modulator for 802.11a/b/g WLAN implemented with a hierarchical bottom-up optimization methodology

This paper presents a 3rd-order continuous-time Delta-Sigma modulator with a resolution of 10 bits for a 10 MHz signal bandwidth. It is designed in a standard 0.18 μm CMOS technology and consumes only 6 mW. After the design/selection of the topologies for the integrators, comparator and D/A converters, optimal sizing of the complete modulator was ensured by using a hierarchical bottom-up, multi-objective evolutionary design methodology. With this methodology, a set of Pareto-optimal modulator designs is generated by using Pareto-optimal performance solutions of the hierarchically decomposed lower-level subblocks. From the generated Pareto-optimal design set, a final optimal design is chosen that complies with the specifications for the 802.11a/b/g WLAN standard and has minimal power consumption.     

A Design-Optimized Continuous-Time Delta–Sigma ADC for WLAN Applications

A third-order continuous-time delta-sigma (DeltaSigma) analog-to-digital converter (ADC) is presented for the conversion of an input signal bandwidth of 10 MHz. Design optimization towards minimal power consumption is demonstrated for the high-speed low-power building blocks of the DeltaSigma modulator. From this point of view, it is shown that GmC integrators are preferred over RC integrators in the low-pass filter of the modulator because they show a better tradeoff between power, speed, and accuracy. A new single-bit quantizer topology is presented that incorporates a local feedback path that improves stability using a switched-voltage technique. Finally, a design methodology for the single-bit digital-to-analog converter (DAC) in the feedback loop is proposed, focusing on the impact of high sampling rates on the stability of the converter. The presented continuous-time ADC achieves a simulated dynamic range of 72 dB and a signal-to-noise-and-distortion-ratio of 66 dB in a 10-MHz signal bandwidth. Therefore, it can be applied for WLAN broadband communication. The power consumption of the DeltaSigma modulator is limited to 7.5 mW. The chip is designed in a 0.18-mum triple-well CMOS technology     

Transposition of the IS21-related element IS1415 in Rhodococcus erythropolis

Three copies of the IS21-related transposable element IS1415 were identified in Rhodococcus erythropolis NI86/21. Adjacent to one of the IS1415 copies, a 47-bp sequence nearly identical to the conserved 5' end of integrons was found. Accurate transposition of IS1415 carrying a chloramphenicol resistance gene (Tn5561) was demonstrated following delivery from a suicide vector to R. erythropolis SQ1.     

Care transitions in the outpatient surgery preoperative process: facilitators and obstacles to information flow and their consequences

Patient care transitions have been shown to be critical points at which failure as well as recovery from potential failure may occur. The purpose of this research was to identify transitions in patient care and the flow of associated information at different steps in the outpatient surgery preoperative care process and, in turn, attempt to identify breakdowns in the information flow process and their ramifications. A study of one organization’s preoperative process for outpatient surgery was conducted, employing four means of data collection to gather information on preoperative work processes: employee shadowing, patient shadowing, clinic observation, and dictated feedback. Various facilitators and obstacles in information flow were found to be present in the preoperative care process. Obstacles often resulted in negative consequences for healthcare providers and patients. Helping care providers understand how their actions affect the various elements of the preoperative process, through improved awareness, may be one way to improve information flow problems within the outpatient surgery process.     

Design Optimization of Multibody Systems by Sequential Approximation

Design optimization of multibody systems is usually established by a direct coupling of multibody system analysis and mathematical programming algorithms. However, a direct coupling is hindered by the transient and computationally complex behavior of many multibody systems. In structural optimization often approximation concepts are used instead to interface numerical analysis and optimization. This paper shows that such an approach is valuable for the optimization of multibody systems as well. A design optimization tool has been developed for multibody systems that generates a sequence of approximate optimization problems. The approach is illustrated by three examples: an impact absorber, a slider-crank mechanism, and a stress-constrained four-bar mechanism. Furthermore, the consequences for an accurate and efficient accompanying design sensitivity analysis are discussed.     

Simulation based optimization of stochastic systems with integer design variables by sequential multipoint linear approximation

Optimization problems are considered for which objective function and constraints are defined as expected values of stochastic functions that can only be evaluated at integer design variable levels via a computationally expensive computer simulation. Design sensitivities are assumed not to be available. An optimization approach is proposed based on a sequence of linear approximate optimization subproblems. Within each search subregion a linear approximate optimization subproblem is built using response surface model building. To this end, N simulation experiments are carried out in the search subregion according to a D-optimal experimental design. The linear approximate optimization problem is solved by integer linear programming using corrected constraint bounds to account for any uncertainty due to the stochasticity. Each approximate optimum is evaluated on the basis of M simulation replications with respect to objective function change and feasibility of the design. The performance of the optimization approach and the influence of parameters N and M is illustrated via two analytical test problems. A third example shows the application to a production flow line simulation model. Received April 28, 2000     

Late revascularization for partial amputation of the thumb]

The authors report a case of partial amputation of the thumb, still attached to the medial branch of its nerve, and which was successfully revascularized after 18 hours of ischemia with the thumb still warm. They discuss the operative technique employed, and other similar cases from the literature.     

VLAN auditing for preliminary assessment of after hours networked equipment electricity wastage

Powering networked equipment after business hours is a primary source of electricity wastage in office buildings. In situ surveys, deployment of software agents and power measurements are generally conducted to estimate how well an IT infrastructure performs before enforcing energy-efficient solutions. Those approaches have cost and deployment constraints, obstacles for companies unwilling to invest time and money if return on investment is uncertain. This work proposes a novel approach based on virtual local area network (VLAN) auditing, capable of producing at low-cost and non-invasively a preliminary assessment of after hours networked equipment electricity wastage, providing factual insights to support the deployment of more expensive solutions. Experimentation within a University department, comprising more than 450 unique networked machines, has shown that (1) 10% of client machines regularly used have been constantly powered on, 68% have had nighttime activity and 53% week-end daytime activity; (2) 38% of machines have exhibited clear patterns of electricity wastage at nighttime, representing 5–6% of the School total power consumption, and (3) 35% of machines have exhibited clear patterns of electricity wastage during week-end days, representing 12–15% of the School total power consumption.