Patient-centered measurement at an academic medical center.

BACKGROUND: Harborview Medical Center (Seattle, Wash) has collected patient data on operations since 1988 and has participated in the University HealthSystem Consortium's (UHC; Oak Brook, III) patient satisfaction measurement program since 1996. The patient feedback program is intended to provide data suitable for the quality improvement process and benchmark Harborview's performance against that of other academic medical centers (AMCs). USE OF PATIENT FEEDBACK AT HARBORVIEW: The Picker Institute Adult Inpatient survey's seven dimensions of care are used to disseminate the patient data and focus the action plans. The areas with the largest problem scores and the highest correlation with overall satisfaction are identified, and then specific actions are devised to address those areas. For example, patient satisfaction data collected in May 1997 led the quality council to highlight information and education as an area for improvement for both inpatients and outpatients. Patients reported that they often got answers they could not understand. Also, they did not always get enough information at discharge to feel comfortable about going home. A Discharge/Transition Center CQI (continuous quality improvement) team was charged with developing a discharge/transition process that ensures continuity of care for patients as they move throughout the system. In addition, a hospitalwide Patient and Family Information team has been working on improving information delivery by developing both patient-friendly processes and useful educational materials. FUTURE DIRECTIONS: Harborview will continue to gather feedback through not only more targeted, specific surveys but also focus groups, which have been conducted around specific issues such as diabetes care, clinical pathways, pain management, and teen health.     

An explanation of disproportionate growth using linear 3-dimensional informetrics and its relation with the fractal dimension

Summary We study new and existing data sets which show that growth rates of sources usually are different from growth rates of items. Examples: references in publications grow with a rate that is different (usually higher) from the growth rate of the publications themselves; article growth rates are different from journal growth rates and so on. In this paper we interpret this phenomenon of “disproportionate growth' in terms of Naranan's growth model and in terms of the self-similar fractal dimension of such an information system, which follows from Naranan's growth model. The main part of the paper is devoted to explain disproportionate growth. We show that the “simple' 2-dimensional informetrics models of source-item relations are not able to explain this but we also show that linear 3-dimensional informetrics (i.e. adding a new source set) is capable to model disproportionate growth. Formulae of such different growth rates are presented using Lotkaian informetrics and new and existing data sets are presented and interpreted in terms of the used linear 3-dimensional model.     

Identifying the mechanism of biosensing with carbon nanotube transistors

Carbon nanotube transistors have outstanding potential for electronic detection of biomolecules in solution. The physical mechanism underlying sensing however remains controversial, which hampers full exploitation of these promising nanosensors. Previously suggested mechanisms are electrostatic gating, changes in gate coupling, carrier mobility changes, and Schottky barrier effects. We argue that each mechanism has its characteristic effect on the liquid gate potential dependence of the device conductance. By studying both the electron and hole conduction, the sensing mechanisms can be unambiguously identified. From extensive protein-adsorption experiments on such devices, we find that electrostatic gating and Schottky barrier effects are the two relevant mechanisms, with electrostatic gating being most reproducible. If the contact region is passivated, sensing is shown to be dominated by electrostatic gating, which demonstrates that the sensitive part of a nanotube transistor is not limited to the contact region, as previously suggested. Such a layout provides a reliable platform for biosensing with nanotubes.     

Contextual model of leadership influence in hospital units.

Using Kerr and Jermier's (1978) taxonomy of substitute and neutralizer variables, the contextual model indicates that the staff nurse's education, group cohesion, and work technology substitute for the head nurse's leadership behavior by having direct and indirect effects on job performance. The hospital's administrative climate appeared to neutralize leadership influence.     

Comparison of radiation dose to patient and staff for two interventional cardiology units: a phantom study

The purpose of this investigation was to measure the patient and staff dose during routine interventional cardiology procedures for an image intensifier-based and a flat detector system using a water phantom. The Integris BH3000 image intensifier-based (Philips) and the Axiom Artis flat detector-based (Siemens) angiography units were used in this study. The accuracy of tubes potential and irradiation timers and also internal dosimeters were verified and confirmed. A water phantom with a thickness of 18 cm was used for patient and staff dose measurements. For the Philips system, phantom entrance dose rates were 2.77 and 38.97 microGym(2) s(-1) during fluoroscopy and cineangiography. The respective dose rates for the Siemens were 1.98 and 13.46 microGym(2) s(-1). Phantom entrance dose rate was 28.5 and 65% higher for the Philips system during fluoroscopy and cineangiography, respectively. Comparing the scattered dose rates at the operator location showed that the flat detector-based Siemens system delivers five times lower dose to the operator in comparison with the image intensifier-based Philips unit. The results suggest that the decrease in received dose of the patient and staff is achievable using the flat detector system. In addition, application of lead curtain and glass is recommended to lower the cardiologist dose especially for the image intensifier-based Philips system.     

Contamination control by a greenhouse for emergency medical treatment of the contaminated patient

In emergency medical treatment of patients contaminated with radioactivity, air contamination control is very important to prevent the secondary contamination of medical staff. In order to optimize design of a greenhouse, a numerical analysis was made by using the Flow Designer software. As a scenario of air contamination, the breathing air of the patient was assumed to be highly contaminated with radioactive gaseous or particulate matter. It was found that air contamination strongly depended on the characteristics of the contaminants. The contamination map of the coarse aerosols with low diffusivity was quite different from those of the fine aerosols and gas. If the setting conditions of air-flow rate of the ventilation and the exhausting position were optimized, secondary contamination of the medical staff standing by the patient is prevented securely by a greenhouse.     

MD.E.1: Determination of moisture distribution and level using radar in masonry built with regular units

RILEM Technical CommitteesRecommendations of RILEM TC 177-MDT: ‘Masonry Durability and on-site Testing’

MD.E.1: Determination of moisture distribution and level using radar in masonry built with regular units     

Association between patient psychosocial characteristics and receipt of in‐center nocturnal hemodialysis among prevalent dialysis patients

Introduction: Compared to traditional in‐center hemodialysis (HD), in‐center nocturnal dialysis (INHD) is characterized by longer sessions and nighttime administration, which may lead to better outcomes for some patients. Given the importance of patient choice in the decision to initiate INHD, we explored associations between patients’ psychosocial characteristics and their receipt of INHD. Methods: Among hemodialysis patients at a medium‐sized dialysis organization, we identified INHD patients as those for whom ≥80% of dialysis sessions were INHD sessions—starting at 6:30 pm or later and lasting ≥5 hours—over the 3 months (≥20 sessions total) after their first INHD session. We extracted dialysis session data from electronic medical records and psychosocial data from social worker assessments. We tested associations of patients’ psychosocial characteristics—as well as demographic and clinical characteristics—with INHD receipt among all hemodialysis patients (INHD and HD) in bivariate analyses and multivariable logistic regression models. Findings: Among 759 patients with complete data, we identified 47 (6.2%) as INHD patients. On average, these patients were more likely than HD patients to be employed (full‐time 10.6% vs. 5.2%; part‐time 17.0% vs. 4.2%; P < 0.001), and they were significantly less likely to require ambulatory assistance (14.9% vs. 39.6%, P < 0.001). In multivariable regressions, we found that part‐time employment (versus being unemployed) was associated with a 7.1 percentage‐point higher likelihood of being an INHD patient (P = 0.01), and the negative association with ambulatory assistance needs approached statistical significance (P = 0.056). No other psychosocial factors included in this main regression analysis were statistically significantly associated with INHD patient status. Discussion: Researchers comparing the outcomes of patients undergoing INHD versus other treatment modalities will need to account for differences in employment status—and other factors like requiring ambulatory assistance and age which may predict the ability to work—between INHD users and comparison patients to avoid bias in estimates.     

Early carbonation curing of concrete masonry units with Portland limestone cement

The effect of carbonation curing on the mechanical properties and microstructure of concrete masonry units (CMU) with Portland limestone cement (PLC) as binder was examined. Slab samples, representing the web of a CMU, were initially cured at 25 °C and 50% relative humidity for durations up to 18 h. Carbonation was then carried out for 4 h in a chamber at a pressure of 0.1 MPa. Based on Portland limestone cement content, CO₂ uptake of PLC concrete after 18 h of initial curing reached 18%. Carbonated and hydrated concretes showed comparable compressive strength at both early and late ages due to the 18-h initial curing. Carbonation reaction converted early hydration products to a crystalline microstructure and subsequent hydration transformed amorphous carbonates into more crystalline calcite. Portland limestone cement could replace Ordinary Portland Cement (OPC) in making equivalent CMUs which have shown similar carbon sequestration potential.     

Reconstruction of operating loads in wind turbines with inertial measurement units

Wind turbines are a major source of renewable energy. Load monitoring is considered to improve reliability of the systems and to reduce the cost of operation. We propose a load monitoring system which consists of inertial measurement units. These track the movement of rotor blade, hub and tower top. In addition, wind turbine states, e.g. yaw angle, pitch angle and rotation speed, are recorded. By solving a navigation algorithm with a Kalman Filter approach, the raw sensor data is combined with an error model to reduce the tracking error. In total, five inertial measurement units are installed on the research wind energy converter AD 8–180 on the test site in Bremerhaven. Results show that tracking the blade movement in full operation is possible and that loads can be estimated with a model-based approach. In comparison to simulations, the blade deflections can be approximated by an aeroelastic model. The presented approach can be used as basis for comprehensive load monitoring and observer system with additional increase of system robustness by measurement redundancy.

     

Performance analysis of an inbound call center with skills-based routing

Many call centers provide service for customers of different classes with differently qualified groups of agents. Since call arrivals and call handling times are random in inbound call centers, we investigate queueing models for their performance analysis. This paper describes a Markov queueing model with two customer classes and three groups of specialized or flexible agents. The mean call handling time may depend on the respective customer class as well as on the agent group serving this call. The customers are assumed to be impatient. We consider skills-based routing with priority-based rules and derive both steady-state probabilities and performance measures. We present some numerical experiments and show the impact of different mean processing times. The influence of the allocation of the agents into the three groups is analyzed for different levels of patience.Correspondence to: Raik Stolletz . R. Stolletz, S. Helber: The authors thank the anonymous referees for their helpful comments and suggestions.     

一类带配送中心运输问题的容量扩张模型研究

运输问题一般采用表上作业法来解决，考虑一类带配送中心的运输问题，若仍采用表上作业法，会使问题复杂化，文中采用一种构造辅助网络的方法：在运输网络中将每个配送中心均拆分成2个点，连接两点形成新弧，构造出新的网络，并给每条弧赋予参数，将此类运输问题转换为最小费用流模型来解决，可以使问题模型和运算简单化．在此基础上，考虑运输网络中配送中心和边的容量扩张问题．     

Image quality evaluation and patient dose assessment of medical fluoroscopic X-ray systems: a national study

This study presents the results from a survey conducted by the Greek Atomic Energy Commission (GAEC), during the period 1998-2003, in 530 public and private owned fluoroscopic X-ray systems in Greece. Certain operational parameters for conventional and remote control systems were assessed, according to a quality control protocol developed by GAEC on the basis of the current literature. Public (91.5%) and private (81.5%) owned fluoroscopic units exhibit high-contrast resolution values over 1 lp mm(-1). Moreover, 88.5 and 87.1% of the fluoroscopic units installed in the public and private sector, respectively, present Maximum Patient Entrance Kerma Rate values lower than 100 mGy min(-1). Additionally, 68.3% of the units assessed were found to perform within the acceptance limits. Finally, the third quartile of the Entrance Surface Dose Rate distribution was estimated according to the Dose Reference Level definition and found equal to 35 mGy min(-1).     

Towards dose reduction in CT: patient radiation dose assessment for CT examinations at university health center in Canada and comparison with national diagnostic reference levels

Dose indicators such as the computed tomography dose index (CTDI) and dose-length product (DLP) were gathered for all routine abdomen-pelvis, chest and head examinations performed on all computed tomography (CT) scanners at a University Health Center (UHC) in Canada. These indicators were analysed and compared with the range of diagnostic reference levels (DRLs) suggested by Health Canada and with DRLs in other countries. Mean DLP values varied from one scanner to another, but mean values at the UHC (750 mGy cm(-1) for abdomen-pelvis CT, 349 mGy cm(-1) for chest CT and 1181 mGy cm(-1) for head CT) were all below the upper limit of the range of DRLs suggested by Health Canada. Local DRLs at the UHC were set to 810 mGy cm(-1) for abdomen-pelvis CT, 345 mGy cm(-1) for chest CT and 1205 mGy cm(-1) for head CT. Results, however, show the need for protocols revisions, since some scanners exhibit mean DLP values slightly below or above the upper limit of the range of DRLs suggested by Health Canada.