Normal Office Research Articles

Ceiling-mounted personalized ventilation system integrated with a secondary air distribution system - a human response study in hot and humid climate

The benefits of thermal comfort and indoor air quality with personalized ventilation (PV) systems have been demonstrated in recent studies. One of the barriers for wide spread acceptance by architects and HVAC designers has been attributed to challenges and constraints faced in the integration of PV systems with the work station. A newly developed ceiling-mounted PV system addresses these challenges and provides a practical solution while retaining much of the apparent benefits of PV systems. Assessments of thermal environment, air movement, and air quality for ceiling-mounted PV system were performed with tropically acclimatized subjects in a Field Environmental Chamber. Thirty-two subjects performed normal office work and could choose to be exposed to four different PV airflow rates (4, 8, 12, and 16 L/s), thus offering themselves a reasonable degree of individual control. Ambient temperatures of 26 and 23.5 degrees C and PV air temperatures of 26, 23.5, and 21 degrees C were employed. The local and whole body thermal sensations were reduced when PV airflow rates were increased. Inhaled air temperature was perceived cooler and perceived air quality and air freshness improved when PV airflow rate was increased or temperature was reduced. The newly developed ceiling-mounted PV system offers a practical solution to the integration of PV air terminal devices (ATDs) in the vicinity of the workstation. By remotely locating the PV ATDs on the ceiling directly above the occupants and under their control, the conditioned outdoor air is now provided to the occupants through the downward momentum of the air. A secondary air-conditioning and air distribution system offers additional cooling in the room and maintains a higher ambient temperature, thus offering significant benefits in conserving energy. The results of this study provide designers and consultants with needed knowledge for design of PV systems.

Bio‐hybrid nanocomposite coatings from sonicated chitosan and nanoclay

AbstractNanocomposite films and coatings with improved properties were produced from ultrasonic dispersed chitosan and hydrophilic bentonite nanoclay. Bio‐hybrid coatings were applied onto argon–plasma‐activated LDPE coated paper. The intercalation of chitosan in the silicate layers was confirmed by the decrease of diffraction angles as the chitosan/nanoclay ratio increased. Nanocomposite films and multilayer coatings had improved barrier properties against oxygen, water vapor, grease, and UV‐light transmission. Oxygen transmission was significantly reduced under all humidity conditions. In dry conditions, over 99% reduction and at 80% relative humidity almost 75% reduction in oxygen transmission rates was obtained. Hydrophilic chitosan was lacking the capability of preventing water vapor transmission, thus total barrier effect of nanoclay containing films was not more than 15% as compared with pure chitosan. Because to very thin coatings (≤1 μm), nanoclay containing chitosan did not have antimicrobial activity against test strains. All coating raw materials were “generally recognized as safe” (GRAS) and the calculated total migration was in all cases ≤6 mg/dm2, thus the coatings met the requirements set by the packaging legislation. Processing of the developed bio‐hybrid nanocomposite coated materials was safe as the amounts of released particles under rubbing conditions were comparable with the particle concentrations in a normal office environment. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

20.1: Perceived Brightness of LED Projector

AbstractIt is commonly observed that the LED projectors can provide with more perceived brightness by less stimulus luminance. In this work, the Helmholtz‐Kohlrausch effect is applied for studying the enhanced perceived brightness of the LED projector. According to the equations developed by Nayatani's group, the ratio of the enhanced perceived brightness of LED projector is evaluated as 25% to 30% as compared to traditional lamp projector in dark environment. However, in the normal office illumination level, the difference between the LED projector and the lamp projector diminishes.

Prepare, plan, practice

Prepare, plan, practice

An Electromechanical Film Sensor Based Wireless Ballistocardiographic Chair: Implementation and Performance

New sensor technologies open possibilities for measuring traditional biosignals in new innovative ways. This, together with the development of signal processing systems and their increasing computing power, can sometimes give new life to old measurement techniques. Ballistocardiogram (BCG) is one such technique, originally promising but later replaced by the now very popular electrocardiogram. It's usability was previously limited by the large size of the devices required to record it, and the complex nature of the recorded signal, which gave little information in visual inspection. In this paper, we present how a lightweight and flexible electromechanical film (EMFi) sensor can be used to record BCG. A ballistocardiographic chair, designed to look like a normal office chair, was built and fitted with two sensitive EMFi sensors. Two different measurement setups to record the signal from the EMFi sensors were developed. The first, so-called wired setup, uses a commercial bio-amplifier, and a special pre-amplifier to interface to it. The latter, so-called wireless setup, uses our own hardware to transmit the recorded digitized signals wirelessly to a nearby PC. Both of these systems are presented and their performance evaluated. Also, the suitability, limitations and advantages of the EMFi sensor over existing sensors and methods are discussed. The validity of the EMFi sensor and amplifier output is tested using a mechanical vibrator. Lastly, a summary of signal analysis methods developed for our system is given. The developed systems have be used for medical BCG measurements, and the recordings indicate that the both the systems are functional and capture useful BCG signal components.

Nontraumatic Dental Complaints in a Pediatric Emergency Department

To determine the prevalence, types, and treatment of nontraumatic dental emergencies that present to a tertiary care pediatric emergency department (ED). A retrospective chart review of all children coming to a tertiary care pediatric emergency department with nontraumatic dental complaints from January 2005 to December 2005 was conducted. Demographic information, the time and day of presentation, presenting complaints, history of previous dental treatment, interventions, and disposition details were collected and analyzed. The 247 visits for nontraumatic dental complaints comprise 0.5% of all patients who presented to the ED in 2005. Fifty-nine percent were younger than 5 years (primary dentition), with males representing 52% of the children. Half of the visits were during normal dental office hours, and more than half presented during the weekday. Fifty-three percent complained of pain. Twenty-eight percent were referred to the dental clinic after being seen by an ED physician. Eight percent of children required hospitalization for intravenous antibiotics. Most children (82%) were discharged from the ED with oral antibiotics. The ED is an important point of care for nontraumatic pediatric dental complaints, and about 60% of these children are younger than 5 years. Only 8% of them had severe infections requiring hospitalization, and most patients could have been treated in the community.

Out-of-office blood pressure measurement in children and adolescents

Out-of-office blood pressure measurement in children and adolescents

Inflammatory and allergic responses to airborne office dust in five human provocation experiments

Five studies on the effects of dust have been published from The Department of Environmental and Occupational Medicine, the University of Aarhus, Denmark. These five studies support that exposures to normal office dust for up to 5 h at concentration ranges occasionally seen in non-occupational indoor environments may cause health effects which can be measured both objectively and subjectively in healthy subjects and subjects with different types of hypersensitivity. In these five studies, the lowest observed effect level was indicated to be 75 microg/m3 (total suspended particulates). However, dust from different buildings may have different toxicity and some of the five studies had higher No Observed Effect Level (NOEL) than this value. The studies give strong evidence that dust exposures cause decreased tear film stability or break-up time and increased number of eosinophil cells in nasal lavages. There is also strong evidence that general well-being decrease during exposures. This is also reflected in increasing general irritation in eyes, nose, and throat. The combined findings support the theory that the subjects' responses to indoor dust exposures are caused by sensory perceptions, weak allergic, or weak inflammatory responses at or in the exposed tissues. More than one biological mechanism may be involved at the same time or subsequently. No signs of effects in non-exposed organs or tissues were seen, not even in sensitive persons. The studies indicate that dust exposures indoors may explain many reported symptoms and health effects and underlines the importance of source reduction.

Analysis of Recent Papers in Hypertension Jan Basile, MD, Senior Editor

Analysis of Recent Papers in Hypertension Jan Basile, MD, Senior Editor

Prevalence of Masked Hypertension in Subjects Treated with Antihypertensive Drugs as Assessed by Morning versus Evening Home Blood Pressure Measurements: The J-HOME Study

To investigate the relationship between morning and evening home blood pressure (BP) measurements to make a diagnosis of masked hypertension, we collected information on the characteristics of 3,303 essential hypertensive outpatients receiving antihypertensive medication in Japan using a physician, self-administered questionnaire. All patients were asked to measure their home BP once every morning and once every evening for two weeks. Morning and evening home BP values of each patient were defined as the average of all morning and all evening home BP values, respectively. The mean BP values of all study subjects were 142.8/80.6 mmHg for office BP, 139.8/81.8 mmHg for morning home BP, 133.7/76.9 mmHg for evening home BP, and 136.8/79.3 mmHg for the average of the morning and evening home BPs. Masked hypertension was defined as an office BP < 140/90 mmHg and a home BP ≥ 135/85 mmHg. The prevalence of masked hypertension diagnosed using morning home BP (23.1%) was higher than that diagnosed by evening home BP (14.7%); the prevalence was 19.0% when diagnosed using the average of the morning and evening home BPs. Among the 1,386 patients with a normal office BP, the diagnosis of masked hypertension based on morning and evening home BP values differed in 28.8% of patients for systolic BP and 20.9% for diastolic BP (kappa coefficient = 0.43). The present study showed that the prevalence of masked hypertension was underestimated when the diagnosis of masked hypertension was made on the basis of evening home BP.

Masked Hypertension Definition, Impact, Outcomes: A Critical Review

The phenomenon of masked hypertension (MH) is defined as a clinical condition in which a patient's office blood pressure (BP) level is <140/90 mm Hg but ambulatory or home BP readings are in the hypertensive range. The prevalence in the population is about the same as that of isolated office hypertension; about 1 in 7 or 8 persons with a normal office BP level may fall into this category. The high prevalence of MH would suggest the necessity for measuring out-of-office BP in persons with apparently normal or well-controlled office BP. Reactivity to daily life stressors and behavioral factors such as smoking, alcohol use, contraceptive use in women, and sedentary habits can selectively influence MH. MH should be searched for in individuals who are at increased risk for cardiovascular complications including patients with kidney disease or diabetes. Individuals with MH have been shown to have a greater-than-normal prevalence of organ damage, particularly with an increased prevalence of metabolic risk factors, left ventricular mass index, carotid intima-media thickness, and impaired large artery distensibility compared with patients with a truly normal BP level in and out of the clinic or office. Also, outcome studies have suggested that MH increases cardiovascular risk, which appears to be close to that of in-office and out-of-office hypertension. The aim of this review was to define the entity of MH, to describe its prevalence in the general population, and to discuss its correlation with cardiovascular events.

Physiological diurnal variability and characteristics of the ocular pulse amplitude (OPA) with the dynamic contour tonometer (DCT-Pascal®)

The Pascal dynamic contour tonometer (DCT) allows measurement of intraocular pressure (IOP) independently of corneal properties. It records, simultaneously, haemodynamic IOP fluctuations and the difference between the systolic and the diastolic IOP corresponding to the ocular pulse amplitude (OPA). The OPA indirectly reflects choroidal perfusion and could be considered as an independent risk factor in glaucoma. We aimed to establish the physiological diurnal variability of the OPA and its correlations with other biophysical parameters because its characteristics remain partly unclear. Prospective study including 52 eyes of 28 normal subjects with Goldmann applanation tonometry (GAT) IOPs < 22 mmHg. Subjects treated with systemic medications that could interfere with blood pressure or heart rate were excluded. IOP was measured at 9:00 am, 1:00 pm, and 4:00 pm by GAT and DCT. Two consecutive GAT followed by three consecutive DCT measurements were performed in each session by the same clinician (SP). Only DCT measurements with quality 1 and 2 were taken into account. Blood pressure, pulse rate, and central corneal thickness (CCT) were recorded after the last IOP measurements. Spearman correlation coefficient was used for assessment of correlations. Mean age was 40 +/- 14 years. Mean DCT values were significantly higher than GAT readings (mean = 16.8 +/- 2.0 vs. 15.2 +/- 2.8 mmHg, P < 0.02). The mean OPA was 2.2 +/- 0.7 mmHg (range: 1-3.4 mmHg). The mean amplitude of diurnal OPA fluctuations was 0.4 mmHg. There was no significant difference in the mean OPA values at each time of the diurnal curve. The intraclass correlation (ICC) of only one OPA measurement in relation to part of total variance due to inter-measurement variation was 78%. Averaging over three independent readings of OPA improved ICC to 91%. The OPA was correlated with GAT (r = 0.31, P < 0.0001) and DCT IOP measurements (r = 0.49, P < 0.0001). It was correlated neither with blood pressure nor with age. OPA values of both eyes of the same individual were highly correlated (r = 0.89, P < 0.0001). In normal healthy eyes, the ocular pulse amplitude remains stable during normal outpatient office hours and was not correlated with blood pressure or age of patients.

Discrepancies in office and ambulatory blood pressure in adolescents: help or hindrance?

The goal of this commentary is to review the most relevant topics concerning the clinical utility of ambulatory blood pressure (BP) monitoring, such as the state of the art "reference BP values", the importance of the discrepant situations between office and ambulatory BP (white-coat and masked hypertension) and those of the recommended clinical indications to now. From a small number of studies, operational thresholds to define hypertension have been established. They are useful tools even though more studies are necessary to create strong reference values. Ambulatory BP measurement is increasingly recognized as being indispensable to the diagnosis and management of hypertension, and it has contributed significantly to our understanding of hypertension by revealing or "unmasking" BP phenomena that were not readily apparent using traditional techniques of measurement in clinical practice. Ambulatory BP monitoring should be performed in adolescents with either office mild essential hypertension before starting antihypertensive drug treatment or a strong family history of hypertension or an early cardiovascular event. Obese children with normal office BP values will also benefit from ambulatory BP monitoring. Other indications are the assessment of refractory hypertension or drug-induced hypotension. Finally, additional BP information in chronic renal failure, diabetes, and autonomic neuropathy can be obtained by using ambulatory BP monitoring.

Behavioral and Psychosocial Interventions in Diabetes

A major task of diabetes care providers is to support patients in performing necessary self-care behaviors using well-accepted strategies such as recommending effective self-care regimens and educating patients in their use. Also critical are behavioral interventions that help patients implement self-care regimens in the face of life's exigencies. The purpose of this article is to identify key behavioral/psychosocial interventions available to diabetes care providers. We present a conceptual framework for organizing the application of these interventions, focusing on practical interventions that can be implemented by a typical health care provider, including referral to a behavioral/psychosocial specialist where this seems the most practical choice. A typical office visit lasts only 15 min (1). Therefore, feasibility is an important consideration in evaluating patient care recommendations. The strategies we propose should be no more time-consuming than these approaches, which are highly recommended for their feasibility. A previously demonstrated, effective counseling strategy for weight loss can be maintained by 15-min visits (2). A behavior change support approach, the 5As (ask, advise, assess, assist, arrange) Model, is estimated to take less than half the time of a normal office visit (3). An emotional support approach, the BATHE (background, affect, trouble, handling, empathy) Model, is estimated to take ∼15 min (4). Feasibility must also be assessed in terms of what it costs to ignore psychosocial problems or to employ an ineffective approach to behavior change. Patients who have psychological problems use health services more intensively, and if patients do not change their behavior, the clinician must spend time dealing with the problem at subsequent visits. Finally, research suggests that dealing with patients' concerns does not require additional time if done correctly (5). Thus, effective clinical procedure may also be efficient. The review we present is not exhaustive. We do not discuss all interventions that have …

Fungi and bacteria in mould-damaged and non-damaged office environments in a subarctic climate

The fungi and bacterial levels of the indoor air environments of 77 office buildings were measured in winter and a comparison was made between the buildings with microbe sources in their structures and those without such sources. Penicillium, yeasts, Cladosporium and non-sporing isolates were the commonest fungi detected in the indoor air and in settled dust, in both the mould-damaged and control buildings. Aspergillus ochraceus, Aspergillus glaucus and Stachybotrys chartarium were found only in environmental samples from the mould-damaged buildings. Some other fungi, with growth requiring of water activity, a w, above 0.85, occurred in both the reference and mould-damaged buildings, but such fungi were commoner in the latter type of buildings. The airborne concentrations of Penicillium, Aspergillus versicolor and yeasts were the best indicators of mould damage in the buildings studied. Penicillium species and A. versicolor were also the most abundant fungi in the material samples. This study showed that the fungi concentrations were very low (2–45 cfu m −3 90% of the concentrations being <15 cfu m −3) in the indoor air of the normal office buildings. Although the concentration range of airborne fungi was wider for the mould-damaged buildings (2–2470 cfu m −3), only about 20% of the samples exceeded 100 cfu m −3. The concentrations of airborne bacteria ranged from 12 to 540 cfu m −3 in the control buildings and from 14 to 1550 cfu m −3 in the mould-damaged buildings. A statistical analysis of the results indicated that bacteria levels are generally <600 cfu m −3 in office buildings in winter and fungi levels are <50 cfu m −3. These normal levels are applicable to subarctic climates for urban, modern office buildings when measurements are made using a six-stage impactor. These levels should not be used in evaluations of health risks, but elevated levels may indicate the presence of abnormal microbe sources in indoor air and a need for additional environmental investigations.

RFID-based mobile robot guidance to a stationary target

Retrieving accurate location information about an object in real-time, as well as any general information pertinent to the object, is a key to enabling a robot to perform a task in cluttered, dynamically changing environment. In this paper, we address a novel technique for the guidance of mobile robots to help them identify, locate, and approach a target in our daily environments. To this end, we propose a standard for the use of radio-frequency identification (RFID) systems and develop a prototype that can be easily installed in the existing mobile robots. Specifically, when an RF signal is transmitted from an RF transponder, the proposed RFID system reads the transponder-encoded data and simultaneously picks up the direction of the transponder using the received signal strength pattern. Based on the angle of signal arrival, we develop the guidance strategies that enable a robot to find its way to the transponder position. Moreover, to cope with multi-path reflection and unexpected distortions of the signals that resulted from environmental effects, we present several algorithms for reconstructing the signals. We demonstrate that an off-the-self mobile robot equipped with the proposed system locates and approaches a stationary target object. Experimental results show that the accuracy of the proposed system operating at a frequency of 315 MHz falls within a reasonable range in our normal office environment.

Personal digital assistant (PDA) cell phone units produce elevated extremely‐low frequency electromagnetic field emissions

Initial tests indicate that personal and occupational use of personal digital assistants (PDAs or palm-held wireless units) produce high intensity bursts of extremely-low frequency electromagnetic fields (ELF-EMF). These emissions could result in comparatively high ELF-EMF exposure in persons that carry a PDA close to the body (i.e., in a pocket or on a belt); or held to the head for cell phone conversations. ELF-EMF emissions of 10 microT were recorded on PDAs during normal office use over a 24 h test period. Results of ELF-EMF measurements show that email transmit and receive functions produce rapid, short-duration ELF-EMF spikes in the 2-10 microT range, each lasting several seconds to over a minute apparently depending on file download size. Some units produced spikes as high as 30-60 microT during email activities. Cell phone activity on PDAs produced continuously elevated ELF-EMF readings in the 0.5-1 microT range, as opposed to the rapid spiking pattern for email receipt and transmission. Switching the PDA unit from "OFF" to "ON" position resulted in single ELF-EMF pulses of over 90 microT on two units. Email downloads into the PDA can occur randomly throughout the day and night when the unit is "ON"; thus the user who wears the PDA may be receiving high-intensity ELF-EMF pulses throughout the day and night. The frequency of email traffic on the PDA, and the power switching unit (battery unit) may affect the frequency and intensity of ELF-EMF emissions.

Injuries to permanent teeth. Part 3: Therapy of root fractures

Diagnostic and therapeutic interventions following dental injuries are not part of the routine practice in the dental office. Quite often, these patients are emergency cases who seek treatment after normal office hours. The objective of this and the future papers is to present the current treatment concepts in dental traumatology at the School of Dental Medicine, University of Berne. The fruitful cooperation in the field of dental traumatology between the Department of Oral Surgery and Stomatology, and the Department of Conservative Dentistry (including pediatric dentistry and endodontology), is based on the interdisciplinary approach that has been established four years ago. Following discussion and evaluation of such treated cases, and considering current clinical and experimental studies, the said concepts have been worked out. The present paper describes the therapeutic approach for root fractures.

Assessment of blood pressure control in hypertensive stroke survivors: an ambulatory blood pressure monitoring study

We compared the sensitivity of office blood pressure and ambulatory blood pressure monitoring recordings in evaluating the effectiveness of antihypertensive treatment and identified factors related to inadequate blood pressure control among hypertensive stroke survivors. Office blood pressure and ambulatory blood pressure monitoring measurements were performed at 120+/-30 days after ictus in 187 first-ever consecutive hypertensive stroke survivors who were receiving blood pressure-lowering medications according to international guidelines. Handicap was assessed by the modified Rankin Scale. Blood pressure was regarded as controlled if office and daytime ambulatory systolic and diastolic blood pressure values were <140/90 and <135/85 mmHg, respectively. Patients were subclassified according to the degree of their nocturnal systolic blood pressure fall [(mean daytime values-mean night-time values)100/mean daytime values] as dippers (>or=10%), nondippers (>or=0% and <10%) and reverse dippers (<0%). Effective blood pressure control was documented in significantly (P<0.001) fewer patients using ambulatory blood pressure monitoring (32.1%) than those using office recordings (43.3%), whereas in 16% of the study population a masked lack of per-treatment blood pressure control (elevated ambulatory blood pressure in the presence of normal office blood pressure levels) was identified. The distribution of dipping patterns differed significantly (P=0.01) between controlled hypertensive individuals (normal office and ambulatory measurements) and patients with isolated ambulatory hypertension (dippers: 31.3 vs. 10.0%; nondippers:56.9 vs. 53.3%; reverse dippers: 11.8 vs. 36.7%). Logistic regression analysis revealed diabetes mellitus and functional independency (modified Rankin Scale score<2) as independent predictors of inadequate blood pressure control. Ambulatory blood pressure monitoring detects a substantial number of treated hypertensive stroke survivors with a masked lack of per-treatment blood pressure control, who present a higher prevalence of abnormal circadian blood pressure patterns (reverse dipping). Diabetes mellitus and poststroke functional independency are the main factors contributing to inadequate blood pressure control.

The Acceptable Air Velocity Range for Local Air Movement in The Tropics

The perception of locally applied airflow was studied with tropical subjects who had become passively acclimatized to hot conditions in the course of their day-to-day life. During the experiments, 24 subjects (male and female) performed normal office work in a room equipped with six workstations. They were exposed to local airflow from the front and toward the face at six air velocities (0.15, 0.3, 0.45, 0.6, 0.75, and 0.9 m/s) at ambient temperatures of 26°C, and 23.5°C and local air temperatures of 26°C, 23.5°C, and 21°C. Each combination was maintained for 15 minutes, during which the subjects responded to computer-administered questionnaires on their thermal and draft sensations using visual-analogue scales. The results showed that the subjects preferred air movement within a certain range, i.e., a higher percentage was dissatisfied at both low and high velocity values. Most dissatisfaction with air movement is caused by thermal sensation, with air movement perception accounting for a smaller proportion. The subjects preferred air movement to be between “just right” and “slightly breezy” and preferred their thermal sensation to be between “neutral” and “slightly cool.” The study also identified an acceptable air velocity range from 0.3 up to 0.9 m/s under the experimental conditions. This velocity range is relevant for the design of personalized ventilation in practice. This preferred velocity range is higher than the maximum velocity permissible under ASHRAE Standard 55 (ASHRAE 2004) in situations where subjects have no control over local air movement.