Animation in relational information visualization

In order to be able to navigate in the world without memorizing each detail, the human brain builds a mental map of its environment. The mental map is a distorted and abstracted representation of the real environment. Unimportant areas tend to be collapsed to a single entity while important landmarks are overemphasized. When working with visualizations of data we build a mental map of the data which is closely linked to the particular visualization. If the visualization changes significantly due to changes in the data or the way it is presented we loose the mental map and have to rebuild it from scratch. The purpose of the research underlying this thesis was to investigate and devise methods to create smooth transformations between visualizations of relational data which help users in maintaining or quickly updating their mental map

Clinical applications of the forced oscillation technique: bronchial hyperresponsiveness and effects of bronchodilators

Contains fulltext : mmubn000001_117138851.pdf (publisher's version ) (Open Access)Promotores : C. van Herwaarden en H. FolgeringVIII, 119 p

Bronchial hyperresponsiveness, measured with forced expirations and with the forced oscillation technique.

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Discontinuation of furosemide decreases PaCO(2) in patients with COPD.

Item does not contain fulltextSTUDY OBJECTIVE: To evaluate whether the discontinuation of furosemide treatment resulted in a decrease in PaCO(2) and an increase in daytime and nocturnal oxygenation. BACKGROUND: Furosemide is widely prescribed in patients with COPD for the treatment of peripheral edema. It is known that furosemide causes a metabolic alkalosis. A diminished chemoreceptor stimulation may cause a decreased alveolar ventilation. DESIGN: Randomized, double-blind, placebo-controlled, crossover trial. SETTING: Department of Pulmonology, Rijnstate Hospital Arnhem, the Netherlands. PATIENTS: Twenty patients with stable COPD (10 men; median age, 70 years [range, 58 to 81 years]; FEV(1) 35% predicted [range, 19 to 70% predicted]). Subjects were included if they had received furosemide, 40 mg/d, for the treatment of peripheral edema for at least a month and if they had a mean nocturnal arterial oxygen saturation (SaO(2)) < 92%. Patients with cardiac left and/or right ventricular dysfunction, sleep apneas, and patients receiving other diuretics, angiotensin-converting enzyme inhibitors, potassium or chloride replacement therapy, or long-term oxygen treatment were excluded. INTERVENTION: Furosemide was discontinued for 1 week and replaced by placebo treatment in the first or the second week. MEASUREMENTS AND RESULTS: Ventilation, daytime arterial blood gas levels, and nocturnal SaO(2) were measured at baseline, after 1, and after 2 weeks. Sixteen subjects completed the study. Ventilation increased from 10.4 L/min (range, 6.7 to 15.4 L/min) at baseline to 11.6 L/min (range, 8.7 to 14.0 L/min) after discontinuation of furosemide (p < 0.05). PaCO(2) decreased from 45 mm Hg (range, 35 to 64 mm Hg) to 41 mm Hg (range, 32 to 61 mm Hg; p < 0.01). Daytime and nocturnal oxygenation did not improve. CONCLUSIONS: Although it does not improve oxygenation, the discontinuation of furosemide decreases PaCO(2) in patients with COPD

Underestimation of nocturnal hypoxemia due to monitoring conditions in patients with COPD.

Item does not contain fulltextSTUDY OBJECTIVES: COPD patients run a risk of developing nocturnal oxygen desaturation. When evaluating patients with nocturnal hypoxemia, an unfamiliar hospital environment and the monitoring equipment may cause sleep disturbances. It was hypothesized that increased sleep disruption will lead to fewer instances of desaturation during a night of monitoring. DESIGN:The following forms of monitoring were evaluated prospectively on 3 nights for each patient: oximetry at home; polysomnography (PSG) at home; and PSG in the hospital. SETTING: Department of Pulmonology, Rijnstate Hospital Arnhem, The Netherlands. PATIENTS: Fourteen stable COPD patients (7 men; median age, 71.5 years; age range, 59 to 81 years; FEV(1), 32.5% predicted; FEV(1) range, 19 to 70% predicted) participated in the study. All subjects had significant instances of nocturnal arterial oxygen desaturation. Those patients with a sleep-related breathing disorder or cardiac failure were excluded from the study. MEASUREMENTS AND RESULTS: The mean nocturnal arterial oxygen saturation (SaO(2)) level was higher during PSG monitoring at home (89.7%; range, 77 to 93%) than during oximetry monitoring (88.5%; range, 80 to 92%) [p 4%) was lower during PSG monitoring at home (22.1%; range, 3 to 63%) during PSG monitoring at home than during oximetry monitoring (50.4%; range, 4 to 91%) [p < 0.01]. A correction for actual sleep during PSG monitoring reduced the differences between PSG monitoring at home and oximetry monitoring, although a difference in the desaturation time remained (PSG monitoring at home, 31.9% [range, 2 to 75%]; oximetry monitoring, 50.4% [range, 4 to 91%]) [p = 0.041]. A comparison of sleep architectures for nights when PSG was being monitored showed a higher arousal index in the hospital than at home (PSG monitoring in the hospital, 5.6 arousals per hour [range, 2 to 16 arousals per hour]; PSG monitoring at home, 2.5 arousals per hour [range, 1 to 6 arousals per hour]) [p < 0.025], but no differences in SaO(2) levels were found between PSG monitoring at home and PSG monitoring in the hospital. CONCLUSION: The artifacts due to sleep-monitoring equipment may cause an underestimation of the degree of nocturnal hypoxemia in COPD patients. The addition of an unfamiliar environment causes more sleep disruption, but this does not affect nocturnal SaO(2) levels further

Long-term effects of mattress-covers on house dust mite (Der-p-1)

Contains fulltext : 20575___.PDF (publisher's version ) (Open Access

Tension pneumopericardium caused by positive pressure ventilation complicating anaerobic pneumonia.

A 22-year-old man was admitted with pneumonia. He was immediately intubated and positive pressure ventilation was initiated. Blood and sputum cultures showed Bacteroides fragilis and Corynebacterium sp., which were treated with metronidazole and clindamycin. Three weeks later his blood pressure suddenly dropped with an elevation of the central venous pressure. Chest X-ray revealed a pneumopericardium. A parasternal mediastinotomy with partial pericardiectomy was immediately performed. On opening the pericardium his blood pressure normalised. The patient gradually recovered and six weeks after admission he was extubated. Two weeks later he was discharged. A pneumopericardium without previous thorax trauma is very rare and early recognition is imperative because a tension pneumopericardium with cardiac tamponade may develop, as happened in this case. A tension pneumopericardium has to be treated with immediate pericardiocentesis followed by partial pericardiectomy to avoid recurrence

Tension pneumopericardium caused by positive pressure ventilation complicating anaerobic pneumonia.

Item does not contain fulltextA 22-year-old man was admitted with pneumonia. He was immediately intubated and positive pressure ventilation was initiated. Blood and sputum cultures showed Bacteroides fragilis and Corynebacterium sp., which were treated with metronidazole and clindamycin. Three weeks later his blood pressure suddenly dropped with an elevation of the central venous pressure. Chest X-ray revealed a pneumopericardium. A parasternal mediastinotomy with partial pericardiectomy was immediately performed. On opening the pericardium his blood pressure normalised. The patient gradually recovered and six weeks after admission he was extubated. Two weeks later he was discharged. A pneumopericardium without previous thorax trauma is very rare and early recognition is imperative because a tension pneumopericardium with cardiac tamponade may develop, as happened in this case. A tension pneumopericardium has to be treated with immediate pericardiocentesis followed by partial pericardiectomy to avoid recurrence

Influence of two different inhalation devices on therapy compliance in asthmatic patients.

Contains fulltext : 140849.pdf (publisher's version ) (Open Access)OBJECTIVE: To examine the influence of inhalation device (Autohaler versus metered dose inhaler) and patients' subjective opinion towards the different devices, as well as daily frequency and duration of treatment on medication compliance. DESIGN: Prospective study measuring compliance in the same patients of the Autohaler twice daily with the metered dose inhaler twice daily, as well the Autohaler twice daily with the Autohaler four times daily. SETTING: Primary health care. SUBJECTS: 34 subjects with asthma. MAIN OUTCOME MEASURES: Patients preference and compliance. RESULTS: Patients preferred the Autohaler. The percentage of patients with a negative opinion towards the metered dose inhaler was 38% compared with 12% towards the Autohaler. The median values of the compliance rate of the Autohaler with twice and four times daily frequency were 90.8% (25-75th percentile 61.6-98.0%) and 78.5% (25-75th percentile 49.0%-91.2%), respectively (p < 0.001). The duration of treatment period had a significant negative influence on compliance when four times daily dosage frequency was prescribed (p = 0.05). CONCLUSION: In conclusion, the devices (metered dose inhaler and Autohaler) and the patients' opinion about the devices did not significantly contribute to the compliance rates. Compliance towards the medication treatment, however, is negatively influenced by a high daily frequency

Metabolic acidosis improves airway conductance in patients with asthma.

Contains fulltext : 79556.pdf (publisher's version ) (Closed access)The objective was to investigate whether acute metabolic acidosis could cause bronchodilation in patients with asthma. Twelve patients with asthma (8 females, mean age 39 (+/- SD 12) years, forced expiratory volume in 1 second [FEV(1)] 93 [+/-9] % predicted, PC(20) 1.9 (+/-1.0) mg/mL) participated in a double-blind, placebo-controlled trial. Subjects ingested calculated amounts of ammonium chloride to induce acidosis or saline as placebo, in random order, each on a separate day. Airway resistance (R(aw)), specific airway conductance (sG(aw)), FEV(1), and PEF were measured as primary variables. To evaluate the consequences of alterations in bronchial contractility on the airway responsiveness, the histamine provocation test (PC(20)) was measured as secondary variable. The intervention resulted in a mean (SD) decrease in base excess from -0.5 (+/-1.4) to -3.9 (+/-1.1) mmol/L (p < 0.01) and a decrease in pH from 7.41 (+/-0.02) to 7.36 (+/-0.02) (p < 0.01). This caused a statistically significant increase in sG(aw) from 1.15 (+/-0.16) to 1.26 (+/-0.13) 1/kPa.s) (p < 0.05). Tendencies towards increase were found in PEF (7.79 (+/-2.2) versus 8.09 (+/-1.9) (NS, p = 0.10) and in FEV(1) (2.98 (+/-0.9) versus 3.06 (+/-0.9) (NS, p = 0.15). PC(20) did not change significantly. It was concluded that acute metabolic acidosis has a modest bronchodilating effect in patients with asthma