Instrumentarium Science Foundation

Ausgehend vom bildungspolitischen Ziel einer erhöhten Weiterbildungsteilnahme stellt der Beitrag ein Instrumentarium vor, mit dem das Lern- und Bildungsverhalten erwachsener Menschen statistisch erfassbar wird. Am Beispiel ausgewählter Daten aus dem Berichtssystem Weiterbildung (BSW) und dem Adult Education Survey (AES) werden Analysepotenzial und Erkenntnisgewinn der Weiterbildungsstatistik ausgeleuchtet. Hierzu werden Daten zum Weiterbildungsvolumen, zur Anzahl und Dauer von Lernaktivitäten und zur sektoralen Zuordnung der Weiterbildungsaktivitäten in einen internationalen Vergleich gestellt.

Numerical implementation of the reconstruction formulae of Nakamura and Tanuma [Recent Development in Theories and Numerics, International Conference on Inverse Problems 2003] is presented. With the formulae, the conductivity and its normal derivative can be recovered on the boundary of a planar domain from the localized Dirichlet to Neumann map. Such reconstruction method is needed as a preliminary step before full reconstruction of conductivity inside the domain from boundary measurements, as done in electrical impedance tomography. Properties of the method are illustrated with reconstructions from simulated data.

Datex-Ohmeda Division, Instrumentarium AB, Stockholm, Sweden. ola.lassborn@se.datex-ohmeda.comIn Reply:—This article is related to a particular customer complaint reported to us on March 17, 2003. We investigated the Fresh Gas Control Unit related to the report and identified the root cause as being a malfunction in the one-way valve. The corrective action for this customer was to install a replacement Fresh Gas Control Unit, including a new one-way valve. As a preventive action, we have initiated an investigation aiming to evaluate if this was an individual component failure or a potential systematic issue.

Hodgkin’s lymphoma is characterized by an increase in circulation cytokines, which are known to be able to induce nitric oxide (NO) production. Exhaled nitric oxide (FENO) has been proposed as an inflammatory marker of the airways, and it has also been shown to be increased in lung cancer (1). So far no reports have used exhaled NO to follow the progress of cancer during treatment. The authors followed-up a patient with Hodgkin’s disease with extended NO analysis of the exhaled breath. The patient’s alveolar NO fraction was 9 ppb NO before diagnosis, which decreased to 7 ppb NO after four treatment periods, and after eight periods the fraction was 3 ppb NO. We conclude that extended NO analysis is a simple noninvasive tool to follow-up an inflammatory process in the human body, as well as following treatment during disease. Case report. A 27-year-old female with epilepsy and atopic dermatitis complained of coughing and shortness of breath. She had no history of airway atopy or asthma-like symptoms. She was referred to the lung clinic where the diagnosis of asthma was excluded. However, the exhaled NO levels were extremely high. Exhaled NO was measured with a chemiluminescence analyser (Sievers NOA 280, Sievers, Boulder, CO, USA) and a flow sensor, (D-lite TM , Datex-Ohmeda, Helsinki, Finland) was used to measure NO at different expiratory flow rates. Following the ATS guideline for NO measurement (2), it was seen that patient had more then tenfold increase in exhaled NO. Using an extended NO analysis (3) revealed high alveolar fraction (FANO), as well as an increase in airway wall fraction (FwNO) and airway wall diffusion rate of NO (DwNO), see Table 1. During a four-month period she developed fever, night sweats, and weight loss (BMI 24). Her symptoms became aggravated and she developed a vena cava superior compression with an oedema of upper thorax, head and neck. She had lymph node enlargement in the neck and axillae. Chest x-ray showed a large mediastinal mass. Laboratory analysis revealed elevated LDH, C-reactive protein and peripheral Blymphocytes. Fine-needle aspiration and lymph node biopsy showed a Hodgkin’s disease of mixed cellularity. The disease was classified as stage II by staging with CT-scan and bone marrow biopsy. She received treatment with eight courses of baseline BEACOPP, i.e. Bleomycin 10 mg/m 2 day 8, Etoposide 100 mg/m 2 day 1 � /3, Doxorubicin 25 mg/m 2 day 1, Cyclophosphamide 650 mg/ m 2 day 1, Vincristine 1.4 mg/m 2 (max 2 mg) day 8, Procarbazine 100 mg/m 2 day 1 � /7 and Prednisone 40 mg/m 2 day 1 � /14 (4). When she had finished four out of eight treatment periods the exhaled NO, CRP and B-lymphocytes had decreased. The CT scan showed shrinkage of the lymphoma mass. The patient developed severe haematological toxicity after every

Effects of x-ray scattering on full-field digital mammography are analyzed with the scattering model of Seibert and Boone [Med. Phys. 15, 567-575 (1988)]. A new method is introduced for the estimation of model parameters from measurements. It is shown that with breasts thinner than a certain threshold, removing the anti-scatter grid leads to an improved contrast-to-noise ratio with a smaller patient dose. A fast approximate algorithm is presented for determining the scattered field in a gridless digital mammogram.

The purpose of the study was to find out whether the image quality in full-field digital mammography can be improved while lowering the patient dose by removing the anti-scatter grid. Moreover, a fast approximate computational algorithm was developed for determining the scattered field in a real mammogram. The method is non-iterative, robust against noise, and works without modification for any scatter-to-primary ratio. Furthermore, it is computationally effective since it is based on fast Fourier transform (FFT). It was found out that the wide dynamic range of digital detectors leads to decrease in patient dose from 10.9% up to 46.6% at breast thickness of 2cm and from 0.8% up to 40.8% at breast thickness of 4cm depending on the efficiency of the removed grid. At constant patient dose the increase in contrast-to-noise ratio is 5.8% - 36.9% and 0.4%-30.0% accordingly at those two breast thickness. The convolution-based X-ray scatter model was considered. The developed scatter removal method was demonstrated with simulated mammograms and applied to clinical full-field digital mammograms acquired with a high-end digital flat panel detector based on amorphous selenium. Errors in reconstructed scattered fields were 0.3% in case of an ideal simulated mammogram and 7.4% in case of a real simulated mammogram (3cm breast). Applications where the scattered field needs to be determined include 3-D mammography and dual-energy breast imaging. In screening mammography gray-scale optimization eliminates the effect of scattering.

In x-ray tomography, the structure of a three-dimensional body is reconstructed from a collection of projection images of the body. Medical CT imaging does this using an extensive set of projections from all around the body. However, in many practical imaging situations only a small number of truncated projections are available from a limited angle of view. Three-dimensional imaging using such data is complicated for two reasons: (i) typically, sparse projection data do not contain sufficient information to completely describe the 3D body, and (ii) traditional CT reconstruction algorithms, such as filtered backprojection, do not work well when applied to few irregularly spaced projections. Concerning (i), existing results about the information content of sparse projection data are reviewed and discussed. Concerning (ii), it is shown how Bayesian inversion methods can be used to incorporate a priori information into the reconstruction method, leading to improved image quality over traditional methods. Based on the discussion, a low-dose three-dimensional x-ray imaging modality is described.

For the first time a silicon IR-source and CO/sub 2/-chamber system for measurement of CO/sub 2/ concentration is presented. This new miniaturized infrared sensor is specially designed for the measurement of respiratory gases present in patient airways during anaesthesia or intensive care. The IR-sensor assembly consists of an IR-source chip with two pairs of diagonally arranged IR-sources for the generation of two switched "sample" and reference beams. The gas filter chip is arranged with two CO/sub 2/ chambers directly beneath the two reference sources. These chambers "pre-absorb" the reference beam at the CO/sub 2/ wavelength band around 4.26 /spl mu/m. The reference beam is needed for long term stability and for compensation against cuvette window contamination. The electrically modulated IR-sources consist of incandescent polysilicon filaments coated with silicon nitride across a 220 /spl mu/m deep cavity. The CO/sub 2/-chambers with a length of 1 mm are fabricated by silicon fusion and anodic bonding at a chosen CO/sub 2/ pressure for optimal filter characteristics. Test measurements of the infrared sensor system show high CO/sub 2/-sensitivity meaning that the stringent requirements for this respirator application can be reached.

During large surgical operations the patient is usually anaesthesized, whereby his muscles are relaxed. This blocks the patient’s spontaneous breathing and during the operation an anaesthesia machine usually takes care of the breathing function. It transfers the chosen amount of anaesthetic gas mixture to the patient’s lungs during the inspiratory phase and transfers approximately the same amount of gas away from there during the expiratory phase.