We have divided the rehabilitation process in patients with insulin-dependent diabetes mellitus into the following four phases. The basic phase, the so-called 'phase 0', provides information about literature, different strategies of treatment and introduces the use of regular insulin as well as blood sugar self-monitoring. During 'phase 1' (i.e. 'diabetes education common sense') all the initial information from 'phase 0' will be used practically and discussed in depth. After the patient's actual insulin need (U/24 h) has been estimated, initial algorithms for functional insulin use can be defined. And this is the turning point to 'phase 2' of the group rehabilitation process, the so-called education in functional insulin use. Initial algorithms should be understood as a preliminary answer to the patient's questions, 'What is my basal insulin need?', 'How much insulin do I need for a particular amount of carbohydrates?', and 'What is the hypothetical response of my blood glucose to a particular amount of insulin?'. These algorithms are going to be used and optimised now by the patient (under the supervision of the physician) during the so-called 'insulin games' (fasting or 24 h, experimental violation of traditional dietary rules, etc.) to demonstrate (1) how to influence actual glycaemia through immediate correction of blood sugar off blood sugar target (primary adjustment of insulin dosing), and (2) how to optimise algorithms for insulin use (secondary insulin adjustment) in future conditions of different insulin sensitivity. The 'phase 3' of individual teaching is an ongoing process of updating the patient's knowledge and practical skills.(ABSTRACT TRUNCATED AT 250 WORDS)

Algorithms↗

PubMedDate not supplied

PCDD/F- and PAH-emission from house heating systems.

Combustion experiments were carried out in different house heating systems using various fuels. The emission samples and the chimney soot samples were analyzed for polychlorinated dibenzo-p-dioxins/furans (PCDD/F) and polycyclic-aromatic-hydrocarbons (PAH). The PCDD/F-concentrations in fluegases using untreated wood were in the range of 2-25 pg I-TE/m3. The combustion of paper, cartons, painted wood and wood with 2-5% PVC gave PCDD/F-concentrations from 38 to 952 pg I-TE/m3 and 380 to 2,240 ng I-TE/kg (chimney soot). The PAH-concentrations in flue gas were about 30 times higher using an old technology in relation to a new one.

Air Pollution↗

PubMedDate not supplied

Polyhalogenated dibenzo-p-dioxins and dibenzofurans in the exhaust air during textile processings.

5 textile finishing processes were investigated for polychlorinated dibenzo-p-dioxins/furans (PCDD/F), polybrominated dibenzo-p-dioxins/furans (PBDD/F) and mixed polychlorinated-brominated dibenzo-p-dioxins/furans (PBCDD/F). For the purpose of these investigations the complete balance--dioxins input from the raw textiles, output over the finished textiles and output through the air path--was done. In the exhaust air only small PXDD/F concentration were detected. The textiles contain before and after the process nearly the same PCDD/F-concentrations. The concentrations of PBCDD/F arises after the process. Only the chimney depositions contain higher PCDD/F-concentrations up to 1,806.1 ng I-TE/kg, PBDD/F-concentrations up to 1,572.6 ng/kg and PBCDD/F-concentrations up to 40,801.4 ng/kg.

Air Pollution↗

PubMedDate not supplied

Analysis of flame retarded polymers and recycling materials.

Recycling activities on polymeric materials are increasing and becoming more and more important in recent years. For polymers containing no flame retardants, suitable recycling strategies already exist. In order to investigate the recyclability of flame retarded polymers that contain brominated flame retardants, a number of samples were analysed as received from a recycling company. Following the identification and sorting of the samples according to type of polymers and flame retardants, material recycling was tested for the flame retarded polymers identified to occur most frequently. The reactivity of the flame retardants during the recycling procedure was studied by analysing for brominated dioxins and furans. The results demonstrate that flame retarded polymers can be recycled under certain experimental conditions.

Bromine↗

PubMedDate not supplied

Investigation on organic pollutants from a domestic heating system using various solid biofuels.

Various herbaceous biofuels (straw, whole plant cereals and set aside hay) and spruce wood were tested for their potential to form PCDD/F, PCPh, PCBz and PAH during combustion. The trials were conducted in an automatically charged multi-fuel furnace for domestic applications (50 kWth). Both, flue gas and the different ash fractions were analysed. CO-emission results show, that combustion conditions were relatively uniform (mean CO-level: 200 mg/m3 at 13% O2 in flue gas). Likewise, the TOC- and PAH-emissions in the fuel gas remained constantly on a relatively low level. However, for the PCDD/F, PCPh and PCBz increased emissions were detected when herbacious fuels were applied. This may be attributed to their higher chlorine concentration and the high ash content, which is responsible for increased dust emissions during combustion. Similar observations were also found for the PCDD/F-concentrations in the ashes. Combustion chamber ashes usually showed a drastically reduced contamination with highly toxical compounds, compared to the ash fraction from the heat exchanger ash or to chimney soot.

Air Pollutants↗

PubMedDate not supplied

[Functional electrostimulation of paraplegic patients--1 year's practical application. Results in patients and experiences].

In October 1982 two patients suffering from paraplegia ware, world wide for the first time, implanted two 8-channel-stimulation-devices at the II. Surgical Clinics Vienna. Four electrodes were fixed to the nervus femoralis and the nervus gluteus inferior with the help of microsurgical techniques. The aim of the operation is to enable the paralysed patient to "stand up himself" and to "cover a short distance on crutches". They must learn to manipulate the implanted "more-channel-device" with their fingers, and to coordinate this with the supporting function and the balance function of their arms. The wheel-chair shall not and cannot be substituted with this method: Not without, but with wheel-chair and functional electrostimulation. A comprising training-programme for building up muscles, balance control and gait training was necessary. After 4 months muscle-force and endurance had increased 200%. The patients could stand up stimulatedly without help between parallel bars. At the rehabilitation center Bad Häring the first steps were done in March 1983 (= 5. month after operation). The greatest success was when a patient could get stimulatedly out of her car and do the through-swing-gait over a distance of 60 meters. After one year the muscle force was quadrupled, the endurance was increased 20-30 times, depending on the type of gait. Both patients are able to walk in the 4-P-gait or swing-through-gait on crutches over short distances without help from others. Riding a bicycle stimulatedly on even ground was demonstrated.

Adult↗

PubMedDate not supplied

Technology and long-term application of an epineural electrode.

An epineural electrode (ENE) was developed to achieve a controllable, progressive muscle contraction and reduce muscle fatigue during functional electrostimulation. In vitro studies of annular (torus-shaped) electrodes have been carried out to select adequate electrode materials and electrode diameters. We investigated the long-term stability of ENEs using different intensities of current (range: 0.8-1.2 mA) in sheep and rat experiments. Depending upon size and material, ENE tolerates anodic and cathodic impulses of up to 1 msec and 8 mA (peak current). ENEs were used during clinical application in four paraplegic patients (16 channel implants) for stimulation of lower extremities, and in nine quadruplegic patients (eight channel implants) for diaphragm pacing, for a total observation time of 37 patient years. The low rate of clinical complications, including no corrosion of the electrodes or significant loss of nerve fibers, seems related to the small dimensions of the electrode (less than 1 mm2).

Animals↗

PubMedDate not supplied

Effect of stationary guiding vanes on improvement of the washout behind the rotor in centrifugal blood pumps.

In centrifugal pumps, there always exists an area of stagnation between the rear of the rotor and the rear housing wall that promotes thrombus formation around the axle. Some current devices overcome the problem by using holes in the rotor plane, leading to increased hydrodynamic losses and shear stress. In this study, a simple apparatus was developed to overcome this problem. Guiding vanes were fixed to the rear housing wall. These vanes decrease the tangential velocity of the fluid and thus the centrifugal force, leading to an increased secondary flow toward the axle. The effect of such vanes was studied in videographic and ultrasound studies. An increase of washout and mixing between the flow layers could be demonstrated (stay time < 200 msec versus several seconds without vanes). In the first animal experiment using nonoptimized vanes, there was no thrombus at the back plane or the seal, and only a small thrombus at the transition between axle and rotor. Hemolysis was slightly elevated (3.2 mg/dl versus 2.5 mg/dl in control experiments). In conclusion, it is highly likely that this simple system will improve the flow characteristics in centrifugal pumps.

Animals↗

PubMedDate not supplied

[Method and clinical use of functional electrostimulation].

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Adolescent↗

PubMedDate not supplied

[ISO 9001 conformity in research, teaching and rehabilitation].

Quality assurance, in particular in the areas of development and production of medical devices, is one of the tasks of biomedical engineering. The interdisciplinary working group "Functional Rehabilitation and Group Education, Vienna" is committed to the development and implementation of group education models on three levels: (1) direct education/instruction of patients with chronic diseases, (2) university research and teaching, and (3) development of technical aids for rehabilitation and the means for disseminating group education models in rehabilitation and therapy. Major aims were, by generating conformity with ISO 9001 standards, to achieve greater transparency and process optimization with very small resources in university (teaching, research, technical aids) and extra-university (rehabilitation) areas. A secondary aim was the establishment of interdisciplinary (clinical and biomedical) cooperation at university level. In all main areas (research, teaching and group education/instruction), ISO 9001-conformity was achieved by our activities on three methodological levels: (1) description and analysis of processes, (2) use of ISO 9001 standards for evaluating internal processes, and (3) optimization measures. The following article contains relevant elements of the quality manual and quality assurance system, and offers a typical example of innovative cooperation between medicine and medical engineering.

Austria↗

PubMedDate not supplied

Laryngeal pacemaker: activity of the posterior cricoarytenoid muscle (PCM) and the diaphragm during respiration in sheep.

Electromyograms (EMG) of the PCM and the diaphragm were evaluated in 6 sedated female sheep. Corresponding pneumatograms were recorded simultaneously by means of thermocontrolled respiration flowmeter. Evidence was obtained on considerable intra- and inter-individual differences in the duration of respiratory cycles as well as PCM- and diaphragmatic activity. Most of the evaluated respiratory periods showed either a phase coincidence between the PCM and the diaphragm, or a leading edge of about 40-80 ms of the posticus muscle. Due to this minimal phase shift, the diaphragmatic myogram seems to be a valuable trigger for an external PCM stimulation unit in bilateral recurrent nerve palsy.

Animals↗

PubMedDate not supplied

Computer simulation of the circulatory system during support with a rotary blood pump.

In order to investigate the performance characteristics of nonpulsatile centrifugal pumps and their interaction with the pulsating heart, a computer simulation model was developed. A model of the pump, including the cannulae and the interference of the cannula and the left atrial wall, was added to a simulator of the circulation. It was implemented on a PC-AT using the analog simulating software AGO1000. An interval of 1 msec real-time per calculation step was evaluated to provide stable results. The calculation speed was approximately 100 msec per step. First simulation studies showed that both the positioning and resistance of the cannulae exert a major influence on system performance and equalized the different pressure-flow characteristics of vaneless and impeller pumps (difference of dp/dQ decreases from more than 6 times without cannulae to 130% with cannulae). In addition, the effects of suction in the atrial cannula, and changes of ventricular performance during changes in pumping power, could be properly simulated. The comparison with animal tests proved that the model is a suitable tool for testing control algorithms for centrifugal pumps.

Algorithms↗

PubMedDate not supplied

The phrenic pacemaker. Substitution of paralyzed functions in tetraplegia.

Explore the source record for details and available documents.

Animals↗