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Biomedical subjects

M Schütze

Publications and source records attributed to M Schütze.

18 recordsLinked to original sources
PubMed2006

Image transfer by mobile phones in neurosurgery.

Image transfer by mobile phones with built-in cameras (1 Megapixel CCD digital camera, 7 stage digital zoom, max. picture size 858 x 1 144 pixels, display resolution 240 x 320 dots, 262 K colour system CGS LCD) was introduced into clinical practice in the author's department in July 2004 to improve communication between neurosurgeons. During the first 12 months of use 13-72 images per month with an average of 1.4 images/case were transmitted via the regular German mobile phone net (GRPS standard, 40 KBit/s) among all neurosurgeons. Most images were transferred from the resident on call to the senior neurosurgeon backing him up. Overall, the system was extremely reliable, quick, and enabled immediate decisions in all emergency situations. In conclusion, image transfer by mobile phones has significantly improved communication within our department.

Cell Phone↗
PubMed2005

Concurrent chemoradiotherapy and adjuvant chemotherapy with Topotecan for patients with glioblastoma multiforme.

PURPOSE: The prognosis for patients with glioblastoma multiforme remains poor. Phase II studies, meta-analyses and a phase III study show that concurrent chemoradiotherapy has an advantage over irradiation alone. In this study the effectiveness of concurrent chemoradiotherapy with Topotecan and an adjuvant chemotherapy with Topotecan was investigated. PATIENTS AND METHOD: Forty-two patients with predominantly unfavourable prognosis factors were included in the study and treated as follows: hyperfractionated accelerated radiotherapy (2x1.75Gy to 45.5 + 12.25 Gy (RP)) with a concurrent, continuous infusion of Topotecan (0.5 mg/m(2)/d, days 1-21). On day 28 the adjuvant chemotherapy (three courses) was begun according to the same scheme. RESULT: Haematological toxicities were 13/42 (30%) grade III leucopenia, 2/42 (4%) grade IV, as well as 5/42 (10%) grade III thrombopenias and 1/42 (2%) grade IV. 30/42 (71%) patients showed improvement or stabilisation of an existing neurological symptomatic complex. The median time to progression was 7.2 (+/- 0.8) months, the median total survival was 10 (+/- 1.2) months, the 2 year survival rate 4.7 (+/- 0.3)%. Prognostic factors were age, surgical radicality, performance status and the tumour volume before therapy. SUMMARY: Concurrent chemoradiotherapy and an adjuvant chemotherapy with Topotecan is feasible at acceptable toxicity levels also for patients with a moderate performance status. The patients benefit from the improvement of the clinical symptomatic complex and, even with unfavourable prognosis factors, have a higher median survival in comparison to data published on similar groups of patients given only radiotherapy.

Adult↗
PubMed2005

An integrated modelling concept for immission-based management of sewer system, wastewater treatment plant and river.

Today's planning standards deal with the individual urban drainage components (sewer system, wastewater treatment plant and receiving water) separately, i.e. they are often designed and operated as single components. As opposed to this, an integral handling considers the drainage components jointly. This novel approach allows a holistic and more sustainable planning of urban drainage systems. This paper presents an integrated modelling concept. The aim is to analyse fluxes through the total wastewater system and to integrate pollution-based control in the upstream direction, that is, e.g., managing the combined water retention tanks as a function of state variables in the WWTP or the receiving water. All models of the different subsystems are based on the Activated Sludge Model (ASM) concept of IWA, including River Water Quality Model No. 1 (RWOM). Simulations can be done in truly parallel mode using the simulation environment SIMBA. The integrated modelling concept is applied to the river Dhuenn and the urban wastewater system of the municipality of Odenthal (Germany). An optimised operation of the system using RTC proves to be a very effective measure.

Models, Theoretical↗
PubMed2003

On-line measurement data of wastewater systems via WAP mobile phones.

In order to support the operation of wastewater systems a system was developed which allows us to access plant data by standard mobile devices such as WAP mobile phones. This system is suited complement the standard application of alarm and message systems based for example on SMS or pager services. This technology provides useful options for mobile remote monitoring and remote control of automated plants. This technology is particularly appropriate for the use in remote facilities where no staff is available. The technology has been implemented succesfully and shows how standard IT and Internet technologies can be utilised to support the operation of spatially distributed plants with reasonable effort. Two implementations are presented which access plant data via WAP mobile phones and via mobile pocket PCs. First application experiences are presented.

Automation↗
PubMed2002

[Optimized image processing with modified preprocessing of image data sets of a transparent imaging plate by way of the lateral view of the cervical spine].

PURPOSE: To improve the diagnostic quality of lateral radiographs of the cervical spine by pre-processing the image data sets produced by a transparent imaging plate with both-side reading and to evaluate any possible impact on minimizing the number of additional radiographs and supplementary investigations. MATERIAL AND METHODS: One hundred lateral digital radiographs of the cervical spine were processed with two different methods: processing of each data set using the system-imminent parameters and using the manual mode. The difference between the two types of processing is the level of the latitude value. Hard copies of the processed images were judged by five radiologists and three neurosurgeons. The evaluation applied the image criteria score (ICS) without conventional reference images. RESULTS: In 99 % of the lateral radiographs of the cervical spine, all vertebral bodies could be completed delineated using the manual mode, but only 76 % oft the images processed by the system-imminent parameters showed all vertebral bodies. Thus, the manual mode enabled the evaluation of up to two additional more caudal vertebral bodies. The manual mode processing was significantly better concerning object size and processing artifacts. This optimized image processing and the resultant minimization of supplementary investigations was calculated to correspond to a theoretical dose reduction of about 50 %. CONCLUSION: The introduction of optimized organ programs for the upper and lower cervical spine based on the 12-bit data of the images should improve the evaluation of the lateral radiograph of the cervical spine without reducing the latitude value.

Cervical Vertebrae↗
PubMed2002

Criteria for assessment of the operational potential of the urban wastewater system.

Application of real-time control (RTC) is one possible measure to increase the performance of the urban wastewater system. However, the potential and the benefits of control depend strongly on the characteristics of the individual site under question. Conventionally, to evaluate this potential, a detailed feasibility study had to be carried out. In some cases, such a study may well conclude that, for the given site, real-time control does not have any significant potential, thus resulting in unnecessarily having spent precious resources for a detailed study. It would be desirable to have a methodology that allows simple, and cost-effective, screening of sites for which the analysis of real-time control may be beneficial. Earlier research led to the provision of an easy-to-apply scoring system which allows a quick assessment of the RTC potential of controlling flow in sewer systems. However, since this procedure does not take into account water quality aspects, or the treatment plant or the receiving water body, it cannot be used for assessing the potential of RTC of the complete system, let alone for integrated RTC. This paper describes the first part of an on-going project which aims at establishing an enhanced procedure for assessing the real-time control potential for the entire urban wastewater system. After providing a definition of the term "RTC potential", a large number of (partly hypothetical) case studies (varying a number of key parameters of the wastewater system) is simulated, using the simulation tool SYNOPSIS. For each of these sites, a number of real-time control algorithms are developed and optimised, following a general procedure, which allows for local, global and integrated scenarios to be considered. Analysis of the results reveals those system parameters which are of particular significance to the RTC potential of urban wastewater systems. These are discussed and assessed in this paper. Furthermore, the results of a simulation study are provided which indicate a clear potential of integrated control even for many case studies for which local control provides hardly any benefits. Subsequent studies will complement the simulation study by comparison with a number of real case studies in various countries.

Cities↗
PubMed2002

Deterministic modelling of integrated urban drainage systems.

Today, the main concepts required for describing the dynamics of drainage in an entire urban area are known and models are available that can reasonably simulate the behaviour of the urban water system. Still, such integrated modelling is a complex exercise not only due to the sheer size of the model, but also due to the different modelling approaches that reflect the history of the sub-models used and of the purpose they were built for. The paper reviews the state of the art in deterministic modelling, outlines experiences and discusses problems and future developments.

Cities↗
PubMed2001

Ophthalmodynamometry: a reliable method for measuring intracranial pressure.

Under physiological conditions, the pressure in the central retinal vein is equal to or higher than the intracranial pressure (ICP) because the cerebrospinal fluid (CSF) passes the sheath of the optic nerve before draining into the cavernous sinus. The optic nerve sheath is where the ICP affects the retinal venous pressure. Ophthalmodynamometry (ODM) is a useful method for determining the central retinal artery pressure. While papilledema and a lack of venous pulsations are commonly used as a vague indication of the ICP, ODM may be advantageous for determining the pressure in the central retinal vein. Until now, however, the venous pressure has never been compared with the intracranial pressure. In the present study, the pressure in the central retinal vein was recorded in 31 patients while the ICP was simultaneously being recorded for various reasons. The results demonstrate a linear correlation (r = 0.968) between the pressure in the central retinal vein and the ICP. This correlation is of great practical value since until now, reliable intracranial pressure monitoring has only been possible by invasive means, by placing a probe either in the brain parenchyma or the ventricle. Ophthalmodynamometry is useful for momentary assessment of the ICP, can easily be repeated, and may be used whenever an elevated ICP is suspected in hydrocephalus, brain tumors and after head injury. However, it is not suitable for continuous ICP monitoring.

Adolescent↗
PubMed2001

Parameter optimisation of real-time control strategies for urban wastewater systems.

Real-time control (RTC) of wastewater systems has been a topic of research and application for over two decades. Attempts so far have mainly focused on one of the parts of the urban wastewater system: either the sewer system, or the treatment plant or the river. Approaches to integrate these subsystems and considering them jointly for control purposes have been pursued only recently. Control of the systems aims at pursuing one (or several concomitant) objectives, which are expressed, for example, in terms of overflow volumes, loads, effluent concentrations, receiving water quality or monetary costs, to name just a few. This paper provides a general and formal definition of the problem to define a real time control algorithm for a given urban wastewater system. A general mathematical optimization problem is formulated, which describes the task of finding an (in some sense) optimum control algorithm. Since this optimization problem is, in the general case, highly non-linear with only limited information available about the objective function itself, optimization methods appropriate for this type of problem are identified. Here, the similarity of the problem to find a control algorithm and of the parameter estimation problem common in mathematical modelling becomes apparent. Hence, methods (and problems encountered) in parameter estimation can be transferred to the problem of determining optimum RTC algorithms. This parallelism is outlined in the paper. As an application of the parameterisation and optimization of control strategies, integrated control of an urban wastewater system is discussed. Since the analysis of integrated control as just described poses certain requirements on a simulation engine, a novel modelling tool, called SYNOPSIS, is utilized here. This simulation tool, comprising of modules simulating water quantity and quality processes in all parts of the urban wastewater system, is embedded into a suite of optimization procedures. An integrated RTC algorithm for the urban wastewater system is formulated, the parameters of which are optimized using various global optimization routines. Comparison of their efficiency indicates good performance for the Controlled Random Search and for the genetic algorithms. The findings suggest that integrated control can indeed lead to an increase in performance of the urban wastewater system. These results appear to be encouraging and justify further work. Areas for further development are identified in the final section of the paper.

Algorithms↗
PubMed2000

[Ophthalmodynamometry. A reliable procedure for noninvasive determination of intracranial pressure].

BACKGROUND: Central vein pressure depends on intracranial pressure (ICP). Baurmann in 1925 therefore recommended measuring central vein pressure to determine ICP, but the accuracy of this method has not yet been verified. To test the method we measured venous outflow pressure (VOP) by noninvasive ophthalmodynamometry (ODM). METHODS AND MATERIALS: We studied 31 patients with suspected increased ICP. ICP was recorded continuously for a minimum of 24 h by intraventricular catheters, and ODM was performed during ICP measurement. The findings were compared with the results of conventional invasive ICP measurement. RESULTS: Pressure in the central retinal vein was highly correlated with ICP. CONCLUSION: Measuring VOP by ODM seems to be a reliable method for noninvasive recording of ICP. It is a useful screening test in all cases of presumed ICP elevation.

Adolescent↗
PubMed2000

Venous opthalmodynamometry: a noninvasive method for assessment of intracranial pressure.

OBJECT: The goal of this study was to examine the potential use of ophthalmodynamometry in the noninvasive assessment of intracranial pressure (ICP). Under normal conditions, pressure within the central retinal vein is equal to or greater than ICP, because the central retinal vein basses through the optic nerve before it drains into the cavernous sinus. The optic nerve sheath is the place where ICP affects retinal venous pressure. Suction ophthalmodynamometry is an established method of investigation in ophthalmology to determine the pressure of the central retinal artery. Although observations of papilledema and lack of venous pulsations are commonly used to provide a vague assessment of ICP, ophthalmodynamometry may be used to determine the pressure of the central retinal vein. This venous pressure has never been compared with ICP. METHODS: In this study the pressure of the central retinal vein was recorded in 22 patients who underwent continuous simultaneous registration of ICP for various reasons, mainly for suspected hydrocephalus. A comparison of the two pressures was made. The results indicated a highly significant linear correlation between central retinal vein pressure and ICP. These results are of great practical value because up-to-date reliable ICP monitoring has only been possible by using invasive means, by placing a probe extradurally or subdurally into the brain parenchyma or a ventricle. CONCLUSIONS: Ophthalmodynamometry can be relevant for momentary assessment and is not suitable for continuous monitoring. However, this technique can easily be repeated and may be used whenever increased ICP is suspected in a patient suffering from hydrocephalus, brain tumors, or head injury.

Adolescent↗
PubMed1999

[Risk factors for posttraumatic fits and epilepsy].

There is still a considerable controversy about the usefulness of antiepileptic prophylaxis after traumatic brain injury. Overall incidence of posttraumatic fits and epilepsy's is well known, but an individual decision on prophylaxis requires knowledge about the individual risk. We performed a prospective observational study on 612 patients with traumatic brain injury of every degree of severity. Follow-up by phone call included 96.2% of the study population after 6 month and 91.2% after 36 month, respectively. The overall incidence for early fits (within 7 days after trauma), late fits (up to 36 month) and epilepsy (as defined by the International League Against Epilepsy) was 4.2%, 3.7% and 2.5%, respectively. These incidences increased according to the severity of the trauma, but the most powerful single predictor was intracranial hemorrhage. There was no significant difference related to the hemorrhage localisation. Development of epilepsy was much more common after late fits (48%) than after early fits (17%). These features established a hierarchy of risks for the development of epilepsy: no intracranial hemorrhage/no fit: 1% (4/437), intracranial hemorrhage/no fit: 8% (10/122), intracranial hemorrhage/early fit: 16% (3/19), intracranial hemorrhage/late fit: 53% (7/13). If prophylactic antiepileptic treatment is desired, but should be restricted to patients at high risk. These are patients with intracranial hemorrhage--are a well defined high risk group--when their first fit is a late fit.

Brain Injuries↗
PubMed1996

[Post-traumatic seizure prevention--results of a survey of 127 neurosurgery clinics].

Starting in November, 1993, until January, 1994, we performed a survey among 127 Neurosurgical Departments in Austria, Germany, and Switzerland concerning the practice of antiepileptic prophylaxis in head injured patients. Seventy seven percent of the 12-item multiple choice questionnaires were completed and returned. They indicate a variety of attitudes towards prophylaxis for seizures: in 12% of the responding institutions, antiepileptic prophylaxis is given to every brain trauma patient, in 36%, no prophylaxis is carried out. and in 52% some patients receive prophylaxis while others do not. Penetrating injuries, intracranial haemorrhages and electroencephalographic abnormalities were the most frequent reasons why prophylaxis was initiated. Phenytoin is by far the most popular drug, given usually for at least three months, and in most cases monitored by routine serum level observations. Nevertheless, about three out of four neurosurgeons conceded that a general renunciation of antiepileptic prophylaxis after brain trauma might be justified. There is no uniform way in which patients are informed about a possible risk of seizures, as it may be relevant, for instance, in respect of driving abilities.

Anticonvulsants↗
PubMed1988

[HIV transmission via blood transfusions: a study by the Swiss Red Cross blood bank service].

An inquiry amongst blood transfusion services served to establish at 19 the number of known transfusion associated HIV infections in Switzerland. In 12 cases the transfusion of an anti-HIV positive blood unit could be proven retrospectively, while in 7 cases an HIV-infected blood donor could not be found but the association of the infection with blood transfusion is highly probable by exclusion of other risk factors. All these infections occurred before introduction of anti-HIV screening in Switzerland in November 1985. After this date no new transfusion associated HIV infections have been reported. It is estimated that there are fewer than 170 transfusion associated HIV infections in Switzerland. The probability of infection with AIDS by blood transfusion is less than 1:500,000. Blood transfusion today appears to be as safe as before the emergence of the AIDS epidemic.

Acquired Immunodeficiency Syndrome↗
PubMed1986

[Transfusion-associated LAV/HTLV-III infections in Switzerland. Report of 2 cases].

Two patients developed signs of LAV/HTLV-III infection one and two years respectively after a blood transfusion. The leading symptom in one patient was generalized lymphadenopathy, while the other patient presented with Candida stomatitis. In both cases, blood transfusions administered in 1983 were found to be the only possible source of infection; one blood donor of each patient was anti-LAV/HTLV-III positive. Family members and sexual partners of the two were negative for antibodies against LAV/HTLV-III. Our findings document the first two cases of LAV/HTLV-III associated disease most probably related to blood transfusions in Switzerland.

Acquired Immunodeficiency Syndrome↗