Biomedical subjects

Helmut Hutten

Publications and source records attributed to Helmut Hutten.

3 recordsLinked to original sources

PubMed2005

KISS--a new approach to self-controlled e-learning of selected chapters in Medical Engineering and other fields at bachelor and master course level.

Modern life style requires new methods for individual lifelong learning, based on access at every time and from every place. This fundamental requirement is provided by the Internet. The Internet technology promises an increasing potential in the future for e-learning or tele-learning. Some special requirements are password-controlled access, applicability of most commercially available PCs and laptops equipped with standard software (Microsoft Internet Explorer 6.0), central evaluation of the students' performance, inclusion of an examination part, provision of a picture gallery and a comprehensive glossary accessible in the learning mode. The KISS-shell has been developed based on the Oracle 10g application server in combination with a relational data base (Oracle 8i) on the server side and a web browser based interface using JavaScript for user control of data input on the client side (Kontrolliertes Intelligentes Selbstgesteuertes Studium, KISS). The first tutorial application has been realized with a chapter about cardiac pacemakers. The weight of that chapter (or module) is about 2 ECTS (i.e. the equivalent of 30 working hours; European Credit Transfer System, ECTS). The internal structure of the chapter is organized in sequential mode. It consists of five main sections. Each of those five sections is subdivided into five subsections of comparable length. Progression from one subsection to the next is possible only after successfully passing through the respective examination. The whole learning programme with the pacemaker chapter has been evaluated by 10 students. The system will be presented together with first experiences including the evaluation results. Until now the program has not been used for training purposes.

Austria↗

PubMed2004

Ventricular evoked response as clinical marker for hemodynamic changes in dilative cardiomyopathy.

The potential value of ventricular evoked response (VER) evaluation by implantable pacemakers as clinical marker for disease induced hemodynamic changes in the heart, has so far not been explicitly evaluated. We conducted a study to evaluate the reproducibility of the R spike and T wave measurements (R(VER) and T(VER)) under controlled clinical conditions and examine the correlation between VER parameters and standard echocardiographic measurements in the left ventricle. Additionally, the utility of the VER as a marker for NYHA classification and the presence of cardiomyopathy was investigated. The Physios CTM 01 pacemaker capable of recording authentic VER signal morphology, was used with low polarization fractal coated pacing leads to obtain high-fidelity VER recordings in 26 patients with conventional pacing indications (mean age: 69.1 +/- 11.8 years; 20 men). Three patients suffered from dilative cardiomyopathy (DCM), 14 from hyperthropic nonobstructive cardiomyopathy (HNCM), and nine had no myopathy but suffered from coronary artery disease (CAD). Five patients were in NYHA Class IV, 19 in Class III, and two in Class II. Mean R(VER) and T(VER) amplitudes were calculated from one-minute VER recordings. Standard echocardiography parameters were determined during this recording. Two follow-ups at a mean distance of 11.3 +/- 5.7 month were performed. The reproducibility of R(VER) or T(VER) (correlation factors: 0.992 and 0.981, respectively) was superior to the reproducibility of any echocardiographic parameter (correlation factors 0.404-0.943). There was no strong correlation between VER and any echo parameter. Both R(VER) and T(VER) were significantly reduced in NYHA Class IV patients (P < 0.05), and nearly significantly reduced in DCM versus other patients (P = 0.05-0.09). HNCM made no difference to CAD. The investigation shows that analysis of VER parameters bears a promising potential for dynamic monitoring of diseases affecting the hemodynamics, and of therapeutic effects, by means of regular, nonburdening pacemaker follow-up examinations.

Aged↗

PubMed2003

Direct estimation of Cole parameters in multifrequency EIT using a regularized Gauss-Newton method.

A major drawback of electrical impedance tomography is the poor quality of the conductivity images, i.e., the low spatial resolution as well as large errors in the reconstructed conductivity values. The main reason is the necessity for regularization of the ill-conditioned inverse problem which results in excessive spatial low-pass filtering. A novel regularization method (SMORR (spectral modelling regularized reconstructor)) is proposed, which is based on the inclusion of spectral a priori information in the form of appropriate tissue models (e.g. Cole models). This approach reduces the ill-posedness of the inverse problem, when multifrequency data are available. An additional advantage is the direct reconstruction of the (physiological) tissue parameters of interest instead of the conductivities. SMORR was compared with posterior fitting of a Cole model to the conductivity spectra obtained with a classical iterative reconstruction scheme at various frequencies. SMORR performed significantly better than the reference method concerning robustness against noise in the data.

Algorithms↗