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M Weidenbach

Publications and source records attributed to M Weidenbach.

7 recordsLinked to original sources
PubMed2004

Intelligent training system integrated in an echocardiography simulator.

Computer simulators play an important role in medical education. We have extended our simulator EchoComJ with an intelligent training system (ITS) to support trainees adjusting echocardiographic standard views. EchoComJ is an augmented reality application that combines real three-dimensional ultrasound data with a virtual heart model enabling one to simulate an echocardiographic examination. The ITS analyzes the image planes according to their position, orientation and the visualization of anatomical landmarks using fuzzy rules. An adaptive feedback is provided that colors the specific anatomic landmarks within the contours of the virtual model based on the quality of the image plane.

Artificial Intelligence↗
PubMed2001

An enabling system for echocardiography providing adaptive support through behavioral analysis.

Echocardiography requires the integrated application of a broad spectrum of cognitive and practical skills, e.g. diagnostic knowledge (symbolic), image interpretation (visual perception) and handling of the ultrasound probe (sensorimotor). This complex expertise is acquired through extensive practical training guided by a skilled cardiologist that is often incompatible with clinical reality. Especially for beginners, the most critical point during an echocardiographic examination is the steering of the ultrasound probe to navigate between different cardiological standard planes (sensorimotor skill) without loosing orientation. These transitions or "standard trajectories" can roughly be described by specific movement patterns. We propose an enabling system based on an Augmented Reality simulator for two-dimensional echocardiography imitating this apprenticeship [1]-[3]. During a simulated ultrasound examination the system monitors the activities of the trainee and analyzes the motion pattern of the ultrasound probe. The simulator reacts by mapping the motion patterns onto cognitive orientation demands and providing adaptive feedback in the form of context sensitive help (animations). It partly takes the role of the critical teacher.

Computer-Assisted Instruction↗
PubMed2000

Augmented reality simulator for training in two-dimensional echocardiography.

In two-dimensional echocardiography the sonographer must synthesize multiple tomographic slices into a mental three-dimensional (3D) model of the heart. Computer graphics and virtual reality environments are ideal to visualize complex 3D spatial relationships. In augmented reality (AR) applications, real and virtual image data are linked, to increase the information content. In the presented AR simulator a 3D surface model of the human heart is linked with echocardiographic volume data sets. The 3D echocardiographic data sets are registered with the heart model to establish spatial and temporal congruence. The heart model, together with an animated ultrasound sector represents a reference scenario, which displays the currently selected two-dimensional echocardiographic cutting plane calculated from the volume data set. Modifications of the cutting plane within the echocardiographic data are transferred and visualized simultaneously and in real time within the reference scenario. The trainee can interactively explore the 3D heart model and the registered 3D echocardiographic data sets by an animated ultrasound probe, whose position is controlled by an electromagnetic tracking system. The tracking system is attached to a dummy transducer and placed on a plastic puppet to give a realistic impression of a two-dimensional echocardiographic examination.

Computer Graphics↗
PubMed2000

[Augmented reality in echocardiography. A new method of computer-assisted training and image processing using virtual and real three-dimensional data sets].

Augmented reality (AR) applications link real with virtual image data, in order to increase their information content. In medicine they are especially useful for education and for supporting the interpretation of three-dimensional (3D) image data. Simulators are used to train risky or expensive procedures. In the AR application EchoCom2 a 3D surface model of the human heart is linked with echocardiographic volume data sets. The 3D echocardiographic data sets are registered with the heart model to synchronize it's temporal and spatial orientation. The heart model together with an animated ultrasound sector represents a reference scenario, which displays the currently selected cutting plane within the echocardiographic volume data set. Modifications of the cutting plane within the echocardiographic data are transferred simultaneously and in real time to the reference scenario. The AR application is used as a simulator to train two-dimensional echocardiographic examinations and as an orientation and navigation aid for the exploration of 3D echocardiographic data sets. Beginners in echocardiography have only a rudimentary conception of the spatial relationship between the actual ultrasound image and the 3D anatomy of the heart. They are unable to translate multiple two-dimensional slices into a coherent 3D mental image of the heart. In EchoCom2 the trainee can interactively explore the 3D heart model and the registered 3D echocardiographic data sets by the animated ultrasound sector, whose position is controlled by an electromagnetic orientation and position system (EPOS). The data from the EPOS are used to calculate the echocardiographic images that are analogue to the position of the animated ultrasound sector. EchoCom2 is also used to support the interpretation of 3D echocardiographic data sets. The analysis of 3D echocardiographic data has to be done during a post processing. Defining the exact position of a cutting plane within the volume is difficult due to the lack of a standardized representation, the independence of the cutting plane of any transducer position and the possibility to calculate an indefinite number of views. The simultaneous representation of the current cutting plane both in the volume data, and in the heart model enables the examiner ad hoc to recognize it's position and the visualized structures.

Computer Simulation↗
PubMedDate not supplied

Acute mitral regurgitation due to chordal rupture in a patient with neonatal Marfan syndrome caused by a deletion in exon 29 of the FBN1 gene.

The neonatal Marfan syndrome is an autosomal dominantly inherited disease with an extremely poor prognosis. This report gives a clinical and echocardiographic description of an infant with a mutation in exon 29 of the fibrillin-1 gene (FBN1), a region in which this severe form of Marfan syndrome seems to cluster. The infant died at the age of 3 months due to severe acute mitral regurgitation leading to intractable heart failure.

Acute Disease↗