Patient-specific fibre-based models of muscle wrapping.

In many biomechanical problems, the availability of a suitable model for the wrapping of muscles when undergoing movement is essential for the estimation of forces produced on and by the body during motion. This is an important factor in the Osteoporotic Virtual Physiological Human project which is investigating the likelihood of fracture for osteoporotic patients undertaking a variety of movements. The weakening of their skeletons makes them particularly vulnerable to bone fracture caused by excessive loading being placed on the bones, even in simple everyday tasks. This paper provides an overview of a novel volumetric model that describes muscle wrapping around bones and other muscles during movement, and which includes a consideration of how the orientations of the muscle fibres change during the motion. The method can calculate the form of wrapping of a muscle of medium size and visualize the outcome within tenths of seconds on commodity hardware, while conserving muscle volume. This makes the method suitable not only for educational biomedical software, but also for clinical applications used to identify weak muscles that should be strengthened during rehabilitation or to identify bone stresses in order to estimate the risk of fractures.

Visualization and simulated surgery of the left ventricle in the virtual pathological heart of the Virtual Physiological Human.

Ischaemic heart failure remains a significant health and economic problem worldwide. This paper presents a user-friendly software system that will form a part of the virtual pathological heart of the Virtual Physiological Human (VPH2) project, currently being developed under the European Commission Virtual Physiological Human (VPH) programme. VPH2 is an integrated medicine project, which will create a suite of modelling, simulation and visualization tools for patient-specific prediction and planning in cases of post-ischaemic left ventricular dysfunction. The work presented here describes a three-dimensional interactive visualization for simulating left ventricle restoration surgery, comprising the operations of cutting, stitching and patching, and for simulating the elastic deformation of the ventricle to its post-operative shape. This will supply the quantitative measurements required for the post-operative prediction tools being developed in parallel in the same project.

Accessing a WWW reference library of 3D models of pathological organs to support medical education.

A major aspiration of the medical community is to use multimedia databases to disseminate important research or clinical information and for education. We describe a WWW reference library of 3D models of human organs containing pathological and normal organs organised in cases, together with a variety of educational and supporting tools. Although the emphasis is chiefly on the teaching of medical students and the continuing education of physicians, the library is also a potentially-valuable resource for diagnostic investigation. This paper describes the environment, methodologies and tools for supporting 3D models in medical education. The prototype of the system is currently being completed; the full system is scheduled for public access in the year 2000 through multimedia publishers.

Organisation, transmission, manipulation of pathological human organs on the WWW.

The paper describes an integrated methodology for the development of a WWW computer system which addresses issues of the organisation, retrieval and manipulation of 3D volumetric models of pathological human organs. The library of organs is distributed on the WWW since medical expertise and needs are typically expensive resources and also because many pathological conditions are often restricted to local diffusion. Users are provided with a WWW viewer for interactive manipulation of the models of the organs. The system supports low-cost MS-Windows 32 platforms and requires no specialised hardware. Early results demonstrate that the compression techniques employed provide near real-time response for retrieval/manipulation, not only over high-speed expensive network lines, but also over low/medium network connections.