MIAS: Minimally invasive articular surgery

• Research unit: EU RFP
• Project number: 95.0854-2

Key words (English)

Virtual surgery; surface reconstruction; medical imaging

Alternative project number (English)

EU project number: BMH4CT960865

Research programs (English)

EU-programme: 4. Frame Research Programme - 4.2 Agriculture and agroindustry

Short description (English)

See abstract

Partners and International Organizations (English)

Scuola Superiore Sant'Anna (I), Instituti Ortopedici Rizzoli (I), University Islas Balears (E), University of Bristol (UK), University Hospital Lund (S), Karl Storz GmbH & Co (D), Swiss Federal Institute of Technology(CH)

Abstract (English)

The goal of MIAS project is to provide an application to simulate surgical operations of the knee. In this project, we have made these following tasks:
· We have finished our reconstruction tools.
· We have worked on the integration of these tools to the final application
· We have developed a method for real-time collision detection among tools and organs during the surgical operation.

Reconstruction tools:

We have developed two packages for segmentation and 3D reconstruction of preoperative images. The first package is based on manually operated snake technique, in which the contour of interest is approximately outlined by manually defining a snake on the image. Minimization of a cost function made of internal and external forces gives the true contour. 3D reconstruction from segmented images is done with the 'Nuages' program. Output is in OpenInventor™ format. Manual editing of the output is possible. The program runs on Windows Platform.
The second package permits segmentation and reconstruction by fitting a generic 3D model to the data in a set of CT or MR scans. Deformation of the input model is done by internal shape memory forces and external image interest forces. The topology of the input model is preserved. Manual editing of the output model is possible. The program runs on SGI and the output format is OpenInventor™.
Finally, we have integrated these tools into the final application.

Real-time collision detection and its response:

In the frame of this project, we have developed a library for real-time collision detection. This library will be used to detect the collision among the surgical tools and the organs. This library will be used with another one that computes the real-time deformation of tissues. Collision detection is a complex problem. Organ surfaces are composed of several thousand polygons however testing every polygon with every other polygon for potential collisions is an unrealistic task. Therefore we have developed a hierarchical algorithm to solve this problem. The second task is to compute the response to collision detection. This response is modeled as a constraint that prevents the vertices of an organ entering the volume of the surgical tool.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 95.0854-2