Working on the human skeleton
The National Centres of Competence in Research (NCCR) achieve groundbreaking results. The NCCR "CO-ME (Computer-aided and image-guided medical interventions)", for instance, supplies three-dimensional surgical tools. There are few the world over who can rival NCCR "CO-ME" researchers when it comes to bone modelling.
A neo-classical villa houses management and administration, behind this is a factory with huge windows. Here in the north of Berne, the finest textiles were once produced; today it is an address for cutting-edge research. For four years now, the spacious factory that once belonged to the Schwob linen weavers has been home to the Institute for Surgical Technology and Biomechanics at the University of Bern. This is where Chilean Engineer, Maurico Reyes and his team are working on the design of the "statistical human being". He receives exceptional support from the NCCR "CO-ME" where computer technologies are developed for medical purposes.
While the subject may sound abstract, it is highly beneficial in orthopaedic surgery, that is in operations on the human musculoskeletal system. Mauricio Reyes and his colleagues have developed a new mathematic model. Based on bone image data, the average skeleton of certain groups of persons can be calculated and displayed on the computer in three dimensions.
Bone length, shape and stability vary in people of different origins. The researchers from Bern have therefore made separate calculations for the mass of the typical skeleton for ethnic groups from East Asia and Europe. For example, the three-dimensional computer image of a European thighbone provides the surgeon with the average shape at first glance. He can however also identify the extent of anatomical variance he will encounter later in the operating theatre.
The scientists have also developed a process that calculates and provides images of the bones of a specific patient based on an average model. "All that is required is a simple two-dimensional x-ray photo as template. Often an ultrasound picture will suffice," explains Mauricio Reyes. This way doctors in practicing in smaller hospitals can rotate the patients' hip joints on the computer, study them from all sides and plan the operation in detail beforehand.
"This approach makes it possible to perform more precise operations on the skeleton," comments Maurico Reyes. The great advantage of modelling is that patients no longer need CAT scans on bones or joints before complex operations. As a result, costs are cut and exposure to radiation is reduced. The scientists have tested their model in the NCCR "CO-ME" network with over 30 clinics, universities and research institutes.
There are only three or four other research groups in the world that have mastered the technique of bone modelling with such skill as the team led by Mauricio Reyes. While competitors must be satisfied with relatively small data sets, the researchers in Switzerland have integrated thousands of bones in their models, including thighbones, hips and lower jaws. They are now working to create a corresponding database for the entire human skeleton. And it is not just the shape of the bones that are examined. Information on the structure of bones, in particular the density of bone mass and therefore their stability are captured. This additional knowledge makes it possible to adjust implants, like artificial hip joints, so that they fit the patient perfectly. It is already possible to calculate the mechanical properties of an implant, as well as the position, length or orientation of screws used to secure it, through computer modelling. "Previously, all these parameters had to be painstakingly optimised on the bone by hand," explains Mauricio Reyes. Customised implants, tailored to fit the specific individual, is a goal that is now within reach.
It is not surprising that Maurico Reyes regularly receives requests from companies that manufacture implants – from Switzerland and abroad. They are primarily interested in the bone data of specific groups of persons for optimising their products. Maurico Reyes shares his expertise with industry through development and research partnerships. Supported by the Federal Commission for Technology and Innovation, an initial project has already been implemented with a Swiss company.
New York, Boston or Lyon: the researchers from Berne continue to receive invitations to present their work at scientific conferences. Scientific interest is enormous. Yet the true strength of Maurico Reyes and his team lies in not losing touch with the real world. Recently an eye specialist from Bern University Hospital asked if they could model the eye to improve fitting of artificial lenses. Mauricio Reyes is very enthusiastic about the idea.