Patents by Inventor Johannes F. A. M. Ypma

Johannes F. A. M. Ypma has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method of shaping an endo-prosthesis, a femoral head prosthesis, an acetabulum prosthesis and a method of fixing a femoral head prosthesis in a bone
    Patent number: 5041141
    Abstract: According to the present invention, the stress patterns at the interface between bone and cement of an existing prosthesis are calculated by a finite element model. For this model the external load, material properties and boundary conditions are provided. By means of advanced digital computers, stresses and strains in the model are calculated. Desired stress patterns are achieved through an optimization procedure to determine that geometry which generates those stress patterns which approximate the desired ones best.
    Type: Grant
    Filed: November 3, 1988
    Date of Patent: August 20, 1991
    Assignee: Orthopaedic Technology B.V.
    Inventors: Johannes F. A. M. Ypma, Hendrik W. J. Huiskes, Pierre J. T. M. Jaspers