Computer assisted orthosis design system for malformed ears - Automatic shape modification method for preventing excessive corrective force

A. Hanafusa, T. Isomura, Y. Sekiguchi, H. Takahashi, T. Dohi

Research output: Contribution to journalConference article


Most malformed ears of neonates can be treated by mounting a suitably shaped orthosis. However, it needs much experience to make a orthosis that produces adequate corrective force. Especially, excessive force may cause a decubitus-like inflammation on the auricle. We are studying computer assisted system to support the orthosis design. And we have already developed fundamental design and manufacturing system. This paper describes automatic orthosis shape modification method to prevent the excessive corrective force using three dimensional finite element method. Incremental method inserting the orthosis in the auricle is used to handle non-linear material property of the auricle. In each insertion step, corrective force of every nodal point of the orthosis is calculated. The shape is modified by canceling the insertion of nodal point where excessive contact force is produced. The auricle and the orthosis were modeled by triangular shell elements and beam elements respectively. Finally the sample result of analysis showed that the orthosis modified by the method can reduce maximum force compared to that of the original shape.

Original languageEnglish
Pages (from-to)1976-1978
Number of pages3
JournalAnnual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
Publication statusPublished - 2000 Dec 1
Event22nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society - Chicago, IL, United States
Duration: 2000 Jul 232000 Jul 28



  • Automatic modification
  • Computer assisted design
  • Finite element analysis
  • Malformed ears
  • Orthosis

ASJC Scopus subject areas

  • Signal Processing
  • Biomedical Engineering
  • Computer Vision and Pattern Recognition
  • Health Informatics

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