Knowledge Center

Your Resource for Training and Technical Support

What is the difference between a CAHM and a IHM?

CAHM stands for Conformal Atlas Head Model.  This is an atlas-based head model with the added incorporation of the individual sensor position information (derived from a solved GPSR file).  This means that the atlas scalp surface, skull and atlas brain are warped to fit the individual sensor positions and the sensor position information is taken into account for the source calculations. 

IHM stands for Individual Head Model. This head model also has the individual sensor position information incorporated, but rather than being derived from an atlas, the IHM is created from the subject/patient's own MRI such that the cortical surface, volume and seven different tissue types are fully described. The source calculations are performed within the volume of the patient's own MRI and also take into account the individual sensor positions.

Conformal Atlas Head Models are available in Geosource 3.1 Research Intermediate and Geosource 3.1 Research Advanced.

Individual Head Models are available in Geosource 3.1 Research Advanced.

Additional Info

  • Product Type: GeoSource and GPS
  • Information Type: Implementation Theory
Last modified on Thursday, 01 June 2017 15:46

Return to Knowledge Center Home