title: Holographic interferometry of cerebral pulsations.
abstract: BACKGROUND
  Holographic interferometry is a noninvasive method used to analyze the mechanical displacement affecting an object undergoing deformation. This technique has been primarily applied to inanimate entities owing to the difficulty in producing stress forces in living subjects. In this report, the possibility of harnessing cerebral pulsations as a displacement force to produce interferograms in neurosurgical patients was studied.
  
  
  METHODS
  This work evaluates the application of this technology to patients with areas of calvarial defects. Using a pulse ruby laser, holographic interferograms were created in neurosurgical patients with areas of calvarial loss. The cardiac cycle was used to trigger the firing of the laser.
  
  
  RESULTS
  The holographic interferograms were accurate up to within 0.5 mm in outlining the region of bony deficiency.
  
  
  CONCLUSIONS
  Holographic interferometry imaging was successfully accomplished using cerebral pulsations as a cyclic displacement-producing force. This method accurately outlined the area of bony loss. A discussion of this technology is included.
authors.affiliation: Department of Neurological Surgery, Cornell University, New York, NY 10021, USA. k@gyrus.cc
authors.forename: Kathryn
authors.initials: K
authors.lastname: Ko
authors.forename: Ronald
authors.initials: R
authors.lastname: Erickson
authors.forename: Tim
authors.initials: T
authors.lastname: Schmidt
authors.forename: John
authors.initials: J
authors.lastname: Webster
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000379:methods; D002555:Cerebrospinal Fluid / Q000502:physiology; D004867:Equipment Design; D006696:Holography / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007368:Interferometry / Q000295:instrumentation / Q000379:methods*; D007427:Intracranial Pressure / Q000502:physiology*; D007834:Lasers; D019635:Neurosurgical Procedures; D012886:Skull / Q000293:injuries* / Q000601:surgery; D014947:Wounds and Injuries / Q000175:diagnosis / Q000503:physiopathology; D014948:Wounds, Gunshot / Q000175:diagnosis / Q000503:physiopathology