title: Clinical evaluation of intraparenchymal Spiegelberg pressure sensor.
abstract: OBJECTIVE
  The Spiegelberg 3-PN intraparenchymal pressure sensor was clinically evaluated.
  
  
  METHODS
  The Spiegelberg intraparenchymal pressure sensor is a low-cost device that uniquely performs regular automatic zeroing in situ throughout the measurement period.
  
  
  METHODS
  The Spiegelberg sensor was inserted in 87 patients who required intracranial pressure monitoring as part of their routine management. Complications were assessed by postoperative computed tomographic scanning and clinical investigation. The automated zeroing procedure was assessed after implantation of the sensor and during long-term measurement. In five patients, the "gold standard' of intraventricular pressure was measured simultaneously and compared with the intraparenchymal or subdural Spiegelberg 3-PN pressure.
  
  
  RESULTS
  No complications associated with the Spiegelberg sensor were observed. The duration of monitoring ranged from 3 to 28 days (mean, 10 d). In 3 patients, technical problems occurred, and in 84 patients, the pressure measurement was successful, including the automatic zeroing procedures performed by the monitor after insertion and hourly thereafter. The absolute difference between the Spiegelberg reading and the intraventricular pressure was less than +/-3 mm Hg in 99.6% and less than +/-2 mm Hg in 91.3% of readings. An Altman-Bland bias plot revealed good agreement between the two methods, with an average bias of 0.5 mm Hg, but revealed a significant trend toward 10% lower Spiegelberg readings with increasing intracranial pressure of >25 mm Hg. There was no difference between intraparenchymal and subdural locations.
  
  
  CONCLUSIONS
  The Spiegelberg 3-PN sensor was reliable and simple to use. It can be recommended for routine intraparenchymal and subdural pressure measurement at a considerably lower price compared with other tip transducers and has the unique advantage of automated zeroing in vivo.
authors.affiliation: Department of Neurosurgery, Neurocenter, Johann Wolfgang Goethe University, Schleusenweg 2-16, 60528 Frankfurt am Main, Germany.
authors.forename: Josef-Michael
authors.initials: JM
authors.lastname: Lang
authors.forename: Jürgen
authors.initials: J
authors.lastname: Beck
authors.forename: Michael
authors.initials: M
authors.lastname: Zimmermann
authors.forename: Volker
authors.initials: V
authors.lastname: Seifert
authors.forename: Andreas
authors.initials: A
authors.lastname: Raabe
mesh_terms: D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002552:Cerebral Ventricles / Q000503:physiopathology; D014695:Cerebral Ventriculography; D006259:Craniocerebral Trauma / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003399:Craniotomy / Q000009:adverse effects; D013354:Empyema, Subdural / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006408:Hematoma, Subdural / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology*; D008991:Monitoring, Physiologic / Q000009:adverse effects* / Q000295:instrumentation*; D011183:Postoperative Complications; D015203:Reproducibility of Results; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013355:Subdural Space / Q000000981:diagnostic imaging / Q000503:physiopathology; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D014160:Transducers, Pressure / Q000009:adverse effects