title: Interactions between programmable shunt valves and the iPad 3 with Smart Cover.
abstract: BACKGROUND
  In patients with programmable CSF shunt valves, the risk of unintentional valve adjustment associated with the environmental magnetic influence is ever present. We tested whether the iPad 3 with Smart Cover is capable of changing the setting of individual programmable valves ex vivo using direct fluoroscopic visualization.
  
  
  METHODS
  The following valves were tested: Strata NSC Adjustable Pressure Valve, Strata NSC Burr Hole Valve, Strata II small valve, Sophysa Polaris model SPV, Aesculap valve proGAV, and Codman Certas Programmable Valve. The left front edge of the iPad 3 with Smart Cover was found to have the strongest magnetic flux, measuring approximately 1,200 G and was moved linearly directly over the tested valve and then parallel to the first path at approximately 30 cm/s. Also, this area was rotated once at varying distances above the valve at approximately 1 rad/s.
  
  
  RESULTS
  Almost all shunt valves were immune to reprogramming by the iPad 3 at varying distances (including direct contact) except for the Strata II small valve, where rotating the peak flux location 4 mm above the valve changed the valve pressure settings every time.
  
  
  CONCLUSIONS
  The iPad 3 can change pressure settings of the Strata II small valve at a distance comparable to the thickness of certain regions of the scalp. Although the specific rotational motion described here may be uncommon in real life, it is nevertheless recommended that children with hydrocephalus, caregivers, educators, and therapists are informed of the now-apparent risks of close contact with this increasingly popular technology.
authors: Department of Neurological Surgery, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA. hey@wusm.wustl.edu
authors: Yizheng
authors: Y
authors: He
authors: Rory K J
authors: RK
authors: Murphy
authors: Jarod L
authors: JL
authors: Roland
authors: David D
authors: DD
authors: Limbrick
mesh_terms: D002557:Cerebrospinal Fluid Shunts / Q000295:instrumentation*; D034201:Computers, Handheld; D004867:Equipment Design; D004868:Equipment Failure; D006801:Humans; D006849:Hydrocephalus / Q000601:surgery; D008280:Magnetics / Q000295:instrumentation