[1] LINKOPING UNIV HOSP,DEPT ANESTHESIOL,S-58185 LINKOPING,SWEDEN
[2] LINKOPING UNIV HOSP,DEPT NEUROSURG,S-58185 LINKOPING,SWEDEN
[3] LINKOPING UNIV HOSP,DEPT BIOMED ENGN,S-58185 LINKOPING,SWEDEN
[4] LINKOPING UNIV HOSP,CLIN RES CTR,S-58185 LINKOPING,SWEDEN