Transcript Freiburg Database Session

EUROPEAN EPILEPSY DATABASE
• Aims
– Implementation of large, high-quality polymodal data from patients
with epilepsy for the purpose of advanced analyses leading to an
improved prediction of epileptic seizures
• Planned data content
• 250 surface, 50 intracranial continuous long-term EEG data sets
with annotations
• Imaging data (3D MR data sets)
• Structured metadata (clinical)
• Derived features based on EEG analysis
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Database: preparatory steps
• Specific issues:
– Safety of personal data
• Pseudonymization of patient data
• Deletion of data contents with
identifying character
– Ethical issues
• Individual informed patient consent
• Restrictions of access and use
Replicated
European database
– Management of multimodal data
• raw data (e.g. EEG/MRI data)
• meta data (e.g. patient history, seizure
counts, semiological characteristics,
EEG annotations, electrode positions)
Coimbra
– Multisite access to local databases
of consortium members
(data warehouse approach)
• Multiple local databases
• Procedures do assure identical data
content
Freiburg
Paris
SQL
Client
interfaces
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Clinical procedures
•
•
•
Consortium consent on Inclusion criteria
(Paris, 2008):
Patient selection
• Patients with focal and multifocal epilepsy
Criteria for data quality
• Minimum duration of continuous EEG
– Standardized annotations
recordings: 96h (4 days)
(types and positioning of seizure• Minimal number of seizures: 5
related markers:
with an interseizure interval of ≥ 3.5h
• Clinical seizure onset / first • Information on subclinical EEG events and
behavioural alteration
sleep stages in the preictal period
• EEG seizure onset / first EEG • Appropriate electrode implantation for
focus identification
change
• Spikes
• Subclinical events
– Uniform nomenclature of EEG
channels
– EEG review
Metadata (types and inclusion form)
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T1.1: clinical procedures
Sleep staging
EEG onset
Early propagation
EEG pattern morphology
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Database client interfaces
Coimbra
Freiburg
Paris
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Database development
Storage of sample values:
• External binary files: space efficient
& the way people are used to work
• Inside database tables: flexible for
querying
Database system:
• Open source (PostgreSQL) vs. Oracle
(commercial)
• Decision for Oracle to allow the
storage of the samples inside the
database
Replicated vs. distributed database
• Local datatbase at every site,
replicated content
• Not a single distributed database
because of immense data traffic
• Estimation of data volume: > 50Tb
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Present status
The database is open for collaboration with US-databases
www.epilepsiae.eu