ASTM_E_1467_-_94.pdf

Designation:E 1467 94An American National StandardStandard Specification forTransferring Digital Neurophysiological Data BetweenIndependent Computer Systems1This standard is issued under the fixed designation E 1467;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers transmission of digitally re-corded electrophysiologic waveform data and related textualannotations between laboratories or clinics,or between com-puter systems in a given laboratory or clinic.This includes allelectroneurophysiology(EN)studies such as electroencepha-lograms(EEG)and magnetoencephalograms(MEG),poly-somnograms(PSG)and multiple sleep latency tests(MSLT),evoked potentials(EP)and evoked magnetic fields(EMF),event-related potentials(ERP),electromyograms(EMG)andnerve conduction studies(NCS),and many others in either aclinical or research environment.Although this specification isconcerned primarily with electroneurophysiology,the methodsused for encoding waveform and related data would be suitablefor other tests involving waveforms,such as electrocardio-grams(EKG),vascular/intracranial pressure monitoring,oxim-etry,or gastrointestinal motility studies.1.2 This specification defines a format for waveform databased on Specification E 1238(developed in cooperation withHL7(Health Industry Level 7),with extensions to support thetransmission of multichannel time-series waveforms.1.3 This specification may be applied either to two-waytransmission of data over medium-to high-speed data commu-nication networks,or one-way transmission of data by record-ing on and later playback from magnetic or optical digitalstorage media.It defines the blocked stream of data,called amessage,which is transmitted over a network connection orrecorded on a storage medium.It does not define the hardwareor software network protocols or storage media formats neededfor message transmission(for example,see ISO 8072),or theformats used to store data internally by the sender or receiver.1.4 Recognizing,however,that some standardization instorage media format and network protocols would help topromote exchange of data between computer systems withdiverse hardware and software,it is suggested that readilyavailable universal media and formats be used,when possible,for data exchange.An example suitable for transmission oflarge amounts of digital waveform data would be the use ofindustry-standard magnetic tape or digital audio tape(DAT),with ANSI standard tape labels,employing variable lengthblocked records(lines)with a maximum block size of 4092bytes.Individual lines within the blocks would be terminatedby carriage return characters,Code 13 in the AmericanStandard Codes for Information Interchange(ASCII).Asanother example,for the transmission of moderate amounts ofdigital waveform data,floppy disks written in MS-DOS(1)2format(or another commonly used directory and file structure)would be appropriate;the data would be contained within asingle sequential file on the disk,with lines within the filedelimited by carriage return(ASCII 13)or carriage returnfollowed by linefeed(ASCII 10)characters.An example ofnetwork hardware and software suitable for transmission ofwaveform data would be Ethernet(2)and the TCP/IP(3)protocol.1.5 The major topics can be found in the following sections.SectionSignificance and Use3General Approach3.1Levels of Implementation3.2Direction of Information Exchange3.3Types of Communication Supported3.4Description of Implementation3.5Message General Content Considerations4Relation to Specification E 1238 and HL7 Standards4.1Extensions to Specification E 1238 and HL7 Standard Formats4.2Specifying Information Categories in OBR and Q Segments4.2.1Specific Code Table Identifiers in Coded Entries4.2.2Maximum Field Lengths in OBX Segments4.2.3Message Acknowledgment(MSA)Segment4.2.4Subject Filter and Qualifiers Field in Q Segments4.2.5Message Characteristics and Terminology4.3Characters4.3.1Segments4.3.2Fields4.3.3Delimiters4.3.4Case Sensitivity4.3.5Field Lengths4.3.6Maximum Line Length4.3.7Not Present and Null Values4.3.8Units of Measure4.3.9Data Types4.4Address Data(AD)4.4.1Coded Entry Data(CE)4.4.2Composite ID with Check Digit Data(CK)4.4.3Composite Miscellaneous Data(CM)4.4.41This specification is under the jurisdiction of ASTM Committee E-31 onHealthcare Informatics and is the direct responsibility of Subcommittee E31.16 onInterchange of Electrophysiologic Waveforms and Signals.Current edition approved July 15,1994.Published December 1994.Originallypublished as E 1467 92.Last previous edition E 1467 92.2The boldface numbers in parentheses refer to the list of references at the end ofthis specification.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.Co