<?xml version="1.0"?><ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-08-28</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000806168</issuerCik><issuerName>INVIVO CORP</issuerName>        <issuerTradingSymbol>safe</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0000898243</rptOwnerCik><rptOwnerName>HAWKINS JAMES B</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>4900 HOPYARD RD</rptOwnerStreet1><rptOwnerStreet2></rptOwnerStreet2><rptOwnerCity>PLEASANTON</rptOwnerCity><rptOwnerState>CA</rptOwnerState><rptOwnerZipCode>94588</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>PRESIDENT/CEO</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>COMMON STOCK</value></securityTitle><transactionDate><value>2003-08-28</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>30000</value></transactionShares><transactionPricePerShare><value>22</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>139467</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>COMMON STOCK</value></securityTitle><transactionDate><value>2003-08-28</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>312</value></transactionShares><transactionPricePerShare><value>22.99</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>BY CHILDREN</value><footnoteId id="F1" /></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>COMMON STOCK</value></securityTitle><transactionDate><value>2003-08-28</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>700</value></transactionShares><transactionPricePerShare><value>22.98</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>BY CHILDREN</value><footnoteId id="F1" /></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>COMMON STOCK</value></securityTitle><transactionDate><value>2003-08-28</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>412</value></transactionShares><transactionPricePerShare><value>22.83</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>BY CHILDREN</value><footnoteId id="F1" /></natureOfOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes><footnote id="F1">SHARES HELD BY REPORTING PERSON'S CHILDREN</footnote></footnotes><remarks></remarks><ownerSignature><signatureName>/S/ JAMES B. HAWKINS</signatureName><signatureDate>2003-08-28</signatureDate></ownerSignature></ownershipDocument>

