claim: Pulmonary embolism is indicated by alterations in blood oxygen levels.
evidence: Rory Christopher Patterson -LRB- born 16 July 1984 -RRB- is a Northern Irish footballer who plays as a forward for Derry City .. Derry City. Derry City F.C.. Northern Irish. Northern Ireland. footballer. Association football. forward. Forward ( association football ). He also played for the Northern Ireland national team .. Northern Ireland. Northern Ireland national football team. Northern Ireland national team. Northern Ireland national football team. Having played youth football for Sion Swifts , Moorfield Celtic and Townsend United , Patterson joined Rochdale in 2002 before having spells with Radcliffe Borough and Mossley .. Rochdale. Rochdale A.F.C.. Radcliffe Borough. Radcliffe Borough F.C.. Mossley. Mossley A.F.C.. In 2005 , he joined up with the newly formed club F.C. United of Manchester , where he stayed until 2008 becoming their all-time top goalscorer in the process , scoring 99 times .. F.C. United of Manchester. F.C. United of Manchester. He subsequently joined up with Bradford Park Avenue before having a short spell with Droylsden .. Bradford Park Avenue. Bradford Park Avenue A.F.C.. Droylsden. Droylsden F.C.. In 2009 , he moved back to Northern Ireland to join Coleraine where he had a successful one season spell -- scoring 30 league goals , and he subsequently joined Glentoran before moving back to England to join Football League One side Plymouth Argyle .. Coleraine. Coleraine F.C.. Glentoran. Glentoran F.C.. Plymouth Argyle. Plymouth Argyle F.C.. Northern Ireland. Northern Ireland national football team. Football League One. Football League One. After a two-year spell with League of Ireland Premier Division club Derry City , Patterson moved to Western Australian side Cockburn City SC in January 2015 , before returning to F.C. United of Manchester in October 2015 .. F.C. United of Manchester. F.C. United of Manchester. Derry City. Derry City F.C.. Cockburn City. Cockburn City SC. League of Ireland Premier Division. League of Ireland Premier Division. Cockburn City SC. Cockburn City SC. He is now currently playing once again for Derry City F.C.. Derry City. Derry City F.C.