The iPhone is at the centre of a patent dispute brought against Apple by a doctor who was convicted for defrauding US government health insurance programmes.

Peter Boesen, a surgeon from Iowa, was convicted last year of seeking reimbursement from Medicare and Medicaid for medical procedures that were unnecessary or not performed. He’s also tried to get money by filing patent claims against companies including Canon, LG Electronics, Kyocera and now Apple, according to news reports.

Boesen and Thomas Mann were granted a patent in 2004 that says they invented “a method of entering data on a touchscreen display” with a graphical keyboard area that automatically terminates once input is received.

Boesen, through a company called SP Technologies in Florida, sued Apple last week in US District Court in Tyler, Texas. The suit reportedly demands a permanent injunction against Apple, as well as damages and attorney's fees.

InformationWeek reported that Boesen was sentenced to 51 months in prison in May and ordered to repay $900,000 to the state of Iowa and private insurers.

“Boesen is free pending an appeal. No word on whether he is using an iPhone to text his lawyer,” InformationWeek’s Paul McDougall writes.

SP Technologies claims it warned Apple in February that the iPhone would violate the patent, but says Apple did not respond. Apple has not yet filed a formal response to the lawsuit, news reports say.

Boesen’s patent, which was termed “absurdly generic” by one Wired blogger, includes drawings of a touchscreen keyboard and pages worth of programming code.

“External programming may selectively access the input area through a dynamic link library,” the patent states. “The input area has no task bar and may not be minimized, maximized or deleted. Therefore, the input area becomes an integral component and provides the user with a constant and reliable method of inputting information into the computer program."