Please find attached the link to an old(ish) interesting article on the above subject (September 2013) from the Times Educational Supplement.
The article does not explore formal ownership of University intellectual property, including patents, whether developed or created by Students with Universities, or independently. However if the starting point is in relation to Intellectual property formally owned by the University, consideration would need to be given to the policy as to whether it was the intention that the Student owned IP generated during coursework or studies, or whether the University owns it. If the policy was that University owned, we would also need to consider whether the University should formally assign all rights in intellectual property to the Student. These are all well known policy choices; some Universities assert (for themselves) formal ownership of all IP generated by Students, and then in suitable cases assign rights back to the Student; others as a matter of policy start from a base where the Student owns all IP created or developed by them during the period of their studies or coursework.
The picture would inevitably change if there was Course work or research privately funded by external parties, and in cases where the Student has ceased formal studies. It is not clear (to me) whether this is the case in the two examples. In general, it is recommended to work out claims as to ownership on a case by case basis. The article discusses two interesting examples of Student inventors working in the field of fibre optic sensing technology, and secondly in the field of surgical devices. Universities should be able to provide workable legal frameworks for current and former Students in start ups, and the attached article contains two good examples for discussion.
It is true that the preliminary legal framework can be rigid and out of date; but we have to start the discussion somewhere – I recommend the case of Kelly and Chiu v GE Healthcare  EWHC 181, a case involving valuation of contribution to inventions by employees (pursuant to sections 40 and 41 of the Patents Act 1977), Unilever v Shanks  EWCA 1283.
The other elements (whether students or the educational institution formally owns) inventions are often in many circumstances, matters of policy, depending on who had actually made the invention, or contributed to an outstanding benefit. The two attached cases explore the difficult issue of valuing outstanding benefit and contribution of inventions, albeit in the context of the employer/employee relationship. The two valuation cases hopefully mirror the two examples of start ups in the Times Higher Education article.
Times Higher Education Article:
Kelly v Chiu
Shanks v Unilever: