What is necessary for a patent?


To receive a patent an invention must be new. This may mean:

It must not be part of the current ‘state of the art,’ which in patent law comprises all matter, such as other products, processes, information, etc.  The Arnold patent met the novelty requirement as it was a new way of treating pain that had not been recognised before.

The invention also must not have been known by others or disclosed to the public.  However a major difference between the US and other patent systems is that the US allows inventors a 12 month “grace period” meaning an inventor must file their patent application within one year after he or she discloses the invention to the public.  For example, if the inventor presents a conference paper in which the invention is discussed, they must file for patent protection within one year of that presentation.  After one year the invention is no longer novel and cannot be patented.  In contrast, in Europe, the inventor must have filed for patent protection before they make the invention public or it becomes unpatentable.


The invention must involve an inventive step to be patentable; it must not have been obvious for someone who is skilled in the area of the invention.  The reason for this is that the patent system is trying to encourage inventive improvements in technology, not merely workshop improvements which any skilled person could achieve. One way to prove that the advance was inventive is to show that others have tried but failed to solve the problem that was subsequently solved by the invention. 

The Arnold patent passed the non-obviousness requirement, because the ‘prior art’ available did not provide concrete evidence that combining analgesics would in fact produce the effect found by the inventor.


To meet the usefulness requirement:

Arnold’s invention lent itself easily to industrial application.  A new compound with analgesic properties is clearly useful in medicine and could be made by the pharmaceutical industry. The details of the patent application would have included details on how the analgesics could be combined and what kind of formulation could be produced and marketed.


The last criterion is disclosure. The patent application must include:

In exchange for making these details public, the inventor is granted protection to exploit their invention as discussed earlier.  The quid pro quo is that:

Science and industry cannot move forward if innovative ideas are hidden away; new information must be exchanged for knowledge to progress. The invention in the Arnold patent was no doubt properly disclosed. Research data was also presented in court that showed the product did provide effective pain relief in people.

Interactive tutorial

To view this interactive tutorial, you need the latest Flash player.