Following a similar decisions from the EPO and UKIPO late last year, the USPTO has concluded patent inventors must be humans, and machines cannot be designated as inventors of patents under the current legislation. 

In one of several test cases filed 29 July 2019 at the USPTO, a patent applicant named the inventor as "DABUS (invention generated by artificial intelligence)".  The machine's owner then executed the assignment on behalf of the machine and clarified inventor was amachine via the statement of inventorship .

It was argued that the machine, implemented as a series of neural networks and provided with general information in the field, was not trained in respect of any specific problem. As a result the machine itself recognised the novelty and salience of the invention in question. In other words the machine was responsible for the inventive endeavour in this case.  

The ruling considered statute, the manual of examining practice, Code of Fed Regs, and several instances of Fed circuit case law concerning the difference between inventors and applicants.  Whilst nothing in the statute appeared to expressly rule out machine inventors, the USPTO was adamant that only a mental act of a natural person could lead to inventorship under the patent statute.  

So for now at least it seems AI remains a tool created by humans with the humans being recognised for the increased innovation.  Whilst humans can create patentable machines, and also patentable methods of operating such machines, the machines themselves are not currently recognised as inventors of patent applications.