I know this question has been asked like a lot but I really need help on this. Attached below is an image of the diagram taken from US 7535131 patent. Here is the link where you can find the similar images if you want to have a look.
Can anyone please help me to find the software which was used to create diagrams like these? I doubt it could be AutoCAD but not really sure about that. I was working on a project and have got some diagrams to create, now there are tons of software available but I was really interested to find the software used here.
Also if this was not the right place to ask the question kindly move this to appropriate place.
Thank you for the support.