I'm not a patent lawyer, but I suspect that patent wouldn't get approved in that form, or would get invalidated if it were.
There are lots of things that cause blood vessels to dilate. The vast majority don't seem to be very useful in erectile dysfunction. Which blood vessels do you need to dilate? Which ones do you need to contract?
If you leave it too vague, you won't likely get through the patent process, and if you do it's likely that someone will have tried something that fits within your vague description before and your patent will be invalidated.
If you make it too narrow, someone will find a way to accomplish the same goal without following your narrowly defined claims. Which is why there exists a wide variety of patented erectile dysfunction drugs.
A lot of people make the mistake of readin patent abstracts and thinking that the patent is extremely vage and broad. Patents are writen in very specific language and the meaning of their claims is parsed very carefully when determining if something violates them.
Read over the appeals court ruling in this case for a better idea of how the courts look at patents to see if they are being infringed upon. They go through the notes from the patent office on what was originially claimed and how it was narrowed down and more clearly specified while going through the long process of attaining the patent.
Patents aren't simply vague claims like some people act like they are.
Suppose someone finds out that a company is planning to release a refrigerator powered by replaceable metal hydride bottles; should a person be allowed to patent the concept of using a hydride-powered refrigerator to cool lemon-lime soda
I think you're going to have a hard time convincing anyone that using a new method of refrigeration to refrigerate a commonly refridgerated item is a novel idea. The new method of refridgeration might be novel and patentable, but using it for common purposes isn't novel even if you narrow the scope to lemon lime soda.
Incidentally, very shortly after the Pentium FDIV fiasco, I pondered the problem of long division and happened to independently develop a practical method of rapid division which it turned out Cyrix had just patented (I did a patent search after confirming that my method worked). I don't know if any programs like PGP use the method, though it would be suitable for both hardware and software implementations (and would be quite excellent for something like PGP). Even though the idea behind that patent might not have been "obvious", I would guess that the inventor and I aren't the only two people to have thought of it.
Well, if it was being used before the person who applied for the patent "invented" it's use, then that's prior art which would invalidate the patent.
That's not saying
There are many approved patents that are about that specific and useful. Yes, someone with sufficient time and money could get them invalidated, but in many cases companies decide to license the patents rather than fight them--not only because it's cheaper, but also because the patents will then help stifle the competition.
Patents aren't simply vague claims like some people act like they are.
Some are.
I think you're going to have a hard time convincing anyone that using a new method of refrigeration to refrigerate a commonly refridgerated item is a novel idea. The new method of refridgeration might be novel and patentable, but using it for common purposes isn't novel even if you narrow the scope to lemon lime soda.
People will patent anything. Someone patented the process of field-stripping a Glock, putting a round in the chamber, and then carefully reassembling it without cocking it so as to have a round in the chamber of the decocked Glock. The person then went on to list various claims regarding features to allow firearms to be carried striker-down and easily recocked.
Carrying a decocked firearm with a round chambered is hardly a novel idea. Field-stripping a firearm for the purpose of loading it without cocking it may be novel, but it would be pretty useless unless the firearm had added features to make it useful. And if a firearm did have such added features, the procedure probably wouldn't be necessary in the first place. Nonetheless, there's a patent for it.
I still maintain that unproven ideas are a dime a dozen; the person who can show how to make an idea useful deserves more reward than someone who thought up the idea but had no practical application for it. Usually ideas are thought up by the same people who make them useful, but when they're not, the real payback should be for the person who made the idea practical.