Adding useful and unobvious functionality to existing patent

Question

Alice owns the patent for a blood pressure measurement device consisting of three elements:

A) a sensor

B) a particular signal processing circuit (the juice of the novel and unobvious functionality)

C) a display

Shortly after the patent is granted, Alice realizes that monitoring one of the signals already available inside element B would allow to obtain additional diagnostic informations, besides blood pressure, which are on their own useful and unobvious. A key point is that said signal is available if and only if elements A, B, and C, are combined together exactly as disclosed in Alice patent. Now, here are some considerations that would appear "common sense" to me:

• Alice is afraid that Bob, her strongest competitor on the market, also realizes this possibility and might perhaps succeed in filing for a patent on the novel functionality/use of her patent before she had any chance to do it herself.

• But in this case, in order to manufacture and sell such a product, would Bob need to obtain permission from Alice to use her patent? (e.g.: via a license Agreement, which Alice is anyway unlikely to find interesting).

• Though, by filing for said "enhanced" blood pressure monitor, the most likely purpose of Bob is simply to prevent that Alice could manufacture and sell it herself, further etching away Bob's market share.

• What about if Alice, upon realising the possibility for said additional functionality/use, quickly advertises it in her company's web site (article in the technical blog section, preliminary datasheet for the "enhanced" product, etc.), and this before Bob has had the time to file for a patent. Would the practical result be that only Alice can manufacture and market also the "enhanced" blood pressure monitor? this because her valid patent is anyway needed also for the "enhanced" product, which, after her public disclosure of said additional functionality/use, can no longer be patented by Bob (or any other competitor, for that matter). Compared with filing for a Continuation-In-Part patent, wouldn't this approach represent a much simpler, faster, and lower cost solution for Alice, while featuring practically the same advantages in terms of legal protection of her product IP?

Though the above conclusions appear reasonable to me, I am not at all sure about possible hidden pitfalls.

Answer 1

Would Bob need to obtain permission from Alice to use her patent?

Yes, in the countries that Alice has a patent, Bob would need to obtain a licence before he could manufacture and sell his product.

Would the practical result [of publication by Alice mean that the improvement] can no longer be patented by Bob?

Yes, assuming it is sufficiently detailed so as to completely destroy the novelty of the improvement.

Wouldn't this approach represent a much simpler, faster, and lower cost solution for Alice, while featuring practically the same advantages in terms of legal protection of her product IP?

It is simpler, faster, and lower cost. But it's got a lot of disadvantages.

First, the improvement would have a slightly longer patent term. This could mean an extra few years of monopoly profits.

Also, damages may be affected. The way that damages are assessed is a bit of a complex art. But there is a correlation between the number of claims and patents infringed and the specificity of those claims and the damages awarded for infringement. If Bob infringed, Alice would almost certainly be better off (in terms of the quantum of damages) by suing for infringing the general patent as well as a specific patent for the improvement.

Similarly, Alice might decide to licence out the general technology while keeping the improvement exclusive to herself. Indeed, it may be required that she offer a licence in certain cases (though this mostly relates to standards, and especially telecommunication standards).

Finally, it could well be that the general patent is invalid for some reason. It may end up being obvious, or it may have been improperly prosecuted, or any of a number of reasons that no one could predict. Having a backup patent is a much better position to be in, compared to having no protection at all.

A defensive publication is therefore a suitable option for a party who wants to minimize IP expenditure. But it is almost certainly the wrong option for a party who wants to maximize their IP position.