Which by their patent irrelevance

Hi,

Q1 Does the defintion of "patent" fit the contex ?

N-COUNT A patent is an official right to be the only person or company allowed to make or sell a new product for a certain period of time? I hightlight "patent" in red.

I don't think the definition of patent fits the context below, but I don't find a better definition.

Q2 which = techique ? I highlight "which" I am questioning in red.

Q3 Could you rephrase the sentence in blue for me? I don't understand it. Here's my try.

It's a technique about employing clear, comprehensive dieas, but the technique is not relevant to the patinet -phsican relationship and the situation distract the patient.

Q 4. What is the function of "by" in red?

Thanks!

The technique is one that I have employed on the illiterate subject and upon the college graduate, in experimental situations and for clinical purposes. Often it has been used to secure, to fixate, and to hold a difficult patient's attention and to distract him from creating difficulties that would impede therapy. It is a technique employing ideas that are clear, comprehensible, but which by their patent irrelevance to the patient-physician relationship and situation distract the patient. Thereby the patient is prevented from intruding unhelpfully into a situation which he cannot understand and for which he is seeking help.