As of April 14th of this year, her doctor can't even talk to you about her care, ... can't even acknowledge she is under his care, ... Federal law, (HIPAA) ... huge fines and jail time for the doctor who would do what you are thinking.
Hard as it may be,... based on your past issues, I would calmly ask your wife to read SSM. I would say to her,... "This is a book that is about both of us, ... focusing on the fact there is a connection, with differences, ... but not a right or wrong. That is no guarantee she will read it, ... but I read it cover to cover, and I know Michele did not put a guarantee in the last chapter, ... just solid heartfelt advice throughout.
My W's first response, when I asked her to read it, was that "It is too late!" But I figure I stay here, and stay calm,... and begin to modify how I behave, and the sort of H I am day to day, there may come a day when she WILL read it.
For the sake of trust and love between you both, ... stash any notions of secret blood test, spanish fly in her soup, or testosterone patches on her back in the middle of the night.
SSM drove home again what I already knew, ... that my W's sexiest part is somewhere between her ears. My job is to go back and find where I last saw it a while back, and work harder to understand her. While it might not work, I know any shortcuts will have an even smaller chance of succeeding.
30 years! You have the patience, ... it might need a quick polish, but there is no one in the world who deserves a little more of it now,... than your wife and you as a couple.
I guess the only way to stop divorce is to stop marriage.
--Will Rogers