How to learn sexopathologists sexual desire women?

Until recently, sexual pathologists engaged exclusively in erectile dysfunction. And that should be considered a violation of women's sexual function, researchers have only recently agreed. For example, violations of sexual desire women (sexual arousal), we can say that if the lack of sexual desire in women is her problem, which causes stress. So far there are no "decent" way to measure sexual desire women. Special rate as the blood sugar level, no. But the existing methods or unpleasant, or subjective. For example, vaginal photoplethysmography -  device that measures blood flow to the vagina during sexual stimulation did not agree to use each woman. A degree of hydration sheaths ─ figure unreliable.
The only real way to assess ─ tests to determine the woman's sexual desire. They are more like a psychological tool, for example, "The index of sexual function of women / FSFI", consists of 19 items that assess the six groups of indicators, including sexual desire, sexual arousal, genital moisture, orgasm, sexual satisfaction and pain.