Putting People First links to several articles about the usability research that went into the development of Philips "intimate massager" products. Here, for example, is a clip from "The Birth of a New Category" written by the product team at Philips:

The delicate nature of the subject meant that exhaustive research was carried out. Early propositions were validated through qualitative testing panels, followed by quantitative testing on the Internet. More than 100 working prototypes were tried out in Austria by typical representatives of the target group. And testing wasn't limited to consumers; many different stakeholders from Consumer Lifestyle, Healthcare and Lighting became involved as well. Even financial analysts were consulted. "In my 25 years of business experience, I've never been associated with a line of products which has been so thoroughly vetted," said Jim Hey, Senior Vice President and Business Unit Leader for Health & Wellness.

[via Putting people first]