Halt Medical, a secretive Pleasanton, Calif., company, has raised $12 million in a third funding round as it prepares for human trials of a device designed to remove uterine fibroids without hysterectomy, VentureWire is reporting (subscription required).

Uterine fibroids — also sometimes known as fibromyomas, leiomyomas or myomas — are noncancerous growths of the uterus. Although generally not threatening to health, these fibroids can sometimes cause complications ranging from pain and heavy menstrual bleeding to backache, incontinence or constipation. Hysterectomy is the only proven solution to fibroid problems, although doctors can also try to surgically remove the fibroids, shrink them with drugs, or “embolize” them by injecting uterine arteries with small particles that cut off fibroids’ blood supply.

Publicly traded private-equity firm American Capital Strategies led the round, contributing $8.9 million. Returning individual investors — who in the past have included William Richter, co-founder of buyout firm Cerberus Capital Management, and former Federal Reserve Chairman Paul Volcker — provided $2.1 million, with Halt Medical management investing the remaining $1 million.

The company has previously raised roughly $5 million from individual investors. Halt Medical plans to begin human trials of its device by the end of the year, CEO Jeff Cohen said.