BioBehavioral Diagnostics Co., which is developing a system to diagnose attention-deficit hyperactivity disorder, closed a $7 million tranche in a Series B round it hopes will reach $10 million.

The Westford, Mass.-based company said it will use the money to expand its sales and marketing operation and fund additional clinical work for its Quotient system.

Venture capital firms Sevin Rosen Funds and Tullis-Dickerson led the round, which included $500,000 raised in a debt sale last December.

BioBehavioral Diagnostics said its system gathers objective data on hyperactivity, impulsivity and inattention, allowing clinicians to integrate its report with information from other diagnostic tools and the clinical evaluation. The company raised $2.5 million in another debt sale last June.