Conformal MedicalStroke prevention technology developer Conformal Medical filed an SEC Form D to confirm the sale of $70 million in an equity offering.

Nashua, N.H.-based Conformal Medical is offering $85 million in equity in total, leaving $15 million left to be sold. It made the first sale in the new notice offering on July 24 and does not intend for it to last longer than one year, according to the filing.

The offering, which has no minimum investment requirement, is not being made in connection with a merger, acquisition or other similar business transaction. The company has already collected investments from 30 participants so far.

Conformal Medical did not list an intended use of proceeds. The company develops a device designed to seal off the heart’s left atrial appendage to help prevent stroke in atrial fibrillation patients.