RFPI Inc., a North Carolina-based health care tech company, raised $3.5 million in a private stock offering, according to a Securities and Exchange Commission filing.

The Greenville-based company filed the Form D on Thursday and it did not disclose what it intended to do with the funds.

It last raised money in March, when it garnered $3.2 million from investors.

RFPI’s patented medical technology is non-invasive and works in real-time to visualize the physiology of blood flow and perfusion. Its technology is called iCertainty and can decrease post-procedural complication, reducing readmission rates and costs, as well and improving clinical quality.

RFPI is led by chairman and angel funder Phil Hodges and CEO Jeffery Basham. Hodges has over 30 years experience in health sciences and also sits on the board of directors for Mayne Pharma Group Ltd.

Basham also has extensive experience in the health care field and previously he was one of the founding CEOs in a group of companies that became Closure Medical, which was sold to Johnson & Johnson for $500 million.

Companies relying on a Reg D exemption do not have to register their offering of securities with the SEC, but they must file what’s known as a Form D electronically with the SEC after they first sell their securities.

The file can be found here.