California-based Sotera Wireless is looking to raise $53.9 million in an ongoing funding round, with about $20.7 million raised as of Monday, regulatory filings show.

The patient monitoring systems maker is offering equity, rights and securities, with 23 unnamed investors listed so far. The total offering amount includes about $2.3 million in securities issued on conversion of indebtedness as well as nearly $3.7 million in un-exercised warrants for preferred stock, according to the SEC filing.

The fundraising is not associated with any other business transactions, the Sotera noted.

The company, which won FDA clearance in October for its ViSi Mobile wireless blood pressure monitor, notched another noteworthy milestone earlier this year when doctors at Palomar Health in Escondido, Calif., became the 1st to use Sotera’s CareAware medical device integration platform. The system transmits patient data from the ViSi vital sign monitor directly into a Cerner electronic health record.

So far the Palomar data integration system combines monitoring blood pressure, pulse rates and oxygen saturation for patients in one of the hospital’s surgical units. In the future the system may also incorporate streaming data from ECGs and respiratory monitors, according to a Sotera press release.