Leaf Healthcare, Pleasanton, California-based wireless patient monitoring company, has raised $3.3 million, according to an SEC filing. The company has not disclosed investors, but SDL Ventures lists Leaf Healthcare as a portfolio company.

Leaf Healthcare's first product is the Leaf Patient Monitoring system, a small clip-on wearable for patients in hospital beds. The sensor monitors patient movement in bed, then uses that data to calculate when the patient needs to be turned to prevent the formation of pressure ulcers. That data is uploaded wirelessly to central monitoring stations or mobile devices so clinicians can monitor the readings. The system also alerts nurses or staff when a patient needs to be turned.

Since Leaf received 510(k) clearance from the FDA last November, the company has piloted its technology with a number of hospitals including El Camino Hospital and the Boise, Idaho VA Medical Center.

The company's major claim to fame is that it's one of the first wearables to ever be required by hospital safety protocols. Last December, the Chino Valley Medical Center began requiring that any patient who scores 18 or lower on the Braden Scale for Predicting Pressure Ulcer Risk use the sensor. They made this decision after a clinical trial showed that use of the sensor increased compliance with hospital turn procedures from a baseline 64 percent to 98 percent.

In addition to preventing ulcers, some hospitals have recently begun to help women in labor to move around more, which may help to speed up labor.

"We hope that turning women who are in labor and on epidurals will speed their labor and reduce the need for c-sections," Patrick Reinhard, Chief Nursing Officer of Desert Valley Hospital, where the sensor is being tested for its new application, said in a statement last May. "We hope the use of Leaf wireless monitoring technology will reduce the length and discomfort of labor and provide expectant mothers with a much easier birth experience."