The CardioMEMS™ HF System is a US Food and Drug Administration-approved wireless heart failure (HF) monitor that is placed within a pulmonary artery. It measures heart rate along with pulmonary artery pressures 1.
Note the large nitinol loops on either end of the sensor that secure it into the branch pulmonary artery by their outward force 2.
Disclosure: I, Daniel Chonde, have no actual or potential ethical or financial conflict of interest in relation to this device. This case is not intended to be a personal endorsement or recommendation of this product.