For infants born with a single ventricle heart, the Norwood Stage I operation is a life-saving procedure. This procedure is the first in a three-step pathway that begins to correct a newborn?s circulation by providing flow to both the systemic circulation and pulmonary circulation from the one ventricle. After the surgery however, there is no way to continually monitor the flow that is going to the pulmonary and systemic circulations (cardiac output) to be sure each has adequate flow. The long term objective of this project is to provide the first implantable wireless blood flow monitor for patients after Norwood Stage I Single Ventricle Palliation surgery. The perivascular sensor used for measuring flow/cardiac output will be placed on the right ventricle-pulmonary artery shunt that is created during the surgery. Unlike existing technology, this will be able to provide continuous measurements to identify changes in cardiac output after surgery. This will allow for timely therapy for the patient. Additionally intermittent measurements using an injection of saline with provide information regarding the distribution of blood flow in the heart. Based on preliminary work and the prototype algorithms, this project will begin by developing a sensor system capable of transmitting and recording changes in the ultrasound velocity of blood. The meter component of the system will be made to receive these changes and programmed to automatically produce and display the flow measurements. Animal studies will then be performed on 6 piglets at the Animal Research Facility at Children?s National Medical Center in order to validate the Qp/Qs calculations in a single ventricle animal model. Phase I will end with a preliminary clinical study at Children?s National Medical Center. 4-6 patients will be recruited for a feasibility test of the sensor placement and dilution calculations.
A wireless implantable blood flow monitor for patients after Stage 1 Single Ventricle Palliation surgery will assist physicians in guiding urgent treatment. In the operating room, in the intensive care unit, and at home after surgery, physicians will be able to monitor the distribution of blood flow in the patient?s heart and lungs to ensure proper treatment and decrease mortality associated with lack of blood flow.
