Abstract: An embodiment of the invention is an in-vivo blood pressure sensor device including a strain transducer and flexible biocompatible material that carries the strain transducer. The flexible biocompatible material is configured to encircle the outside of a blood vessel when surgically installed. A preferred embodiment in-vivo blood pressure sensor device of the invention includes a strain transducer carried by a flexible biocompatible ring that is configured to be surgically installed to encircle a blood vessel. The device also includes passive circuitry encased in biocompatible material for sensing strain in the strain transducer and for providing data to an external reader. The passive circuitry is also configured to be surgically installed in a subject.

Abstract: A device and method for maintaining a constant average pressure difference between the inlet and outlet of a pump for a body fluid, leading to an adequate flow for different pathological and physiological conditions, is described. The device and method allow for automatic adjustment of the pump operation to increase or decrease the flow rate of a body fluid to meet the physiological demand of the patient. The device and method also allow the physiological constraints on the pump to be accounted for, preventing suction and minimizing back flow of the body fluid. The device and method allow implicit synchronization of the pump with the natural regulatory mechanism for meeting patient's demand. The natural regulatory system continuously adjusts the parameters of the circulatory system to meet physiological demand for a body fluid.

Abstract: A device and method for maintaining a constant average pressure difference between the inlet and outlet of a pump for a body fluid, leading to an adequate flow for different pathological conditions. The device and method allow for automatic adjustment of the pump to meet the physiological demand of the patient. The device and method also allow the physiological constraints on the pump to be accounted for, preventing suction and minimizing back flow of the body fluid. The device and method allow implicit synchronization of the pump with the natural regulatory mechanism for meeting patient's demand. Thus, the pump can be continually adjusted to an optimal level in response to the patient's physiological condition.