A power system for and method of operation of an arteriovenous access valve system including two valves positioned near arteriovenous grafts, an actuator assembly in fluid communication with the valves and including a driver assembly, at least one pressure sensor, a separate activator device for driving the driver assembly, and a sensor communications device communicatively coupled to the at least one pressure sensor for wirelessly transmitting pressure measurements. The power system and method also include using an initiator device located in the activator device to power remotely the sensor communications device, for example via near field communication such as via a radio frequency field.